Event-related potentials were recorded while 5-year-olds (N = 44) watched slides of a woman posing happy, angry, and fearful expressions. In 1 session, children were instructed to press a button whenever they saw the happy face, and in another, they were instructed to respond to the fearful face. Four event-related potential components (N170, P280, N400, and P700) differed in amplitude, latency, or both at right compared to left hemisphere recording sites, and hemispheric differences were present at both anterior (F3, F4) and posterior (T5, T6) recording sites. Hemispheric differences in the amplitude of the P700 were influenced by the task instructions: The P700 was larger at the right posterior than the left posterior recording site for nontarget, but not for target, faces. In contrast, hemispheric differences in the components preceding the P700 were not affected by task instructions. These results suggest that hemispheric differences in brain activity related to recognition of expressions are modulated by the neurocognitive processes involved in attending to a particular expression.
Bibliographical noteFunding Information:
This research was supported by a training grant from the National Institutes of Health (NIH) to the Center for Research in Learning, Perception and Cognition to the University of Minnesota (HD07151); by a PGSB Award from the Natural Sciences and Engineering Research Council of Canada and a Doctoral Dissertation Fellowship from the University of Minnesota to Michelle de Haan; by a grant from the NIH (NS32976) to Charles A. Nelson; by a National Institutes of Mental Health (NIMH) Research Scientist Development Award to Megan R. Gunnar (MH00946); and by a NIMH Predoctoral Fellowship to Kathryn A. Tout.