Prefrontal Cortex Modulation during Anticipation of Working Memory Demands as Revealed by Magnetoencephalography
Figure 5
Group maps during the encoding, delay and retrieval epochs of the working memory task at beta frequency (14–30 Hz); corrected. (a) The encoding epoch was associated with fairly symmetrical ERD in primary visual and visual association cortex. The map shows an epoch of 500 ms duration (from 200 ms to 700 ms after the memory set presentation). (b) The delay epoch was associated with beta ERS in bilateral visual areas and beta ERDs in left IFG and left premotor regions. The map shows an epoch of 400 ms duration (from 300 ms to 700 ms after the delay began). (c) The response period beta was associated with beta ERDs over a distributed network including left DLPFC, left IFG and premotor areas, right IFG, temporal and parietal regions. The map shows an epoch of 300 ms duration (from 0 ms to 300 ms after the presentation of the probe. DLPFC: dorsolateral prefrontal cortex; IFG: inferior frontal gyrus; PM: premotor area; IPL: inferior parietal lobe; STG: superior temporal gyrus; MTG: middle temporal gyrus; MOG: middle occipital gyrus. Red color coding indicates task related power increase; blue color coding indicates task related power decrease. The figure shows data rendered onto a Talairach-space surface template.
