A theory of working memory without consciousness or sustained activity

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• Working memory and conscious perception are believed to share neural mechanisms.
• Recent studies suggest the possibility of non-conscious working memory, challenging this view.

Purpose of the Study:

• To investigate the existence and neural mechanisms of non-conscious working memory.
• To differentiate neural signatures of conscious versus non-conscious working memory.

Main Methods:

• Utilized magnetoencephalography (MEG) combined with visual masking.
• Employed a spatial delayed-response task to assess working memory performance.

Main Results:

• Participants demonstrated above chance-level performance in reporting target locations for non-conscious working memory.
• Conscious perception and working memory showed sustained alpha/beta band desynchronization and decodable neural representations.
• These neural signatures were absent during non-conscious working memory.

Conclusions:

• Findings challenge models linking working memory solely to sustained neural firing.
• Results support 'activity-silent' working memory models, where information is stored via synaptic changes.
• A theoretical framework and simulations suggest dormant cell assemblies can be retrieved after delays.