It’s a matter of time (perspectives): shifting valence responses to emotional ambiguity

Associations of state and chronic loneliness with interpretation bias: The role of internalizing symptoms

Loneliness is common and, while generally transient, persists in up to 22% of the population. The rising prevalence and adverse impacts of chronic loneliness highlight the need to understand its underlying mechanisms. Evolutionary models of loneliness suggest that chronically lonely individuals demonstrate negative interpretation biases towards social information. It may also be that such biases are exacerbated by momentary increases in state loneliness, or elevated anxiety or depression. Yet, little research has tested these possibilities. The current study aimed to advance understandings of loneliness by examining associations of chronic loneliness with individual differences in negative interpretation bias for social (relative to non-social) stimuli, and testing whether these associations change in the context of increased state loneliness and current levels of anxiety and depressive symptoms. These aims were explored in 591 participants who completed an interpretation bias task before and after undergoing a state loneliness induction. Participants also self-reported chronic loneliness, anxiety, and depression. Linear mixed models indicated that only state (but not chronic) loneliness was associated with more positive interpretations of non-social stimuli, with greater anxiety and depressive symptoms predicting more negative interpretations. Implications of these findings for present theoretical models of loneliness are discussed.

A biphasic response to blueberry supplementation on depressive symptoms in emerging adults: a double-blind randomized controlled trial

PURPOSE

The aim of the present study was to examine the acute and chronic effects of wild blueberry supplementation on mood, executive function, and serum biomarkers of neuroplasticity, inflammation, and oxidative stress in emerging adults with moderate-to-severe depressive symptoms.

METHODS

In this double-blind trial, 60 emerging adults (Mage = 20.0 years, 32% male) with self-reported depressive symptoms were randomly assigned to receive a single blueberry drink (acute phase), followed by 6 weeks of daily blueberry supplementation (chronic phase), or a matched placebo drink. The primary outcome was Beck Depression Inventory-II (BDI-II) scores at 6-week follow-up. Further measures included momentary affect (PANAS-X) and accuracy on an executive function task. The data were analyzed using ANCOVAs adjusted for baseline values, sex, and habitual fruit and vegetable intake. Estimated marginal means were calculated to compare the treatment arms.

RESULTS

The blueberry drink significantly improved positive affect (p = 0.026) and executive function (p = 0.025) at 2 h post-ingestion, with change scores being positively correlated in the blueberry group (r = 0.424, p = 0.017). However, after six weeks of supplementation the reduction in BDI-II scores was greater in the placebo group by 5.8 points (95% CI: 0.8-10.7, p = 0.023). Generalized anxiety and anhedonia also decreased significantly more in the placebo group. No significant differences were found for any of the biomarkers.

CONCLUSIONS

Six weeks of wild blueberry supplementation were inferior to placebo in reducing depressive symptoms. Nevertheless, the correlated improvements in positive affect and executive function after a single dose of blueberries point to a beneficial, albeit transient, psychological effect. These contrasting results suggest a biphasic, hormetic-like response that warrants further investigation.

TRIAL REGISTRATION

NCT04647019, dated 30 November, 2020.

Think again: the role of reappraisal in reducing negative valence bias

Stimuli such as surprised faces are ambiguous in that they are associated with both positive and negative outcomes. Interestingly, people differ reliably in whether they evaluate these and other ambiguous stimuli as positive or negative, and we have argued that a positive evaluation relies in part on a biasing of the appraisal processes via reappraisal. To further test this idea, we conducted two studies to evaluate whether increasing the cognitive accessibility of reappraisal through a brief emotion regulation task would lead to an increase in positive evaluations of ambiguity. Supporting this prediction, we demonstrated that cuing reappraisal, but not in three other forms of emotion regulation (Study 1a-d; n = 120), increased positive evaluations of ambiguous faces. In a sign of robustness, we also found that the effect of reappraisal generalised from ambiguous faces to ambiguous scenes (Study 2; n = 34). Collectively, these findings suggest that reappraisal may play a key role in determining responses to ambiguous stimuli. We discuss these findings in the context of affective flexibility, and suggest that valence bias (i.e. the tendency to evaluate ambiguity more positively or negatively) represents a novel approach to measuring implicit emotion regulation.

Age-Related Differences in Amygdala Activation Associated With Face Trustworthiness but No Evidence of Oxytocin Modulation

The amygdala has been shown to be responsive to face trustworthiness. While older adults typically give higher face trustworthiness ratings than young adults, a direct link between amygdala response and age-related differences in face trustworthiness evaluation has not yet been confirmed. Additionally, there is a possible modulatory role of the neuropeptide oxytocin in face trustworthiness evaluation, but the results are mixed and effects unexplored in aging. To address these research gaps, young, and older adults were randomly assigned to oxytocin or placebo self-administration via a nasal spray before rating faces on trustworthiness while undergoing functional magnetic resonance imaging. There was no overall age-group difference in face trustworthiness ratings, but older compared to young participants gave higher trustworthiness ratings to ambivalently untrustworthy-looking faces. In both age groups, lower face trustworthiness ratings were associated with higher left amygdala activity. A comparable negative linear association was observed in right amygdala but only among young participants. Also, in the right amygdala, lower and higher, compared to moderate, face trustworthiness ratings were associated with greater right amygdala activity (i.e., positive quadratic (U-shaped) association) for both age groups. Neither the behavioral nor the brain effects were modulated by a single dose of intranasal oxytocin administration, however. These results suggest dampened response to faces with lower trustworthiness among older compared to young adults, supporting the notion of reduced sensitivity to cues of untrustworthiness in aging. The findings also extend evidence of an age-related positivity effect to the evaluation of face trustworthiness.

Exploring valence bias as a metric for frontoamygdalar connectivity and depressive symptoms in childhood

Negativity bias is a core feature of depression that is associated with dysfunctional frontoamygdalar connectivity; this pathway is associated with emotion regulation and sensitive to neurobiological change during puberty. We used a valence bias task (ratings of emotional ambiguity) as a potential early indicator of depression risk and differences in frontoamygdalar connectivity. Previous work using this task demonstrated that children normatively have a negative bias that attenuates with maturation. Here, we test the hypothesis that persistence of this negativity bias as maturation ensues may reveal differences in emotion regulation development, and may be associated with increased risk for depression. In children aged 6-13 years, we tested the moderating role of puberty on relationships between valence bias, depressive symptoms, and frontoamygdalar connectivity. A negative bias was associated with increased depressive symptoms for those at more advanced pubertal stages (within this sample) and less regulatory frontoamygdalar connectivity, whereas a more positive bias was associated with more regulatory connectivity patterns. These data suggest that with maturation, individual differences in positivity biases and associated emotion regulation circuitry confer a differential risk for depression. Longitudinal work is necessary to determine the directionality of these effects and explore the influence of early life events.

The limited roles of cognitive capabilities and future time perspective in contributing to positivity effects

When compared to younger adults, older adults tend to favor positive over negative information in attention and memory. This is known as the positivity effect. Although this is a robust phenomenon, there is still debate about how it relates to individual differences in cognitive capabilities and future time perspective (FTP). To address this, we investigated how measures of fluid cognitive capabilities and FTP related to positivity effects within the domains of episodic memory, visual attention, and autobiographical memory. Cognitive capabilities were assessed using the National Institute of Health Toolbox Cognition battery, and included assessments of executive function, working memory, episodic memory, and processing speed. FTP was assessed via the Carstensen and Lang (1996) scale. Within our final sample (N = 196), we replicated positivity effects in all three task domains, which were all driven by age differences in how people responded to negative (but not positive) information. However, there was limited evidence that the magnitude of these age-related reductions in negativity varied as a function of individual differences in older adults' cognitive capabilities or FTP. Furthermore, when FTP did emerge as a predictor, the pattern was not in line with expectations based upon socioemotional selectivity theory. Thus, the positivity effect may be less reliant on cognitive capabilities and self-reported FTP than is often assumed. Given that there was also very little consistency in the extent to which participants displayed positivity effects across the task domains, these results also raise the possibility that there may be multiple mechanisms underlying positivity effects.

One step at a time: Physical activity is linked to positive interpretations of ambiguity

Background

Extensive research has established a clear positive relationship between physical activity (PA), even in small amounts, and psychological well-being, including benefits for emotional and mental health (e.g., decreased depression). However, little research has examined the relationship between PA and decision-making within emotionally ambiguous contexts. The purpose of the present cross-sectional study was to examine the relationship between reported amount and intensity of PA and interpretations of emotional ambiguity.

Methods

Adults (n = 611) recruited through Amazon’s Mechanical Turk were assessed on their interpretations of ambiguous and clear (unambiguous) emotional stimuli and reported habitual PA and exercise.

Results

More positive ratings of ambiguity were associated with greater amount of vigorous activity (p = .002), but not with moderate activity (p = .826) or walking (p = .673). Subsequent analyses demonstrated that this relationship between vigorous PA and positive interpretations of ambiguity was most pronounced when comparing individuals who reported any amount of vigorous PA to those who reported no vigorous activity at all.

Conclusions

Our findings suggest that higher amounts of vigorous, but not moderate, PA are associated with more positive interpretations of ambiguity, and that even small amounts of PA seem to be sufficient to promote this more positive valence bias when compared to individuals conducting no vigorous PA at all. Future work should examine the longitudinal effects of PA among individuals participating in structured activity programs.

Individual differences in valence bias: fMRI evidence of the initial negativity hypothesis

Facial expressions offer an ecologically valid model for examining individual differences in affective decision-making. They convey an emotional signal from a social agent and provide important predictive information about one's environment (presence of potential rewards or threats). Although some expressions provide clear predictive information (angry, happy), others (surprised) are ambiguous in that they predict both positive and negative outcomes. Thus, surprised faces can delineate an individual's valence bias, or the tendency to interpret ambiguity as positive or negative. Our initial negativity hypothesis suggests that the initial response to ambiguity is negative, and that positivity relies on emotion regulation. We tested this hypothesis by comparing brain activity during explicit emotion regulation (reappraisal) and while freely viewing facial expressions, and measuring the relationship between brain activity and valence bias. Brain regions recruited during reappraisal showed greater activity for surprise in individuals with an increasingly positive valence bias. Additionally, we linked amygdala activity with an initial negativity, revealing a pattern similarity in individuals with negative bias between viewing surprised faces and maintaining negativity. Finally, these individuals failed to show normal habituation to clear negativity. These results support the initial negativity hypothesis, and are consistent with emotion research in both children and adult populations.