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.