Attention- and action-related oscillatory dynamics in a visuomotor network.

A network model of a "selection-for-action" system was proposed with the primary idea that the functions of stimulus and response selection are carried out within a visuomotor oscillatory network. To examine the network's dynamics under different sensorimotor demands, an electroencephalographic experiment was performed, contrasting visual detection and discrimination variants of a Posner cueing task. In the former, the required response can be prepared before target onset, whereas in the latter-only after target onset. Using the generalized eigenvalue decomposition method for EEG source isolation, we identified four network subcomponents: lateral motor, lateral visual, midfrontal, and midparietal sources. The local and inter-source activity relevant for spatial attention (visual and midparietal sources) were involved before target onset in both tasks but stronger for the discrimination task. The local activity and inter-source connectivity relevant for action control (motor and midfrontal sources) were involved before target onset only in the detection task. Importantly, in line with the model's predictions, we observed that proactive response preparation in the detection task entailed beta-band connectivity between the response control areas and visual areas. Moreover, we observed a response-related spatial modulation of pre-target local visual alpha activity in the detection task. These results likely reflect automatic visuomotor integration.