TMS induced theta phase synchrony reveals a bottom up network in working memory
Global theta phase synchronization between the frontal and sensory areas has been suggested to connect the relevant areas for executive processes of working memory (WM) However, little is known regarding network directionality (i.e. top down or bottom up) of this interaction. To address the issue, the present study conducted transcranial magnetic stimulation (TMS) electroencephalography (EEG) experiment during WM tasks. Results showed that TMS induced increases in theta phase synchronization were observed only when TMS was delivered to the sensory areas but not the frontal area. These findings suggest that network directionality represented in WM is bottom up rather than top down.
Neuroscience Letters