Mood and physiological effects of visual stimulation with images of the natural environment in individuals with depressive and anxiety disorders.

BACKGROUND: Nature therapies are gaining attention as non-pharmacological treatments for depressive and anxiety disorders, but research on their effectiveness in patients is limited. This study investigates the mood-improving effects of visual stimulation with natural environmental images in patients with depressive and anxiety disorders. METHODS: We conducted a randomized crossover comparison trial involving 60 right-handed adult participants with depressive or anxiety disorders and receiving outpatient treatment. Visual stimuli of natural environments consisted of green-themed nature images, while the control stimuli featured urban scenes dominated by buildings. The stimulation lasted for 3 min, during which orbital prefrontal brain activity was measured using a 2-channel Near-infrared Spectroscopy (NIRS) system, and heart rate variability was assessed using fingertip accelerated plethysmography. RESULTS: Mood enhancement effects were observed in both the depressive and anxiety disorder groups following visual stimulation with nature images. In the depression group, orbital prefrontal oxygenated hemoglobin concentration significantly increased after visual stimulation with nature images, while there were no significant changes in the anxiety group. However, in the anxiety group, a correlation was found between reduced orbital prefrontal oxygenated hemoglobin in response to nature images and increased mood-enhancement. Furthermore, the severity of depressive symptoms did not significantly affect the intervention effects, whereas heightened anxiety symptoms was associated with a smaller mood enhancement effect. DISCUSSION: Our study demonstrates the benefits of nature image stimulation for patients with depressive and anxiety disorders. Differential orbital prefrontal brain activity impacts notwithstanding, both conditions exhibited mood enhancement, affirming the value of nature image stimulation.

Evaluating the impact of a short bout of stair-climbing on creative thinking in a between-subjects pretest posttest comparison study.

Recent studies have indicated potential links between short bouts of physical activity like stair-climbing and enhanced creative thinking. However, previous research featured limitations, such as using an uncommon 3 flights round-trip design and lacking baseline creative thinking evaluations. To rectify these limitations and build a more comprehensive understanding, the present study adopts a between-subjects pretest posttest comparison design to scrutinize the effects of ascending stair-climbing on both divergent and convergent thinking. 52 subjects underwent a pretest, followed by random assignment to one of four interventions: ascending stair-climbing for 2, 5, or 8 flights, or taking an elevator for 8 flights, before progressing to a posttest. The results revealed a notable improvement in convergent thinking, measured by the increased number of solved matchstick arithmetic problems (d = 1.165), for participants who climbed 2 flights of stairs compared to those who took the elevator. However, climbing 5 or 8 flights showed no such impact on convergent thinking, and stair-climbing, regardless of the number of flights, did not influence divergent thinking. These findings underscore the utility of brief stair-climbing as an accessible means to enhance convergent thinking in everyday settings, providing a nuanced insight into the relationship between physical activity and creative thinking processes.

Toward a computational understanding of how reminiscing about positive autobiographical memories influences decision-making under risk.

Recent computational psychiatric research has dissected decision-making under risk into different underlying cognitive computational constructs and identified disease-specific changes in these constructs. Studies are underway to investigate what kind of behavioral or psychological interventions can restore these cognitive, computational constructs. In our previous study, we showed that reminiscing about positive autobiographical memories reduced risk aversion and affected probability weighting in the opposite direction from that observed in psychiatric disorders. However, in that study, we compared positive versus neutral memory retrieval by using a within-subjects crossover posttest design. Therefore, the change of decision-making from baseline is unclear. Furthermore, we used a hypothetical decision-making task and did not include monetary incentives. We attempt to address these limitations and investigated how reminiscing about positive autobiographical memories influences decision-making under risk using a between-subjects pretest posttest comparison design with performance-contingent monetary incentives. In thirty-eight healthy, young adults, we found that reminiscing about positive memories reinforced the commonly observed inverted S-shaped nonlinear probability weighting (f = 0.345, medium to large in effect size). In contrast, reminiscing about positive memories did not affect risk aversion in general. Given that the change in probability weighting after reminiscing about positive memories is in the opposite direction from that observed in psychiatric disorders, our results indicate that positive autobiographical memory retrieval might be a useful behavioral intervention strategy for amending the altered decision-making under risk in psychiatric diseases.

The effect of positive autobiographical memory retrieval on decision-making under risk: A computational model-based analysis.

Psychiatric disorders such as depressive and anxiety disorders are associated with altered decision-making under risk. Recent advances in neuroeconomics and computational psychiatry have further discomposed risk-based decision-making into distinct cognitive computational constructs and showed that there may be disorder-specific alterations in these constructs. As a result, it has been suggested these cognitive computational constructs may serve as useful behavioral biomarkers for these disorders. However, to date, little is known about what psychological or behavioral interventions can help to reverse and manage the altered cognitive computational constructs underlying risk-based decision-making. In the present study, we set out to investigate whether recalling positive autobiographical memories may affect risk-based decision-making in healthy volunteers using a description-based task. Specifically, based on theories of behavioral economics, we dissected risk preference into two cognitive computational constructs, utility sensitivity and probability weighting. We found that compared to recalling neutral memories, retrieving positive autobiographical memories increased utility sensitivity (Cohen's d = 0.447), indicating reduced risk aversion. Meanwhile, we also tested the influence of memory retrieval on probability weighting, the effect, however, was unreliable and requires further in-depth investigation. Of clinical relevance, the change in risk aversion after recalling positive memories was in the opposite direction compared to those reported in psychiatric disorders. These results argue for the potential therapeutic effect of positive autobiographical memory retrieval for the amendment of altered risk-based decision-making in psychiatric disorders.