EEG dynamics reflects the partial and holistic effects in mental imagery generation

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Human Brain Activity

Background:

• Mental imagery is crucial for knowledge retrieval and storage.
• Holistic mental imagery is easier to assess than partial imagery.
• The precise relationship between partial and holistic mental imagery remains unclear.

Purpose of the Study:

• To investigate electroencephalogram (EEG) spectral dynamics during partial versus holistic mental imagery generation.
• To clarify the relationship between partial and holistic mental imagery processes.
• To analyze phase coupling between the two imagery conditions.

Main Methods:

• Acquired EEG signals from 18 healthy participants during a designed imagery task.
• Performed statistical analysis of spectral dynamics across frequency bands.
• Utilized bicoherence spectrum analysis to assess phase coupling.

Main Results:

• EEG activity for partial imagery emerged earlier and was stronger than holistic imagery in the theta band (5-8 Hz) between 220-300 ms post-cue.
• A decrease in the alpha band (8-12 Hz) was noted around 270 ms.
• Significant phase coupling was observed at high frequencies, with distinct frontal and central-temporal scalp topographies.

Conclusions:

• Partial and holistic mental imagery exhibit complex interrelations.
• Partial imagery generation is not a simple subprocess of holistic imagery.
• Partial imagery is relevant to holistic imagery and requires modification based on holistic information.