Neural Activity When People Solve Verbal Problems with Insight
(Same conventions as in Figure 4). (A) Time course of EEG power at 9.8 Hz (in v2) at right parietal-occipital electrode (PO8). The x-axis represents time (in seconds), with the green horizontal bars above the x-axis representing the time intervals used in the statistical analyses and topographic maps. The yellow arrow and R (at 0.0 s) signify the time of the button-press response.
(B) Time-frequency plots of the insight minus noninsight difference shown in (A).
(C) Insight minus noninsight alpha-band differences plotted as topographic maps of scalp current density (in v2/m2). Note that alpha-band power is significantly greater for insight solutions than noninsight solutions during the −1.31 to −0.56 s interval, but not during the preceding (−2.06 to −1.56 s) or subsequent (−0.31 to +0.06 s) intervals. This alpha burst was embedded in a slow decrease in alpha (see [A]), probably reflecting a general increase in cortical activity as effort increases during the course of problem solving.