Wenfu Li

Examining brain structures associated with perceived stress in a large sample of young adults via voxel-based morphometry

Perceived stress reflects the extent to which situations are appraised as stressful at a given point in ones life. Past brain imaging studies have examined activation patterns underlying the stress response, yet focal differences in brain structures related to perceived stress are not well understood, especially when considering gray matter (GM) and white matter (WM) structures simultaneously. In this study, voxel-based morphometry was used to investigate relations between GM/WM volume and perceived stress levels in a large young adult sample. Participants (138 men, 166 women) completed the Perceived Stress Scale (PSS; Cohen et al., 1983) and underwent an anatomical magnetic resonance imaging scan. Higher PSS scores were associated with larger GM volume in a cluster that included regions in the bilateral parahippocampal gyrus, fusiform cortex, and entorhinal cortex and smaller GM volume in a cluster that included regions of the right insular cortex. Higher PSS scores were also related to smaller WM volume in a cluster that included the body of the corpus callosum. This pattern of results remained significant even after controlling for effects of general intelligence, socioeconomic status, and depression. Together, findings suggest a unique structural basis for individual differences in perceived stress, distributed across different GM and WM regions of the brain.

Association of creative achievement with cognitive flexibility by a combined voxel-based morphometry and resting-state functional connectivity study

Although researchers generally concur that creativity involves the production of novel and useful products, the neural basis of creativity remains elusive due to the complexity of the cognitive processes involved. Recent studies have shown that highly creative individuals displayed more cognitive flexibility. However, direct evidence supporting the relationship between creativity and cognitive flexibility has rarely been investigated using both structural and functional neuroimaging techniques. We used a combined voxel-based morphometry and resting-state functional connectivity (rsFC) analysis to investigate the relationship between individual creativity ability assessed by the creative achievement questionnaire (CAQ), and regional gray matter volume (GMV), as well as intrinsic functional connectivity. Results showed that CAQ scores negatively correlated with GMV in the rostral anterior cingulate cortex (ACC) and the bilateral dorsal ACC (dACC) extending to supplementary motor area, but positively correlated with GMV in the bilateral superior frontal gyrus and ventral medial prefrontal cortex (vmPFC). Further functional connectivity analysis revealed that higher creative achievement was inversely associated with the strength of rsFC between the dACC and medial superior frontal gyrus (mSFG), right middle frontal gyrus, and left orbito-frontal insula. Moreover, the association between the dACC-mSFG connectivity and CAQ scores was mediated by cognitive flexibility, assessed by a task-switching paradigm. These findings indicate that individual differences in creative achievement are associated with both brain structure and corresponding intrinsic functional connectivity involved in cognitive flexibility and deliberate creative processing. Furthermore, dACC-mSFG connectivity may affect creative achievement through its impact on cognitive flexibility.

Neural Basis of Scientific Innovation Induced by Heuristic Prototype

A number of major inventions in history have been based on bionic imitation. Heuristics, by applying biological systems to the creation of artificial devices and machines, might be one of the most critical processes in scientific innovation. In particular, prototype heuristics propositions that innovation may engage automatic activation of a prototype such as a biological system to form novel associations between a prototypes function and problem-solving. We speculated that the cortical dissociation between the automatic activation and forming novel associations in innovation is critical point to heuristic creativity. In the present study, novel and old scientific innovations (NSI and OSI) were selected as experimental materials in using learning-testing paradigm to explore the neural basis of scientific innovation induced by heuristic prototype. College students were required to resolve NSI problems (to which they did not know the answers) and OSI problems (to which they knew the answers). From two fMRI experiments, our results showed that the subjects could resolve NSI when provided with heuristic prototypes. In Experiment 1, it was found that the lingual gyrus (LG; BA18) might be related to prototype heuristics in college students resolving NSI after learning a relative prototype. In Experiment 2, the LG (BA18) and precuneus (BA31) were significantly activated for NSI compared to OSI when college students learned all prototypes one day before the test. In addition, the mean beta-values of these brain regions of NSI were all correlated with the behavior accuracy of NSI. As our hypothesis indicated, the findings suggested that the LG might be involved in forming novel associations using heuristic information, while the precuneus might be involved in the automatic activation of heuristic prototype during scientific innovation.

Regional gray matter volume and anxiety-related traits interact to predict somatic complaints in a non-clinical sample

Somatic complaints can be important features of an individuals expression of anxiety. Anxiety-related traits are also risk factors for somatic symptoms. However, it is not known which neuroanatomical mechanisms may be responsible for this relationship. In this study, our first step was to use voxel-based morphometry (VBM) approaches to investigate the neuroanatomical basis underlying somatic complaints in a large sample of healthy subjects. We found a significant positive correlation between somatic complaints and parahippocampal gyrus (PHG) volume adjacent to the entorhinal cortex. Further analysis revealed that the interaction between PHG volume/entorhinal cortex and neuroticism-anxiety (N-Anx) predicted somatic complaints. Specifically, somatic complaints were associated with higher N-Anx for individuals with increased PHG volume. These findings suggest that increased PHG volume and higher trait anxiety can predict vulnerability to somatic complaints in the general population.

Individual Differences in Brain Structure and Resting Brain Function Underlie Cognitive Styles: Evidence from the Embedded Figures Test

Cognitive styles can be characterized as individual differences in the way people perceive, think, solve problems, learn, and relate to others. Field dependence/independence (FDI) is an important and widely studied dimension of cognitive styles. Although functional imaging studies have investigated the brain activation of FDI cognitive styles, the combined structural and functional correlates with individual differences in a large sample have never been investigated. In the present study, we investigated the neural correlates of individual differences in FDI cognitive styles by analyzing the correlations between Embedded Figures Test (EFT) score and structural neuroimaging data [regional gray matter volume (rGMV) was assessed using voxel-based morphometry (VBM)] / functional neuroimaging data [resting-brain functions were measured by amplitude of low-frequency fluctuation (ALFF)] throughout the whole brain. Results showed that the increased rGMV in the left inferior parietal lobule (IPL) was associated with the EFT score, which might be the structural basis of effective local processing. Additionally, a significant positive correlation between ALFF and EFT score was found in the fronto-parietal network, including the left inferior parietal lobule (IPL) and the medial prefrontal cortex (mPFC). We speculated that the left IPL might be associated with superior feature identification, and mPFC might be related to cognitive inhibition of global processing bias. These results suggested that the underlying neuroanatomical and functional bases were linked to the individual differences in FDI cognitive styles and emphasized the important contribution of superior local processing ability and cognitive inhibition to field-independent style.

Gender-specific neuroanatomical basis of behavioral inhibition/approach systems (BIS/BAS) in a large sample of young adults: A voxel-based morphometric investigation

The behavioral inhibition system (BIS) and the behavioral activation system (BAS) are two fundamental motivational systems which are not only responsible for affective states, behavior and personality, but also related to predispositions for various forms of psychopathology. A wide range of previous studies revealed sex differences in both BIS/BAS and affective disorders (e.g., anxiety disorder) and externalizing disorders (e.g., addictive and impulsive behaviors), and a close link might exist between them. It remains to be clarified, however, whether the relationships between neuroanatomical characteristics and BIS/BAS exhibit sex differences. To investigate, voxel-based morphometry (VBM) was used to examine sex differences in the correlations between regional gray matter volume (rGMV) and scores on the Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scale in a large sample of healthy young adults (n=353). Results showed that females displayed a negative correlation between BIS sensitivity and rGMV in the parahippocampal gyrus (PHG), as well as positive correlations between BAS sensitivity and rGMV in the ventromedial prefrontal cortex (vmPFC) and inferior parietal lobule (IPL), whereas males showed the opposite pattern. These findings suggest that the brain regions associated with processing of negative emotions (PHG) and reward-related information (vmPFC and IPL) may contribute to sex-related differences in rGMV correlates of BIS and BAS, respectively. The present findings demonstrated the evidence of sex-linked neuroanatomical background of BIS and BAS among non-clinical subjects and might encourage future research into the gender-specific relationships between BIS/BAS and related affective disorders and externalizing disorders.

The correlation between Emotional Intelligence and gray matter volume in university students

A number of recent studies have investigated the neurological substrates of emotional intelligence (EI), but none of them have considered the neural correlates of EI that are measured using the Schutte Self-Report Emotional Intelligence Scale (SSREIS). This scale was developed based on the EI model of Salovey and Mayer (1990). In the present study, SSREIS was adopted to estimate EI. Meanwhile, magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to evaluate the gray matter volume (GMV) of 328 university students. Results found positive correlations between Monitor of Emotions and VBM measurements in the insula and orbitofrontal cortex. In addition, Utilization of Emotions was positively correlated with the GMV in the parahippocampal gyrus, but was negatively correlated with the VBM measurements in the fusiform gyrus and middle temporal gyrus. Furthermore, Social Ability had volume correlates in the vermis. These findings indicate that the neural correlates of the EI model, which primarily focuses on the abilities of individuals to appraise and express emotions, can also regulate and utilize emotions to solve problems.

Directed Forgetting of Negative Self-Referential Information Is Difficult: An fMRI Study

A large body of evidence suggested that both emotion and self-referential processing can enhance memory. However, it remains unclear how these two factors influence directed forgetting. This study speculates that directed forgetting of negative self-referential memory is more difficult than forgetting of other-referential memory. To verify this speculation, we combined the directed forgetting paradigm with the self-reference task. The behavioral result suggested that although both self-referential and other-referential information can be directly forgotten, less self-referential information can be forgotten than other-referential information. At the neural level, the forget instruction strongly activated the frontal cortex, suggesting that directed forgetting is not memory decay but an active process. In addition, compared with the negative other-referential information, forgetting of the negative self-referential information were associated with a more widespread activation, including the orbital frontal gyrus (BA47), the inferior frontal gyrus (BA45, BA44), and the middle frontal gyrus. Our results suggest that forgetting of the self-referential information seems to be a more demanding and difficult process.

Neuroticism and extraversion mediate the association between loneliness and the dorsolateral prefrontal cortex

Loneliness is an unpleasant and distressing feeling that a person experiences when he/she perceives that his/her social relationships are lacking in someway, either quantitatively or qualitatively; this can be linked to anxiety, depression, and suicide risk. Previous studies have found that certain personality traits (which are temporally stable and heritable) are predictors of loneliness. However, little empirical evidence is available on the brain structures associated with loneliness, as well as how personality traits impact the relationship between loneliness and brain structure. Thus, the current study used voxel-based morphometry to identify the brain structures underlying individual differences in loneliness (as measured by the UCLA Loneliness Scale) in a large sample, and then, applied multiple mediation analyses to explore the nature of the influence of personality traits on the relationship between loneliness and brain structure. The results showed that lonely individuals had greater regional gray matter volume in the left dorsolateral prefrontal cortex (DLPFC), which might reflect immature functioning in terms of emotional regulation. More importantly, we found that neuroticism and extraversion partially mediated the relationship between the left DLPFC and loneliness. In summary, through morphometric and multiple mediation analyses, this paper further validates the influence of both neuroticism and extraversion on loneliness.

Neuroanatomical Differences between Men and Women in Help-Seeking Coping Strategy

Help seeking (HS) is a core coping strategy that is directed towards obtaining support, advice, or assistance as means of managing stress. Women have been found to use more HS than men. Neural correlates of sex differences have also been reported in prefrontal-limbic system (PLS) regions that are linked to stress and coping, yet structural differences between men and women relating to HS in the PLS are still unknown. Thus, the association between gray matter volume (GMV) and HS was investigated using voxel-based morphometry (VBM) in a large healthy sample (126 men and 156 women). Results indicated women reported more HS than men did. VBM results showed that the relation between HS scores and GMV differed between men and women in regions of the bilateral orbitofrontal cortex extending to the subgenual anterior cingulate cortex(OFC/sgACC). Among women, higher HS scores were associated with smaller GMV in these areas while a positive correlation between GMV and HS scores was observed among men. These results remained significant after controlling for general intelligence, stress, anxiety and depression. Thus, this study suggested that structural differences between men and women are correlated to characteristic brain regions known to be involved in the PLS which is considered critical in stress regulation.