Can prior expectancies shape attention to threat? To answer this question, we manipulated the expectancies of spider phobics and nonfearful controls regarding the appearance of spider and bird targets in a visual search task. We observed robust evidence for expectancy influences on attention to birds, reflected in error rates, reaction times, pupil diameter, and heart rate (HR). We found no solid effect, however, of the same expectancies on attention to spiders; only HR revealed a weak and transient impact of prior expectancies on the orientation of attention to threat. Moreover, these asymmetric effects for spiders versus birds were observed in both phobics and controls. Our results are thus consistent with the notion of a threat detection mechanism that is only partially permeable to current expectancies, thereby increasing chances of survival in situations that are mistakenly perceived as safe.

optimism bias, i.e. expecting the future to hold more desirable than undesirable outcomes, also extends to people that we like or admire. However, it remains unknown how the brain generates this social optimism bias. in this study, respondents estimated the likelihood of future desirable and undesirable outcomes for an in-group and three out-groups: warm-incompetent, cold-competent, and cold-incompetent. We found a strong social optimism bias for the in-group and the warm outgroup and an inverted pattern for the cold-incompetent out-group. for all groups, scores of social optimism bias correlated with the brain activity in structures that respondents differentially engaged depending on the target social group. in line with our hypotheses, evaluating the in-group recruited the ventromedial prefrontal cortex and the precuneus/posterior cingulate cortex, whereas evaluating the warm out-group engaged the posterior insula, mid cingulate cortex, and somatosensory cortices. these findings suggest different underlying cognitive mechanisms of social optimism bias for these groups, despite similar behavioural patterns. thinking about the cold out-groups recruited the right anterior temporal lobe, and temporoparietal junction. evaluating the cold-incompetent out-group additionally recruited the anterior insula, inferior frontal cortex and dorsomedial frontal cortex. We discuss these neuroimaging findings with respect to their putative cognitive functions. Human minds are highly capable of solving problems at hand, anticipating prospective issues and benefits, and planning accordingly. At the core of these skills lies the capacity to gauge the likelihood of future events 1-3. The way we assess the likelihood of future events in the general population is different from how we assess it for ourselves 4-6 , for those close to us 7-10 , and for in-group 11,12 and out-group members 11-19. Through various motivational 20,21 and cognitive mechanisms 22,23 , we manifest an optimism bias whenever we think about our future and the future of those close to us 4,8,10,11,13 but not of acquaintances or dissimilar others 8,11,14,24,25. Specifically, we expect that the future holds significantly more desirable than undesirable outcomes for ourselves and those we identify with 26. Despite a modest body of behavioural research on social optimism bias, i.e. optimism manifested towards people that we like and feel close to, very little is known about how the brain gives rise to this phenomenon 18. The primary focus of the current study was to investigate the neural correlates of group membership-driven optimism biases. To pursue this research aim and inform our hypotheses, we considered the neuroimaging literature on person perception and social cognition. A hallmark of social cognition is that individuals think differently about in-group and out-group members 27-32. Although what determines in-group and out-group membership is flexible and highly contextual 30,33 , people perceive in-group and out-group members as part of different entities wi...

Optimism bias and positive attention bias have important highly similar implications for mental health but have only been examined in isolation. Investigating the causal relationships between these biases can improve the understanding of their underlying cognitive mechanisms, leading to new directions in neurocognitive research and revealing important information about normal functioning as well as the development, maintenance, and treatment of psychological diseases. In the current project, we hypothesized that optimistic expectancies can exert causal influences on attention deployment. To test this causal relation, we conducted two experiments in which we manipulated optimistic and pessimistic expectancies regarding future rewards and punishments. In a subsequent visual search task, we examined participants’ attention to positive (i.e., rewarding) and negative (i.e., punishing) target stimuli, measuring their eye gaze behavior and reaction times. In both experiments, participants’ attention was guided toward reward compared with punishment when optimistic expectancies were induced. Additionally, in Experiment 2, participants’ attention was guided toward punishment compared with reward when pessimistic expectancies were induced. However, the effect of optimistic (rather than pessimistic) expectancies on attention deployment was stronger. A key characteristic of optimism bias is that people selectively update expectancies in an optimistic direction, not in a pessimistic direction, when receiving feedback. As revealed in our studies, selective attention to rewarding versus punishing evidence when people are optimistic might explain this updating asymmetry. Thus, the current data can help clarify why optimistic expectancies are difficult to overcome. Our findings elucidate the cognitive mechanisms underlying optimism and attention bias, which can yield a better understanding of their benefits for mental health.