Event Related Potentials associated to the feedback stimuli. Event Related Potentials at the Cz electrode associated to the feedback stimuli indicating wins or losses for the performers and the three different observer conditions. Black lines indicate trials in which the performer won (averaged across 25 and 5 cent conditions), whereas red lines indicate the responses associated performer's losses. Note that the observers in the neutral and parallel conditions and the performers showed an increased negativity for performer's losses in the 200-400 ms range. The scalp topographies (isovoltage maps of the loss minus gain difference wave, relative scaling, blue indicating negative, red indicating positive voltages) showed a similar mediofrontal maximum in these three groups. By contrast, observers in the reverse condition showed a more negative response for the performer's gains which translated to losses of the observer. Again, the scalp topography of the difference had a mediofrontal maximum.
Marco-Pallarés et al. BMC Neuroscience 2010 11:86 doi:10.1186/1471-2202-11-86