Synesthesia and the Nature of Perception Essay example -- Biology Essa

Synesthesia and the Nature of Perception Although scientists do not fully understand the workings of the brain and perception, the basic concept seems fairly simple on an intuitive level. The brain interprets one set of stimuli in a specific way. Certain people with synesthesia, however, can experience a single stimulus in different ways. Are they naturally predisposed to hear red? Do these people have extra neural connections allowing them to taste green? Some scientists claim that all humans begin their lives as synaesthetes until they learn to differentiate their senses. It brings into question the nature of perception, and how the brain perceives reality. Synaesthetes experience "cross-modal" associations involuntarily, so that the feeling of one sense stimulates the sensations of another (1). Five features for clinical synesthesia exist (1): People with the rare condition of synesthesia experience it passively, but it requires a certain stimulus to elicit a response. The individual projects the sensations into his peri-personal space. The sensations do not change over time, and are generic, unelaborated sensory perceptions. In addition, the experiences are very memorable; one subject said that "he was merely a passive observer as the reminiscence unfolded itself" (1). Experiments with a single synesthetic subject show perfect consistency for colour descriptions of words, compared to a 17% consistency rate of a control subject with similar intelligence and memory levels (3). Not only did the subject seem genuine, based on her high level of consistency, but she gave far more detailed and vivid descriptions of the associated colours than the control subject. In a larger group of nine subjects, the consistency rate fo... ...until the brain learns to separate sensations. The source of the connections, the limbic brain, still serves as an emotional guide to the rational objective world, giving reality different perspective for each individual. Internet Sources 1)http://psyche.cs.monash.edu.au/v2/psyche-2-10-cytowic.html, in Psyche 2)http://www.psychiatry.cam.ac.uk/isa/whatis.html, Overview on the ISA homepage 3)http://www.psychiatry.cam.ac.uk/isa/expinv.html, Experiments on the ISA website 4) http://www.ozemail.com.au/~ddiamond/synth.html,paper on Synesthesia 5)http://psyche.cs.monash.edu.au/v2/psyche-2-27-baron_cohen.html, in Psyche 6)http://www.cnn.com/HEALTH/9511/synesthesia/, article on CNN 7)http://www.ad-i.com/viral/what/synes2.html, paper by Kamel 8)http://www.healthlink.usa/synesthesia.html,health information about synesthesia from Healthlink