Influence of facial expression on memory for facial identity: effects of visual features or emotional meaning?

Research has shown that neutral faces are better recognized when they had been presented with happy rather than angry expressions at study, suggesting that emotional signals conveyed by facial expressions influenced the encoding of novel facial identities in memory. An alternative explanation, however, would be that the influence of facial expression resulted from differences in the visual features of the expressions employed. In this study, this possibility was tested by manipulating facial expression at study versus test. In line with earlier studies, we found that neutral faces were better recognized when they had been previously encountered with happy rather than angry expressions. On the other hand, when neutral faces were presented at study and participants were later asked to recognize happy or angry faces of the same individuals, no influence of facial expression was detected. As the two experimental conditions involved exactly the same amount of changes in the visual features of the stimuli between study and test, the results cannot be simply explained by differences in the visual properties of different facial expressions and may instead reside in their specific emotional meaning. The findings further suggest that the influence of facial expression is due to disruptive effects of angry expressions rather than facilitative effects of happy expressions. This study thus provides additional evidence that facial identity and facial expression are not processed completely independently.