The brain is the most complex organ in the human body, and as such, it is responsible for the control and regulation of everything else within us. While its functions vary greatly in number and in role, the underlying physiological processes that are responsible for each given function tend to be quite similar. Throughout the history of neuroscience, there have been multiple attempts to identify these processes and explain them, and I have described some of these attempts (Dualism, Descartes' model) in my previous entries. And like I have also said before, we now realise that the brain is a large aggregation of nervous tissue in which a few glands of the endocrine system are present, such as the pituitary gland and the pineal gland. Specifically, nervous tissue refers to neurons, the nervous cells which communicate information, and the cells which provide them with nutrients. About 20 days after conception, the origin of the nervous system, the neural tube, will be formed after a portion of the posterior of the embryo hardens and curls inward. This tube will close off at the bottom and form the bottom of the spinal cord, and the top will send forth progenitor cells which give rise to the neurons and nutrient-providing cells of the brain. These cells will arrange themselves in a manner specified by the genetic instructions coded for by the DNA of the organism, and, once they have all been formed and moved to their specified locations, they will send out extensions of themselves, or processes, to connect with the other neurons of the brain. Meanwhile, the neurons which comprise the rest of the nervous system are being formed from progenitor cells located down the rest of the soon-to-be spinal cord, and will connect with each other, the cells of the brain, and the organs of the body. All this entails, really, is that the brain is a complex conglomeration of nerve cells. Ergo, the functionality of the brain can be attributed to biological processes of the cells, or, at least, this was the classic model of the brain until a scientist I had referenced in my previous post, "The Rhythm of Memories," introduced a new model which used another variable to explain the processes of the brain: time.
A function of neurons is that they propagate messages along their bodies using electricity. The aforementioned scientist whose name is Rodolfo Llinas, discovered in the mid 80s that the electric charge of a group of neurons would become constant in that grouping, and that those charges would then begin to oscillate in rhythm with one another. He found that this would occur without any perceptual or cognitive stimulus, and is, as a result, intrinsically present as a process of the brain. The scientist used this intrinsic oscillation, and therefore time, as a variable in a model of the brain he proposed. As I had described and subsequently challenged in my previous post, Llinas found that regions of the brain that were responsible for movement, such as the cerebellum, oscillated at a different frequency than regions of the brain responsible for interpretation of sensory information, such as the cerebrum. Another region of the brain, the thalamus, is also comprised of groups of neurons which oscillate together, however the inside of the thalamus naturally does so at the same frequency those regions of the brain involved with movement oscillate at (around 10 Hz), and the outside oscillates in conjunctive frequency with sensory information processing regions of the brain, around 40 Hz. Rodolfo Llinas used these findings to conclude that we move at a frequency of about 10 Hz, whereas we perceive and sense at a frequency of about 40 Hz. The neuroscientist stipulated that this disparagement between oscillation frequencies of movement and perception was in part to an evolutionary 'allowance' of sorts, so that the brain could have time to process information before it acted.
As his research continued, Llinas began to focus moreso on the thalamus, a region of the brain commonly known as the sensory relay station. That is true to an extent, however the outside of the thalamus is what is majorly responsible for this, and the inside is mainly responsible for attentiveness, or arousal. Because the inside of the thalamus and areas of the brain responsible for movement oscillate at the same frequency, it can be asserted that they are connected to each other, both in anatomy and functionality, and it can then be logically concluded that an organism will make movements that are not caused by reflex arcs based on what it is paying attention to. Following this line of reasoning, the outside of the thalamus is connected to the sensory information processing areas of the brain such as the cerebrum (a set of connections which Llinas coined to be the thalamocortical system), and that the functionality of those regions is based on the information being relayed by the thalamus. Furthermore, as I had originally described in my post, "Subjective Perception," multiphasic cognitive relay is a term which I use to refer to the general illusory state of consciousness, being that the individual will be conscious of something if two or more cognitive faculties are perceiving information from it. Because regions of the brain which oscillate at the same frequency play a role in the processes of one another, Llinas found that if the outside and inside of the thalamus are oscillating at the same frequencies, then the individual is paying attention to, or aroused by, the cognition, from (as I personally stipulate) two or more sensory systems, which the thalamus is perceiving, and is therefore conscious of it. Simply put, an organism is conscious of what it is paying attention to, be it vision, audition, proprioception, interoception, or any of the senses.
As further proof of concept, Llinas continued onward to discover a class of disorders collectively known as thalamocortical dysrhythmia. These disorders entail a region of the thalamus oscillating at a 'mismatched' frequency than the rest of the brain area, and, depending on the region, will produce a different disorder. The neuroscientist, along with other neuroscientists who have been taking increasingly vested interests in thalamocortical dysrhythmia, discovered that it is the cause of disorders such as Parkinson's Disease, tinnitus, and even schizophrenia, among other previously recognised conditions and disorders. Specifically, schizophrenia is a disorder which humans have known of since the classical age of Ancient Rome and Greece. The word literally means "broken mind" in Greek, and is philosophically referred to as perceiving reality as if it were a dream. But what is a dream?
As I said in my introductory paragraph of this entry, the brain is responsible for a myriad of functions, however the physiological processes which perform these functions are not as varied, in fact I would go so far as to assert that they all revolve around the same intrinsic chattering that occurs between groups and circuits of neurons. In my posts "The Genius Gene" and "The Memory Circuit," I go into detail concerning the nature of what a memory is, and attribute it to a circuit of neurons that "loops" through different regions of the brain depending on which regions were activated due to the experience the stored memory entails. I've also said that the frontal lobe of the cerebrum is responsible for the planning of behaviours and strategies as well as the solving of problems. Because the brain is capable of synthesising stored memories to create new concepts, ideas, strategies, etc., I stipulate that a dream is simply a conglomeration of synthesised memories. Moreover, it has been found that brain activity during dream-sleep, or REM (Rapid Eye Movement) sleep, is consistent with levels of brain activity during wakefulness, and logic can then lead to the conclusion that a dreaming individual can be considered conscious. And as I had said before, you are conscious of something if you are paying attention to it, so an individual is, very simply, paying attention to the conglomerate memory synthesis when he is dreaming. Furthermore, because of the illusory nature of consciousness, it is not something which is able to actually to "do" anything at all, which means that processes such as conglomerate memory synthesis are not ones that are initiated by functions classically thought of as conscious. However does that mean this synthesis process is one that is facilitated by sensory information, or one that happens intrinsically, similar to the chatter-like neuronal oscillation?
A commonly referred to phenomenon is one in which the given individual reports to have been dreaming about a TV show he had been watching before he went to bed. Another instance of this would be if the individual is upset by something. He would then report that his dreams were related to that feeling of being upset in some way. Therefore it can be asserted that previously perceived cognition can and does play a role in dreams. Somnambulism, or sleepwalking, is, very simply, interaction with the environment as if the interacting individual was awake. These interactions tend to be repeated behaviours such as cleaning, and could be attributed to some type of cognition the individual did not consciously perceive due to his inherent focus on his dreaming, and therefore has no ability to inhibit the habitual behaviour. The interactions might also have the possibility of being driven by events the individual is dreaming of. The recurring theme in each of the aforementioned cases is that the sensory events are affecting the dream state, which means that the conglomerate memory syntheses would occur intrinsically, without any need for cognitive manipulation. For example, when we daydream, we tend to "zone out" and focus on the daydream, however we are capable of "snapping out of it" due to some outside stimulus, perhaps someone yelling. The daydream originally occurred, though, because the individual began to pay attention more and more to it.
Schizophrenia is, as I had mentioned previously, generally refers to difficulty in differentiating between reality and dreams. Because dream-like processes, or conglomerate memory syntheses, occur intrinsically, a difficulty in reality and dream differentiation would simply refer to the frontal lobe having difficult solving the 'problem' of whether or not something is real, which would be, as Rodolfo Llinas has found, in part to thalamocortical dysrhythmia. To conclude, it is becoming more and more evident that using time as a variable in a model of brain functionality is critical to the realism of the model, and the processes of the thalamocortical system, as well as the thalamus itself, point further to the plausibility of my original concept of multiphasic cognitive relay.
Friday, August 31, 2012
Friday, August 10, 2012
The Rhythm of Memories
I recently read an article from Discovery magasine called "Brainsong," in which the author had interviewed a neuroscientist by the name of Rodolfo Llinas. The string of questions concerned Llinas' perspective as to how the brain functions, and this perspective "emphasizes frequency, time, and coherence as much as anatomy and neurochemistry." Llinas has found that neurons intrinsically communicate with each other in low-level electric oscillatory rhythms, and that they do so intrinsically. That is, this rhythmic neural oscillation occurs without the need for any sort of sensory input. The generally thought of model of the brain is that it is akin to a computer, where it simply receives an efferent, sensory input, and then outputs a response using afferent motor neurons, however what actually happens is that incoming stimuli simply alter the inherent "chatting" that is already occurring between neurons of a given group, and then other neurons in that group will adjust to that altered oscillation frequency. This is similar to the beating of the heart: it can be slowed or sped up, but it will always pump, and, in the case of the neural oscillations, they can be increased or decreased in frequency, but they will still already be occurring. Furthermore, according to Rodolfo, regions of the brain that are involved in movement and coordination, such as the cerebellum, oscillate at 10 Hertz (Hz), or cycles per second, whereas faculties such as perception and cognition oscillate at 40 Hz, a frequency which is called gamma band. But, while Llinas' findings are indisputable, I stipulate that his interpretation of what they entail is mistaken. Why?
In my post "The Memory Circuit," I had said that memories are comprised of circuits of neurons which "loop" through different areas of the brain. What I did not say, however, is that each of these memory circuits are maintained by constant low-level electrical oscillations. These oscillations could be what Llinas refers to when he said the cerebellum oscillates at 10 Hz, something which he interpreted to be the simple functioning of the region. As I had referenced in my post "The Genius Gene," the brain stores basic statements, ideas or movements that it deems to be axiomatic in nature as memories, and then connects multiples of these simpler memories to form more complex conclusions. I think that the memory of a simple movement or complex behaviour would be comprised of a neural circuit which "loops" through corresponding regions of the brain, such as the cerebellum, and I further stipulate that the neuroscientist's observation of brain regions responsible for movement oscillating at 10 Hz instead refers to memory circuits that involve movements in their stored recollections. As a final point, I convict that if a memory circuit were to begin oscillating at 40 Hz, the individual would still only consciously recall it if multiple different cognitive stimuli were responsible for increasing the oscillatory frequency.
My next few posts will concern various points which Rodolfo Llinas made in the interview featured in a special edition of the Discovery magasine.
References
"Brainsong." Interview by Kat McGowan. Discover May 2012: 15-22. Print.
In my post "The Memory Circuit," I had said that memories are comprised of circuits of neurons which "loop" through different areas of the brain. What I did not say, however, is that each of these memory circuits are maintained by constant low-level electrical oscillations. These oscillations could be what Llinas refers to when he said the cerebellum oscillates at 10 Hz, something which he interpreted to be the simple functioning of the region. As I had referenced in my post "The Genius Gene," the brain stores basic statements, ideas or movements that it deems to be axiomatic in nature as memories, and then connects multiples of these simpler memories to form more complex conclusions. I think that the memory of a simple movement or complex behaviour would be comprised of a neural circuit which "loops" through corresponding regions of the brain, such as the cerebellum, and I further stipulate that the neuroscientist's observation of brain regions responsible for movement oscillating at 10 Hz instead refers to memory circuits that involve movements in their stored recollections. As a final point, I convict that if a memory circuit were to begin oscillating at 40 Hz, the individual would still only consciously recall it if multiple different cognitive stimuli were responsible for increasing the oscillatory frequency.
My next few posts will concern various points which Rodolfo Llinas made in the interview featured in a special edition of the Discovery magasine.
References
"Brainsong." Interview by Kat McGowan. Discover May 2012: 15-22. Print.
Monday, August 6, 2012
The Memory Circuit
In 1997, a doctor named Itzhak Friend experimented on a number of his epilepsy patients. He placed tiny brain activity monitors, or electrodes, in various regions of the patients' brains, and he then flashed various images of Marilyn Monroe at different rates to them. He had found that the same neurons, in a given patient's brain, were stimulated by different, yet similar images of Marilyn Monroe, as long as those neurons had been first exposed to a picture of her for the duration of a minimum time frame (less than a sixth of a second). Those neurons were also stimulated when the individual saw Monroe's name. Fried concluded that sets of neurons such as the ones stimulated by Marilyn Monroe are capable of retaining the "idea" of something (a place, an individual, etc.), for a brief period of time, and will be excited by stimuli which are similar to that idea. I stipulate this ability to be what I will refer to as short-term plasticity, or the ability of neurons to briefly alter their synaptic connections when posed with same or similar yet repeating stimuli in a small period of time (Plasticity, or neuroplasticity, is an ability of neurons I describe in my post "Habits, neuroplasticity, and the origin of emotion). Furthermore, this process is, essentially, the beginnings of a newly forming memory, and can be converted to one via long-term potentiation: the ability of neurons to alter their synaptic connections, in accordance with incoming stimulus, and to maintain that alteration for longer periods of time. But how and why does this conversion occur?
Memories tend to be more intense, and can be recalled more easily, if there is emotion associated with them. An example of this would be what is called, commonly, emotional scarring. This entails a situation which is so traumatic, or negative, in relation to a given individual, that the events of this occurrence are "burned" into the individual's mind ad infinitum. I would further convict that not only emotion, but the more mental processes, or faculties, involved in the memory, the more easily it can be recalled. For instance, learning is found to be easier if the subject interests the learner. Learning, as I had described in my post "The Genius Gene," is the process of the brain synthesising a new conclusion from multiple previously held memories that it deems axiomatic. Moreover, the brain is able to focus more of itself on certain processes or activities that it deems interesting via more widespread releases of a chemical called norepinephrine. Norepinephrine is involved in enhancing the vigilance, or attention to stimuli, of a given individual, and widespread releases of it will act on multiple regions of the brain, causing these regions to focus, more so, on the interesting process or activity. Therefore, the memory of the aforementioned new conclusion will be more easily remembered by the learner, if the subject at hand is one they find interesting. Another example of multiple mental faculties allowing easier recall of a given memory, as well as the associated memory or sensory information, would be cognitive association. The reason you are "reminded" of a particular memory in relation to an incoming stimulus is because one of the three lobes of the cerebrum responsible for cognitive association (the temporal, parietal, and occipital lobes) have associated that stimulus with the memory. And, the more stimulus associated with a memory, the greater the probability of, as well as ease in, the brain's recollection, because multiple different regions of the cerebrum would be involved in that remembrance (the brain is able to process more quickly depending on the amount of white matter involved in making the relevant connections, ergo the more regions of the brain involved, the faster the recollection). This concept correlates directly with multiphasic cognitive relay, a process I describe in my post "Subjective Perception." I suppose that just as multiple cognitions create the illusion of the individual being aware of that cognition, and just as multiple cognitions or mental faculties involved in the recall of a memory speeds up the process, the individual will be aware of that recall so long as multiple different cognitive associations are made by the cerebrum. In other words, the individual will become aware of the recollection of a memory if the brain had processed and stored multiple different stimuli regarding that memory, and if that information is being associated with other multiphasic cognition, be it present perception, past perception, or the frontal lobe formulating a strategy or behaviour. The remaining question, though, is how are these memories converted from short-term plasticity to long-term potentiation, and then stored?
A set of proteins, known as protein kinase, are responsible for a number of different regulatory functions. A recently discovered class of protein kinase, known as PKM-Zeta, is the single protein which is responsible for the maintaining of long-term potentiation between neurons. This protein acts as a sort of "glue" which keeps intact the altered synaptic connections, connections originally altered by the preceding short-term plasticity. Moreover, as I had stated in the previous paragraph, that the more mental faculties involved in a memory, the more easily it can be recalled, I stipulate that this is due to the nature of memory storage in the brain, a nature which I will describe as a memory circuit. A memory circuit is an interconnecting set of neurons, held together in the long-term by PKM-Zeta, that processes, or "loops," through the different regions of the brain that had been active in regards to the memory at the time of said memory. These regions are then stimulated in the same or similar manner as they had been, and this similar stimulation causes the individual to be "reminded" of the previous instances when it had occurred. As discussed in my post "Habits, Neuroplasticity, and the Origin of Emotion," neurons can undergo neuroplasticity and alter their synaptic connections in such a way that matches repeated stimuli, and I further stipulate that this neuroplasticity is the foundation on which a memory circuit is formed by the brain. As my final point, I convict that short-term plasticity is converted to long-term potentiation so long as the repeating stimuli which caused the short-term plasticity is repeated for a longer period of time. This time frame can vary depending on the intelligence, or speed at which an individual's brain makes connections, of the given individual.
I have been receiving a number of requests to create entries in regards to a number of different concepts, such as drugs and positive association. I will, in due time, write these, however for now I must start with one of the principal bases of brain function: the memory circuit.
Memories tend to be more intense, and can be recalled more easily, if there is emotion associated with them. An example of this would be what is called, commonly, emotional scarring. This entails a situation which is so traumatic, or negative, in relation to a given individual, that the events of this occurrence are "burned" into the individual's mind ad infinitum. I would further convict that not only emotion, but the more mental processes, or faculties, involved in the memory, the more easily it can be recalled. For instance, learning is found to be easier if the subject interests the learner. Learning, as I had described in my post "The Genius Gene," is the process of the brain synthesising a new conclusion from multiple previously held memories that it deems axiomatic. Moreover, the brain is able to focus more of itself on certain processes or activities that it deems interesting via more widespread releases of a chemical called norepinephrine. Norepinephrine is involved in enhancing the vigilance, or attention to stimuli, of a given individual, and widespread releases of it will act on multiple regions of the brain, causing these regions to focus, more so, on the interesting process or activity. Therefore, the memory of the aforementioned new conclusion will be more easily remembered by the learner, if the subject at hand is one they find interesting. Another example of multiple mental faculties allowing easier recall of a given memory, as well as the associated memory or sensory information, would be cognitive association. The reason you are "reminded" of a particular memory in relation to an incoming stimulus is because one of the three lobes of the cerebrum responsible for cognitive association (the temporal, parietal, and occipital lobes) have associated that stimulus with the memory. And, the more stimulus associated with a memory, the greater the probability of, as well as ease in, the brain's recollection, because multiple different regions of the cerebrum would be involved in that remembrance (the brain is able to process more quickly depending on the amount of white matter involved in making the relevant connections, ergo the more regions of the brain involved, the faster the recollection). This concept correlates directly with multiphasic cognitive relay, a process I describe in my post "Subjective Perception." I suppose that just as multiple cognitions create the illusion of the individual being aware of that cognition, and just as multiple cognitions or mental faculties involved in the recall of a memory speeds up the process, the individual will be aware of that recall so long as multiple different cognitive associations are made by the cerebrum. In other words, the individual will become aware of the recollection of a memory if the brain had processed and stored multiple different stimuli regarding that memory, and if that information is being associated with other multiphasic cognition, be it present perception, past perception, or the frontal lobe formulating a strategy or behaviour. The remaining question, though, is how are these memories converted from short-term plasticity to long-term potentiation, and then stored?
A set of proteins, known as protein kinase, are responsible for a number of different regulatory functions. A recently discovered class of protein kinase, known as PKM-Zeta, is the single protein which is responsible for the maintaining of long-term potentiation between neurons. This protein acts as a sort of "glue" which keeps intact the altered synaptic connections, connections originally altered by the preceding short-term plasticity. Moreover, as I had stated in the previous paragraph, that the more mental faculties involved in a memory, the more easily it can be recalled, I stipulate that this is due to the nature of memory storage in the brain, a nature which I will describe as a memory circuit. A memory circuit is an interconnecting set of neurons, held together in the long-term by PKM-Zeta, that processes, or "loops," through the different regions of the brain that had been active in regards to the memory at the time of said memory. These regions are then stimulated in the same or similar manner as they had been, and this similar stimulation causes the individual to be "reminded" of the previous instances when it had occurred. As discussed in my post "Habits, Neuroplasticity, and the Origin of Emotion," neurons can undergo neuroplasticity and alter their synaptic connections in such a way that matches repeated stimuli, and I further stipulate that this neuroplasticity is the foundation on which a memory circuit is formed by the brain. As my final point, I convict that short-term plasticity is converted to long-term potentiation so long as the repeating stimuli which caused the short-term plasticity is repeated for a longer period of time. This time frame can vary depending on the intelligence, or speed at which an individual's brain makes connections, of the given individual.
I have been receiving a number of requests to create entries in regards to a number of different concepts, such as drugs and positive association. I will, in due time, write these, however for now I must start with one of the principal bases of brain function: the memory circuit.
Wednesday, August 1, 2012
Habits, Neuroplasticity, and the Origin of Emotion
There are two manners in which an individual grows and develops: genetically, or pathologically. Genetic development refers to processes which are both defined and initiated by the genetic code, or DNA. The DNA of humans is located in the nuclei (plural of nucleus), or centers, of the individual cells that compose all organisms, and sequences of it, known as genes, account mainly for the development and functionality of these cells that lend themselves to the collective organism's mass, function, and growth. Essentially, genes build organisms from the ground-up. Pathological development, on the other hand, refers not to development which originates from the genetic code, but rather that which is formed or altered in part to what is known as sensory input. In the context of development, it also always refers to the nervous system, and the many 'pathways it contains.' Sensory input occurs when some manner of stimulus, for example, the heat source referenced in my post, "The Decision Reflex," acts on receptors located on neurons that connect to, or innervate, whatever other bodily system the sensory input corresponds to (in this instance, the sensory input corresponds to the integumentary system, or the skin). The input will be communicated by the sensory neurons (whose receptors it originally acted on) to other areas of the body, where it will temporarily alter current functionality. An example of this would be if you were told by a trainer or instructor to begin to run. This stimulus will be received by the auditory system, and communicated to the brain. The brain will then formulate a plan that corresponds to the trainer's instruction, and then communicate with muscles in the legs, so that the individual begins to run. Although something like this is considered a behaviour (and a conscious one at that), the course of events remained the same: you received a stimulus in the form of a command, and it thereafter altered the current functionality of the body, both by the brain processing the command, and the muscles of the legs carrying it out. However, the alterations described above are only temporary. In order for sensory input to cause pathological development, the same or similar sensory inputs must occur repeatedly over a larger period of time. For example, according to the text The Physiology of Behaviour, an infant must begin to experience seeing things with both eyes simultaneously at around two months of age, or else he will be cross-eyed. But in respect to biology, what actually happens?
In my post, "The Genius Gene," I referenced the limbs, or processes, of neurons, which are known as axons and dendrites. What I did not mention, is that both axons and dendrites branch off into smaller processes of themselves, and axons specifically terminate in what are known as terminal buttons. These buttons then form what are called synapses with one of the dendrites, cell body (or "soma"), or even an axon of another neuron (how synapses are created will be discussed in a later post). A synapse formed by a terminal button and a dendrite is axodendritic, one formed by a button and a soma is axosomatic, and one formed by a button and an axon is axoaxonic (Use the below visual as a reference). Chemicals known as neurotransmitters are released by terminal buttons when the rest of the neuron is stimulated by a communication from a sensory input or another neuron, and are the neurons' primary method of information transmission. Released neurotransmitters will briefly float through the space between the button, and the surface it has formed a connection with, known as the synaptic cleft, and consequently affect the dendrite, soma, or axon of whatever neuron with which the synapse had been formed. The newly affected neuron will then either propagate or inhibit the transmission which caused the original release of chemicals into the synaptic cleft, and this depends on the type of the neurotransmitter. This will continue, from neuron to neuron, until the transmission is inhibited, or completes the communication of the information being transmitted.
Neurons are actually capable of changing the synapses they have formed with other neurons, and are able to cease communication by terminating a synaptic connection with one neuron, and creating a connection with another. This process is referred to collectively as neuroplasticity, and will also be discussed in more detail in future posts. For now, though, the ability of neurons to alter their synaptic connections are the changes caused by the aforementioned gradually altering sensory input which I had called pathological development. An example of this would be habitual behaviour, or recurring behaviours of an individual that he did not consciously initiate. This can refer to many behaviours, including (but by no means limited to) grinding teeth, biting nails, and a psychological disorder that entails the habitual pulling out of hair known as trichotillomania. Habits are formed when the individual receives a sensory input which causes him to consciously perform a given behaviour, and then receives the same or a similar sensory input on a few later occasions which cause him to consciously repeat the same given behaviour (the neurons which communicate the brain's plan to initiate a behaviour to the necessary muscles are known as motor neurons). After enough instances of the same sensory input causing the same behavioural response, the neurons which have been involved with the communication of the sensory input, known as efferent neurons, and the motor neurons (or afferent neurons), will display neuroplasticity and rearrange some of their synaptic connections in what can be described as an attempt to predict the transmission of both sensory and motor information in instances similar to those which caused the original sensory inputs. Therein lies a question: why are these recurring processes, or habits, not initiated consciously?
In my post entitled "Subjective Perception," I had discussed what I stipulate to be the nature of consciousness, a phenomenon which I had referred to as multiphasic cognitive relay. Essentially this term entails the requirement for a sensory system to be processing information that corresponds to information currently being processed by other sensory systems in order for the individual to become aware of the information. In the previous paragraph, I had said that before a behaviour becomes habitual, it is still planned and initiated consciously. The frontal lobe, responsible for the planning of behaviours (among other things), communicates with the other three lobes of the cerebrum: the temporal, parietal, and occipital lobes. These lobes are responsible for processing their corresponding sensory information, possibly storing that information as memory, and then associating previously stored sensory information with either that which is currently being perceived, other memories, or plans the frontal lobe might be formulating. I will refer to this process of association as cognitive association, and the frontal lobe employs thus each time it attempts to create a plan. In the case of a behaviour which is not habitual, I stipulate the individual is conscious of cognitive association relative to the given situation because the brain is using multiple different cognitive faculties in order to process the sensory inputs of the situation. Furthermore, I convict that the individual is not conscious of the initiation of habitual behaviour because of the pathological development that caused the efferent and afferent neurons that communicated information on same or similar previous occasions where perception and response, on the part of the given individual, was consistent, to display neuroplasticity and alter their synaptic connections in order to "predict" similar transmissions of information. Therefore, only one sensory input would be necessary in order to at least begin the efferent transmission of information to the brain, where the same cognitive association would occur, and the same afferent motor neurons would be triggered, thus resulting in a habitual behaviour. This would also account for conscious interruption of a habit, that if another sensory system receives an input from the situation whilst the first sensory input is being processed or the motor neurons are carrying out the consequent behaviour, the individual will become aware of the process.
Neuroplasticity entails the alteration of synaptic connections on the parts of involved neurons. However, what had the original state of the synaptic connections been, before any processes displaying neuroplasticity had occurred? In my previously referenced post, "The Genius Gene," the brain of the child learning basic addition creates what I referred to as intellectual precedents that correlate to the basic postulates that are needed to prove the legitimacy of addition. And just as the infant needs to begin experience what is known as stereoscopic vision (vision with both eyes) early in their life, I hypothesise that it is at this point in the child's life, it also experiences the emotional reactions to different situations of those around him, for example his parents, and his brain then creates intellectual precedents which correspond to those emotional reactions, and uses them as a basis for how the child himself will feel in relation to different situations. After that initial intellectual precedent, neuroplasticity can occur repeatedly and alter the way in which the individual will feel about the same or similar situations, or situations which remind him of the ones in which he witnessed his parents respond emotionally, as an infant.
As in my previous posts, I will reference both the plausibility as well as hypothetical nature of my stipulations. What is interesting to note, however, is that my idea as to how emotions originate within individuals correlates to what I have recently discovered to be the most generally accepted theory of emotion within the scientific community: the James-Lange Theory. I will actually go more into detail concerning the actual nature of emotions, or irrational thought processes, in later posts, as well as all else I made clear I would discuss further. I also suggest you read my previous posts if you have not already, because I use each one as a reference point in this post, and I will continue to do so in future entries.
References
Carlson, Neil R. Physiology of Behavior. Boston: Allyn and Bacon, 2011. Print.
In my post, "The Genius Gene," I referenced the limbs, or processes, of neurons, which are known as axons and dendrites. What I did not mention, is that both axons and dendrites branch off into smaller processes of themselves, and axons specifically terminate in what are known as terminal buttons. These buttons then form what are called synapses with one of the dendrites, cell body (or "soma"), or even an axon of another neuron (how synapses are created will be discussed in a later post). A synapse formed by a terminal button and a dendrite is axodendritic, one formed by a button and a soma is axosomatic, and one formed by a button and an axon is axoaxonic (Use the below visual as a reference). Chemicals known as neurotransmitters are released by terminal buttons when the rest of the neuron is stimulated by a communication from a sensory input or another neuron, and are the neurons' primary method of information transmission. Released neurotransmitters will briefly float through the space between the button, and the surface it has formed a connection with, known as the synaptic cleft, and consequently affect the dendrite, soma, or axon of whatever neuron with which the synapse had been formed. The newly affected neuron will then either propagate or inhibit the transmission which caused the original release of chemicals into the synaptic cleft, and this depends on the type of the neurotransmitter. This will continue, from neuron to neuron, until the transmission is inhibited, or completes the communication of the information being transmitted.
 |
| Three synaptic connections: leftmost is axodendritic, center is axosomatic, rightmost is axoaxonic |
In my post entitled "Subjective Perception," I had discussed what I stipulate to be the nature of consciousness, a phenomenon which I had referred to as multiphasic cognitive relay. Essentially this term entails the requirement for a sensory system to be processing information that corresponds to information currently being processed by other sensory systems in order for the individual to become aware of the information. In the previous paragraph, I had said that before a behaviour becomes habitual, it is still planned and initiated consciously. The frontal lobe, responsible for the planning of behaviours (among other things), communicates with the other three lobes of the cerebrum: the temporal, parietal, and occipital lobes. These lobes are responsible for processing their corresponding sensory information, possibly storing that information as memory, and then associating previously stored sensory information with either that which is currently being perceived, other memories, or plans the frontal lobe might be formulating. I will refer to this process of association as cognitive association, and the frontal lobe employs thus each time it attempts to create a plan. In the case of a behaviour which is not habitual, I stipulate the individual is conscious of cognitive association relative to the given situation because the brain is using multiple different cognitive faculties in order to process the sensory inputs of the situation. Furthermore, I convict that the individual is not conscious of the initiation of habitual behaviour because of the pathological development that caused the efferent and afferent neurons that communicated information on same or similar previous occasions where perception and response, on the part of the given individual, was consistent, to display neuroplasticity and alter their synaptic connections in order to "predict" similar transmissions of information. Therefore, only one sensory input would be necessary in order to at least begin the efferent transmission of information to the brain, where the same cognitive association would occur, and the same afferent motor neurons would be triggered, thus resulting in a habitual behaviour. This would also account for conscious interruption of a habit, that if another sensory system receives an input from the situation whilst the first sensory input is being processed or the motor neurons are carrying out the consequent behaviour, the individual will become aware of the process.
Neuroplasticity entails the alteration of synaptic connections on the parts of involved neurons. However, what had the original state of the synaptic connections been, before any processes displaying neuroplasticity had occurred? In my previously referenced post, "The Genius Gene," the brain of the child learning basic addition creates what I referred to as intellectual precedents that correlate to the basic postulates that are needed to prove the legitimacy of addition. And just as the infant needs to begin experience what is known as stereoscopic vision (vision with both eyes) early in their life, I hypothesise that it is at this point in the child's life, it also experiences the emotional reactions to different situations of those around him, for example his parents, and his brain then creates intellectual precedents which correspond to those emotional reactions, and uses them as a basis for how the child himself will feel in relation to different situations. After that initial intellectual precedent, neuroplasticity can occur repeatedly and alter the way in which the individual will feel about the same or similar situations, or situations which remind him of the ones in which he witnessed his parents respond emotionally, as an infant.
As in my previous posts, I will reference both the plausibility as well as hypothetical nature of my stipulations. What is interesting to note, however, is that my idea as to how emotions originate within individuals correlates to what I have recently discovered to be the most generally accepted theory of emotion within the scientific community: the James-Lange Theory. I will actually go more into detail concerning the actual nature of emotions, or irrational thought processes, in later posts, as well as all else I made clear I would discuss further. I also suggest you read my previous posts if you have not already, because I use each one as a reference point in this post, and I will continue to do so in future entries.
References
Carlson, Neil R. Physiology of Behavior. Boston: Allyn and Bacon, 2011. Print.
Monday, July 30, 2012
Subjective Perception
Suppose you are the parent of a family of five that is facing poverty. You need to support yourself, your partner, your two teenage children and your 4 month-old newborn, and yet you have almost no money, no job, and are soon to be forced from your home. You are desperate for cash, so that your family may be kept safe and warm, and to compensate, you attempt to rob a convenient store. Using what you can scrape together, you purchase a sidearm with the serial number filed off, and break into the nearby 7-11 a couple of hours after closing. Upon entry, you begin to search for the manager's office where you convict a safe brimming with monetary notes will be hidden, and, after a few minutes, you happen upon it and burst into the room. You find yourself faced with the manager of the store, whose facial expression is contorting into a mixture of confusion, realisation, and consequential anger as he comes to understand the scope of the situation. He begins to argue with you, and you come to learn that this man's family is as well about to be forced from their home due to a lack of funds, and that stealing from his store would essentially sentence his family to life in a box in the alley leading off from 3rd Street. After a brief yet passionate dissertation, he steps in front of his safe, and declares that he will die before he allows you access to it. Herein you are faced with a decision. Will you kill the man, rob his store of its money, and save your family? Or will you let him live, and submit your family, your newborn child, to a life on the cold streets, one which will in all likelihood kill them?
The situation described above is one riddled with conflicting morality. On one side, the man is breaking a number of laws and threatening to kill the manager of the convenient store in order to save his family. On the other, the manager needs the money he makes from the store to save his own family, and in comes a man who is threatening to take that all away from him. The only absolute truth to this hypothetical occurrence is that the man is attempting to commit armed robbery. This is what I will refer to as an objective constant, because the action is the same regardless of a given individual's relation to it. What can and does change is the perception of the morality of the actions. One could argue that this man is committing these crimes to essentially save the lives of him and his family, and his actions are therefore justified. It could also be said that he is still committing a violent and criminal act, and no end morally justifies those means. This variation is what I will refer to as subjective perception, because it is relative to the morality of the given individual. However, in order for the aforementioned individual to form an opinion, or to acquire a subjective perception of the situation, his brain must first gather information regarding it, and does so through what is known as cognition.
Cognition, or the state of sensing, refers to a number of different faculties, or processes, of the brain. These processes are the ten senses (yes, ten), and are vision (sight), audition (hearing), gustation (taste), tactition (touch), olfaction (smell), thermoception (temperature), equilibrioception (balance), proprioception (spatial sense, or your body's ability to recognise where it is and how it is positioned), nociception (pain), and interoception (the awareness of processes occurring within one's body). In later posts, I will go into more depth concerning the senses, however for now I will say that being cognisant, or sensing something, does not mean you are consciously aware of it. To clarify, I will use the visual system as an example. According to Neil R. Carlson's The Physiology of Behaviour (a text which I have referenced in previous posts), the visual system is actually divided into two systems: the primitive visual system, and the mammalian visual system. The individual is not aware of information, or stimuli, the primitive visual system gathers, however is conscious of stimuli the mammalian system receives. As a point of reference, the primitive visual system is responsible for creating the illusion that our eyesight and eye movement is smooth, along with perceiving reaching movements with the hands and other simple behaviours.
In my post entitled "The Decision Reflex," I described what I hypothesise to be the decision making mechanism of the brain. The frontal lobe begins to formulate a plan or strategy, and then communicates with other lobes in order to gather more information about how the plan could be executed, and that communication is what causes the individual to become aware of it. This sense of communication between regions of the cerebrum is known as interoception, and can also refer to sensations such as being aware of indigestion or muscle cramps. Moreover, a stipulation of mine that I did not reference in my previous post is that the frontal lobe is almost constantly forming plans, and that we are, in actuality, hardly ever aware of it. The idea communication between different regions of the nervous system is required in order for the individual to become conscious of something, such as decision making or a reflex, can be extended to include cognition and the senses. That is, I hypothesise that in order to be considered conscious, either some, most, or all of the sensory systems must be communicating with each other. Using the decision reflex as an example, I would convict that the individual would become aware of the frontal lobe's plan to, for instance, get pizza, and its consequent interface with the other lobes of the brain in order to further define its plan if the individual sensed something, a stimulus, using one of his ten senses, that the brain could associate with the frontal lobe's developing plan (such as the olfactory sensation of pizza), then the individual would become aware of that plan. I will refer to this phenomenon as multiphasic cognitive relay, because the senses are relaying information between each through multiple different connection points, which creates as well as accounts for what I consider to be the illusion of consciousness.
The nature of consciousness is, as I had said in my introductory entry, perhaps one of the most enigmatic conventions in the universe. It has been debated by the philosophers and scientists of classic Greece, the renaissance period, the modern day world, and everywhere in between. I, however, convict that consciousness is an illusion, a blending of the senses created by the functions of the brain, and I will use my next series of entries to further develop my hypothesis into one that might be considered plausible.
References
The situation described above is one riddled with conflicting morality. On one side, the man is breaking a number of laws and threatening to kill the manager of the convenient store in order to save his family. On the other, the manager needs the money he makes from the store to save his own family, and in comes a man who is threatening to take that all away from him. The only absolute truth to this hypothetical occurrence is that the man is attempting to commit armed robbery. This is what I will refer to as an objective constant, because the action is the same regardless of a given individual's relation to it. What can and does change is the perception of the morality of the actions. One could argue that this man is committing these crimes to essentially save the lives of him and his family, and his actions are therefore justified. It could also be said that he is still committing a violent and criminal act, and no end morally justifies those means. This variation is what I will refer to as subjective perception, because it is relative to the morality of the given individual. However, in order for the aforementioned individual to form an opinion, or to acquire a subjective perception of the situation, his brain must first gather information regarding it, and does so through what is known as cognition.
Cognition, or the state of sensing, refers to a number of different faculties, or processes, of the brain. These processes are the ten senses (yes, ten), and are vision (sight), audition (hearing), gustation (taste), tactition (touch), olfaction (smell), thermoception (temperature), equilibrioception (balance), proprioception (spatial sense, or your body's ability to recognise where it is and how it is positioned), nociception (pain), and interoception (the awareness of processes occurring within one's body). In later posts, I will go into more depth concerning the senses, however for now I will say that being cognisant, or sensing something, does not mean you are consciously aware of it. To clarify, I will use the visual system as an example. According to Neil R. Carlson's The Physiology of Behaviour (a text which I have referenced in previous posts), the visual system is actually divided into two systems: the primitive visual system, and the mammalian visual system. The individual is not aware of information, or stimuli, the primitive visual system gathers, however is conscious of stimuli the mammalian system receives. As a point of reference, the primitive visual system is responsible for creating the illusion that our eyesight and eye movement is smooth, along with perceiving reaching movements with the hands and other simple behaviours.
In my post entitled "The Decision Reflex," I described what I hypothesise to be the decision making mechanism of the brain. The frontal lobe begins to formulate a plan or strategy, and then communicates with other lobes in order to gather more information about how the plan could be executed, and that communication is what causes the individual to become aware of it. This sense of communication between regions of the cerebrum is known as interoception, and can also refer to sensations such as being aware of indigestion or muscle cramps. Moreover, a stipulation of mine that I did not reference in my previous post is that the frontal lobe is almost constantly forming plans, and that we are, in actuality, hardly ever aware of it. The idea communication between different regions of the nervous system is required in order for the individual to become conscious of something, such as decision making or a reflex, can be extended to include cognition and the senses. That is, I hypothesise that in order to be considered conscious, either some, most, or all of the sensory systems must be communicating with each other. Using the decision reflex as an example, I would convict that the individual would become aware of the frontal lobe's plan to, for instance, get pizza, and its consequent interface with the other lobes of the brain in order to further define its plan if the individual sensed something, a stimulus, using one of his ten senses, that the brain could associate with the frontal lobe's developing plan (such as the olfactory sensation of pizza), then the individual would become aware of that plan. I will refer to this phenomenon as multiphasic cognitive relay, because the senses are relaying information between each through multiple different connection points, which creates as well as accounts for what I consider to be the illusion of consciousness.
The nature of consciousness is, as I had said in my introductory entry, perhaps one of the most enigmatic conventions in the universe. It has been debated by the philosophers and scientists of classic Greece, the renaissance period, the modern day world, and everywhere in between. I, however, convict that consciousness is an illusion, a blending of the senses created by the functions of the brain, and I will use my next series of entries to further develop my hypothesis into one that might be considered plausible.
References
Carlson, Neil R. Physiology of Behavior. Boston: Allyn and Bacon, 2011. Print.
Saturday, July 28, 2012
The Genius Gene
How do we understand things? In a geometry class, the student is first exposed to what is known as a postulate. A postulate is a statement that is so simple and basic in nature that it is axiomatic, and can be considered as such without the need for evidence. For example, the ruler postulate dictates that every point on a line can be assigned a real number. After the student becomes acquainted with several postulates, he will then be introduced to what are known as theorems: statements which are proven by use of previously established statements, or, in this case, postulates. The process of using previously known statements regarded as fact in order to prove something else, more complex in nature, to be true is how we learn. At a young age, children are taught basic principles of mathematics, such as numbers. They are taught to accept that each number has its own value, and that each number that supersedes any other given number has a greater value. Based on these two statements, they can then conclude that if two numbers were to be combined together, their collective value would increase at a rate relative to the values of the original, independent numbers. Needless to say, it is not explained in this manner, however therein lies a question: how does this manifest on a neurobiological level?
Refer back to the example of the child learning basic principles of math. In order to understand that two numbers such as two and three equate to five, his brain must first establish the original two statements as fact, and does so by storing them as memories. In the same way, the brain uses the memory of the experience of, for instance, seeing the clear sky as blue, to set what might be considered an intellectual precedent, and thereafter the individual will always make the assumption that he will see the clear sky as blue. It will then use the memories of the aforementioned mathematical principles to conclude that two and three equate to five. In other words, the brain connects the two memories together, and combines them, and will understand the more complex concept of addition due to this memory combination. The newly conceived concept will then enter into the process of becoming a long-term memory (not relevant to this post). The connections between the two memories are made by what are known as axons: long, slender tubes which project from the cell body of a neuron (a cell of the nervous system that transmits information) which transmit information between different regions of the nervous system. For the purposes of this entry, simply assume that there are a pair of axons which allow for intercommunication between the two memories. The axons are known collectively as white matter, because they are coated in a fatty substance (known as the myelin sheath) that is coloured white. Furthermore, we can assume that because the axons of the white matter form connections between memories, allowing more complex concepts to be conceived and understood, the ability of an individual to understand these concepts, which is known as intelligence, is directly correlated to the amount of white matter in that individual's brain. But what dictates the amount of white matter in a person's brain?
While intelligence has been known to change throughout childhood development, the amount of white matter in an individual's brain is dependent on the genes which control the development of the brain of a baby during pregnancy, development which is referred to as neonatal neural development. Neil R. Carlson's The Physiology of Behaviour describes the process in which the nervous system forms. Early in embryonic development, a portion of the ectodermal (out layer) tissue of the embryo hardens into a plate, which then curls into what is called the neural tube. This tube will develop into the spinal cord, and the cells at the top of the tube will begin to divide and produce neurons and other nerve cells in the brain, which will then also be positioned by the cells from whence they divided. After these cells fall into their designated places, they will begin to sprout axons as well as small, branchlike processes known as dendrites (refer to the figure below). These axons will attempt to find other neurons to connect to, and ones that fail to do so will undergo apoptosis, or programmed cell death. The cells, of course, are programmed to do so by their genes. I stipulate that if one of the genes responsible for causing neurons whose axons do not make connections with other neurons to undergo apoptosis was perhaps faulty in some way, then maybe some or all of those neurons might remain alive, and they could then be able to form connections with other neurons (as neurons continuously do throughout life) after the child is born. This increase in white matter due to the faulty gene (or genes) would therefore correlate to an increase in the potential intelligence of the child, or perhaps even allow for the possibility of what might be interpreted as genius.
As I had said in my last post, my stipulation as to the possibility of this "genius gene" is just that- stipulation. It is a hypothesis I do not yet have evidence for or against, nor do I at the moment have means of acquiring any beyond reading the work of others. As with my post on the 'decision reflex,' though, I find this concept as well entirely plausible, and will continue to broach my ideas concerning neurobiology and the state of what we perceive to the internet using this blog.
References
Refer back to the example of the child learning basic principles of math. In order to understand that two numbers such as two and three equate to five, his brain must first establish the original two statements as fact, and does so by storing them as memories. In the same way, the brain uses the memory of the experience of, for instance, seeing the clear sky as blue, to set what might be considered an intellectual precedent, and thereafter the individual will always make the assumption that he will see the clear sky as blue. It will then use the memories of the aforementioned mathematical principles to conclude that two and three equate to five. In other words, the brain connects the two memories together, and combines them, and will understand the more complex concept of addition due to this memory combination. The newly conceived concept will then enter into the process of becoming a long-term memory (not relevant to this post). The connections between the two memories are made by what are known as axons: long, slender tubes which project from the cell body of a neuron (a cell of the nervous system that transmits information) which transmit information between different regions of the nervous system. For the purposes of this entry, simply assume that there are a pair of axons which allow for intercommunication between the two memories. The axons are known collectively as white matter, because they are coated in a fatty substance (known as the myelin sheath) that is coloured white. Furthermore, we can assume that because the axons of the white matter form connections between memories, allowing more complex concepts to be conceived and understood, the ability of an individual to understand these concepts, which is known as intelligence, is directly correlated to the amount of white matter in that individual's brain. But what dictates the amount of white matter in a person's brain?
While intelligence has been known to change throughout childhood development, the amount of white matter in an individual's brain is dependent on the genes which control the development of the brain of a baby during pregnancy, development which is referred to as neonatal neural development. Neil R. Carlson's The Physiology of Behaviour describes the process in which the nervous system forms. Early in embryonic development, a portion of the ectodermal (out layer) tissue of the embryo hardens into a plate, which then curls into what is called the neural tube. This tube will develop into the spinal cord, and the cells at the top of the tube will begin to divide and produce neurons and other nerve cells in the brain, which will then also be positioned by the cells from whence they divided. After these cells fall into their designated places, they will begin to sprout axons as well as small, branchlike processes known as dendrites (refer to the figure below). These axons will attempt to find other neurons to connect to, and ones that fail to do so will undergo apoptosis, or programmed cell death. The cells, of course, are programmed to do so by their genes. I stipulate that if one of the genes responsible for causing neurons whose axons do not make connections with other neurons to undergo apoptosis was perhaps faulty in some way, then maybe some or all of those neurons might remain alive, and they could then be able to form connections with other neurons (as neurons continuously do throughout life) after the child is born. This increase in white matter due to the faulty gene (or genes) would therefore correlate to an increase in the potential intelligence of the child, or perhaps even allow for the possibility of what might be interpreted as genius.
 |
| A basic visual of a neuron, a nerve cell, which displays the axon and dendrites. |
References
Carlson, Neil R. Physiology of Behavior. Boston: Allyn and Bacon, 2011. Print.
Felten, David L., Anil Narsinha. Shetty, and David L. Felten. Netter's Atlas of Neuroscience. Philadelphia, PA: Saunders/Elsevier, 2010. Print.
Friday, July 27, 2012
The Decision Reflex
What are humans? Certain religions would have us believe we are the center of the universe, however from a scientific and secular viewpoint, we are simply one of the myriad of products of a long and winding evolutionary 'road.' We are the last surviving species of the genus 'homo,' however we are still organisms, as are house cats and fruit flies. What makes us different is the long-held concept of consciousness, or a higher level of thinking than most of the animals with which we cohabitate the world. Does this entail that there is something more in us, as homo sapiens, than there are in other organisms such as horses? Or are we composed of the same six elements, and bound together by electricity and atomic bonds, just as every other organism that lives or has once lived? Science has long ago proven the latter to be true, although the nature of consciousness itself has eluded our full comprehension. In this post, I am going to broach my hypothesis as to how the 'mind' functions, as well as support it.
What would happen if one's finger was placed on an source of immense heat? The body would react by immediately retracting the finger, or perhaps the entire arm. However this is not voluntary. In a situation such as this one, the nerves in the finger which sense the heat communicate that intense sensation to the spinal cord, which is a 'cord' of neural tissue (nerves and cell bodies of nerves), where it meets another nerve that will then send that communication back to the point of the sensation's origin, where muscles in that general area will react by contracting, thus pulling the finger backwards. Only after this process, known as a reflex, will the individual become aware of it, because the spinal cord will also project this information to the brain, but by the time the individual might reach a state of awareness of the sensation of heat (in most cases, less than a second) the reflex will have already been completed.
Suppose the reflex described in the previous paragraph did not occur, and that in order for the finger to be pulled from the heat, the brain must make the decision to retract it. The same nerves in the finger would sense the heat, and communicate it to the spinal cord. The spinal cord would send the information to the brain, where it would pass through a number of systems until it reached a particular area of what is known as the cerebrum. The cerebrum is the largest portion of the brain, and what most think of when they attempt to visualise it. It is divided into two portions, which are known as the cerebral hemispheres. It is the topmost region of the brain, and its cortex ("bark" in Greek), or the external layer, has many grooves and fissures in it, and these are known as cortical folding. The cortex of the cerebrum is called the cerebral cortex, and the frontal portion of the cerebrum is called the frontal lobe. Each cerebral hemisphere has a frontal lobe, as well as one of each of the other three lobes (they are not to be referenced in this post), and the two hemispheres are connected by what is called the corpus callosum ("tough body" in Latin), which allows the two hemispheres to share information with one another (see the below figure). The frontal lobe is responsible for planning movements, strategies, and things of that nature (all of which can be conscious processes), and the information the aforementioned nerves received from the heat source would have to be processed by the frontal lobe, and then processed back to the point of the sensation's origin before the finger would be retracted. But what exactly causes this process to become 'conscious?'
According to Sam Harris, a neurologist as well as author of a number of books including Free Will, the decision making process of the brain is principally subconscious in nature: that is, the decision is made before the individual is aware of it. The time it takes the individual to become aware of the decision is, as it was in the case of the reflex, much less than a second, although it has led myself to stipulate that perhaps the process of making a decision is akin to a reflex, and that the individual becomes aware of it due to the information being sent to a different region of the brain, as one might become conscious of a reflex due to the spinal cord sending the information concerning it to a different region of the nervous system: the brain. Therein lies another question: which region?
Neil R. Carlson's eleventh edition of his textbook The Physiology of Behaviour references a procedure known as the split-brain operation. This operation is performed on those afflicted with epilepsy so severe that it cannot be controlled with drugs. Epilepsy is a disorder in which the nerves of one of the cerebral hemispheres becomes overactive. Those nerves then process through the corpus callosum, and cause nerves in the other hemisphere to become overactive, resulting in what's known as a seizure. The purpose of the split-brain operation is to cut the corpus callosum, so that the overactive neurons cannot reach the other hemisphere. This prevents the hemispheres from taking part in interhemispheric communication, or the sharing of information and perceptions between hemispheres, as well as causes rather interesting side effects. In a case referenced by the same text, a post-op split-brain patient had been reading a book. The book was in the patient's left hand, and the holding of the book therefore correlated to the right side of the brain (connections to the brain are inverted, i.e. left hand to right hemisphere, etc.). In the brain of this patient, the right hemisphere could not interpret individual components of something, such as words to a text. Because the right cerebral hemisphere could not read what the book said, it became bored with it and caused the left hand to throw it away. When it was later discussed, the patient was not aware that the right hemisphere had decided to do so, and simply witnessed his own hand "having a mind of its own." In his textbook, Carlson has interpreted this as a region of the left cerebral hemisphere being involved in consciousness, and I would agree with this. However, I would further stipulate that it is not the only region of the cerebrum so involved, so much as any region besides the one from whence the communication originated.
For example, perhaps the frontal lobe is planning to contract the humerus, the long bone in the forearm. The individual is at first not aware of this, however becomes so when the frontal lobe communicates with one of the regions of the cerebral hemisphere, either ipsilateral (on the same side) or contralateral (on the other side) to it, that is responsible for associating vision, audition, or other sensory information with memories. At the point in which these two regions of the brain communicate, is the point at which the individual becomes aware of the frontal lobe's current activity. An analogy which might be employed to conceptualise this process would be two individuals who are having a conversation, and a third who is listening in. Equate one of the conversing individuals, individual A, to the frontal lobe, and the other individual, individual B, to the region to which the front lobe is communicating with. The third person (individual C) is the individual whose brain this is occurring in. Individual A is planning to buy a pizza to eat. Individual C is not yet aware of this because individual A has not shared this plan. When he shares it with individual B, individual B can help individual A figure out where to buy the pizza and how much it might cost. Individual C is not aware of how each of the individual are forming these ideas, however he has now become aware of the plan to buy the pizza due to his listening to the communication between individuals A and B. This is what I convict consciousness to be: the communication between different regions of the cerebrum, or perhaps between regions of the cerebrum and different areas of the brain in general.
In the paragraph previous to my analogy, I stipulated that the region of the cerebrum that did not communicate with the right hemisphere (due to the split-brain op) in the patient was not the only one involved in consciousness. Why? The patient was not aware of the right hemisphere's boredom with the book, nor was he aware of its plan to throw the book away, which was due to the procedure performed to cure his severe epilepsy. Would that then not mean that consciousness is isolated to only one hemisphere (left, in this case) of the brain? Not necessarily, otherwise how would the individual have made the decision to read the book in the first place? As I had mentioned previously, I convict the process of formulating plans and decisions is a subconscious one, and that this decision 'reflex' would cause the individual to become aware of it after the fact. My hypothesis would entail the region of the brain that received the communication from the frontal lobe about its plan to pickup the book caused the individual to become aware of it, however the region of the brain that was supposed to receive information from the frontal lobe of the right cerebral hemisphere about its boredom of reading the book had been disconnected due to the split-brain operation, thus preventing the individual from becoming aware of it.
This is but one of the many ideas I have concerning the brain and the nature of consciousness, and while I cannot yet ascertain whether or not there is truth in the concept of a 'decision reflex,' I deem it to be entirely plausible, and I look forward to being able to either prove or disprove myself in the future, when I have the means to.
References:
What would happen if one's finger was placed on an source of immense heat? The body would react by immediately retracting the finger, or perhaps the entire arm. However this is not voluntary. In a situation such as this one, the nerves in the finger which sense the heat communicate that intense sensation to the spinal cord, which is a 'cord' of neural tissue (nerves and cell bodies of nerves), where it meets another nerve that will then send that communication back to the point of the sensation's origin, where muscles in that general area will react by contracting, thus pulling the finger backwards. Only after this process, known as a reflex, will the individual become aware of it, because the spinal cord will also project this information to the brain, but by the time the individual might reach a state of awareness of the sensation of heat (in most cases, less than a second) the reflex will have already been completed.
Suppose the reflex described in the previous paragraph did not occur, and that in order for the finger to be pulled from the heat, the brain must make the decision to retract it. The same nerves in the finger would sense the heat, and communicate it to the spinal cord. The spinal cord would send the information to the brain, where it would pass through a number of systems until it reached a particular area of what is known as the cerebrum. The cerebrum is the largest portion of the brain, and what most think of when they attempt to visualise it. It is divided into two portions, which are known as the cerebral hemispheres. It is the topmost region of the brain, and its cortex ("bark" in Greek), or the external layer, has many grooves and fissures in it, and these are known as cortical folding. The cortex of the cerebrum is called the cerebral cortex, and the frontal portion of the cerebrum is called the frontal lobe. Each cerebral hemisphere has a frontal lobe, as well as one of each of the other three lobes (they are not to be referenced in this post), and the two hemispheres are connected by what is called the corpus callosum ("tough body" in Latin), which allows the two hemispheres to share information with one another (see the below figure). The frontal lobe is responsible for planning movements, strategies, and things of that nature (all of which can be conscious processes), and the information the aforementioned nerves received from the heat source would have to be processed by the frontal lobe, and then processed back to the point of the sensation's origin before the finger would be retracted. But what exactly causes this process to become 'conscious?'
 |
| A visual of the cerebrum, its cortex, its hemispheres, and the corpus callosum. |
Neil R. Carlson's eleventh edition of his textbook The Physiology of Behaviour references a procedure known as the split-brain operation. This operation is performed on those afflicted with epilepsy so severe that it cannot be controlled with drugs. Epilepsy is a disorder in which the nerves of one of the cerebral hemispheres becomes overactive. Those nerves then process through the corpus callosum, and cause nerves in the other hemisphere to become overactive, resulting in what's known as a seizure. The purpose of the split-brain operation is to cut the corpus callosum, so that the overactive neurons cannot reach the other hemisphere. This prevents the hemispheres from taking part in interhemispheric communication, or the sharing of information and perceptions between hemispheres, as well as causes rather interesting side effects. In a case referenced by the same text, a post-op split-brain patient had been reading a book. The book was in the patient's left hand, and the holding of the book therefore correlated to the right side of the brain (connections to the brain are inverted, i.e. left hand to right hemisphere, etc.). In the brain of this patient, the right hemisphere could not interpret individual components of something, such as words to a text. Because the right cerebral hemisphere could not read what the book said, it became bored with it and caused the left hand to throw it away. When it was later discussed, the patient was not aware that the right hemisphere had decided to do so, and simply witnessed his own hand "having a mind of its own." In his textbook, Carlson has interpreted this as a region of the left cerebral hemisphere being involved in consciousness, and I would agree with this. However, I would further stipulate that it is not the only region of the cerebrum so involved, so much as any region besides the one from whence the communication originated.
For example, perhaps the frontal lobe is planning to contract the humerus, the long bone in the forearm. The individual is at first not aware of this, however becomes so when the frontal lobe communicates with one of the regions of the cerebral hemisphere, either ipsilateral (on the same side) or contralateral (on the other side) to it, that is responsible for associating vision, audition, or other sensory information with memories. At the point in which these two regions of the brain communicate, is the point at which the individual becomes aware of the frontal lobe's current activity. An analogy which might be employed to conceptualise this process would be two individuals who are having a conversation, and a third who is listening in. Equate one of the conversing individuals, individual A, to the frontal lobe, and the other individual, individual B, to the region to which the front lobe is communicating with. The third person (individual C) is the individual whose brain this is occurring in. Individual A is planning to buy a pizza to eat. Individual C is not yet aware of this because individual A has not shared this plan. When he shares it with individual B, individual B can help individual A figure out where to buy the pizza and how much it might cost. Individual C is not aware of how each of the individual are forming these ideas, however he has now become aware of the plan to buy the pizza due to his listening to the communication between individuals A and B. This is what I convict consciousness to be: the communication between different regions of the cerebrum, or perhaps between regions of the cerebrum and different areas of the brain in general.
In the paragraph previous to my analogy, I stipulated that the region of the cerebrum that did not communicate with the right hemisphere (due to the split-brain op) in the patient was not the only one involved in consciousness. Why? The patient was not aware of the right hemisphere's boredom with the book, nor was he aware of its plan to throw the book away, which was due to the procedure performed to cure his severe epilepsy. Would that then not mean that consciousness is isolated to only one hemisphere (left, in this case) of the brain? Not necessarily, otherwise how would the individual have made the decision to read the book in the first place? As I had mentioned previously, I convict the process of formulating plans and decisions is a subconscious one, and that this decision 'reflex' would cause the individual to become aware of it after the fact. My hypothesis would entail the region of the brain that received the communication from the frontal lobe about its plan to pickup the book caused the individual to become aware of it, however the region of the brain that was supposed to receive information from the frontal lobe of the right cerebral hemisphere about its boredom of reading the book had been disconnected due to the split-brain operation, thus preventing the individual from becoming aware of it.
This is but one of the many ideas I have concerning the brain and the nature of consciousness, and while I cannot yet ascertain whether or not there is truth in the concept of a 'decision reflex,' I deem it to be entirely plausible, and I look forward to being able to either prove or disprove myself in the future, when I have the means to.
References:
Carlson, Neil R. Physiology of Behavior. Boston: Allyn and Bacon, 2011. Print.
Harris, Sam. Free Will. New York: Free, 2012. Print.
Thursday, July 26, 2012
My Introduction
What is consciousness? Perhaps one of the most enigmatic conventions the universe features. Does it perhaps allude to entities that exist within each of our bodies, rendering the silicon, phosphorous, oxygen, nitrogen, carbon, and hydrogen of which we are composed simply a vestige? Or is it simply a manifestation of the inner workings of the nervous system? The former question is the principal component of a philosophical concept known as dualism, a concept which dictates the mind, or consciousness, as it were, and the body (the integumentary system, the digestive system, etc.) are separate entities. Dualism is a premise which had been in the favour of the scientific community moreso in the time of French philosopher Rene Descartes. He believed a gland within the brain known as the Pineal body was akin to a joystick: the brain received information from the sensory systems (vision, audition, etc.) and then transferred it to the 'soul,' which, when it made its decision, titled the Pineal body in a particular direction, and fluid in the brain (known as cerebrospinal fluid) would flow in that direction. Descartes also convicted that our nerves were to our bodies as pipes were to machines, and that muscles were cylinders. Once the soul chose where to direct the fluid, it would flow through the nerves and then to the muscles, where they would either fill up or empty with fluid, causing contraction or relaxation. We now know that anatomy of the body is not as he thought, however he laid the foundation for further study. Today we have many fields which principally concern the nervous system, fields such as neurology, and cognitive and behavioural neuroscience. The evidence these fields garner suggest consciousness is as the latter of my two previously broached questions suggested-a manifestation of the nervous system. As such, the scientific community now generally accepts the concept of monism (the mind and body being the same entity) to be axiomatic. Even so, there is still so very much left to learn. Neuroscience is a relatively new field, as well as one which I hope to benefit in my future. My name is Andrew, and I have created this blog for the purpose of aggregating my conjectures, hypotheses, ideas, and thought processes concerning this immensely interesting and enigmatic topic to the information super highway. And maybe along the way, I might be able to actually help us understand what truly is 'the human experience.'
Subscribe to:
Posts (Atom)