Distinct neural signatures underlying information maintenance and manipulation in working memory

Area of Science:

• Cognitive Neuroscience
• Neurophysiology

Background:

• Working memory involves maintaining and manipulating information.
• Electroencephalography (EEG) studies show stimulus representations in voltage and alpha-band activity.
• The precise functions of these neural signals in memory manipulation are debated.

Purpose of the Study:

• To investigate the distinct contributions of voltage and alpha-band activity to working memory manipulation.
• To differentiate the spatiotemporal dynamics and functional roles of these neural signals.

Main Methods:

• Human participants performed a spatial working memory task involving maintenance and mental rotation.
• Multivariate decoding was applied to electroencephalography (EEG) data.
• Analysis focused on low-frequency voltage and alpha-band oscillatory activity.

Main Results:

• Robust spatial location representations were found in both voltage and alpha-band activity.
• Voltage signals showed prominent representations in anterior/central channels, while alpha activity was strongest in posterior channels.
• Central voltage representations emerged earlier and were higher-dimensional, predicting behavioral performance.

Conclusions:

• Voltage and alpha-band activity exhibit distinct spatiotemporal dynamics and functional roles in working memory.
• Central voltage may support internal stimulus-specific signal generation, whereas alpha activity might reflect feedback processing.
• These findings underscore the importance of central voltage in working memory manipulation.