Related Experiment Videos
Multisensory processing and oscillatory gamma responses: effects of spatial selective attention
Daniel Senkowski1, Durk Talsma, Christoph S Herrmann
1Center for Cognitive Neuroscience, Duke University, Box 90999, Durham, NC 27708-0999, USA.
Experimental Brain Research
|September 10, 2005
Summary
This study shows that attention enhances early brain responses to combined audio-visual stimuli, detected via gamma-band responses (GBRs). These early effects were not seen with single sensory inputs or in event-related potentials (ERPs).
Area of Science:
- Neuroscience
- Cognitive Science
- Sensory Processing
Background:
- Multisensory integration combines information from different senses.
- Spatial attention modulates sensory processing.
- Gamma-band responses (GBRs) are neural oscillations linked to cognitive functions.
Purpose of the Study:
- To investigate the interaction between multisensory integration and spatial attention using electroencephalography (EEG).
- To compare findings with previous event-related potential (ERP) data.
- To explore the neural mechanisms underlying attentional modulation of multisensory processing.
Main Methods:
- EEG recording during a task involving unisensory (auditory, visual) and multisensory (audio-visual) stimuli.
- Stimuli presented to left and right hemispaces with participants attending to a specific side.
- Analysis of evoked gamma-band responses (GBRs) and event-related potentials (ERPs).
Main Results:
- Larger evoked GBRs were observed for attended multisensory stimuli compared to unattended ones (40-50 ms post-stimulus).
- Attentional enhancement of multisensory integration may involve stimulus-triggered phase resetting of gamma-band oscillations.
- No comparable early attention effects (<90 ms) were found in ERPs, suggesting GBRs are more sensitive to early attention effects.
- Attention did not affect GBRs for unisensory stimuli, indicating a specific effect on audiovisual integration.
Conclusions:
- Oscillatory GBRs are more sensitive than ERPs to early attentional modulation of multisensory integration.
- Attention specifically enhances the early integrative processing of audiovisual stimuli.
- Phase resetting of gamma-band oscillations might underlie the attentional modulation of multisensory processing.