Xiting Huang

Emotional primes modulate the responses to others’ pain: an ERP study

Previous event-related potential (ERP) and brain imaging studies have suggested observer responses to others’ pain are modulated by various bottom-up and top-down factors, including emotional primes. However, the temporal dynamics underlying the impact of emotional primes on responses to others’ pain remains poorly understood. In the present study, we explored effects of negative, neutral, and positive emotional priming stimuli on behavioral and cortical responses to visual depictions of others in pain. ERPs were recorded from 20 healthy adults, who were presented with painful and non-painful target pictures following observation of negative, neutral, and positive emotional priming pictures. ERP analyses revealed that relative to non-painful pictures, differential P3 amplitudes for painful pictures were larger followed by negative primes than either neutral or positive primes. There were no significant differential P3 amplitudes for painful pictures relative to non-painful pictures were found followed neutral and positive emotional primes. These results suggest that negative emotional primes strengthen observers’ attention toward others’ pain. These results support the threat value of pain hypothesis.

Pain perception in the self and observation of others: an ERP investigation.

The nature of interactions between observing pain in others (other-pain) and subjective pain perception (self-pain) has been debated. To test whether other-pain and self-pain primes increase or decrease responsiveness to complementary self-pain or other-pain targets, two ERP studies were conducted. In Study 1, twenty participants (10 women, 10 men) were exposed to pictures depicting other-pain or other non-painful situations, followed by self-pain or non-nociceptive heat stimulation delivered to the forearm. Significant visual prime×sensory target interactions indicated that compared to other non-painful primes, other-pain visual primes predicted faster reaction times (RTs) and smaller P2 amplitudes in response to self-pain stimuli while responses to self-heat stimuli were not affected by priming images. However, effects of other-pain primes on elevations in intensity ratings were not specific to self-pain and extended to self-heat targets. In Study 2, self-pain and self-heat stimuli were applied to the same participants followed by other-pain and other non-painful visual targets. Similar to the pattern for Study 1, sensory prime×visual target interactions indicated that compared to self-heat primes, self-pain sensory primes predicted marginally faster RTs and smaller P3 amplitudes in response to other-pain targets while responses to other non-painful targets were unaffected by sensory priming stimuli. Again, self-pain primes predicted higher intensity ratings for both target types compared to self-heat primes. Together, findings supported the shared-representation model of pain empathy more strongly than the threat value of pain hypothesis.

Effects of threatening information on interpersonal responses to pain.

Emerging evidence indicates that meanings attributed to pain contribute to tolerance and coping among affected individuals. However, links between pain appraisals and coping responses have received little attention within a broader interpersonal context. In this experiment, effects of appraisal on pain tolerance and coping were examined in adult dyads. Eighty‐six acquaintance/friend pairs were randomly assigned to the role of Participant in a cold pressor test (CPT) or observer–helper who assisted in coping. Before the task, pairs in the threat condition read about frostbite symptoms and consequences, while those in the reassurance condition read about the safety of the task. In a mixed condition, Participants and Observers read the reassurance and threat passage, respectively. Between‐groups analyses revealed threat group participants had lower pain tolerance and reported less cognitive coping than did participants in other appraisal conditions. Threat group observers reported less attention diversion, coping self‐statements and ignoring in helping their partner than did reassured observers. Pain language was also most prominent in transactions of threatened dyads. Finally, use of attention diversion by observers contributed to pain tolerance, independent of participant factors (reported pain, appraisal condition, reported coping) and pain language in conversations during immersions. The study highlights how appraisal contributes not only to pain tolerance and coping in the affected individual but also to care‐giving efforts of others in their social environment.

Regional Homogeneity of Intrinsic Brain Activity in Happy and Unhappy Individuals

Background Why are some people happier than others? This question has intrigued many researchers. However, limited work has addressed this question within a neuroscientific framework. Methods The present study investigated the neural correlates of trait happiness using the resting-state functional magnetic resonance imaging (rs-fMRI) approach. Specifically, regional homogeneity (ReHo) was examined on two groups of young adults: happy and unhappy individuals (N = 25 per group). Results Decreased ReHo in unhappy relative to happy individuals was observed within prefrontal cortex, medial temporal lobe, superior temporal lobe, and retrosplenial cortex. In contrast, increased ReHo in unhappy relative to happy individuals was observed within the dorsolateral prefrontal cortex, middle cingulate gyrus, putamen, and thalamus. In addition, the ReHo within the left thalamus was negatively correlated with Chinese Happiness Inventory (CHI) score within the happy group. Limitations As an exploratory study, we examined how general trait happiness is reflected in the regional homogeneity of intrinsic brain activity in a relatively small sample. Examining other types of happiness in a larger sample using a multitude of intrinsic brain activity indices are warranted for future work. Conclusions The local synchronization of BOLD signal is altered in unhappy individuals. The regions implicated in this alteration partly overlapped with previously identified default mode network, emotional circuitry, and rewarding system, suggesting that these systems may be involved in happiness.

The aftereffect of perceived duration is contingent on auditory frequency but not visual orientation

Recent sensory history plays a critical role in duration perception. It has been established that after adapting to a particular duration, the test durations within a certain range appear to be distorted. To explore whether the aftereffect of perceived duration can be constrained by sensory modality and stimulus feature within a modality, the current study applied the technique of simultaneous sensory adaptation, by which observers were able to simultaneously adapt to two durations defined by two different stimuli. Using both simple visual and auditory stimuli, we found that the aftereffect of perceived duration is modality specific and contingent on auditory frequency but not visual orientation of the stimulus. These results demonstrate that there are independent timers responsible for the aftereffects of perceived duration in each sensory modality. Furthermore, the timer for the auditory modality may be located at a relatively earlier stage of sensory processing than the timer for the visual modality.

Components of Implicit Stigma against Mental Illness among Chinese Students

Although some research has examined negative automatic aspects of attitudes toward mental illness via relatively indirect measures among Western samples, it is unclear whether negative attitudes can be automatically activated in individuals from non-Western countries. This study attempted to validate results from Western samples with Chinese college students. We first examined the three-component model of implicit stigma (negative cognition, negative affect, and discriminatory tendencies) toward mental illness with the Single Category Implicit Association Test (SC-IAT). We also explored the relationship between explicit and implicit stigma among 56 Chinese university college students. In the three separate SC-IATs and the combined SC-IAT, automatic associations between mental illness and negative descriptors were stronger relative to those with positive descriptors and the implicit effect of cognitive and affective SC-IATs were significant. Explicit and implicit measures of stigma toward mental illness were unrelated. In our sample, womens overall attitudes toward mental illness were more negative than mens were, but no gender differences were found for explicit measures. These findings suggested that implicit stigma toward mental illness exists in Chinese students, and provide some support for the three-component model of implicit stigma toward mental illness. Future studies that focus on automatic components of stigmatization and stigma-reduction in China are warranted.

Negativity bias of the self across time: an event-related potentials study

To investigate the neural basis of self-evaluation across time as a function of emotional valence, event-related potentials were recorded among participants instructed to make self-reference judgments when evaluating their past, present and future selves. Results showed that, when evaluating present and past selves, negative words elicited a more positive ERP deflection in the time window between 650ms and 800ms (LPC) relative to positive words. However, when evaluating the future selves, there was no significant difference on the amplitude of the LPC evoked by negative versus positive words. Findings provided evidence for the effect of emotional valence on the self across time at a neurophysiological level and identified the time course of negative bias in the temporal self. More specifically, people were inclined to be relatively less negative and optimistic about their future self but had mixed emotions about past and present selves.

Modulation of Alpha and Beta Oscillations during an n-back Task with Varying Temporal Memory Load

Temporal information can be retained and manipulated in working memory (WM). Neural oscillatory changes in WM were examined by varying temporal WM load. Electroencephalography was obtained from 18 subjects performing a temporal version of the visual n-back WM task (n = 1 or 2). Electroencephalography revealed that posterior alpha power decreased and temporal region-distributed beta power increased as WM load increased. This result is consistent with previous findings that posterior alpha band reflects inhibition of task-irrelevant information. Furthermore, findings from this study suggest that temporal region-distributed beta band activity is engaged in the active maintenance of temporal duration in WM.

Task interference from event-based prospective memory : an event-related potentials study

Event-related potentials (ERPs) technique was used to examine brain activity related to task interference during event-based prospective memory. The behavioral data indicated that there existed task interference. Data from ERPs record on non-prospective memory trials suggested that there were significant differences in the time windows of 200–300, 300–350, and 350–400 ms after the onset of stimulus. The ERP difference wave showed the maximum amplitude over the central site (Fz) with a peak latency of 250 ms (N250). The topographical map in the time window of 200–300 ms indicated that the components reflected activation mainly in the frontal lobe. The results seemed to support preparatory attentional processes and memory processes theory and revealed that frontal lobe was involved in monitoring, which caused task interference effect.

Coping when pain is a potential threat: The efficacy of acceptance versus cognitive distraction

This experiment investigated the impact of brief training in acceptance versus distraction‐based pain management on experimental pain tolerance in conditions of lower and higher potential threats. One hundred fifty‐one pain‐free Chinese adults (93 women, 58 men) randomly assigned to acceptance, distraction or pain education control conditions engaged in a cold pressor test (CPT) after reading validated orienting information designed to prime either the safety of the CPT (lower threat) or symptoms and damaging effects of exposure to extreme cold (higher threat). A 2 (threat level) × 3 (training strategy) analysis of covariance, controlling for pre‐intervention pain tolerance and education, indicated the acceptance group was more pain tolerant than other training groups. This main effect was qualified by an interaction with threat level: in the lower threat condition, acceptance group participants were more pain tolerant than peers in the distraction or pain education groups while no training group differences were found in the higher threat condition. Supplementary analyses identified catastrophizing as a partial mediator of training group differences in pain tolerance. In summary, findings suggested acceptance‐based coping is superior to distraction as a means of managing experimental pain, particularly when pain sensations are viewed as comparatively low in potential threat.