Jiemin Yang

Pleasant mood intensifies brain processing of cognitive control: ERP correlates.

The present study investigated the impact of auditory-induced mood on brain processing of cognitive control using a Stroop color-word interference task. A total of 135 positive, negative, and neutral sounds (45 of each) were presented in separate blocks for a mood induction procedure, which was then followed by a Stroop color-word task in each trial. Event-related potentials (ERPs) were recorded for color-word congruent, incongruent and neutral (color-word irrelevant) words and subjects named the printed colors of the words by pressing the appropriate key (irrespective of word meaning). Response latency was delayed during incongruent vs. neutral trials, and this cost did not interact significantly with mood states. ERP data showed prolonged peak latencies in the P200 component and more negative deflections in the Late Positive Component (LPC, 450-550 ms) during incongruent vs. neutral conditions, regardless of mood states. Moreover, the negative deflections (N450) in the 450-550 ms interval of the incongruent- neutral difference waves, which index cognitive control effect in brain potentials, was more pronounced in the pleasant, but not in the unpleasant, mood state when compared with the neutral mood state. These data suggest that, pleasant mood intensifies brain processing of cognitive control, in a situation requiring effective inhibition of task-irrelevant distracting information. In addition, N450 component serves as an affective marker, embodying not only cognitive control effect in the brain but also its interaction with mood states.

The valence strength of unpleasant emotion modulates brain processing of behavioral inhibitory control: neural correlates.

As an ability critical for adaptive social living, behavioral inhibitory control (BIC) is known to be influenced substantially by unpleasant emotion. Nevertheless, how unpleasant emotion of diverse strength influences this control, and the spatiotemporal dynamics underlying this influence, remain undetermined. For this purpose, Event-related potentials (ERPs) were recorded for standard stimulus which required no BIC, and for deviant stimuli that required controlling habitual responses, during highly unpleasant (HU), mildly unpleasant (MU) and Neutral blocks. The results showed delayed response latencies for deviant compared to standard stimuli, irrespective of emotionality. Moreover, there were significant main effects of stimulus type, and significant stimulus type and block interaction effects on the averaged amplitudes of the 230-310 ms and 330-430 ms intervals. In the deviant-standard difference waves which directly index BIC-relevant processing, these interactions were manifested by increased negative potentials as a function of the strength of unpleasant emotion across N2 and P3 components. In addition, these influences are specific to unpleasant emotion, as pleasant emotion of diverse strength produced a similar impact in the control experiment. Therefore, unpleasant emotion of diverse strength is different in impact on brain processing of behavioral inhibitory control. This impact is evident not only in early monitoring of response conflicts, but also in late processing of response inhibition.

The impact of emotion valence on brain processing of behavioral inhibitory control: spatiotemporal dynamics.

Emotion is known to interact with behavioral inhibitory control (BIC), an ability critical for adaptive living. Nevertheless, how emotion valence influences this control, and the spatiotemporal dynamics underlying this influence, remain undetermined. For this purpose, the present study recorded event-related potentials (ERPs) for a standard stimulus which required no BIC, and for deviant stimuli that required controlling habitual responses during pleasant, neutral and unpleasant blocks. Behavioral results showed prolonged reaction times (RTs) and diminished accuracy rates for deviant than for standard stimuli, irrespective of the emotionality of deviants. Moreover, there were significant main effects of stimulus type, and significant stimulus and emotion interaction effects on the averaged amplitudes of the 200-300ms and 300-500ms intervals. Through analyzing the deviant-standard difference ERPs that index BIC directly, we found larger N2 and smaller P3 amplitudes during the unpleasant block than during the neutral block. The pleasant block, in contrast, showed a trend of more pronounced P3 amplitudes than the neutral block. Thus, by synchronizing BIC with emotion induction, we found distinct impact of pleasant and unpleasant emotions on behavioral inhibitory processing, not only in early monitoring of response conflicts but also in the late stage of response inhibition.

Neural mechanisms underlying the higher levels of subjective well-being in extraverts: Pleasant bias and unpleasant resistance

The present study investigated the neural mechanisms that underlie the higher levels of subjective well-being in extraverts. The impact of extraversion on the human sensitivity to pleasant and unpleasant pictures of diverse emotional intensities was examined. We recorded event-related potentials (ERPs) for highly positive (HP), moderately positive (MP), and neutral stimuli in the pleasant session, and for highly negative (HN), moderately negative (MN), and neutral stimuli in the unpleasant session, while subjects (16 extraverts and 16 ambiverts) performed a standard/deviant categorization task, irrespective of the emotionality of the deviant stimuli. The results showed significant emotion effects for HP and MP stimuli at the P2 and P3 components in extraverts, but not in ambiverts. Despite a pronounced emotion effect for HN stimuli across the P2, N2, and P3 components in both samples, ambiverts displayed a significant emotion effect for MN stimuli at the N2 and P3 components that was absent in extraverts. The posterior cingulate cortices, which connect multiple neural regions that are important in interactions of emotion and extraversion, may mediate the extravert-specific emotion effect for pleasant stimuli. Thus, extraverts are less susceptible to unpleasant stimuli of mild intensity than are ambiverts, while extraverts have an additional enhanced sensitivity to pleasant stimuli, regardless of emotion intensity. Consequently, the decreased threshold for pleasant emotion and the increased threshold for unpleasant emotion might be essential neural mechanisms that underlie the higher levels of subjective well-being in extraverts.

Event-related potential correlates of the extraverts' sensitivity to valence changes in positive stimuli.

This study investigated whether the human sensitivity to valence intensity changes in positive stimuli varies with extraversion. Event-related potentials were recorded for highly positive, moderately positive, and neutral stimuli while participants (extraverts and nonextraverts) performed a standard/deviant categorization task, irrespective of the emotionality of deviants. The results of extraverts showed larger P2 and P3 amplitudes during highly positive condition than during moderately positive condition which, in turn, elicited larger P2 than neutral condition. Conversely, nonextraverts showed no differences at both P2 and P3 components. Thus, extraverts, unlike less extraverted individuals, are sensitive to valence changes in positive stimuli, which may be underlain by certain biogenetic mechanism.

Suppression dampens unpleasant emotion faster than reappraisal: Neural dynamics in a Chinese sample

The timing dynamics of regulating negative emotion with expressive suppression and cognitive reappraisal were investigated in a Chinese sample. Event-Related Potentials were recorded while subjects were required to view, suppress emotion expression to, or reappraise emotional pictures. The results showed a similar reduction in self-reported negative emotion during both strategies. Additionally, expressive suppression elicited larger amplitudes than reappraisal in central-frontal P3 component (340–480 ms). More importantly, the Late Positive Potential (LPP) amplitudes were decreased in each 200 ms of the 800–1600 ms time intervals during suppression vs. viewing conditions. In contrast, LPP amplitudes were similar for reappraisal and viewing conditions in all the time windows, except for the decreased amplitudes during reappraisal in the 1400–1600 ms. The LPP (but not P3) amplitudes were positively related to negative mood ratings, whereas the amplitudes of P3, rather than LPP, predict self-reported expressive suppression. These results suggest that expressive suppression decreases emotion responding more rapidly than reappraisal, at the cost of greater cognitive resource involvements in Chinese individuals.

Expectation decreases brain susceptibility to fearful stimuli: ERP evidence from a modified emotion evaluation task

Expectation decreased the susceptibility to fearful stimuli in prior studies using distracting tasks. The present study tests whether expectation remains effective in decreasing this susceptibility, when subjects focus attention on emotional properties. Event-related potentials were recorded for fearful and neutral faces, while subjects performed a modified emotion evaluation task during unpredictable and predictable conditions. Behavioral data showed faster response latencies during predictable versus unpredictable conditions. ERP data showed prolonged peak latencies in N1 (80-130ms) and larger amplitudes in P2 (130-180ms) and N200-300 components, for unpredictable fearful versus neutral faces. Conversely, all these components showed similar responses to predictable fearful and neutral faces. Source analysis suggested that medial temporal lobe mediated ERPs elicited by unpredictable fearful faces, while ventromedial prefrontal cortex mediated those elicited by predictable fearful faces, in the 130-180ms interval. Thus, we propose emotional expectation as a cognitive regulation strategy that reliably dampens human susceptibility to fearful stimuli.

Enhanced brain susceptibility to negative stimuli in adolescents: ERP evidences

Background: Previous studies investigated neural substrates of emotional face processing in adolescents and its comparison with adults. As emotional faces elicit more of emotional expression recognition rather than direct emotional responding, it remains undetermined how adolescents are different from adults in brain susceptibility to emotionally stressful stimuli. Methods: Event-Related Potentials (ERPs) were recorded for highly negative (HN), moderately negative (MN), and neutral pictures in 20 adolescents and 20 adults while subjects performed a standard/deviant distinction task by pressing different keys, irrespective of the emotionality of deviant stimuli. Results: Adolescents exhibited more negative amplitudes for HN vs. neutral pictures in N1 (100–150 ms), P2 (130–190 ms), N2 (210–290 ms), and P3 (360–440 ms) components. In addition, adolescents showed more negative amplitudes for MN compared to neutral pictures in N1, P2, and N2 components. By contrast, adults exhibited significant emotion effects for HN stimuli in N2 and P3 amplitudes but not in N1 and P2 amplitudes, and they did not exhibit a significant emotion effect for MN stimuli at all these components. In the 210–290 ms time interval, the emotion effect for HN stimuli was significant across frontal and central regions in adolescents, while this emotion effect was noticeable only in the central region for adults. Conclusions: Adolescents are more emotionally sensitive to negative stimuli compared to adults, regardless of the emotional intensity of the stimuli, possibly due to the immature prefrontal control system over the limbic emotional inputs during adolescence.

Individual Differences in Spontaneous Expressive Suppression Predict Amygdala Responses to Fearful Stimuli: The Role of Suppression Priming

Though the spontaneous emotion regulation has received long discussions, few studies have explored the regulatory effects of spontaneous expressive suppression in neural activations, especially in collectivistic cultural context. The functional magnetic resonance imaging (fMRI) study aimed to examine whether individual differences in the tendency to use suppression are correlated with amygdala responses to negative situations when individuals are unconsciously primed with expressive suppression. Twenty-three healthy Chinese undergraduates completed an fMRI paradigm involving fear processing, and a synonym matching task was added to prime participants with the unconscious (automatic) expressive suppression goal. Participants completed measures of typical emotion regulation use (reappraisal and suppression), trait anxiety, and neuroticism. Results indicated that only in emotion suppression prime condition, greater use of suppression in everyday life was related to decreased amygdala activity. These associations were not attributable to variation in trait anxiety, neuroticism, or the habitual use of reappraisal. These findings suggest that in collectivistic cultural settings, individual differences in expressive suppression do not alter fear-related neural activation during suppression-irrelevant context. However, unconscious suppression priming facilitates the manifestation of individual differences in the neural consequence of expressive suppression, as reflected by the priming-specific decrease of emotional subcortical activations with more use of expressive suppression.

Trait self-consciousness predicts amygdala activation and its functional brain connectivity during emotional suppression: an fMRI analysis

The present functional magnetic resonance imaging study investigated how trait neuroticism and its heterogeneous subdimensions are related to the emotional consequences and neural underpinnings of emotion regulation. Two levels of neuroticism assessments were conducted with 47 female subjects, who were required to attend to, suppress emotion displays to, or cognitively reappraise the meanings of negative images. The results showed reduced emotional experience and bilateral amygdala activation during reappraisal, and this regulation effect is unaffected by individual differences in neuroticism and its subdimensions. By contrast, the emotion downregulation effect of suppression in the right amygdala is compromised with increasing self-consciousness but not overall neuroticism dimension. This association holds robust after controlling the potential contribution of habitual suppression. Moreover, the psychophysiological interaction (PPI) analysis revealed that self-consciousness predicts weaker functional coupling of the right amygdala to supplementary motor area and putamen during expressive suppression, two regions mediating the control and execution of motor actions. These findings suggest that self-consciousness predicts increased difficulty in emotional regulation using expressive suppression; and that the heterogeneous nature of trait neuroticism needs to be considered in exploring the association of neuroticism and emotion regulation.