Figure 9.

Prestimulus oscillatory activity associated with punishment. Spectral amplitudes in baseline alpha (A) and gamma (B) frequency bands are parametrically modulated by punishment. Scalp maps indicate the slope of change in spectral amplitudes as a function of the amount of punishment (using linear regression), estimated for each sensor separately. Black dots indicate sensors for which the slope is significantly different from 0 (top row). For illustration purposes, the corresponding mean spectral amplitudes over significant sensors are plotted as a function of punishment (bottom row). Negative slopes indicate a reduction in spectral amplitude as punishment increases (frontal and occipitoparietal sensors for alpha, frontal sensors for gamma), whereas positive slopes indicate an increase in spectral amplitude with punishment (occipitotemporal sensors for gamma).