Differences in early sensory-perceptual processing between synaesthetes and controls: an evoked potentials study
Single Paper Presentation

Kylie J Barnett
School of Psychology, TCIN, Trinity College

John J Foxe
Cognitive Neurophysiology Lab, Nathan Kline Institute for Psychiatric Research, USA

Simon P Kelly
Cognitive Neurophysiology Lab, Nathan Kline Institute for Psychiatric Research, USA

Sophie Molholm
Cognitive Neurophysiology Lab, Nathan Kline Institute for Psychiatric Research, USA

Michelle McCormick
School of Psychology, Trinity College

Kevin J Michell
Smurfit Institute of Genetics

Fiona N Newell
School of Psychology, TCIN, Trinity College

     Abstract ID Number: 14
     Full text: Not available
     Last modified: March 2, 2007
     Presentation date: 07/05/2007 8:40 AM in Quad General Lecture Theatre
     (View Schedule)

Abstract
Although it has been established that synaesthesia is a genuine perceptual phenomenon, its underlying neural substrates are not well understood. Recent neuroimaging studies show that linguistic-chromatic synaesthetes activate colour-processing cortical regions in response to non-chromatic stimuli that induce the experience of colour (Nunn et al., 2002). However, there is considerable debate as to where in the hierarchy of processing illusory colour arises and little is known about the time course and activation of sensory-perceptual processing in synaesthesia. The current study utilises high-density 128-channel EEG to determine differences between synaesthetes and non-synaesthetes. The aim was to determine the time-course of neural activation in synaesthesia in response to veridical colour stimuli (colour and achromatic Mondrians) and stimuli that elicit illusory colour (letters of the alphabet). Differences between synaesthetes and controls were manifest in the early sensory P1 component and findings are discussed with reference to current models of synaesthesia.