Modality-specific sensory readiness for upcoming events revealed by slow cortical potentials

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Sensory Perception

Background:

• Human brain activity anticipates future events and prepares actions.
• Event-related potential (ERP) studies have localized preparatory activity in premotor and prefrontal cortex.
• Previous research has not extensively investigated preparatory activity within sensory cortical regions.

Purpose of the Study:

• To investigate preparatory activity in sensory cortical regions during passive tasks.
• To test the hypothesis that perceptual anticipatory mechanisms are modality-specific.
• To identify novel sensory readiness components in visual, auditory, and somatosensory modalities.

Main Methods:

• Slow cortical potentials were recorded during passive perceptual tasks.
• Participants (three groups of 21 young adults) underwent tasks in visual, auditory, or somatosensory modalities.
• Analysis focused on identifying modality-specific preparatory components and their cortical sources.

Main Results:

• Confirmed a visual negativity (vN) component originating in extrastriate areas, starting ~800 ms before visual stimulus.
• Identified a novel auditory positivity (aP) component in auditory cortices, starting ~800 ms before auditory stimulus.
• Discovered a somatosensory negativity (sN) component in the secondary somatosensory cortex, starting ~500 ms before somatosensory stimulus.

Conclusions:

• The study identified modality-specific sensory readiness components (vN, aP, sN) in the human brain.
• These preparatory activities are mirrored with inverted polarity in early post-stimulus components (P1, N1, P100).
• Findings expand the understanding of slow wave preparatory components and the interplay between top-down and bottom-up sensory processing.