Not Just About Faces in Context: Face–Context Relation Moderates the Impact of Contextual Threat on Facial Trustworthiness

Recent work showed that the attribution of facial trustworthiness can be influenced by the surrounding context in which a face is embedded: contexts that convey threat make faces less trustworthy. In four studies ( N = 388, three preregistered) we tested whether face–context integration is influenced by how faces and contexts are encoded relationally. In Experiments 1a to 1c, face–context integration was stronger when threatening stimuli were attributable to the human action. Faces were judged less trustworthy when shown in threatening contexts that were ascribable (vs. non-ascribable) to the human action. In Experiment 2, we manipulated face–context relations using instructions. When instructions presented facial stimuli as belonging to the “perpetrators” of the threatening contexts, no difference with the control (no-instructions) condition was found in face–context integration. Instead, the effect was reduced when faces were presented as “victims.” We discussed the importance of considering relational reasoning when studying face–context integration.

Acetaminophen Potentiates Fear Processing: A Comparison Between Ancestral and Modern Threats

The painkilling medication acetaminophen produces a variety of unintended psychological effects. In particular, it has been shown to diminish varied forms of psychological distress by attenuating neural activity in the cerebral cortex and enhancing the signaling of serotonin. As a result, this over-the-counter medication appears to dampen overall affective processing and has been termed “an all-purpose emotion reliever.” However, this drug may not necessarily modify all emotions in the same manner. Specifically, fear processing occurs rapidly within the amygdala and is governed by serotonin. Thus, by blunting cortical activity and facilitating serotonergic action, acetaminophen could in fact potentiate reactions to threatening stimuli. This study intersects with the fields of evolutionary psychology and psychopharmacology by investigating whether acetaminophen modulates responses to fear-inducing stimuli that vary in ancestral relevance. We hypothesized that the more subcortical and prewired mechanisms controlling responses to recurring ancestral threats (snakes and spiders) would be more affected by this drug compared to learned threats of modern environments (handguns and hypodermic needles). In a double-blind placebo-controlled design (N = 94), acetaminophen significantly enhanced participants’ evaluations and emotional reactions to threatening stimuli. In addition, ancestral threats were rated as both significantly more negative and emotionally arousing compared to modern threats. Contrary to our predictions, however, acetaminophen altered affective responses to ancestral and modern threats in a highly similar manner. We conclude that acetaminophen does not blunt overall affective processing, and call for further evolutionary-based research examining the various psychoactive effects of this commonly consumed over-the-counter painkiller.

Social Housing Status Impacts Rhesus Monkeys' Affective Responding in Classic Threat Processing Tasks

The established literature clearly demonstrates that whether or not monkeys are socially reared has long term consequences for their affective behavior. Yet, in the context of behavioral neuroscience and pharmacological studies, social context of adult animals is often ignored. When social context has been studied in adult monkeys, such studies have typically focused on welfare-related issues, as social isolation often leads to the development of abnormal behavior, rather than the impact on outcomes in behavioral neuroscience studies. Variation in social housing conditions for adult animals could have an impact on affective responding and may have significant implications for the interpretation of data from biopsychiatry and behavioral neuroscience studies. We evaluated the affective reactivity of rhesus monkeys (Macaca mulatta) maintained in one of four housing conditions (individually-housed, grate-paired, intermittently-paired, and continuously-paired) using two classic threat processing tasks: a test of responsivity to objects and the Human Intruder Test. Individually-housed monkeys exhibited consistently blunted sensitivity to ostensibly threatening stimuli as compared to socially-housed monkeys. Within the three socially-housed conditions, intermittently- and continuously-paired monkeys behaved similarly to each other and grate-paired monkeys exhibited relatively enhanced sensitivity to threatening stimuli. These findings suggest that the adult housing conditions of monkeys can robustly modulate affective responding in a way that may be consistent with behavioral phenotypes observed in human psychiatric conditions. Results are considered in the context of the broad behavioral and psychiatric neuroscience literatures, which have historically used individually-housed animals, pointing to the potential need to reconsider inferences drawn from those studies.

Does Selection History Influence Attentional Capture by Threat in the Dot-Probe Task?

Threatening stimuli are often thought to have sufficient potency to capture spatial attentional resources over neutral stimuli. But few studies have examined if implicit factors like the selection history of the threatening stimulus influences such cases of capture. Here we tested whether capture by threat in the recent past (i.e., the previous trial) would carryover, or influence capture by threat in the present (i.e., the current trial). In two highly powered dot-probe experiments, we observed a small and a reverse capture effect (sometimes referred to as avoidance) for fearful faces (n = 241) and threatening images (n = 82), respectively. Critically, we found no evidence of carryover effects for either type of threatening stimuli. We conclude that within the standard dot-probe paradigm, capture by threat in healthy adults is not moderated by the selection history for threatening stimuli.

The Missing Pieces of the Puzzle: A Review on the Interactive Nature of A-Priori Expectancies and Attention Bias toward Threat

The role of attention bias in the etiology and maintenance of anxiety disorders has been studied extensively over decades. Attention bias reflects maladaptation in cognitive processing, as perceived threatening stimuli receive prioritized processing even when they are task-irrelevant or factually unthreatening. Recently, there has been some interest in the role of a-priori expectancies in attention bias toward threat. The current review article will present recent studies as examples that emphasize the need for more comprehensive research about the interactive effects of various factors that affect the relationship between expectancies and attention bias toward threatening stimuli in anxiety. The current review article suggests a holistic view, which advocates for more integrative research, as a dynamic network could underlie changes in attention bias. The study of the interaction between such factors, with a focus on expectancy, can lead to more ecological and clinically important results, and thus to more informed and fine-tuned treatments that are based on manipulation of expectancies. Such methods, in turn, can also help in shedding light on the research of attention bias, in a mutual relationship between research and therapy.

In or out: Response slowing across housing conditions as a measure of affect in three Western lowland gorillas (Gorilla gorilla gorilla)

Background Individuals experiencing negative affect have shown response slowing, a longer latency to respond in relation to baseline, when presented with aversive stimuli. We assessed response slowing in three male gorillas housed in a bachelor group as a function of daytime and nighttime housing arrangements. Methods In both experiments, three gorillas were rewarded for touching a single image (baseline, non-threatening gorilla or threatening gorilla) on a touchscreen. In Experiment One, they completed 48 50-trial sessions across combinations of three nested daytime and three nighttime conditions. In Experiment Two, they completed eight 50-trial sessions with novel stimuli across two daytime conditions, which were nested within two nighttime conditions. Housing conditions represented different amounts of space and degree of choice. We predicted that the gorillas would show response slowing to threatening stimuli when space and choice were restricted. Results We did not observe response slowing in Experiment One, although daytime and nighttime conditions interacted to predict response latencies. The gorillas responded more slowly when they had access to indoors and outdoors overnight compared to when they were in their stalls or together in an indoor habitat, but only if they had been given access to both indoors and outdoors or locked in the indoor habitat the day before. In Experiment Two, the gorillas did show response slowing to threatening stimuli, but this pattern did not interact with housing conditions. Our results, although limited by a small sample, are somewhat consistent with those of a previous study that did not find significant response slowing for apes as a function of aversive testing conditions, although the procedure has been effective in identifying dysregulated fear (high fear in low threat conditions) in macaques. The utility of this paradigm for testing affect in apes awaits further evaluation.

Prelimbic-dependent activation of amygdala somatostatin interneurons signals non-aversive cues to promote discrimination

The amygdala and prelimbic cortex (PL) communicate during fear discrimination retrieval, but how they coordinate to discriminate a non-threatening stimulus is unknown. Here, we show that somatostatin interneurons (SOM) in the basolateral amygdala (BLA) become active specifically during learned non-threatening cues, when they block sensory-evoked phase resetting of theta-oscillations. Further, we show that SOM activation is PL-dependent, and promotes discrimination of non-threat. Thus, fear discrimination engages PL-dependent coordination of BLA SOM responses to non-threatening stimuli.