Do early birds share their worms? How prosocial behaviour and empathy vary across the day

Human Prosocial Preferences Are Related to Slow-Wave Activity in Sleep

Prosocial behavior is crucial for the smooth functioning of the society. Yet, individuals differ vastly in the propensity to behave prosocially. Here, we try to explain these individual differences under normal sleep conditions without any experimental modulation of sleep. Using a portable high-density EEG, we measured the sleep data in 54 healthy adults (28 females) during a normal night's sleep at the participants' homes. To capture prosocial preferences, participants played an incentivized public goods game in which they faced real monetary consequences. The whole-brain analyses showed that a higher relative slow-wave activity (SWA, an indicator of sleep depth) in a cluster of electrodes over the right temporoparietal junction (TPJ) was associated with increased prosocial preferences. Source localization and current source density analyses further support these findings. Recent sleep deprivation studies imply that sleeping enough makes us more prosocial; the present findings suggest that it is not only sleep duration, but particularly sufficient sleep depth in the TPJ that is positively related to prosociality. Because the TPJ plays a central role in social cognitive functions, we speculate that sleep depth in the TPJ, as reflected by relative SWA, might serve as a dispositional indicator of social cognition ability, which is reflected in prosocial preferences. These findings contribute to the emerging framework explaining the link between sleep and prosocial behavior by shedding light on the underlying mechanisms.

Compensatory health beliefs in women in the first, second and third trimester of pregnancy

BACKGROUND

Compensatory health beliefs may serve as one of many self-regulatory strategies that individuals employ to maintain healthy lifestyles. Past research with samples from a general population has shown, however, that compensatory beliefs are ineffective in this regard and may even lead to inaction in future health-related behaviors such as eating healthily or being active. To better understand this phenomenon, in the present study, changes in compensatory health beliefs regarding various life domains were examined in a group of pregnant women.

PARTICIPANTS AND PROCEDURE

In a longitudinal study design, 166 women completed questionnaires in the first (t1), the second (t2), and the third (t3) trimester of their pregnancies. We assessed the level of their self-control as a trait (t1, t2, t3), compensatory health beliefs (t1, t2, t3), and unhealthy snacking (t3).

RESULTS

As predicted, self-control as a trait decreased and the levels of compensatory beliefs increased over time. A linear mixed effects analysis showed that self-control was the best predictor of compensatory beliefs in the third trimester. Finally, compensatory health beliefs in the third trimester mediated the effect of self-control at the beginning of pregnancy on unhealthy snacking in the third trimester.

CONCLUSIONS

It appears important to support pregnant women in opting for constructive self-regulatory strategies, especially in their final trimesters, when coping resources are exhausted by the challenges of this period.

Tracking perceived stress, anxiety, and depression in daily life: a double-downward spiral process

Introduction

Previous studies using retrospective questionnaires have suggested a complex relationship between perceived stress and related negative emotions and emphasized their importance in mental health. However, how daily perceived stress, anxiety, and depression interact dynamically in a natural context remains largely unexplored.

Methods

This study conducted a longitudinal survey that applied experience sampling methodology to data from 141 Chinese college students (58% women, mean age = 20.1 ± 1.63 years).

Results

The hierarchical linear models confirmed that daily perceived stress and negative emotions (i.e., perceived depression and anxiety) could reciprocally reinforce one another with the characteristic dynamics of a cognitive-emotional downward spiral. Additionally, anxiety and depression could further circularly aggravate each other imminently. These two intertwined downward-spiral processes constitute a double-downward-spiral model.

Discussion

The findings contribute to a better understanding of the interactive mechanisms underlying perceived stress and its related negative emotions in everyday life and highlight the significance of early emotion regulation and stress relief in healthy people.