Effects of High Neuroticism on Ocular Exploration of Face Stimuli
Our study indicates that high neuroticism is characterized by an attentional bias away from salient face regions, which is not affected by emotional valence of the facial expression and is indexed by an abnormal pattern of ocular face exploration. High Ns avoided holding their gaze over the eye region for the whole trial duration, and general face avoidance was significantly correlated with self-rated hostility. This suggests that High Ns may avoid engaging with socially salient stimuli such as faces, reflecting a self-perceived negative disposition towards interpersonal contact. Previous studies have reported a similar pattern in socially phobic patients (Horley et al, 2003). Although we did not collect measures of social anxiety, stress during social interactions is a well-recognized feature of the high neurotic phenotype, contributing to the higher risk for social anxiety (Clark et al, 1994; Watson et al, 2008). Interestingly, this avoidant ocular exploration pattern is consistent with reduced neural response to faces (irrespective of emotional expression) in the amygdala in the same population (Di Simplicio et al, 2013).
Differences in the task demands could explain the discrepancy between our findings and that by Perlman et al (2009), who reported that increased scanning over the eye region, in particular of fearful faces, is associated with high neuroticism during an overt emotion discrimination task. It is possible that when explicitly cued to respond to the emotional expression of the face, highly neurotic subjects can orient their attention to the eyes, which they otherwise avoid when less relevant to their contingent objective. If this were true, the increased eye region exploration over fearful eyes found by Perlman et al (2009) could represent a task-driven strategy, consistent with a recent meta-analysis showing that heterogeneity of results from attention orienting and maintenance data is often context dependent (Armstrong and Olatunji, 2012). Another explanation could lie in our sample focused on High N individuals, whereas Perlman et al (2009) using a continuous measure: ‘extreme' neuroticism, is more likely to present prominent socially anxious features, which could explain an avoidant pattern of eye region exploration (Gamble and Rapee, 2010).
Together, these data suggest that high neuroticism is associated with inadequate capacity to maintain attention over key areas of face stimuli, which could in turn underpin interpersonal difficulties often presented by this group. This may contribute to increased risk of developing anxiety consistent with clinical models (Clark and Wells, 1995) and to lower quality of life, influenced by hypersensitivity to interpersonal stressors and lack of social support (Kendler and Gardner, 2014; Lahey, 2009). Of note, neuroticism is a heterogeneous and multifaceted construct. Our task of covert attention towards emotional facial expression with a short stimulus presentation allows a global assessment of emotion-processing biases, more in particular to those related to general anxiety (hypervigilance—avoidance of negative stimuli) and social anxiety (avoidance of the eye region of faces). Future studies could employ larger samples and identify population subgroups with high neuroticism characterized by more prominent dysphoric, generally anxious, and socially anxious traits. This could be combined with tasks showing concurrent negative and positive facial expressions and longer stimulus presentation in order to investigate more extensively the presence of attentional biases associated with anxiety and depression, respectively.