The time course of implicit affective picture processing: an eye movement study

Consistent with a negativity bias account, neuroscientific and behavioral evidence demonstrates modulation of even early sensory processes by unpleasant, potentially threat-relevant information. The aim of this research is to assess the extent to which pleasant and unpleasant visual stimuli presented extrafoveally capture attention and impact eye movement control. We report an experiment examining deviations in saccade metrics in the presence of emotional image distractors that are close to a nonemotional target. We additionally manipulate the saccade latency to test when the emotional distractor has its biggest impact on oculomotor control. The results demonstrate that saccade landing position was pulled toward unpleasant distractors, and that this pull was due to the quick saccade responses. Overall, these findings support a negativity bias account of early attentional control and call for the need to consider the time course of motivated attention when affect is implici

Multimodal evidence for delayed threat extinction learning in adolescence and young adulthood

Previous research in rodents and humans points to an evolutionarily conserved profle of blunted threat extinction learning during adolescence, underpinned by brain structures such as the amygdala and medial prefrontal cortex (mPFC). In this study, we examine age-related efects on the function and structural connectivity of this system in threat extinction learning in adolescence and young adulthood. Younger age was associated with greater amygdala activity and later engagement of the mPFC to learned threat cues as compared to safety cues. Furthermore, greater structural integrity of the uncinate fasciculus, a white matter tract that connects the amygdala and mPFC, mediated the relationship between age and mPFC engagement during extinction learning. These fndings suggest that age-related changes in the structure and function of amygdala-mPFC circuitry may underlie the protracted maturation of threat regulatory precesses

Its time: a commentary on fear extinction in the human brain using fMRI

The recent meta-analysis by Fullana et al. (2018) is both timely and significant, providing a vital milestone towards understanding the neural networks involved in threat extinction in humans. Fullana et al. (2018) examined both threat extinction and recall separately using sophisticated meta-analytic methods based on raw contrast maps. Importantly, the meta-analysis highlighted a lack of consistent activation across studies for key neural "players" in the threat extinction circuit: the amygdala and ventromedial prefrontal cortex (vmPFC). In the current commentary, we highlight reasons for which this key circuitry may not have resulted from this meta-analysis, and call for a 'gold standard' in the examination of threat extinction using fMRI

The role of threat level and intolerance of uncertainty in extinction

Recent evidence suggests that individual differences in intolerance of uncertainty (IUS) are associated with disrupted threat extinction. However, it is unknown what maintains the learned threat association in high IUS individuals: is it the experienced uncertainty during extinction or the combination of experienced uncertainty with potential threat during extinction? Here we addressed this question by running two independent experiments with uncertain auditory stimuli that varied in threat level (Experiment 1, aversive human scream (n = 30); Experiment 2, neutral tone (n = 47) and mildly aversive tone (n = 49)). During the experiments, we recorded skin conductance responses and subjective ratings to the learned cues during acquisition and extinction. In experiment 1, high IUS was associated with heightened skin conductance responding to the learned threat vs. safe cue during extinction. In experiment 2, high IUS was associated only with larger skin conductance responding to the learned cues with more threatening properties during extinction i.e. mildly aversive tone. These findings suggest that uncertainty in combination with threat, even when mild, disrupts extinction in high IUS individuals. Such findings help us understand the link between IUS and threat extinction, and its relevance to anxiety disorder pathology

It’s not over yet: the impact of worry on emotional recovery

Emotional reactivity and recovery are crucial for maintaining well-being. It remains unknown, however, to what extent emotion modulates the time course of recovery assessed using a simple categorization task and how this varies based on individual differences in worry. To address these questions, 35 participants viewed emotional pictures, followed by abstract greeble targets, which were to be categorized. Greebles were presented between 100 ms and 4,000 ms after picture offset. Physiological measures including skin conductance level and the corrugator supercilii were recorded and served as indicators of responsivity to emotional pictures. Measures of reaction time (RT) and accuracy scores were taken as indicators of the impact of emotion on facilitation or interference to the greeble target. Effects of interference and facilitation were observed up to 4,000 ms after emotional pictures on RT and accuracy scores. High worry was associated with greater (1) corrugator supercilii and skin conductance level to negative versus positive and neutral pictures and (2) interference from emotional pictures on accuracy scores. Overall, these findings suggest that subsequent processing is still impacted up to 4,000 ms after the offset of emotional pictures, particularly for negative events in individuals with high worry

The effect of cycling on cognitive function and well-being in older adults

It has been demonstrated that, on their own, both exercise and stimulation from the environment can improve cognitive function and well-being in older adults. The combined effect of exercising in the outdoor environment on psychological function is less well studied. The aim of the current study was to investigate the effect of an outdoor cycling intervention on cognitive function and mental health and well-being in older adults. A total of 100 older adults took part in the study (aged 50–83), 26 of which were non-cycling controls, 36 were conventional pedal cyclists and 38 were participants using an e-bike (a bike fitted with an electric motor to provide assistance with pedaling), as part of a larger project (www.cycleboom.org). Participants took part in the study for an eight-week period, with cycling participants required to cycle at least three times a week for thirty minutes in duration for each cycle ride. Cognitive function and well-being were measured before and after the intervention period. For executive function, namely inhibition (the Stroop task) and updating (Letter Updating Task), both cycling groups improved in accuracy after the intervention compared to non-cycling control participants. E-bike participants also improved in processing speed (reaction times in go trials of the Stop-It task) after the intervention compared to non-cycling control participants. Finally, e-bike participants improved in their mental health score after the intervention compared to non-cycling controls as measured by the SF-36. This suggests that there may be an impact of exercising in the environment on executive function and mental health. Importantly, we showed a similar (sometimes larger) effect for the e-bike group compared to the pedal cyclists. This suggests that it is not just the physical activity component of cycling that is having an influence. Both pedal cycles and e-bikes can enable increased physical activity and engagement with the outdoor environment with e-bikes potentially providing greater benefits

I feel safe when i know: contingency instruction promotes threat extinction in high intolerance of uncertainty individuals

Extinction-resistant threat is considered to be a central feature of pathological anxiety. Reduced threat extinction is observed in individuals with high intolerance of uncertainty (IU). Here we sought to determine whether contingency instructions could alter the course of threat extinction for individuals high in IU. We tested this hypothesis in two identical experiments (Exp 1 n = 60, Exp 2 n = 82) where we recorded electrodermal activity during threat acquisition with partial reinforcement, and extinction. Participants were split into groups based on extinction instructions (instructed, uninstructed) and IU score (low, high). All groups displayed larger skin conductance responses to learned threat versus safety cues during threat acquisition, indicative of threat conditioning. In both experiments, only the uninstructed high IU groups displayed larger skin conductance responses to the learned threat versus safety cue during threat extinction. These findings suggest that uncertain threat during extinction maintains conditioned responding in individuals high in IU

Escape the bear and fall to the lion: the impact of avoidance availability on threat acquisition and extinction

Pervasive avoidance behaviour is a core feature of anxiety disorders. However, little is known about how the availability of avoidance modulates learned threat responding. To assess this question, we recorded avoidance behaviour, electrodermal activity and expectancy ratings in 53 healthy participants during an associative learning paradigm with embedded unavoidable and avoidable trials. When avoidance was available, we observed greater avoidance behaviour for threat versus safety cues, as well as reduced differential skin conductance responses for unavoidable threat versus safety cues. When avoidance was unavailable, as during the extinction phase, we observed sustained differential skin conductance responses for threat versus safety cues. For all phases, we found greater expectancy ratings for threat versus safe cues. Furthermore, greater avoidance behaviour predicted larger differential skin conductance responses to threat versus safety cues during extinction. Overall, the results show that the conditioned response is attenuated during situations where avoidance is available, but it recovers when avoidance is unavailable, subsequently prolonging threat extinction

Social domain based modulation of neural responses to threat: the different roles of romantic partners versus friends

The neural circuitry associated with threat regulation in the absence of other people is well established. An examination of threat regulatory processes with people from different domains of an individual’s social world is key to understanding social emotion regulation and personality functioning conceptualised as social domain organisation. In this study, 42 healthy female participants completed functional magnetic imaging sessions in which they underwent a scan in the presence of a romantic partner or friend, whilst completing a threat of shock task. In the presence of a romantic partner vs. friend, we found a reduction in amygdala activation to threat vs. safe trials over time. Furthermore, in the presence of a romantic partner vs. friend we observed greater subgenual anterior cingulate cortex and ventromedial prefrontal cortex activation to threat vs safe trials overall. The results support the hypothesis that recruitment of threat regulation circuitry is modulated by romantic partner relative to another person well-known to the individual. Future work needs to examine neural responses to a wider range of stimuli across more social domains, and implications of failures of this neural organisation for psychopathology