which peaks earlier than P3b and has a relatively more frontal midline maximum, is assumed to reflect stimulus-driven attentional processes (e.g., reviewed by Polich, 2007). Because of their temporal and spatial overlap, it may be difficult to disentangle these two components unless appropriate experimental manipulations are employed; however, multivariate analytic approaches have also been proposed to accomplish an adequate separation (e.g., Spencer et al., 1999, 2001).
