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Abstract:
Abstract: Emotional stimuli may either improve or impair
performance. Mechanisms for emotion-cognition interaction have been
suggested, however few studies have compared event-related
potentials (ERP) with behavioural measures. We examined the effects
of emotional stimuli on ERPs and reaction times (RT) in a hemifield
visual discrimination task. Twelve subjects discriminated between
upright and inverted triangles (target; 150 ms duration). Targets
were randomly presented in the left or right visual hemifield. A
brief emotional (pleasant or unpleasant; 150 ms duration) or neutal
picture selected from the International Affective Picture System
was presented centrally 350 ms prior to the subsequent target.
Subjects were instructed to ignore the pictures and respond to the
targets as quickly and accurately as possible. On 18% of the trials
targets were not preceded by a picture. Pictures served as a
warning stimuli, and were associated with a shortened RT (p
< 0.001) and a prominent fronto-central N2. RTs to targets
preceded by unpleasant stimuli were longer (p < 0.05) than to
targets preceded by pleasant or neutral stimuli. Emotional pictures
selectively enhanced a fronto-central P2 and a more frontally
focused P3 amplitudes. Enhanced ERP amplitudes suggest increased
resource allocation to both pleasant and unpleasant emotional
stimuli. However, only unpleasant stimuli had a distinct effect on
performance possibly due to interference at the response production
phase.
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