Decoding auditory working memory content from EEG aftereffects of auditory-cortical TMS.

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Brain States

Background:

• Working memory (WM) is crucial for goal-directed behavior and human cognition.
• A key theory suggests WM content is maintained in transient, "activity-silent" synaptic states.
• Detecting these activity-silent states requires probing the brain with external stimuli.

Purpose of the Study:

• To investigate the neural mechanisms of working memory maintenance.
• To test the hypothesis that WM content is stored in activity-silent brain states.
• To determine if external stimulation can reveal content in these silent states.

Main Methods:

• Employed single-pulse transcranial magnetic stimulation (spTMS) as an impulse stimulus.
• Utilized electroencephalography (EEG) to record brain activity.
• Applied multivariate pattern analysis (MVPA) with non-parametric permutation testing for decoding WM content.

Main Results:

• Decoding accuracy of WM content significantly improved after spTMS.
• The enhancement in decoding was specific to spTMS delivered to the posterior superior temporal cortex.
• Results support the existence of activity-silent states during WM maintenance.

Conclusions:

• Working memory maintenance involves brain states that are relatively activity-silent.
• External impulse stimuli, like spTMS, can probe and reveal information within these silent states.
• This provides evidence for synaptic mechanisms underlying WM.