Journal Article

Changes in Early Cortical Visual Processing Predict Enhanced Reactivity in Deaf Individuals

Giard, Marie-Hélène, Bottari, Davide, Pavani, Francesco, Caclin, Anne

2011

Overview

Individuals with profound deafness rely critically on vision to interact with their environment. Improvement of visual performance as a consequence of auditory deprivation is assumed to result from cross-modal changes occurring in late stages of visual processing. Here we measured reaction times and event-related potentials (ERPs) in profoundly deaf adults and hearing controls during a speeded visual detection task, to assess to what extent the enhanced reactivity of deaf individuals could reflect plastic changes in the early cortical processing of the stimulus. We found that deaf subjects were faster than hearing controls at detecting the visual targets, regardless of their location in the visual field (peripheral or peri-foveal). This behavioural facilitation was associated with ERP changes starting from the first detectable response in the striate cortex (C1 component) at about 80 ms after stimulus onset, and in the P1 complex (100-150 ms). In addition, we found that P1 peak amplitudes predicted the response times in deaf subjects, whereas in hearing individuals visual reactivity and ERP amplitudes correlated only at later stages of processing. These findings show that long-term auditory deprivation can profoundly alter visual processing from the earliest cortical stages. Furthermore, our results provide the first evidence of a co-variation between modified brain activity (cortical plasticity) and behavioural enhancement in this sensory-deprived population.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Adult / Adults / Amplitudes / Auditory deprivation / Auditory plasticity / Behavior - physiology / Biology / Brain / Brain research / Cochlear implants / Cognition & reasoning / Cortex / Cortex (auditory) / Cortex (somatosensory) / Cross-modal / Deaf persons / Deafness / Deafness - physiopathology / Deprivation / Education / Environmental audits / Event-related potentials / Evoked Potentials, Visual / Female / Hearing - physiology / Hearing loss / Humans / Information processing / Male / Middle Aged / Neural plasticity / Neuroplasticity / Neurosciences / Photic Stimulation / Reactivity / Sensorimotor integration / Sensory integration / Social and Behavioral Sciences / Somatosensory cortex / Target detection / Time Factors / Visual cortex / Visual Cortex - physiology / Visual field / Visual fields / Visual perception / Visual stimuli / Visual task performance / Visual tasks / Young Adult