Mechanisms of human attention: event-related potentials and oscillations

Electrophysiological and hemodynamical responses of the brain allow investi gation of the neural origins of human attention. We review attention-relate d brain responses from auditory and visual tasks employing oddball and nove lty paradigms. Dipole localization and intracranial recordings as well as f unctional magnetic resonance imaging reveal multiple areas involved in gene rating and modulating attentional brain responses. In addition, the influen ce of brain lesions of circumscribed areas of the human cortex onto attenti onal mechanisms are reviewed. While it is obvious that damaged brain tissue no longer functions properly, it has also been shown that functions of non -lesioned brain areas are impaired due to loss of modulatory influence of t he lesioned area. Both early (P1 and N1) and late (P3) event-related potent ials are modulated by excitatatory and inhibitory mechanisms.. Oscillatory EEG-correlates of attention in the alpha and gamma frequency range also sho w attentional modulation. (C) 2001 Elsevier Science Ltd. All rights reserve d.