Effects of unilateral anteromedial temporal lobe resections on event-related potentials when reading negative and neutral words

We investigated effects of unilateral left (lTLR, N = 15) or right (rTLR, N = 19) anteromedial temporal lobe resections comprising amygdala and temporal pole on event-related potentials (ERPs) during attentive reading of negative and neutral words, their emotional evaluation, and recognition memory. Content effects on behaviour did not differ between lTLR, rTLR, and controls (N = 18). Negative words elicited larger ERPs than neutral words for P1, Early Posterior Negativity (EPN), and Late Positive Potential (LPP). However, the rTLR group lacked the P1 enhancement and had attenuated EPN effects. Despite showing generally the largest ERP amplitudes, the lTLR group had smaller occipital N1 and left frontal positivity for negative compared with neutral words in the N1 window. Only lTLR also had smaller left parietal P2 and larger right parietal P3 and LPP for negative words. These data help specify left and right anteromedial temporal lobe contributions to the processing of negative and neutral words.