No abstract

Loneliness is thought to serve as an adaptive signal indicating the need to repair or replace salutary social connections. Accordingly, loneliness may influence preferences for interpersonal distance. If loneliness simply motivates a desire to socially reconnect, then loneliness may be associated with a preference for smaller interpersonal distances. According to the evolutionary model of loneliness, however, loneliness also signals an inadequacy of mutual aid and protection, augmenting self-preservation motives. If loneliness both increases the motivation to reconnect and increases the motivation for self-protection, then the resulting approach-avoidance conflict should produce a preference for larger interpersonal distance, at least within intimate (i.e., proximal) space. Here, we report two survey-based studies of participants’ preferences for interpersonal distance to distinguish between these competing hypotheses. In Study 1 (N = 175), loneliness predicted preferences for larger interpersonal distance within intimate space net gender, objective social isolation, anxiety, depressive symptomatology, and marital status. In Study 2 (N = 405), we replicated these results, and mediation analyses indicated that measures of social closeness could not adequately explain our findings. These studies provide compelling evidence that loneliness predicts preferences for larger interpersonal distance within intimate space, consistent with predictions from the evolutionary model of loneliness.

Ruminative thinking is related to an increased risk for major depressive disorder (MDD) and perpetuates negative mood states. Rumination, uncontrollable negative thoughts about the self, may comprise both reflective and brooding components. However, only brooding rumination is consistently associated with increased negativity bias and negative coping styles, while reflective rumination has a less clear relationship with negative outcomes in healthy and depressed participants. The current study examined seed-to-voxel (S2.V) resting-state functional connectivity (FC) in a sample of healthy (HC) and depressed (MDD) adult women (HC: n=50, MDD: n=33). The S2V FC of six key brain regions, including the left and right amygdala, anterior and posterior cingulate cortex (ACC, PCC), and medial and dorsolateral prefrontal cortices (mPFC, dlPFC), was correlated with self-reported reflective and brooding rumination. Results indicate that HC and MDD participants had increased brooding rumination associated with decreased FC between the left amygdala and the right temporal pole. Moreover, reflective rumination was associated with distinct FC of the mPFC, PCC, and ACC with parietal, occipital, and cingulate regions. Depressed participants, compared with HC, exhibited decreased FC between the PCC and a region in the right middle frontal gyrus. The results of the current study add to the understanding of the neural underpinnings of different forms of self-related cognition-brooding and reflective rumination-in healthy and depressed women.

Adults demonstrate aesthetic preferences for natural environments over urban ones. This preference has influenced theories like Biophilia to explain why nature is beneficial. While both adults and children show cognitive and affective benefits after nature exposure, it is unknown whether children demonstrate nature preferences. In the current study, 4-to-11year-old children and their parents rated their preferences for images of nature and urban scenes. Parents' preferences matched those of a normative adult sample. However, children demonstrated robust preferences for urban over natural environments, and those urban preferences significantly decreased with age. Nature exposure around the home and nature-related activities, as reported by parents, did not predict children's preferences. Children with more nearby nature, however, had lower reported inattentiveness, but interestingly, this was unrelated to children's preferences for nature. These results provide an important step into future research on the role of preference in how children and adults benefit from nature.

Although practicing a task generally benefits later performance on that same task ('practice effect'), there are large-and mostly unexplained-individual differences in reaping the benefits from practice. One promising avenue to model and predict such differences comes from recent research showing that brain networks can extract functional advantages from operating in the vicinity of criticality, a state in which brain network activity is more scale-free. As such, we hypothesized that individuals with more scale-free fMRI activity, indicated by BOLD time series with a higher Hurst exponent (H), gain more benefits from practice. In this study, participants practiced a test of working memory and attention, the dual n-back task (DNB), watched a video clip as a break, and then performed the DNB again, during MRI. To isolate the practice effect, we divided the participants into two groups based on improvement in performance from the first to second DNB task run. We identified regions and connections in which H and functional connectivity related to practice effects in the last run. More scale-free brain activity in these regions during the preceding runs (either first DNB or video) distinguished individuals who showed greater DNB performance improvements over time. In comparison, functional connectivity (r 2 ) in the identified connections did not reliably classify the two groups in the preceding runs. Finally, we replicated both H and r 2 results from study 1 in an independent fMRI dataset of participants performing multiple runs of another working memory and attention task (word completion). We conclude that the brain networks can accommodate further practice effects in individuals with higher scale-free BOLD activity.