Affective individual differences and startle reflex modulation

Potentiation of startle has been demonstrated in experimentally produced aversive emotional states, and clinical reports suggest that potentiated startle may be associated with fear or anxiety. To test the generalizability of startle potentiation across a variety of emotional states as well as its sensitivity to individual differences in fearfulness, the acoustic startle response of 17 high- and 15 low-fear adult subjects was assessed during fear, anger, joy, sadness, pleasant relaxation, and neutral imagery. Startle responses were larger in all aversive affective states than during pleasant imagery. This effect was enhanced among high fear subjects, although followup testing indicated that other affective individual differences (depression and anger) may also be related to increased potentiation of startle in negative affect. Startle latency was reduced during high- rather than low-arousal imagery but was unaffected by emotional valence.     

Neural substrates of individual differences in human fear learning: Evidence from concurrent fMRI, fear-potentiated startle, and US-expectancy data

To provide insight into individual differences in fear learning, we examined the emotional and cognitive expressions of discriminative fear conditioning in direct relation to its neural substrates. Contrary to previous behavioral-neural (fMRI) research on fear learning--in which the emotional expression of fear was generally indexed by skin conductance--we used fear-potentiated startle, a more reliable and specific index of fear. While we obtained concurrent fear-potentiated startle, neuroimaging (fMRI), and US-expectancy data, healthy participants underwent a fear-conditioning paradigm in which one of two conditioned stimuli (CS(+) but not CS(-)) was paired with a shock (unconditioned stimulus [US]). Fear learning was evident from the differential expressions of fear (CS(+) > CS(-)) at both the behavioral level (startle potentiation and US expectancy) and the neural level (in amygdala, anterior cingulate cortex, hippocampus, and insula). We examined individual differences in discriminative fear conditioning by classifying participants (as conditionable vs. unconditionable) according to whether they showed successful differential startle potentiation. This revealed that the individual differences in the emotional expression of discriminative fear learning (startle potentiation) were reflected in differential amygdala activation, regardless of the cognitive expression of fear learning (CS-US contingency or hippocampal activation). Our study provides the first evidence for the potential of examining startle potentiation in concurrent fMRI research on fear learning.     

The chronometry of affective startle modulation in unipolar depression

Affective startle eyeblink modulation by unipolar depressed and nondepressed participants was assessed during the anticipation and viewing of emotional pictures. Anticipatory startle probes were presented at 2,000 ms and 750 ms before picture onset. Startle probes during picture viewing were presented at 300 ms and 3,500-4,500 ms after picture onset. Although nondepressed participants demonstrated the predicted quadratic and linear patterns of responding in the 2,000-ms anticipatory and 3,500-4,500-ms viewing conditions, respectively, depressed participants were not significantly responsive to differences among picture valence categories at these probe conditions. There were no between-groups differences in startle modulation at the other two probe intervals, in picture ratings, or in behavioral responses to pictures. There was also little evidence of hyperresponsivity to negatively valenced stimuli in the depressed group. These results indicate that depression-related affective hyporesponsivity extended to startle modulation but that the nature and magnitude of the differences between depressed and nondepressed individuals were conditional on the specific cognitive and motivational processes recruited at different points in time.     

Modification of the startle reflex in a community sample: do one or two dimensions of psychopathy underlie emotional processing?

Recent research on psychopathy has begun to explore two dimensions that possibly underlie psychopathy–one related more to emotional and interpersonal traits, and another related more to antisocial behaviors. A community sample of adults was assessed for psychopathy using Hare's (1991) Psychopathy Checklist-Revised (PCL-R). Eyeblinks elicited by startle probes were recorded while participants viewed pictures of emotionally-laden stimuli. Consistent with previous research, participants scoring high on PCL-R Factor 2 (“antisocial”) showed no affective modification of startle if they also scored high on PCL-R Factor 1 (“emotional detachment”). When the factor scores were analyzed together as continuous variables in a regression analysis, however, affective modification of startle was negatively related to Factor 1 but positively related to Factor 2. The results thus provide further support for a two-factor model of psychopathy.     

Affective outcomes in superficial and intimate interactions: Roles of social anxiety and curiosity

We examined the roles of trait curiosity and social anxiety (and the contributions of the behavioral inhibition and activation systems; BIS, BAS) in predicting positive and negative affect (PA; NA) during social interactions. In Study 1, individuals interacted with same-sex confederates on topics that gradually escalated in emotional self-disclosure. In Study 2, cross-sex pairs of students were randomly assigned to a closeness-generating or small-talk interaction. There were several consistent findings across studies. Higher curiosity uniquely predicted greater interpersonally generated PA. Higher social anxiety uniquely predicted greater interpersonally generated NA in Study 1, and in Study 2, this relationship varied by social context. Specifically, high compared to low socially anxious individuals reported greater NA during small-talk, with no differences during intimate interactions. Furthermore, Study 2 demonstrated that individuals with stronger BAS’s experienced greater PA in the intimate compared to small-talk condition. There appear to be important traits that differentially contribute to appetitive and aversive interpersonal experiences.     

Acute exercise suppresses judgments of facial emotion intensity

The ability to recognize others’ facial expressions is critical to the social communication of affective states. The present work examined how transient states of high physiological arousal during aerobic exercise influence recognizing and rating morphed facial expressions. Participants exercised at either a low or high work rate. While exercising and then during cool-down and rest periods, participants performed a version of the morphed faces task that involved animated faces changing into or away from five target affective states (happy, surprise, sadness, anger, and disgust); they were asked to stop the animation when the face first corresponded to a target state, and rate its emotional intensity. Results demonstrated no differences in animation stop data, but overall lower ratings of perceived emotion intensity during high versus low work rate exercise; these effects dissipated through cool-down and rest periods. Results highlight important interactions between physiological states and processing emotional information.     

Startle modulation in non-incarcerated men and women with psychopathic traits

Past research has demonstrated that individuals with psychopathic characteristics are under-responsive to aversive stimuli, however, much of this work has failed to include non-incarcerated samples, or to examine gender differences in this relationship. Additionally, few studies have examined the role of specific personality characteristics, as they relate to both psychopathic behavior and emotional responsiveness. The current study assessed emotional modulation of the startle response in a community sample of 108 men and women (99 with usable startle data) during perception of emotion-laden photographs. Consistent with previous work, men reporting high levels of psychopathy failed to show the typical increase in the startle response when exposed to aversive photographs, but only when responses were elicited relatively early in picture viewing (i.e., 2.0 s as compared to 4.5 s post-photograph onset). Additionally, both genders showed a significant effect of harm avoidance and anxiety on modulation of the startle response, such that individuals reporting low levels of each trait failed to show significant responses to aversive photographs. These results suggest that while deficits in emotional processing extend to non-incarcerated samples, the relationship may be influenced by additional factors including gender, personality, and attributes related to incarceration.     

Startle modulation in non-incarcerated men and women with psychopathic traits

Past research has demonstrated that individuals with psychopathic characteristics are under-responsive to aversive stimuli, however, much of this work has failed to include non-incarcerated samples, or to examine gender differences in this relationship. Additionally, few studies have examined the role of specific personality characteristics, as they relate to both psychopathic behavior and emotional responsiveness. The current study assessed emotional modulation of the startle response in a community sample of 108 men and women (99 with usable startle data) during perception of emotion-laden photographs. Consistent with previous work, men reporting high levels of psychopathy failed to show the typical increase in the startle response when exposed to aversive photographs, but only when responses were elicited relatively early in picture viewing (i.e., 2.0 s as compared to 4.5 s post-photograph onset). Additionally, both genders showed a significant effect of harm avoidance and anxiety on modulation of the startle response, such that individuals reporting low levels of each trait failed to show significant responses to aversive photographs. These results suggest that while deficits in emotional processing extend to non-incarcerated samples, the relationship may be influenced by additional factors including gender, personality, and attributes related to incarceration.     

Individual differences in emotion elicitation in university examinations: A quasi-experimental study

In a quasi-experimental study, we examined the role of individual differences in the elicitation of emotional states in university examinations. Specifically, we assessed emotional states (a) before the first examination (baseline), (b) after receiving positive or negative feedback, and (c) then, again, before a series of subsequent examinations. We also measured effort in examination preparation and interest for studying. Data were collected during a university course that consisted of seven examinations in one semester; and 94 female students completed the BIS/BAS scales and SPSRQ (to measure sensitivity to punishment, SP, and reward, SR). Results revealed that higher BAS, but not SR, individuals experienced higher positive affect (PA) following positive feedback and they also showed higher levels of interest in studying. More generally, higher BIS and SP individuals experienced higher level of negative affect (NA) and they invested more effort in examination preparation; and both higher levels of SP and SR correlated positively with NA after receiving negative feedback. In addition, following negative feedback, higher BAS individuals experienced lower levels of PA, and higher SR individuals invested less effort in examination preparation. Results are discussed in terms of the reinforcement sensitivity theory (RST) of personality and directions for future research.     

大学生自伤行为的强化敏感性基础

强化敏感性包括惩罚敏感性和奖励敏感性, 它影响个体的情绪、动机和行为过程, 与个体的情绪反应性密切相关。极端的强化敏感性与情绪管理障碍及多种自伤相关行为存在密切联系。为探索强化敏感性与自伤行为的关系, 研究1采用BIS/BAS量表和青少年自我伤害问卷, 对717名大学生进行了调查。研究2在研究1的基础上, 采用Q−任务和CARROT范式, 由127名大学生参加实验, 进一步考察不同功能的自伤行为的强化敏感性基础。结果表明：①惩罚敏感性、奖励敏感性及其愉悦寻求维度均对自伤行为有正向预测作用; ②情绪管理组自伤被试以高惩罚敏感性和接近正常的奖励敏感性为特征, 刺激寻求组自伤被试以高奖励敏感性和接近正常的惩罚敏感性为特征。结论：强化敏感性可有效预测自伤行为; 情绪管理和刺激寻求两种功能的自伤行为具有不同的强化敏感性基础; 对自伤行为进行分类研究十分必要。     

Relating individual differences in internalizing symptoms to emotional attention set-shifting in children

A growing body of evidence points to links between internalizing symptoms and various executive functioning deficits, and especially to inhibition and set-shifting difficulties. However, there is limited developmental research regarding the impact of internalizing symptoms on the shifting function, particularly during middle childhood. The current study investigated attention shifting in a sample of 108 early school age children (7–11 years) using a task-switching paradigm which required participants to alternate between emotional and nonemotional judgments. Results indicated that higher levels of internalizing symptoms (anxiety and depression) had a detrimental effect on performance efficiency (measured by response times) but not on response accuracy. This effect was only observed on emotional (and not on nonemotional) repetition trials and did not affect switching trials; moreover, it was only present when feedback was presented to participants. The findings partially support the predictions of the Attentional Control Theory in a developmental sample and suggest that individual differences in internalizing symptoms play a role in children's ability to flexibly alternate between emotional judgments.     

Negation as a means for emotion regulation? Startle reflex modulation during processing of negated emotional words

This study investigated startle reflex modulation in 33 healthy student participants during the processing of negated emotional items. To build upon previous research, our particular interest was to find out whether processing of negated emotional items modulates emotional responding in line with the logical meaning of the negated expression, or instead leads to paradox emotional effects that point in the direction opposite the one logically implied by the negation. Startle reflex modulation was assessed during silent reading of pleasant and unpleasant nouns. The nouns were either paired with the possessive pronoun my or with the negation word no. The startle eyeblink amplitude was enhanced during processing of the unpleasant pronoun–noun phrases and attenuated during processing of the pleasant phrases. Negation attenuated the startle eyeblink for negated unpleasant nouns and enhanced it for negated pleasant nouns. In line with this finding, negation decreased arousal ratings for unpleasant nouns and reversed the valence ratings for pleasant nouns. Our results are the first to show an effect of negation on both peripheral physiological and subjective indices of affective responding. Our results suggest that negation may be an effective strategy for spontaneous down-regulation of emotional responses to unpleasant, but not to pleasant, stimuli.     

Interactions between emotion regulation strategies and affective style: Implications for trait anxiety versus depressed mood

Affective style reflecting approach and inhibition is thought to be associated in distinct ways with anxious versus depressed mood; relatively few studies, however, consider how the interaction between affective style and the strategies individuals use to regulate mood and emotion might influence these associations. Sixty-seven non-disordered adults self-reported on their use of two emotion regulation strategies (cognitive reappraisal and expressive suppression), behavioral approach (BAS) and behavioral inhibition sensitivity (BIS) dimensions of affective style, and anxious and depressed mood (trait anxiety and symptoms of depression). Trait anxiety versus depressed mood was associated with unique interactive patterns of emotion regulation and affective style: enhanced use of reappraisal was linked to less depressed mood in those reporting low BAS, whereas high suppression was linked to greater trait anxiety in those reporting low BIS. The implications of findings for typical emotional processes and for clinical disorders and interventions are discussed.     

Measuring anxious responses to predictable and unpredictable threat in children and adolescents

Research has highlighted the need for new methods to assess emotions in children on multiple levels to gain better insight into the complex processes of emotional development. The startle reflex is a unique translational tool that has been used to study physiological processes during fear and anxiety in rodents and in human participants. However, it has been challenging to implement developmentally appropriate startle experiments in children. This article describes a procedure that uses predictable and unpredictable aversive events to distinguish between phasic fear and sustained anxiety in children and adolescents. We investigated anxious responses, as measured with the startle reflex, in youths (N = 36, mean age = 12.63 years, range = 7-17) across three conditions: no aversive events (N), predictable aversive events (P), and unpredictable aversive events (U). Short-duration cues were presented several times in each condition. Aversive events were signaled by the cues in the P condition but were presented randomly in the U condition. Participants showed fear-potentiated startle to the threat cue in the P condition. Startle responses were also elevated between cues in the U condition compared with the N condition, suggesting that unpredictable aversive events can evoke a sustained state of anxiety in youths. This latter effect was influenced by sex, being greater in girls than in boys. These findings indicate the feasibility of this experimental induction of the startle reflex in response to predictable and unpredictable events in children and adolescents, enabling future research on interindividual differences in fear and anxiety and their development in youths.     

Personality traits of the behavioural approach and inhibition systems: associations with processing of emotional stimuli

This study examined the relationships of the traits associated with Gray's behavioural approach system (BAS) and behavioural inhibition system (BIS) with cognitive processing of emotional information. Initially, participants completed questionnaires covering trait impulsivity and anxiety, and BAS and BIS sensitivities. They were then tested individually. After completing a questionnaire of current positive and negative moods, they completed three tasks measuring processing of pleasant, unpleasant and neutral information. Consistent with Gray’s theory, the results showed that impulsivity and BAS sensitivity were associated with the processing of pleasant information, while anxiety and BIS sensitivity were associated with the processing of unpleasant information. These findings imply that Gray’s BAS–BIS theory can be extended to cognitive processing of emotional information.     

Emotional avoidance: an experimental test of individual differences and response suppression using biological challenge

The present study examined the affective consequences of response inhibition during a state of anxiety-related physical stress. Forty-eight non-clinical participants were selected on the basis of pre-experimental differences in emotional avoidance (high versus low) and subjected to four inhalations of 20% carbon dioxide-enriched air. Half of the participants were instructed to inhibit the challenge-induced aversive emotional state, whereas the other half was instructed to simply observe their emotional response. Participants high in emotional avoidance compared to those low in emotional avoidance responded with greater levels of anxiety and affective distress but not physiological arousal. Individuals high in emotional avoidance also reported greater levels of anxiety relative to the low emotional avoidance group when suppressing compared to observing bodily sensations. These findings are discussed in terms of the significance of emotional avoidance processes during physical stress, with implications for better understanding the nature of panic disorder.     

The Psychophysiology of Digital Gaming: The Effect of a Non Co-Located Opponent

This article examines the effects of a non co-located opponent on self-reported emotions, psychophysiological responses, and presence experiences during digital game playing. In a within-subjects design, participants played Super Monkey Ball Jr. and Duke Nukem Advance against a computer, a non co-located friend, and a non co-located stranger. In addition to self-report ratings, electromyographic (EMG) activity over zygomaticus major, corrugator supercilii, and orbicularis oculi; cardiac interbeat intervals; and skin conductance level were measured to index positive activation, negative activation, and physiological arousal. When compared to playing against a computer, playing against a human elicited more positive emotional responses and higher arousal, spatial presence, and engagement. In addition, playing against a friend elicited more positive emotional responses (as indexed by facial EMG) and higher self-reported arousal and engagement compared to playing against a stranger. The influence of opponent type on facial EMG responses was dependent on dispositional behavioral activation system (BAS) and behavioral inhibition system (BIS) sensitivities of the player. Orbicularis oculi EMG responses to game violence varied also as a function of the player's impulsivity. These data show that the mere knowledge of who is controlling the opponent character strongly influences emotional and other responses to digital games.     

Application of a behavioral theory of motivation to the concepts of anxiety and impulsivity

Gray's model has been employed in attempts to formulate theories concerning the processes underlying various types of psychopathology. In the most direct application of his model, the dominant mood is assumed to reflect the strength of the underlying motivational system—i.e., strong anxiety with a strong behavioral inhibition system (BIS), strong positive affect with a strong behavioral activation system (BAS). This approach would predict strong anxiety to be associated with a dominance of passive avoidance and extinction and, similarly, strong positive affect with a dominance of impulsivity and other approach behaviors.The present paper has argued that these expectations are based on an implicit assumption that equally stressful environments are encountered—an assumption that would be undermined by individual differences in the very motivational systems under consideration. Examination of the approach-avoidance conflict paradigm supported the argument that, at least in the case of anxiety, one should not expect a strong association between behavior and motivational states. In particular, a weak behavioral inhibition system or strong behavioral activation system is likely to facilitate anxiety-producing impulsive behavior, whereas a strong behavioral inhibition system or weak behavioral activation system may facilitate anxiety-reducing cautious behavior. Other factors were also thought to promote independence of affective states and behavioral traits across individuals.On this argument, trait anxiety conceptualized as resulting from a strong BIS may not be highly correlated with frequent anxiety. Stating this another way, the behavioral correlates of a dominant BIS may be relatively independent of a trait involving a dominance of anxious mood. Using Tellegen's (1985) discussion of self-report measures of mood and personality traits, it was proposed that the trait factor of Constraint may be more strongly associated with behavioral consequences of the BAS and BIS, whereas the Negative Emotionality dimension is largely unrelated to the behavioral effects of the BIS. Since Negative Emotionality corresponds to the traditional anxiety/neuroticism factor, this proposal differs from the customary assumptions about the alignment of Gray's motivational systems and personality traits. The personality trait of Positive Emotionality (cf. extraversion) may be associated with individual differences in the strength of the BAS, with both affective and behavioral components. Thus, the hypothesis of motivational-behavioral uncoupling offers an alternative to the usual intepretations of the three major dimensions seen in most personality inventories. Unfortunately, it remains unclear as to how well the three major personality traits (Positive Emotionality, Negative Emotionality, and Constraint) are aligned with the hypothesized underlying motivational dimensions, and any hypotheses must be seen as extremely tentative.Finally, the question of the validity of self-report measures was discussed briefly. Of greatest interest is the possibility that a subset of subjects are unable to accurately report their emotional states, and that methods are available for identifying these individuals. If so, the validity of these self-report measures may be significantly improved, facilitating research on anxiety and impulsivity.     

Flexible emotional responsiveness in trait resilience

Field studies and laboratory experiments have documented that a key component of resilience is emotional flexibility--the ability to respond flexibly to changing emotional circumstances. In the present study we tested the hypotheses that resilient people exhibit emotional flexibility: (a) in response to frequently changing emotional stimuli and (b) across multiple modalities of emotional responding. As participants viewed a series of emotional pictures, we assessed their self-reported affect, facial muscle activity, and startle reflexes. Higher trait resilience predicted more divergent affective and facial responses (corrugator and zygomatic) to positive versus negative pictures. Thus, compared with their low-resilient counterparts, resilient people appear to be able to more flexibly match their emotional responses to the frequently changing emotional stimuli. Moreover, whereas high-trait-resilient participants exhibited divergent startle responses to positive versus negative pictures regardless of the valence of the preceding trial, low-trait-resilient participants did not exhibit divergent startle responses when the preceding picture was negative. High-trait-resilient individuals, therefore, appear to be better able than are their low-resilient counterparts to either switch or maintain their emotional responses depending on whether the emotional context changes. The present findings broaden our understanding of the mechanisms underlying resilience by demonstrating that resilient people are able to flexibly change their affective and physiological responses to match the demands of frequently changing environmental circumstances.     

Gender differences in the negative affective priming of aggressive behavior

The negative affective priming of aggression was examined across different aversive contexts (general stress exposure and frustration) with a laboratory aggression paradigm that measured the intensity of shocks participants delivered to a putative employee. Participants' emotional responses were gauged via startle eyeblink reactions and self-report mood ratings. Aside from gender differences in overall aggression, men but not women exposed to general stress showed significant increases in aggression across blocks. However, frustration produced increases in aggression in both genders. Although both genders showed robust startle increases during stress, startle activation was related to increases in aggression in men and decreases in aggression in women. These findings suggest that general stress and experiences of negative emotion trigger physical aggressive responses more strongly in men than in women.