Psychophysiology, 35(5):576-590, 1998.
Dissociation of brain ERP topographies for tonal and phonetic oddball tasks
Jürgen Kaysera,b, Craig E. Tenkea, Gerard E. Brudera,b
a Department of Biopsychology, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032, USA
b Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, USA
Received 6 February 1997; accepted 10 February 1998.
Abstract
ERP topographies for 30 scalp electrodes were examined in 26 healthy right-handed volunteers during oddball tasks (20% targets) using binaurally presented consonant-vowel syllables or complex tones. Response hand was counterbalanced across participants. Both window averages and a principal components analysis (PCA) with Varimax rotation revealed task-related (tonal/phonetic) hemispheric asymmetries for N2, early P3, and particularly for N2-P3 amplitude. In the tonal task, N2 was maximal over right lateral-temporal regions, and early P3 over right medial-parietal regions. For the phonetic task, N2 was maximal over the left lateral-parietal regions, and late P3/N3 over left medial-parietal regions. A response-related frontal negativity (N3) interacted with task-related asymmetries in an unbalanced fashion. The distinct, asymmetric N2 and P3 topographies for tonal and phonetic tasks presumably reflect differential involvement of cortical structures in pitch (right fronto-temporal) and phoneme (left parieto-temporal) discrimination.
Keywords: ERP asymmetry; N2 (N200); P3 (P300); Tonal/Phonetic Oddball; Principal Components Analysis (PCA); Response Hand
