Stimulus specific cortical activity associated with ignoring distraction during working memory encoding and maintenance.

Distraction disrupts Working Memory (WM) performance, but how the brain filters distraction is not known. One possibility is that neural activity associated with distractions is suppressed relative to a baseline/passive task (biased competition). Alternatively, distraction may be denied access to WM, with no suppression. Furthermore, behavioural work indicates separate mechanisms for ignoring distractions which occur (1) while we put information into WM (Encoding Distraction, ED) and (2) while we maintain already encoded information during the WM delay period (Delay Distraction, DD). Here we used fMRI in humans to measure category-sensitive cortical activity and probe the extent to which ED/DD mechanisms involve enhancement/suppression during a WM task. We observed significant enhancement of task-relevant activity, relative to a passive view task, which did not differ according to whether or when distractors appeared. For both ED and DD we found no evidence of suppression, but instead a robust increase in stimulus specific activity in response to additional stimuli presented during the passive view task, which was not seen for the WM task, when those additional stimuli were to be ignored. The results indicate that ED/DD resistance does not necessarily involve suppression of distractor-related activity. Rather, a rise in distractor-associated activity is prevented when distractors are presented, supporting models of input gating, and providing a potential mechanism by which input-gating might be achieved.

The power of external influences to modify judgments of facial and moral beauty.

Empirical evidence shows that the often-made positive correlation between human physical and moral beauty is tenuous. In this study, we aimed to learn whether facial and moral beauty can be psychophysically separated. Participants (n = 95) provided beauty and goodness (i.e., trustworthiness) ratings for pictures of faces, after which they were presented with a fictitious peer rating for the same face and asked to re-rate the face. We used the difference between the initial and final ratings to quantify the degree of resistance to external influence. We found that judgments of facial beauty were more resistant to external influence than judgments of facial "goodness"; in addition, there was significantly higher agreement within beauty ratings than within goodness ratings. These findings are discussed in light of our Bayesian-Laplacian classification of priors, from which we conclude that moral beauty relies more upon acquired "artifactual" priors and facial beauty more on inherited biological priors.