Yina Ma

Neural consequences of religious belief on self-referential processing

Abstract Christianity strongly encourages its believers to surrender to God and to judge the self from Gods perspective. We used functional MRI to assess whether this religious belief is associated with neural correlates of self-referential processing distinct from that of non-religious people. Non-religious and Christian participants were scanned while performing tasks of personal-trait judgments regarding the self or public persons. We found that, while self-judgment was linked to better memory of traits related to the self than to others, self-referential processing induced increased activity in the ventral medial prefrontal cortex (MPFC) for non-religious participants but in the dorsal MPFC for Christian participants. In addition, the dorsal MPFC activity was positively correlated with the rating scores of the importance of Jesus’ judgment in subjective evaluation of a persons personality. Because the ventral and dorsal MPFC are respectively engaged in representation of stimulus self-relevance and evaluation of self-referential stimuli, our findings suggest that Christian beliefs result in weakened neural coding of stimulus self-relatedness but enhanced neural activity underlying evaluative processes applied to self-referential stimuli.

Neuropsychological mechanism underlying antidepressant effect: a systematic meta- analysis

Antidepressants are widely used in clinical practice for the treatment of depression and other mood disorders. Numerous neuroimaging studies have recently examined how antidepressants influence emotional processes. However, both clinical trials and neuroimaging studies have reported inconsistent responses to antidepressants. Moreover, the neuropsychological mechanisms by which antidepressants act to improve depressive features remain underspecified. This systematic meta-analysis summarizes pharmacological neuroimaging studies (before February 2013) and the antidepressant effects on human brain activity underlying emotional processes. Sixty fMRI studies (involving 1569 subjects) applying antidepressants vs control were included in the current quantitative Activation Likelihood Estimation (ALE) meta-analysis. Pooling of results by ALE meta-analyses was stratified for population (mood disorder patients/healthy volunteers), emotional valence (positive/negative emotions) and treatment effects (increased/decreased brain activity). For both patients and healthy volunteers, the medial prefrontal and core limbic parts of the emotional network (for example, anterior cingulate, amygdala and thalamus) were increased in response to positive emotions but decreased to negative emotions by repeated antidepressant administration. Moreover, selective antidepressant effects were uncovered in patients and healthy volunteers, respectively. Antidepressants increased activity in the dorsolateral prefrontal (dlPFC), a key region mediating emotion regulation, during both negative and positive emotions in patients. Repeated antidepressant administration decreased brain responses to positive emotions in the nucleus accumbens, putamen, medial prefrontal and midbrain in healthy volunteers. Antidepressants act to normalize abnormal neural responses in depressed patients by increasing brain activity to positive stimuli and decreasing activity to negative stimuli in the emotional network, and increasing engagement of the regulatory mechanism in dlPFC.

Neural representations of close others in collectivistic brains

Our recent work showed that close relationships result in shared cognitive and neural representations of the self and ones mother in collectivistic individuals (Zhu et al., 2007, Neuroimage, 34, 1310-7). However, it remains unknown whether close others, such as mother, father and best friend, are differentially represented in collectivistic brains. Here, using functional magnetic resonance imaging and a trait judgment task, we showed evidence that, while trait judgments of the self and mother generated comparable activity in the medial prefrontal cortex (MPFC) and anterior cingulate (ACC) of Chinese adults, trait judgments of mother induced greater MPFC/ACC activity than trait judgments of father and best friend. Our results suggest that, while neural representations of the self and mother overlapped in the MPFC/ACC, close others such as mother, father and best friend are unequally represented in the MPFC/ACC of collectivistic brains.

Sociocultural patterning of neural activity during self-reflection

Western cultures encourage self-construals independent of social contexts, whereas East Asian cultures foster interdependent self-construals that rely on how others perceive the self. How are culturally specific self-construals mediated by the human brain? Using functional magnetic resonance imaging, we monitored neural responses from adults in East Asian (Chinese) and Western (Danish) cultural contexts during judgments of social, mental and physical attributes of themselves and public figures to assess cultural influences on self-referential processing of personal attributes in different dimensions. We found that judgments of self vs a public figure elicited greater activation in the medial prefrontal cortex (mPFC) in Danish than in Chinese participants regardless of attribute dimensions for judgments. However, self-judgments of social attributes induced greater activity in the temporoparietal junction (TPJ) in Chinese than in Danish participants. Moreover, the group difference in TPJ activity was mediated by a measure of a cultural value (i.e. interdependence of self-construal). Our findings suggest that individuals in different sociocultural contexts may learn and/or adopt distinct strategies for self-reflection by changing the weight of the mPFC and TPJ in the social brain network.

Neural substrates of self-referential processing in Chinese Buddhists.

Our recent work showed that self-trait judgment is associated with increased activity in the ventral medial prefrontal cortex (VMPFC) in non-religious Chinese, but in the dorsal medial prefrontal cortex (DMPFC) in Chinese Christians. The current work further investigated neural substrates of self-referential processing in Chinese Buddhists. Using functional magnetic resonance imaging, we scanned 14 Chinese Buddhists, while they conducted trait judgments of the self, Zhu Rongji (the former Chinese premier), Sakyamuni (the Buddhist leader) and Jesus (the Christian leader). We found that, relative to Zhu Rongji judgment, self-judgment in Buddhist participants failed to generate increased activation in the VMPFC but induced increased activations in the DMPFC/rostral anterior cingulate cortex, midcingulate and the left frontal/insular cortex. Self-judgment was also associated with decreased functional connectivity between the DMPFC and posterior parietal cortex compared with Zhu Rongji judgment. The results suggest that Buddhist doctrine of No-self results in weakened neural coding of stimulus self-relatedness in the VMPFC, but enhanced evaluative processes of self-referential stimuli in the DMPFC. Moreover, self-referential processing in Buddhists is characterized by monitoring the conflict between the doctrine of No-self and self-focus thinking during self-trait judgment.

Neural responses to perceived pain in others predict real-life monetary donations in different socioeconomic contexts.

Empathy has been proposed to be a proximate mechanism underlying altruistic behavior. However, both empathy and altruistic behavior differ between human individuals with low and high socioeconomic status. Here we investigated whether subjective socioeconomic status (SSS) modulates the relationship between neural activity to perceived pain in others and human altruistic behaviors in a real-life situation. After being scanned using functional MRI while observing videos of others in pain, participants were invited to make an anonymous monetary donation to a charitable organization. Painful stimuli increased activity in the inferior frontal, insula and somatosensory cortices compared to non-painful stimuli. A hierarchical regression analysis revealed that neural responses to perceived pain predicted the amount of monetary donations with different patterns in high and low SSS individuals. Stronger neural responses to perceived pain were associated with greater monetary donations in high SSS individuals, whereas a reverse pattern was observed in low SSS individuals. Our results suggest that SSS moderates the functional role of empathy-related neural activity in predicting altruistic behavior. Empathy may follow different mechanisms involved in altruistic behaviors (e.g., donation) depending on the social environment.

Neurocognitive processes of linguistic cues related to death

Consciousness of the finiteness of ones personal existence influences human thoughts and behaviors tremendously. However, the neural substrates underlying the processing of death-related information remain unclear. The current study addressed this issue by scanning 20 female adults, using functional magnetic resonance imaging, in a modified Stroop task that required naming colors of death-related, negative-valence, and neutral-valence words. We found that, while both death-related and negative-valence words increased activity in the precuneus/posterior cingulate and lateral frontal cortex relative to neutral-valence words, the neural correlate of the processing of death-related words was characterized by decreased activity in bilateral insula relative to both negative-valence and neutral-valence words. Moreover, the decreased activity in the left insula correlated with subjective ratings of death relevance of death-related words and the decreased activity in the right insula correlated with subjective ratings of arousal induced by death-related words. Our fMRI findings suggest that, while both death-related and negative-valence words are associated with enhanced arousal and emotion regulation, the processing of linguistic cues related to death is associated with modulations of the activity in the insula that mediates neural representation of the sentient self.

Neural representation of self-concept in sighted and congenitally blind adults

The functional organization of human primary visual and auditory cortices is influenced by sensory experience and exhibits cross-modal plasticity in the absence of input from one modality. However, it remains debated whether the functional architecture of the prefrontal cortex, when engaged in social cognitive processes, is shaped by sensory experience. The present study investigated whether activity in the medial prefrontal cortex underlying self-reflective thinking of ones own traits is modality-specific and whether it undergoes cross-modal plasticity in the absence of visual input. We scanned 47 sighted participants and 21 congenitally blind individuals using functional magnetic resonance imaging during trait judgements of the self and a familiar other. Sighted participants showed medial prefrontal activation and enhanced functional connectivity between the medial prefrontal and visual cortices during self-judgements compared to other-judgements on visually but not aurally presented trait words, indicating that medial prefrontal activity underlying self-representation is visual modality-specific in sighted people. In contrast, blind individuals showed medial prefrontal activation and enhanced functional connectivity between the medial prefrontal and occipital cortices during self-judgements relative to other-judgements on aurally presented stimuli, suggesting that visual deprivation leads to functional reorganization of the medial prefrontal cortex so as to be tuned by auditory inputs during self-referential processing. The medial prefrontal activity predicted memory performances on trait words used for self-judgements in both subject groups, implicating a similar functional role of the medial prefrontal cortex in self-referential processing in sighted and blind individuals. Together, our findings indicate that self-representation in the medial prefrontal cortex is strongly shaped by sensory experience.

5-HTTLPR Polymorphism Modulates Neural Mechanisms of Negative Self-Reflection

Cognitive distortion in depression is characterized by enhanced negative thoughts about both environment and oneself. Carriers of a risk allele for depression, that is, the short (s) allele of the serotonin transporter promoter polymorphism (5-HTTLPR), exhibit amygdala hyperresponsiveness to negative environmental stimuli relative to homozygous long variant (l/l). However, the neural correlates of negative self-schema in s allele carriers remain unknown. Using functional MRI, we scanned individuals with s/s or l/l genotype of the 5-HTTLPR during reflection on their own personality traits or a friends personality traits. We found that relative to l/l carriers, s/s carriers showed stronger distressed feelings and greater activity in the dorsal anterior cingulate (dACC)/dorsal medial prefrontal cortex (dmPFC) and the right anterior insula (AI) during negative self-reflection. The 5-HTTLPR effect on the distressed feelings was mediated by the AI/inferior frontal (IF) activity during negative self-reflection. The dACC/dmPFC activity explained 20% of the variation in harm-avoidance tendency in s/s but not l/l carriers. The genotype effects on distress and brain activity were not observed during reflection on a friends negative traits. Our findings reveal that 5-HTTLPR polymorphism modulates distressed feelings and brain activities associated with negative self-schema and suggest a potential neurogenetic susceptibility mechanism for depression.

Oxytocin and Social Adaptation: Insights from Neuroimaging Studies of Healthy and Clinical Populations

Adaptation to the social environment is critical for human survival. The neuropeptide oxytocin (OT), implicated in social cognition and emotions pivotal to sociality and well-being, is a promising pharmacological target for social and emotional dysfunction. We suggest here that the multifaceted role of OT in socio-affective processes improves the capability for social adaptation. We review OT effects on socio-affective processes, with a focus on OT-neuroimaging studies, to elucidate neuropsychological mechanisms through which OT promotes social adaptation. We also review OT-neuroimaging studies of individuals with social deficits and suggest that OT ameliorates impaired social adaptation by normalizing hyper- or hypo-brain activity. The social adaption model (SAM) provides an integrative understanding of discrepant OT effects and the modulations of OT action by personal milieu and context.