Hemispheric differences in brain activity related to the recognition of emotional expressions by 5-year-old children

Event-related potentials were recorded while 5-year-olds (N= 44) watched sl ides of a woman posing happy, angry, and fearful, expressions. In 1 session , children were instructed to press a button whenever they saw the happy fa ce, and in another, they were instructed to respond to the fearful face. Fo ur event-related potential components (N170,P280,N400, and P700) differed i n amplitude, latency, or both at right compared to left hemisphere recordin g sites, and hemispheric differences were present at both anterior (F3, F4) and posterior (T5, T6) recording sites. Hemispheric differences in the amp litude of the P700 were influenced by the task instructions: The P700 was l arger at the right posterior than the left posterior recording site for non target, but not for target, faces. In contrast, hemispheric differences in the components preceding the P700 were not affected by task instructions. T hese results suggest that hemispheric differences in brain activity related to recognition of expressions are modulated by the neurocognitive processe s involved in attending to a particular expression.