Multiple Electrophysiological Markers of Visual-Attentional Processing in a Novel Task Directed toward Clinical Use

Figure 5

The N2pc component was obtained by subtracting ipsilateral neural activity (recorded over the left hemisphere, PO7, when target stimuli were presented in the left visual field and recorded over the right hemisphere, PO8, when target stimuli were presented in the right visual-field) from Contralateral neural activity (recorded over the left hemisphere, PO7, when stimuli were presented in the right visual field and recorded over the right hemisphere, PO8, when stimuli were presented in the left visual-field). The same subtraction was used to compute the SPCN. To show the scalp distribution of the N2pc, we computed the Grand Average ERP for all trials in which the target was on the left and subtracted from it the Grand Average ERP for all trials in which the target was on the right. As expected if the contralateral response was more negative than the ipsilateral response, the subtraction was positive at left-sided electrodes and negative at right-sided electrodes.