unisensory

Unisensory refers to processing or tasks that rely on a single sensory modality, such as vision, hearing, touch, taste, or smell. It stands in contrast to multisensory processing, in which information from two or more senses is integrated to form a percept or response.

Neural processing of unisensory information begins in primary sensory cortices tailored to each modality—V1 for vision, A1 for audition, S1 for touch— and continues through modality-specific thalamic relays such as the lateral geniculate nucleus for vision and the medial geniculate nucleus for audition. These pathways can operate largely independently, enabling rapid, modality-specific judgments. Higher-level areas and feedback connections, however, can modulate unisensory responses based on attention, expectation, and context, and cross-modal inputs can influence processing even when a single sense is targeted.

In experimental work, unisensory tasks assess baseline perceptual thresholds, detection, discrimination, and reaction times within one modality. Measurements may include behavioral metrics and neural indicators from EEG, MEG, or fMRI that reflect activity in primary and associated sensory cortices.

Clinically and developmentally, unisensory processing can be altered by sensory loss, aging, or neurological disorders. Isolated deficits in a single modality may occur with disorders such as blindness or deafness, illustrating the modular organization of the sensory system as distinct from multisensory integration.