Loss of control and negative emotions: a cortical slow potential topography study

This study investigated cortical steady potential changes in 18 subjects while processing a series of solvable arithmetic items (induction of control) that became unsolvable (withdrawal of control). Two different phases of induction and withdrawal of control (early and late) were dealt with separately in the analyses. The DC EEG was recorded from 20 locations. In all experimental conditions the overall slow potential topographical pattern did not change. However, negative-going DC shifts at occipito-parietal and left posterior-frontal regions were observed during induction of control whereas a generalized positive-going DC shift developed during phases of withdrawal of control. This positive-going shift persisted for the duration of the:he item presentation, resulting in pronounced positive values at temporal sites. The authors assume that temporal lobe activity (inferior and/or ventral surface) correlated to emotional/motivational processes that was picked up via the linked mastoid reference locations contributed essentially to these observed phenomena. (C) 1999 Elsevier Science B.V. All rights reserved.