Abstract
Multisensory integration (MSI) is essential to coordinate complex behaviours. It has a protracted period of development (Gori et al., 2010) and is influenced by early experience (Wallace et al., 2007). For instance, animal studies suggest that a short and transient period of visual deprivation early in life permanently alters the brain mechanisms of MSI (Wallace et al., 2004). In humans, the behavioural consequences of early visual deprivation on the development of MSI remain unclear. Specifically, for « simple » audiovisual stimuli, MSI is sometimes preserved (Putzar et al., 2012) and sometimes altered (Putzar et al., 2007). For « complex » audiovisual stimuli such as the McGurk effect, MSI is often altered (Putzar et al., 2010). To clarify this issue, we measured audiovisual redundancy gains in a group of 13 adult patients who had been treated for bilateral congenital cataracts during early infancy (end of deprivation: 9-238 days) and a group of gender- and age-matched controls. The first task involved simple stimuli (beeps and flashes) designed to target the superior colliculus (Girard et al., 2013; Wallace et al., 2004). The second task was composed of complex face/voice emotional expressions thought to target high-level cortical regions (Collignon et al., 2008). The cataract-reversal group showed a redundancy gain of the same magnitude as controls: for both tasks, detection in the multisensory condition exceeded the best unisensory condition and did so by the same amount as in controls. The results imply that the absence of visual input during the first months of life does not prevent the development of audiovisual cross-modal interactions manifested as redundancy gains.
Meeting abstract presented at VSS 2016