Faster choice-reaction times to positive than to negative facial expressions - The role of cognitive and motor processes

Several studies have shown faster choice-reaction times to positive than to negative facial expressions. The present study examined whether this effect is exclusively due to faster cognitive processing of positive stimuli (i.e., processes leading up to, and including, response selection), or whether it also involves faster motor execution of the selected response. In two experiments, response selection (onset of the lateralized readiness potential, LRP) and response execution (LRP onset-response onset) times for positive (happy) and negative (disgusted/angry) faces were examined. Shorter response selection times for positive than for negative faces were found in both experiments but there was no difference in response execution times. Together, these results suggest that the happy-face advantage occurs primarily at premotoric processing stages. Implications that the happy-face advantage may reflect an interaction between emotional and cognitive factors are discussed.