Clinical EEG and Neuroscience | Psychophysiology Lab

Clinical EEG and Neuroscience, 37(3):269-270, 2006; Psychophysiology, 43:S41, 2006.

Looking for emotional interference in a Stroop-like paradigm: behavioral and event-related potential (ERP) finding

Nathan A. Gates^a,b, JÃ¼rgen Kayser^a,c, Craig E. Tenke^a,c

^a Department of Biopsychology, New York State Psychiatric Institute, New York, New York, USA
^b Queens College at the City University of New York, New York, New York, USA
^c Department of Psychiatry, Columbia University College of Physicians & Surgeons, New York, New York, USA

Abstract

Behavioral interference of emotional content has been found in Stroop-like paradigms, but rarely studied using ERPs. We recorded 67-channel ERPs (average reference) from 28 right-handed adults (15 men) to foveal presentations of colored words (ANEW norms). Content (emotional, neutral) and valence (positive, negative) were systematically manipulated by carefully matching words for arousal and valence (negative vs. neutral and positive vs. neutral), length, and frequency. Color was indicated by 4-choice button press. Response latencies did not reveal emotional interference effects. A clear component structure with a distinct ventroposterior N140 and parietal P500 was present in all ERPs. Spatially and temporally overlapping components were identified and measured by temporal, covariance-based PCA (unrestricted Varimax). Factors of interest within the N2/P3 complex corresponded to: a bilateral negativity over inferior temporoparietal sites (215 ms peak latency), which was reduced in men; a relative negativity over left temporal sites (285 ms), which was greater for emotional than neutral words; and a broad parietal positivity (508 ms), which interacted with emotional content, valence, and gender in a complex fashion that did not readily correspond to emotional interference effects. Whereas the lack of emotional interference effects casts doubt on the generalizability of the phenomenon for healthy adults, the difference between emotional and neutral words between N2 and P3 may reflect physiological processes preceding overt behavioral interference.

Keywords: ERP, emotional Stroop, behavioral interference, principal components analysis (PCA)