THE EFFECT OF EARLY SENSORY DEPRIVATION ON THE TEMPORAL PROFILE OF MULTISENSORY INTEGRATION

Abstract

The animals’ neural system is capable of integrating inputs from different sensory modalities to aid the perception of external events, providing behavioral advantages including quicker reaction time and higher accuracy of response. Highly implicated in such functionalities is the mammalian midbrain structure superior colliculus (SC). SC neurons are capable of responding to cross-modal inputs with an elevated number of neuronal spikes, e.g. brief flashes and noise bursts, in comparison to either modality-specific component. However, such capability is not innate for it fails to develop in animals deprived of early life cross-modal experience. This study revealed animals with such physiological anomaly failed to use cross-modal cues as effectively in a localization task. Recent findings suggest that the temporal profile of multisensory responses in normal animals is featured by a superadditive initial enhancement and a delayed inhibition. In sensory-deprived animals, such features of the multisensory temporal profile were demonstrated to be altered. Even though these neurons still utilized a real-time transform, the initial response enhancement was much weaker which indicated no further enhancement over statistical facilitation. Highly variable cross-modal exposure failed to rescue enhancement level back to normal.