Abstract
Previous studies from our lab showed that stop-action signals engender emotional devaluation of associated stimuli. This effect may result from response inhibition (produced by the stop-action signal) becoming associated with the stored representation of the associated stimulus. When that stimulus is viewed later, this inhibition gets applied to its emotional evaluation, leading to devaluation. Here, we asked whether stop-action devaluation generalises to novel stimuli matched in category to stop-action stimuli and how much it depends on visual memory. We presented successive face images in a go/no-go speeded response task cued by either gender or race (Asian or Caucasian) to Caucasian and Asian participants (allowing us to exploit own-race v. other-race advantages in face memory, Meissner et al., 2001). After each block of 10 trials, we obtained trustworthiness ratings of novel and previously seen go and no-go faces. The response times (RTs) with gender cues were significantly faster than with race cues. Using gender cues (e.g., go males, no-go females), we found no evidence of stop-action devaluation. However, with race cues (e.g., go Asian, no-go Caucasian), previously seen no-go faces were rated as less trustworthy than previously seen go faces. This effect was found for both previously seen exemplars and for novel exemplars that matched the no-go category. Interestingly, stop-action devaluation was only found when the no-go category was own-race faces; other-race no-go faces did not get devalued. These data suggest that stop-action devaluation: (1) results when action inhibition is effortful (indexed by long go-RTs); (2) requires no-go stimuli to be successfully individuated, and (3) can generalize to novel images that share the no-go category if categorization is difficult (as it is for race) and exemplars can be individuated (as they can be for own-race faces). These findings support the idea that stop-action devaluation depends on memorial processes.
With support to N. Westoby from ESRC (UK) and to J. Raymond from BBSRC (UK)