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Updated: Jun 22, 2026
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Methods to Explore the Influence of Top-down Visual Processes on Motor Behavior
Published on: April 16, 2014
Spatiotemporal properties modulate intermodal influences on early somatosensory processing during sensory-guided
Sean K Meehan1, Wynn Legon, W Richard Staines
1Department of Kinesiology, University of Waterloo, 200 University Ave. West, Waterloo, Ont., Canada N2L 3G1.
Summary
Somatosensory evoked potentials (SEPs) reveal that spatial and temporal relationships between visual and vibrotactile stimuli modulate somatosensory processing in the brain. These early sensory gating mechanisms influence tracking performance and sensorimotor transformations.
Area of Science:
- Neuroscience
- Sensory Processing
- Neurophysiology
Background:
- The primary somatosensory cortex (S1) processes tactile information.
- Interactions between different sensory modalities can influence neural processing.
Purpose of the Study:
- Investigate how different sensory inputs affect somatosensory processing in S1.
- Determine the impact of spatiotemporal relationships between visual and tactile stimuli on S1 activity.
- Observe behavioral changes related to intermodal sensory modulation.
Main Methods:
- Median nerve somatosensory evoked potentials (SEPs) were recorded from the scalp.
- Participants tracked either a vibrotactile or visual stimulus.
- Spatial relationships (same/opposite hemi-field) and temporal synchrony (identical/different patterns) of stimuli were manipulated.
Main Results:
- Increased spatial separation reduced the P27 SEP amplitude, while increased temporal synchrony enhanced it.
- Temporal synchrony boosted P50 amplitude during vibrotactile tracking.
- Behavioral tracking performance correlated with early SEP amplitude changes.
- Task-relevance increased N140 amplitude in Experiment 2.
Conclusions:
- Changes in P27 amplitude indicate intermodal somatosensory gating influenced by stimulus spatiotemporal properties.
- P50 amplitude changes suggest multisensory integration in somatosensory processing.
- Observed behavioral changes likely result from early sensory modulation impacting sensorimotor transformations.
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