Showing papers by "Dean Mobbs published in 2015"

The ecology of human fear: survival optimization and the nervous system.

Abstract: We propose a Survival Optimization System (SOS) to account for the strategies that humans and other animals use to defend against recurring and novel threats. The SOS attempts to merge ecological models that define a repertoire of contextually relevant threat induced survival behaviors with contemporary approaches to human affective science. We first propose that the goal of the nervous system is to reduce surprise and optimize actions by (i) predicting the sensory landscape, through simulation of possible encounters with threat, selecting appropriate action by pre-encounter avoidance and (ii) prevention strategies in which the organism manufactures safe environments. When a potential threat is encountered the (iii) threat orienting system is engaged to determine whether the organism ignores the stimulus or switches into a process of (iv) assessment, where the organism monitors the stimulus, weighs the threat value, predicts the actions of the threat, searches for safety, and guides behavioral actions crucial to directed escape. When under imminent attack, (v) defensive systems evoke fast reflexive indirect escape behaviors (i.e. fight or flight). This cascade of responses to threat of increasing magnitude are underwritten by an interconnected neural architecture that extends from cortical and hippocampal circuits, to attention, action and threat systems including the amygdala, striatum, and hard-wired defensive systems in the midbrain. The SOS also includes a modulatory feature consisting of cognitive appraisal systems that flexibly guide perception, risk and action. Moreover, personal and vicarious threat encounters fine-tune avoidance behaviors via model-based learning, with higher organisms bridging data to reduce face-to-face encounters with predators. Our theory unifies the divergent field of human affective science, proposing the highly integrated, interconnected nervous systems are optimized to avoid ecological dangers.

Neuroethological studies of fear, anxiety, and risky decision-making in rodents and humans

Abstract: Prey are relentlessly faced with a series of survival problems to solve. One enduring problem is predation, where the prey's answers rely on the complex interaction between actions cultivated during its life course and defense reactions passed down by descendants. To understand the proximate neural responses to analogous threats, affective neuroscientists have favored well-controlled associative learning paradigms, yet researchers are now creating semi-realistic environments that examine the dynamic flow of decision-making and escape calculations that mimic the prey's real world choices. In the context of research from the field of ethology and behavioral ecology, we review some of the recent literature in rodent and human neuroscience and discuss how these studies have the potential to provide new insights into the behavioral expression, computations, and the neural circuits that underlie healthy and pathological fear and anxiety.

Reflected glory and failure: the role of the medial prefrontal cortex and ventral striatum in self vs other relevance during advice-giving outcomes

Abstract: Despite the risks, people enjoy giving advice. One explanation is that giving beneficial advice can result in reflected glory, ego boosts or reputation enhancement. However, giving poor advice can be socially harmful (being perceived as incompetent or untrustworthy). In both circumstances, we have a vested interest in the advice follower's success or failure, especially when it reflects specifically on us compared with when it is diffused between multiple advisors. We examined these dynamics using an Advisor-Advisee Game, where subjects acted as an Advisor to a confederate Advisee who selected one of the three options when trying to win money: accept the subject's advice, accept the advice of a second confederate Advisor or accept both Advisors' advice. Results showed that having one's advice accepted, compared with being rejected, resulted in activity in the ventral striatum--a core reward area. Furthermore, the ventral striatum was only active when the subject's advice led to the advisee winning, and not when the advisee won based on the confederate's advice. Finally, the medial prefrontal cortex (MPFC) was more active when the Advisee won or lost money based solely on the subject's advice compared with when the second Advisor's advice was accepted. One explanation for these findings is that the MPFC monitors self-relevant social information, while the ventral striatum is active when others accept advice and when their success leads to reflected glory.

Inferences of others' competence reduces anticipation of pain when under threat

Abstract: On a daily basis, we place our lives in the hands of strangers. From dentists to pilots, we make inferences about their competence to perform their jobs and consequently to keep us from harm. Here we explore whether the perceived competence of others can alter one's anticipation of pain. In two studies, participants Receivers believed their chances of experiencing an aversive stimulus were directly dependent on the performance of another person Players. We predicted that perceiving the Players as highly competent would reduce Receivers' anxiety when anticipating the possibility of an electric shock. Results confirmed that high competence ratings consistently corresponded with lower reported anxiety, and complementary fMRI data showed that increased competence perception was further expressed as decreased activity in the bilateral posterior insula, a region localized to actual pain stimulation. These studies suggest that inferences of competence act as predictors of protection and reduce the expectation of negative outcomes.

A Neural Network for Moral Decision Making

Abstract: This article begins by discussing how emotions shape moral choices. We then review the imaging literature, highlighting how moral cognition relies on a broad and decentralized neural network. We focus in particular on the functional roles of the prefrontal cortex, temporal lobes (including the amygdala), and cingulate cortex, emphasizing how each distinct region differentially contributes to moral cognition. We conclude by examining the evidence that lesions to this neural network not only cause deficits in socioemotional responding but also can profoundly disrupt moral behavior.

A Neural Network for Moral Decision Making

Abstract: Some of the most fundamental psychological questions concerning human relations center on morality and altruism. Reinvigorated by the advent of modern technologies such as magnetic resonance imaging (MRI), these questions have been extended to humans, which has resulted in a recent flurry of empirical studies examining the psychological and neural architecture of moral cognition. The depth of this subject is remarkable, and there is insufficient room here to touch on all facets. As a result, this review will cover two questions central to human moral behavior: How do we arrive at our moral judgments? And what is the neural circuitry that underpins these moral judgments?