Synesthesia and the Nature of Perception Essay
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 …show more content…
Cytowic suggests that the "link between a stimulating sensation and the synesthetically-perceived one" exists on a lower level of the neuraxis (1). Synesthesia involves metabolic shifts, occurring only in the left-hemisphere of the brain, away from the neocortex toward limbic structure, reducing rational processes in favor of emotional ones. The hippocampus also contributes greatly to the synesthetic experience, corroborated by altered states of consciousness from seizures and drugs which effect the hippocampus and also produce synesthesia (1).
Further experimentation using PET scans of the brain shows that blindfolded synaesthetes given certain auditory stimuli showed activity in the visual centers of the brain than their control-group counterparts (3). Thus, conscious visual perceptions occur without activation in the primary visual area for those with synesthesia, lending physical evidence to subjects' experiences. The condition has a physiological basis for the neural connections, yet it only appears to effect very few individuals.
Because the way the brain receives all sensory information is the same, all feelings may have a similar neurological origin. Thus, we may all start life in a state of synesthesia until our brains learn to differentiate our sense into different modalities. Maurice Merleau-Ponty believed that "synesthetic perception is the rule, and we are