Synopsis: 200 Words
In terms of cross-modal aural communication, sensory inputs can travel from primarily auditory regions in the thalamus to regions specializing in visual processing (e.g. thalamothalamic interactions). Possible mechanisms that allow for cross-modal plasticity include the formation of new connections or the preservation of previous neural connections between sensory cortices. Also, the loss of a sense (e.g. acquired blindness) can unmask “silent” connections, leading to cross-modal activity. None of these mechanisms are all-encompassing in explaining plasticity, but rather, there might be a variable combination of these mechanisms depending on the age of blindness onset. Through TMS experimentation, there is evidence to show
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Other TMS experiments such as those on individuals’ fingers and tongues demonstrate that cross-modal plasticity is heavily reliant on experience rather than visual deprivation and can be induced through training, leading to activation of …show more content…
The reason for the formation of these connections were to compensate for the loss of a sense, and to maximize the use of every region of the brain. However, once a sense is regained, will these connections still be necessary and thus persist, or will they be subject to neural pruning? If the newly synthesized connections are removed once a sense is regained, this could further suggest that the main mechanism behind cross-modal plasticity is visual or auditory deprivation, rather than increased experience with other senses. On the other hand, if the cross-modal connections are preserved, if would be interesting to do a follow-up study and see how the two connected sensory cortices might interfere with each other, leading to distorted perception. For example, if connections are made between the temporal and occipital cortex and vision is restored to a patient undergoing visual surgery, will the patient’s occipital cortex still respond to auditory stimuli and produce interferences with
Carr mentions the affect that technology has on the neurological processes of the brain. Plasticity is described as the brains response through neurological pathways through experiences. The brain regions “change with experience, circumstance, and need” (29). Brain plasticity also responds to experiences that cause damage to the nervous system. Carr explains that injuries in accidents “reveal how extensively the brain can reorganize itself” (29).I have heard stories in which amputees are said to have a reaction to their amputated limb; it is known as a phantom limb. These types of studies are instrumental in supporting the claim that the brain can be restructured. Carr asserts that the internet is restructuring our brains while citing the brain plasticity experiments and studies done by other scientists. I have experienced this because I feel like by brain has become accustomed to activities that I do on a regular basis. For example, I rarely realize that I am driving when coming to school because I am used to driving on a specific route.
In this essay I outline Casey O’Callaghan’s liberal view of multimodality. I suggest that our current understanding does not justify such an extensive view on the multimodality of the senses, and I critique his stance on the prevalence of crossmodal interactions between the senses as an over interpretation of the current experimental data. I argue for a more conservative account of crossmodal interactions between the senses, and hypothesize that perception is best described in terms of distributions. To support this hypothesis, I provide evidence in the form of Jonathan Cohen’s account of synesthesia.
The merging of certain senses points to a crossing of signals in the brain. Although the theory is an old one, it has come to the forefront of the scientific researcher's minds, with increased focus on the topic.
Let’s say that there is a mechanical sense. If someone touched your hand, your somatosensory system will detect various stimuli by your skin’s sensory receptors. The sensory information is then conveyed to the central nervous system by afferent neurons. The neuron’s dendrites will pass that information to the cell body, and on to its axon. From there it is passed onto the spinal cord or the brainstem. The neuron's ascending axons will cross to the opposite side either in the spinal cord or in the brainstem. The axons then terminates in the thalamus, and on into the Brodmann Area of the parietal lobe of the brain to process.
In 1981 Dr. Roger W. Sperry was awarded the Nobel Prize when his colleague and he studied on epilepsy and trying to reduce or eliminate seizures, it took a turn. He did the unthinkable and cut the corpus callosum that connects both sides of the brain and it not only reduce the seizure, but it started a whole new area of study. The study was to see if the functioning of the both halves of the brain can work or improve over time to perform well without the other hemisphere. His patients had some symptoms after doing the procedure Cherry (2013). When the two hemispheres are surgically disconnected, the mental process of each one is in accessible to deliberate conscious retrieval from the point of view of each other. (Newman, Banks, & Baars (2003))
In closing, the normal functioning of the brain and nervous system is vital for basic bodily functioning and processes. Injury, disease or abnormal structure of the brain will greatly affect one's behaviour, emotional regulation, mental processes and functioning. The brain will respond to any trauma, injury or abnormality to accommodate the dysfunction. During this response, the brain will physically change, the process called neuroplasticity, and attempt to "rewire" the brain to return to normal functioning. In the treatment of many cases as previously discussed, the aim was to reconnect neurons and the theory of neuroplasticity was the foundation behind it.
Lu, Z.-L., Williamson, S.J., & Kaufman L. (1992, Dec 4). Behavioral lifetime of human auditory
The occurrence of synaesthesia in the adult population has been estimated between 1 in 2,000 and 1 in 25,000. There has been evidence that women are more likely to have it, with around six times more females than males. Findings state there can be a genetic predisposition transmitted by an X-linked autosomal dominant gene. Through the more recent studies of synaesthesia they have researched a possible biological cause instead of damage to the brain. One of the propositions is the connectivity between brain areas that help to further the relevant sensory modalities. For example, color-phonemic synaesthesia might result from additional synaptic connections between brain regions that are responsible for processing auditory inputs and those involved in color perception.
McLachlan, N. M., Phillips, D. S., Rossell, S. L., & Wilson, S. J. (2013). Auditory processing
The widely popular research on mirror neurons and various applications of the research findings began with an important, but unexpected finding in the brains of macaque monkeys. The original studies did not intend to look at mirror neurons and in fact the existence of mirror neurons was found by accident. Neuroscientist Giacomo Rizzolatti and his colleagues found a group of cells that fired whenever a monkey prepared to act on a stimulus as well as when it watched another monkey act on the stimulus (Winerman, 2005). For example, the monkeys showed a similar pattern of activation when they were performing a simple motor action like grasping a peanut and when they watched another monkey perform the same action (Winerman, 2005). In other words, monkey see, monkey fire -- monkey do, monkey fire. This grouping of cells was called "mirror neurons." The ...
Current research shows that mental events cause physical events, and scientists believe examining single nerves is the key to understanding how the brain works as a complete unit. Understanding the brain at the nerve cell level will allow scientists to understand how human consciousness works (Blakeslee, 1992). Furthermore, the brain's thalamus is identified as the possible sensory connector because it fires 40 impulses per second that sweep through the entire brain (Blakeslee, 1995a). These findings are a serious implication to Dualism because it states the mind is not physical. If the mind is not physical, it cannot affect the physical body, so the Dualist theory of two-sided interactions between the body and mind are false. The aforementioned argument is supported by many other scientific facts and objections against Dualism.
Bargary and Mitchell (2008) presented a review of the anatomical origins of synesthesia that considered possible molecular mechanisms for structural differences between synesthetic and non-synesthetic brains. They concluded that these structural differences are the primary cause of developmental synesthesia. But researchers by the name of Kadosh and Walsh (2008) challenge that conclusion by stating the study done by Bargary and Mitchell only shows the correlation between anatomy and synesthesia, but does not establish a casual relationship. They hypothesis that cortical disinhibition could be the primary cause of synesthesia. They stated that molecular mechanisms might affect the level of inhibition in synesthesia during early development stages. Developmentally speaking, these molecular differences can also lead to a lack of relative neuronal specialization during sensitive periods. Electroencephalography studies found that compared to non-synesthetes, synesthetes who see color when hearing tones or spoken utterences (hearing-color synesthesia) showed differences in auditory-event related potentials in response to letters, words, pseudo-words or tones (Bargary & Mitchell, 2008). The differences evoked potentials as early as 100 ms after stimulation
Steven W. Smith describes the human ear as an exceedingly complex organ. There are multiple levels of the ear. The outer ear is the flap of skin, the cartilage on the side of the head, and the ear canal. The outer ear leads environmental sounds into the middle and inner ear, which are the organs inside the skull. These sound waves cause the eardrum to vibrate. The vibrations are caught by the middle ear, a set of small bones, which transfer the vibrations to the cochlea (inner ear). Here, the sound waves are converted to neural impulses. The neural network in the human brain decodes information from both ears.
Where are your fingers? This question is easy enough that you should be able to answer it, but how do you know? How does anyone know anything? You may say you know where your fingers are while you look at them, touch them, or feel them. Your senses are a great way to learn things. In fact we have way more than the usual five senses we talk about such as sight, hearing, taste, touch and smell. For instance your kinesthetics sense, proprioception. This is what the police evaluate during a field sobriety test, it allows you to tell yourself where your fingers, arms, head, legs and your body is all in relation to each other without having to look or touch other things. We have at least twice as many senses everyone thinks we have, such as, the initial 5 plus balance and acceleration, temperature, kinesthetic sense, pain, time, tactile illusions and then some. Turn your tongue upside down, and run your finger along the outer edge of the tip of your upside down tongue. Your tongue will be able to feel your finger, but in the wrong place. Our brains never needed to develop an understanding of upside down tongue touch, so when you touch the right side of your tongue when it's flipped over to your left side, you perceive a sensation on the opposite side where your tongue usually is but isn't w...