The decrease in recognition performance after face inversion has been taken to suggest that faces are processed holistically. Three experiments, 1 with schematic and 2 with photographic faces, were conducted to assess whether face inversion also affected visual search for and implicit evaluation of facial expressions of emotion. The 3 visual search experiments yielded the same differences in detection speed between different facial expressions of emotion for upright and inverted faces. Threat superiority effects, faster detection of angry than of happy faces among neutral background faces, were evident in 2 experiments. Face inversion did not affect explicit or implicit evaluation of face stimuli as assessed with verbal ratings and affective priming. Happy faces were evaluated as more positive than angry, sad, or fearful/scheming ones regardless of orientation. Taken together these results seem to suggest that the processing of facial expressions of emotion is not impaired if holistic processing is disrupted.

No abstract

Although socially controlled sex transformation in fishes is well established, the underlying mechanisms are not well understood. Particularly enigmatic is behavioural transformation, in which fish can rapidly switch from exhibiting female to male-typical courtship behaviours following removal of 'supermales'. Bluehead wrasses are a model system for investigating environmental control of sex determination, particularly the social control of sex transformation. Here, we show that the onset of this behavioural transformation was delayed in females that occupied low-ranking positions in the female dominance hierarchy. We also establish that expression of maletypical courtship behaviours in competent initial-phase (IP) females is facultative and gated by the presence of terminal-phase (TP) males. Dominant females displayed reliable TP male-typical courtship behaviours within approximately 2 days of the removal of a TP male; immediately following reintroduction of the TP male, however, females reverted back to female-typical behaviours. These results demonstrate a remarkable plasticity of sexual behaviour and support a 'priming/gating' hypothesis for the control of behavioural transformation in bluehead wrasses.

Social interactions can drive distinct gene expression profiles which may vary by social context. Here we use female sailfin molly fish (Poecilia latipinna) to identify genomic profiles associated with preference behavior in distinct social contexts: male interactions (mate choice) versus female interactions (shoaling partner preference). We measured the behavior of 15 females interacting in a non-contact environment with either two males or two females for 30 min followed by whole-brain transcriptomic profiling by RNA sequencing. We profiled females that exhibited high levels of social affiliation and great variation in preference behavior to identify an order of magnitude more differentially expressed genes associated with behavioral variation than by differences in social context. Using a linear model (limma), we took advantage of the individual variation in preference behavior to identify unique gene sets that exhibited distinct correlational patterns of expression with preference behavior in each social context. By combining limma and weighted gene co-expression network analyses (WGCNA)approaches we identified a refined set of 401 genes robustly associated with mate preference that is independent of shoaling partner preference or general social affiliation. While our refined gene set confirmed neural plasticity pathways involvement in moderating female preference behavior, we also identified a significant proportion of discovered that our preference-associated genes were enriched for 'immune system' gene ontology categories. We hypothesize that the association between mate preference and transcriptomic immune function is driven by the less well-known role of these genes in neural plasticity which is likely involved in higher-order learning and processing during mate choice decisions.

Immune activity in the brain underlies many social behaviors. This immune-behavior relationship can be viewed under a genomics scope by isolating transcriptomic correlates and molecular pathways present following various social encounters. Here we explore how immune genes correlate with different social exposures: mate-choice and social affiliation. Using an established model for sexual selection studies, we compared the immune gene responses in female brains following exposure to either a potential mate or a conspecific female. Females from the Poeciliidae family of fishes, the sailfin molly (Poecilia latipinna), were profiled for their social preference behavior and brain transcriptomes using RNA-seq. During the 30 minute behavioral assay, females were placed into one of two groups: (n=8) given the choice of a large male and small male (‘mate choice’) or a choice between a large and small female (n=8; ‘social affiliation’). The relationship between immune gene responses (categorized using Gene Ontology analysis) and behavior (preference, social affiliation, activity) will be explored using a linear model approach for differential expression (limma; Ritchie ME, et al, 2015) and WGCNA (weighted gene co-expression network analysis; Langfelder & Horvath, 2008). The RNA-seq transcriptomes from each female (n=16) will be analyzed by comparing differential expression between the two groups (‘mate-choice’ vs ‘social preference’).