Eye movements explain decodability during perception and cued attention in MEG.

Area of Science:

• Neuroscience
• Cognitive Science
• Biomedical Engineering

Background:

• Eye movements are crucial for perception but introduce artifacts in magneto-encephalography (MEG) and electroencephalography (EEG) studies.
• Artifacts are typically removed, but consistent eye movement patterns may induce genuine-seeming effects in MEG signals.
• The extent to which eye movements influence observed MEG effects is often unverified due to a lack of control analyses.

Purpose of the Study:

• To investigate the potential influence of eye movements on MEG signals during a working memory task.
• To determine if stimulus location can be decoded from eye movements, suggesting eye movements might explain observed MEG effects.
• To provide methods for checking and minimizing eye movement artifacts in MEG/EEG research.

Main Methods:

• Participants performed a working memory match-to-sample task.
• Eye movements were tracked during task performance.
• MEG data was analyzed to assess the correlation between eye movement patterns and neural signals.
• Decoding analysis was used to determine if stimulus location could be predicted from eye movements.

Main Results:

• Stimulus location was successfully decoded from eye movements during two distinct stages of the working memory task.
• This decoding indicates that observed MEG effects may be partially or wholly attributable to eye movements rather than neural activity.
• The findings highlight a potential confound in MEG studies using similar tasks.

Conclusions:

• Eye movements can significantly confound MEG data, mimicking neural correlates of cognitive processes.
• Researchers should implement control analyses to differentiate between true neural effects and eye movement artifacts.
• Strategies for minimizing eye movement artifacts during data acquisition are crucial for reliable MEG/EEG research.