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Updated: Jul 7, 2026
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Detecting Pre-Stimulus Source-Level Effects on Object Perception with Magnetoencephalography
Published on: July 26, 2019
Attentional changes in pre-stimulus oscillatory activity within early visual cortex are predictive of human visual
Noriko Yamagishi1, Daniel E Callan, Stephen J Anderson
1National Institute of Information and Communication Technology, Biological ICT group, 2-2-2 Hikaridai, Soraku-gun, Kyoto 619-0288, Japan. n.yamagishi@atr.jp
Brain Research
|February 5, 2008
Summary
Attention enhances visual processing by increasing neural coherence and suppressing alpha activity in early visual areas, leading to improved task performance. This top-down control primes the brain for incoming sensory information.
Area of Science:
- Neuroscience
- Cognitive Science
- Visual Perception
Background:
- Attentional mechanisms are thought to exert top-down control on early visual processing.
- This top-down control is believed to prime the visual system for upcoming sensory events, enhancing task performance.
Purpose of the Study:
- To investigate whether attention-driven changes in cortical activity correlate with performance on a visual task.
- To examine the neural mechanisms underlying attentional priming of early visual areas.
Main Methods:
- Magnetoencephalography (MEG) was used to record brain activity.
- Participants performed a line-orientation judgment task following a covert attentional shift.
- Analysis focused on phase-resetting (neural coherence) and alpha activity suppression in the calcarine cortex.
Main Results:
- A significant increase in 2-10 Hz phase-resetting occurred in the calcarine cortex approximately 200 ms after attentional shift.
- This was followed by a suppression of alpha activity (near 10 Hz) until stimulus onset.
- Phase-resetting and alpha suppression levels systematically correlated with behavioral performance, with higher coherence linked to better performance.
Conclusions:
- Top-down attentional control influences early visual areas via phase-resetting in the 2-10 Hz band within the calcarine cortex.
- This process triggers alpha activity suppression, priming visual areas and enhancing behavioral performance.
