High-frequency gamma activity (80-150Hz) is increased in human cortex during selective attention

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• Selective attention is crucial for processing relevant information.
• Gamma oscillations (>30Hz) are implicated in cognitive functions.
• Previous studies using EEG showed gamma activity at lower frequencies.

Observation:

• Electrocorticography (ECoG) recorded neural activity in epilepsy patients.
• Auditory and vibrotactile stimuli were presented asynchronously.
• Subjects selectively attended to one modality to detect amplitude changes.

Findings:

• Increased ECoG gamma activity (80-150 Hz) observed over auditory cortex during auditory attention.
• Increased ECoG gamma activity observed over somatosensory cortex during vibrotactile attention.
• Attended stimuli, regardless of modality, elicited gamma activity in prefrontal cortex.
• Attentional modulation of gamma power began around 400 ms post-stimulus onset.

Implications:

• High-gamma activity (80-150 Hz) is a strong correlate of selective attention in humans.
• These findings suggest a higher frequency range for attentional gamma oscillations than previously reported with EEG.
• This research provides insights into the neural mechanisms of attention.