OUP accepted manuscript

Exploring common and distinct neural basis of procrastination and impulsivity through elastic net regression

Prior work highlighted that procrastination and impulsivity shared a common neuroanatomical basis in the dorsolateral prefrontal cortex, implying a tight relationship between these traits. However, theorists hold that procrastination is motivated by avoiding aversiveness, while impulsivity is driven by approaching immediate pleasure. Hence, exploring the common and distinct neural basis underlying procrastination and impulsivity through functional neuroimaging becomes imperative. To address this, we employed elastic net regression to examine the links between whole-brain resting-state functional connectivity and these traits in 822 university students from China. Results showed that the functional connections between the default network and the visual network were positively associated with both traits, indicating that the dysfunction of higher-order cognition (eg self-control) may account for their tight relationship. A distinct neural basis was also identified: Procrastination was negatively associated with functional connections between the frontal-parietal network and the ventral-attention network and between the cingular-opercular network and the subcortical network. In contrast, connections between the default network and the somato-motor network were negatively associated with impulsivity. These findings suggest that procrastination may be rooted in emotion-regulation deficits, while impulsivity may be rooted in reward-processing deficits. This deeper understanding of their neural basis provides insights for developing targeted interventions.

Sex modulated the relationship between trait approach motivation and decision-making

It has been observed that one's Behavioral Approach System (BAS) can have an effect on decision-making under uncertainty, although the results have been mixed. To discern the underlying neural substrates, we hypothesize that sex may explain the conflicting results. To test this idea, a large sample of participants was studied using resting state fMRI, utilizing fractional Amplitude of Low Frequency Fluctuations (fALFF) and Resting-State Functional Connectivity (rsFC) techniques. The results of the Iowa Gambling Task (IGT) revealed an interaction between sex and BAS, particularly in the last 60 trials (decision-making under risk). Males with high BAS showed poorer performance than those with low BAS. fALFF analysis showed a significant interaction between BAS group and sex in the left superior occipital gyrus, as well as the functional connectivity between this region and the left ventrolateral prefrontal cortex. Additionally, this functional connectivity was further positively correlated with male performance in the IGT, particularly in the decision-making under risk stage. Furthermore, it was found that the functional connectivity between left ventrolateral prefrontal cortex and left superior occipital gyrus could mediate the relationship between BAS and decision-making in males, particularly in the decision-making under risk stage. These results suggest possible sex-based differences in decision-making, providing an explanation for the inconsistent results found in prior research. Since the research was carried out exclusively with Chinese university students, it is essential to conduct further studies to investigate whether the findings can be generalized.

Spontaneous neural activity in the three principal networks underlying delay discounting: a resting-state fMRI study

Delay discounting, the decline in the subjective value of future rewards over time, has traditionally been understood through a tripartite neural network model, comprising the valuation, cognitive control, and prospection networks. To investigate the applicability of this model in a resting-state context, we employed a monetary choice questionnaire to quantify delay discounting and utilized resting-state functional magnetic resonance imaging (rs-fMRI) to explore the role of spontaneous brain activity, specifically regional homogeneity (ReHo), in influencing individual differences in delay discounting across a large cohort (N = 257). Preliminary analyses revealed a significant negative correlation between delay discounting tendencies and the ReHo in both the left insula and the right hippocampus, respectively. Subsequent resting-state functional connectivity (RSFC) analyses, using these regions as seed ROIs, disclosed that all implicated brain regions conform to the three principal networks traditionally associated with delay discounting. Our findings offer novel insights into the role of spontaneous neural activity in shaping individual variations in delay discounting at both regional and network levels, providing the first empirical evidence supporting the applicability of the tripartite network model in a resting-state context.

Sex-based differences in fairness norm compliance and neural circuitry

Human behavior often aligns with fairness norms, either voluntarily or under external pressure, like sanctions. Prior research has identified distinct neural activation patterns associated with voluntary and sanction-based compliance or non-compliance with fairness norms. However, an investigation gap exists into potential neural connectivity patterns and sex-based differences. To address this, we conducted a study using a monetary allocation game and functional magnetic resonance imaging to examine how neural activity and connectivity differ between sexes across three norm compliance conditions: voluntary, sanction-based, and voluntary post-sanctions. Fifty-five adults (27 females) participated, revealing that punishment influenced decisions, leading to strategic calculations and reduced generosity in voluntary compliance post-sanctions. Moreover, there were sex-based differences in neural activation and connectivity across the different compliance conditions. Specifically, the connectivity between the right dorsolateral prefrontal cortex and right dorsal anterior insular appeared to mediate intuitive preferences, with variations across norm compliance conditions and sexes. These findings imply potential sex-based differences in intuitive motivation for diverse norm compliance conditions. Our insights contribute to a better understanding of the neural pathways involved in fairness norm compliance and clarify sex-based differences, offering implications for future investigations into psychiatric and neurological disorders characterized by atypical socialization and mentalizing.

A mini-review on how the COVID-19 pandemic affected intertemporal choice

The coronavirus disease (COVID-19) has extremely harmful effects on individual lifestyles, and at present, people must make financial or survival decisions under the profound changes frequently. Although it has been reported that COVID-19 changed decision-making patterns, the underlying mechanisms remained unclear. This mini-review focuses on the impact of the COVID-19 pandemic on intertemporal choice, and potential psychological, biological, and social factors that mediate this relationship. A search of the Web of Science electronic database yielded 23 studies. The results showed that under the COVID-19 pandemic, people tended to choose immediate and smaller rewards, and became less patient. In particular, people with negative emotions, in a worse condition of physical health, or who did not comply with their government restriction rules tended to become more "short-sighted" in behavioral terms. Future studies should examine more longitudinal and cross-cultural research to give a broad view about the decision-making change under the COVID-19 pandemic.

Gender-specific resting-state rDMPFC-centric functional connectivity underpinnings of intertemporal choice

Although studies have observed gender differences in intertemporal choice, the neural bases of these differences require further research. The current study used resting state functional connectivity (rsFC) to explore the gender-specific neural basis of intertemporal choice in three independent samples (n1 = 86, n2 = 297, n3 = 172). Behaviorally, three samples (S1, S2, and S3) consistently demonstrated that men had larger delay discounting rate (log k) than women. Then, whole-brain functional connectivity analyses were performed for different genders in S2 and S3 using the right dorsomedial prefrontal cortex (rDMPFC) as a region of interest. By subtracting the common rsFC patterns of different genders, we identified gender-specific log k-related rsFC patterns with significant gender differences in S2. This was verified in an independent sample (S3). Specifically, in women, log k was found to be positively correlated with the rsFC between rDMPFC and anterior cingulate cortex/right orbitofrontal cortex. In contrast, in men, log k was negatively correlated with rsFC between rDMPFC and left orbitofrontal cortex/right precuneus. These gender differences were confirmed by slope tests. The findings highlight how gender may differ when engaging in intertemporal choice. They improve the understanding of gender differences in decision impulsivity and its underlying neural bases.