Perception is Everything


The brain is shaped as much by the information it receives as it is by the processes that mediate those perceptions.  There are some interesting examples of how the interaction of body senses and perception have a powerful role in shaping cognition. The brain “becomes” the information it receives. A disturbance in hearing, vision, or touch can impair and drastically change normal brain development. In the field of special education, we frequently encounter children with various sensory deficits and I have often felt how easy it is for people to underestimate the cognitive impact perceptual differences can create, as well as the interaction of concomitant pathology in social skills, emotional functioning, and problem-solving ability. Research on deaf children who use signed English or approximated speech, for example, indicates that these children rarely attain the level of language development of children who use ASL forms, which are considered by some to be a naturally wired form of communication (Sacks, 1989; Cohen, 1994).  Why is this important? Verbal concept formation, vocabulary, spatial concepts, and temporal referencing are “drivers’ of cognitive problem-solving ability. Many tasks are, in effect, verbally mediated (Elliott, 1990).

Ratey (2001) cites another powerful example in the domain of visual perception with his case study of “Rickie”, a woman who could not sustain a visual image for more than a minute without her brain beginning to shut down everything else (p 50). Rickie had exhibited unusual behaviors as a child (eg. thinking trees were marching toward her), never developed appropriate play skills, and spent ten years in and out of psychiatric hospitals (p 49).  In short, she was unable to explain her perceptual experiences to others. We don’t know what we don’t perceive. Rickie’s entire cognitive, social, and emotional development had been built, neurologically speaking, upon a foundation of faulty perception of experience. Brain plasticity works both ways.

Another example of the brain-body connection can be seen in the “rubber hand illusion”. Body “ownership” is a core aspect of self-awareness. Moselly, et al (2008) hypothesized that skin temperature in a specific limb could be changed by psychologically disrupting a subject’s sense of ownership of said limb. Disruption in the sense of “body ownership” is characteristic of pathology, as in the case of autism. People with autism are also frequently plagued by dysregulation of body temperature (Moselly, et. al., 2008).  Moselly, et al (2008) attribute this to damage to brain structures responsible for autonomic control, and hypothesize that sense of body ownership and autonomic control are linked. I think this may possibly provide some validation for Gardner’s Bodily-Kinesthetic Intelligence in terms of “potential for isolation” (Gardner, 2006).

The rubber hand illusion (Nature, vol 391, p 756) involves simultaneously brushing a person’s hand while it is hidden from view and a rubber hand placed within the person’s visual field. Many people (2/3) begin to “take ownership” of the fake limb, perceiving the brushing as if located at the site of the rubber hand. In fact, imaging studies detect cortical responses when the false hand is threatened! Neurological and cognitive “ownership” of the hand also evokes a decrease in the temperature of the test subject’s real hand.

Phantom limbs, or the impression of amputees as well as people with congenitally based missing limbs that the limb is present, has been documented in numerous case studies (Sacks, 1985 p 66; Ramachandran & Hirstein, 1988).   Ramachandran & Hirstein (1988) believe that tactile and proprioceptive input is “remapped”. Tactile input to the face results in sensation in the phantom limb.

When someone has a sensory deficit, there is much more to the picture than hearing, vision and touch sensation. If you spend a few seconds staring at the picture of two monkeys in Jenkins and Wiseman’s Illusion (Perception, 2009, vol 38, p,1413), it will turn into a picture of Charles Darwin—or at least, you will perceive it that way!

 

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