Neural basis responsible for effect of grit on procrastination: The interaction between the self-regulation and motivation neural pathways.

Procrastination has a detrimental impact on academic performance, health, and subjective well-being. Previous studies indicated that grit was negatively related to procrastination. However, the underlying neural basis of this relationship remains unclear. To address this issue, we utilized voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) analysis to identify the neural substrates of how is grit linked to procrastination. Behavioral results showed that procrastination was negatively associated with grit. VBM analysis revealed that gray matter volume (GMV) in the left precuneus was positively associated with the consistency of interest (CI), a subcomponent of grit, while the right medial orbital frontal cortex (mOFC) was positively correlated with the perseverance of effort (PE), another subcomponent of grit. Moreover, the RSFC analysis indicated that both precuneus-medial superior frontal gyrus (mSFG) and precuneus-insula connectivity were positively related to CI, while the functional coupling of right mOFC with left anterior cingulate cortex (ACC) was positively related to PE. Importantly, the structural equation modeling (SEM) results were well suited for the influence of grit on procrastination via both self-regulation (mOFC-ACC) and motivation pathways (precuneus-mSFG, precuneus-insula). Together, these findings imply that self-regulation and motivation could be two neural circuits underlying the impact of grit on procrastination.

Neural basis underlying the relation between internet addiction tendency and sleep quality: The intrinsic default-mode network connectivity pathways.

Internet addiction (IA) tendency is considered an addictive behavior that results from excessive Internet use, and severely affecting an individual's physical health, emotion, and sleep. Although previous studies indicated that IA tendency was negatively correlated with sleep quality, the underlying neural basis of this relationship remained unclear. To address this issue, we utilized resting-state functional connectivity (RSFC) analysis to identify the neural pathways of the relationship between IA tendency and sleep quality. The behavioral results indicated a positive correlation between these two factors. And RSFC results revealed that IA tendency was positively related to the strength of functional connectivity within the default-mode network (DMN), including the right precuneus-left middle temporal gyrus (rPrcu-lMTG), the left anterior cingulate-left superior frontal gyrus (lAC-lSFG), and the left inferior parietal lobe-left medial superior frontal gyrus (lIPL-lMSFG). More importantly, mediation analysis demonstrated that IA tendency could mediate the relationship between these functional couplings and sleep quality. In conclusion, our findings suggest that intrinsic DMN connectivity may be an important neural pathways underlying the effects of IA tendency on sleep quality, and provide neural evidence for understanding the relationship between IA tendency and sleep quality.

The role of valence, arousal, stimulus type, and temporal paradigm in the effect of emotion on time perception: A meta-analysis.

Anecdotal experiences show that the human perception of time is subjective, and changes with one's emotional state. Over the past 25 years, increasing empirical evidence has demonstrated that emotions distort time perception and usually result in overestimation. Yet, some inconsistencies deserve clarification. Specifically, it remains controversial how valence (positive/negative), arousal (high/low), stimulus type (scenic picture/facial expression/word/sound), and temporal paradigm (reproduction/estimation/discrimination) modulate the effect of emotion on time perception. Thus, the current study aimed to conduct a meta-analysis to quantify evidence for these moderators. After searching the Web of Science, SpiScholar, and Google Scholar, 95 effect sizes from 31 empirical studies were calculated using Hedges'g. The included studies involved 3,776 participants. The results a highlighted significant moderating effect of valence, arousal, stimulus type, and temporal paradigm. Specifically, negative valence tends to result in overestimation relative to positive valence; the increasing arousal leads to increasing temporal dilating; scenic picture, facial picture, and sound are more effective in inducing distortions than word; the overestimation can be better observed by discrimination and estimation paradigms relative to reproduction paradigms, and estimation paradigm is likely to be the most effective. These results suggest that the effect of emotion on time perception is influenced by valence, arousal, stimulus type, and temporal paradigm. These mitigating factors should be considered by scientists when studying time perception.

Psychological resilience mediates the association of the middle frontal gyrus functional connectivity with sleep quality.

Psychological resilience is characterized as the ability to recover from stress, which is essential for sleep quality. However, the neurological underpinnings of psychological resilience and the neural substrates of the links between psychological resilience and sleep quality in healthy brains remain not well understood. To address these issues, we adopted the method of resting-state functional connectivity (rs-FC) analysis in 144 young college students. The functional connectivity analysis indicated that psychological resilience was associated with the middle frontal gryus (MFG) functional connectivity, which mainly involved the right middle cingulum gyrus (rMCG), the right precentral gyrus (rPreCG), the left postcentral gyrus (lPoCG), and the left thalamus. Furthermore, mediation analysis suggested that psychological resilience played a mediating role in the relationship between MFG functional connectivity and sleep quality. Overall, the current study offered further evidence for the neurological underpinnings of psychological resilience and provided new insights into the relationship between psychological resilience and sleep quality from a neural basis perspective.

Negative emotions and brain: Negative emotions mediates the association between structural and functional variations in emotional-related brain regions and sleep quality.

IMPORTANCE AND STUDY OBJECTIVE: Emotion plays an important role in sleep quality, meanwhile, poor sleep quality is usually correlated with high negative emotions (NES). However, less is known about the neural basis for NES and the underlying mechanism for how NES affect individuals' sleep quality in the health brain. The present study combined voxel-based morphometry and resting-state functional connectivity analysis to identify the relationship between brain regions and NES, and then explored how NES-related brain structures are related to sleep quality in a large sample of normal young adults. DESIGN AND PARTICIPANTS: The present study used a fMRI procedure. Participants were 339 normal young adults. The NES was represented by the principal components of four measures: the Self-rating Anxiety Scale, Self-rating Depression Scale, Negative Affect Schedule, and Psychosomatic Tension Relaxation Inventory. Sleep quality was measured using the Pittsburgh Sleep Quality Index. RESULTS: Results showed that higher NES scores were associated with larger regional gray matter volume (rGMV) in the left parahippocampal gyrus, right superior temporal gyrus, and right postcentral gyrus. Further functional connectivity analysis demonstrated that the connectivity between these three brain regions and a specific set of emotion-related regions was also significantly associated with NES scores. Moreover, NES acted as a mediator of the relationship between the rGMV of the left parahippocampal gyrus, right superior temporal gyrus, and right postcentral gyrus and sleep quality. NES also mediated the relationship between the connectivity between the right superior temporal-supplementary motor area and the right superior temporal-right precentral gyrus and sleep quality. CONCLUSION: The present study provides the further evidence for neural substrates of NES and reveals a potential mechanism that NES mediates the effect of spontaneous brain activity on sleep quality. Meanwhile, these findings indicate that negative emotions share a common brain structure and function based on sleep quality.

Resting-state functional connectivity of the sensory/somatomotor network associated with sleep quality: evidence from 202 young male samples.

Previous neuroimaging studies have demonstrated that sleep is associated with brain functional changes in some specific brain regions. However, few studies have examined the relationship between all possible functional connectivities (FCs) within the sensory/somatomotor network (SSN) and the sleep quality of young male samples. The SSN consists of two motor cortices and is known to play a critical role in sleep. Poor sleep quality may be associated with increased sensory/somatomotor functional connectivity during rest. Hence, 202 young male participants underwent a resting-state functional magnetic resonance imaging (fMRI) scan and completed the Pittsburgh Sleep Quality Index (PSQI). Results indicated that increased functional connectivity within the SSN was associated with poor sleep quality. Specifically, the total PSQI score was positively correlated with the increased functional connectivity of the left paracentral lobule (PCL), bilateral precentral gyrus (PreCG), supplementary motor area (SMA) and bilateral postcentral gyrus (PoCG). Additionally, our findings also exhibited that (a) the subjective sleep quality factor of PSQI was positively correlated with FC between the bilateral PoCG and the bilateral PCL as well as between the left PreCG and the right SMA; (b) the sleep latency factor of PSQI was positively correlated with FC between the left PoCG and the right precuneus (PCUN); (c) the sleep disturbances factor of PSQI was positively correlated with FC between the left PCL and the right PoCG, and (d) the daytime dysfunction factor of PSQI was positively correlated with FC between the bilateral PoCG and the left PCL as well as between the bilateral PreCG and the SMA. In short, our findings can be comprehensively understood as neural mechanisms of intrinsic SSN connectivity are associated with sleep quality of man. Meanwhile, it may expand our knowledge and provide new insight into a deeper understanding of the neurobiological mechanisms of sleep or sleep problems.

Association of white matter volume with sleep quality: a voxel-based morphometry study.

Many studies have focused on the gray matter volume associated with sleep quality, little is known about the relationship between white matter volume and sleep quality. Brain white structure is a crucial component in the structural neuroanatomy. Therefore, in this study, we investigated the association between white matter volume and sleep quality. Data were collected using the Pittsburgh Sleep Quality Index and voxel-based morphometry among 352 college students. Results showed that the global PSQI score was negatively associated with the white matter volume, including in the right middle occipital gyrus, the left superior temporal gyrus, the right the precentral gyrus, the left supramarginal gyrus, the left middle frontal gyrus, the left precunes, and the right superior frontal gyrus. Results also indicated that the white matter volume in specific regions negatively associated with the factor of PSQI. These specific brain regions may be replicated in brain areas related to sleep quality. In summary, we suggested that exploring brain white structure are related to sleep could help to expound the mechanisms by which sleep quality are associated with brain function, behavior and cognition, as well as potentially the networks and systems responsible for variations in sleep themselves.

The gray matter volume of bilateral inferior temporal gyrus in mediating the association between psychological stress and sleep quality among Chinese college students.

The role of brain regions in the relationship between psychological stress and sleep quality is unclear. This study investigates the neuroanatomical basis of the association between psychological stress and sleep quality. Data were collected using the Pittsburgh Sleep Quality Index, the Psychosomatic Tension Relaxation Inventory, and voxel-based morphometry among 318 healthy students. The results showed that psychological stress was negatively correlated with sleep quality. According to the mediation analysis results, the correlation between psychological stress and sleep quality was partially mediated by the region of the bilateral inferior temporal gyrus. These findings suggest that there is a strong link between sleep quality and psychological stress, highlighting the gray matter volume of the bilateral inferior temporal gyrus related to emotional processing, which plays an essential role in improving sleep quality.

The Effects of Angry Expressions and Fearful Expressions on Duration Perception: An ERP Study.

Little is known about the electrophysiological basis of the effect of threat-related emotional stimuli with different motivational direction on duration perception. Thus, event-related potentials were employed to examine the effects of angry expressions and fearful expressions on perception of different duration (490-910 ms). Behavioral results showed there was a greater underestimation of the duration of angry expressions (approach-motivated negative stimuli) than fearful expressions (withdrawal-motivated negative stimuli), compared with neutral expressions. Event-related potentials results showed that, the area of Contingent Negative Variation (CNV) evoked by angry expression, fearful expression and neutral expression gradually increased. These results indicated that specific electrophysiological mechanisms may underlie the attention effects of angry and fearful expressions on timing. Specifically, compared with neutral expressions, fearful expressions and angry expressions both are likely to distract more attentional resources from timer, in particular, angry expressions attract more attention resources than fearful expressions from timer. The major contribution of the current study is to provide electrophysiological evidences of fear vs. anger divergence in the aspect of time perception and to demonstrate beyond the behavioral level that the categorization of threat-related emotions should be refined so to highlight the adaptability of the human defense system.