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.     

Anxiety and defensiveness: individual differences in affective startle modulation

Anxious individuals selectively attend to threatening information, and defensiveness may influence the experience and expression of anxiety. Fifty-eight undergraduates scoring high and low on measures of anxiety and defensiveness viewed pleasant, neutral, and unpleasant pictures. Acoustic startle probes were presented 60, 240, or 2,000 ms after picture onset. At 60 ms and 240 ms, repressors (low anxiety, high defensiveness) showed weaker blinks during both pleasant and unpleasant compared to neutral pictures, suggesting enhanced early attention to affective stimuli, regardless of valence. At 2,000 ms, high-anxious but not low anxious participants showed potentiated startle responses during unpleasant compared to pleasant pictures. Although this result replicated previous research on anxiety and valence modulation of startle, exploratory analyses suggested that the valence effect was restricted to trait anxious individuals tending toward a defensive coping style. Across probe conditions, defensiveness was associated with heightened startle reactivity independent of self-reported anxiety and foreground stimulus characteristics.

Personality and modulation of the startle reflex by emotionally-toned filmclips

Several researchers have found that pleasant foreground stimuli attenuate the eyeblink component of the startle reflex while unpleasant foreground stimuli potentiate it. The effects of personality factors on such modulation of the eyeblink response, as measured by electromyographic (EMG) activity in reaction to loud acoustic startle probes, were examined in subjects viewing emotionally-toned (pleasant, unpleasant and neutral) filmclips. During the main part of the experiment, introverts had higher baseline EMG activity and lower response probability than extraverts; no differences were observed at the beginning of the experiment, during an acclimatization session. Reflex modulation, as measured by response latency, was influenced by the Psychoticism (P) factor of the Eysenck Personality Questionnaire: subjects high on P showed longer latencies to eyeblink onset when probed during viewing of pleasant filmclips than subjects low on this dimension; no significant differences were observed between subjects low and high on P for neutral and unpleasant filmclips. No influence of personality factors was found on affective modulation as measured by response amplitude/magnitude. The results are discussed in relation to Gray's and Eysenck's theories of personality.     

Trait emotions and affective modulation of the startle eyeblink: on the unique relationship of trait anger

We examined relationships among individual differences in trait emotions and the emotion-modulated startle-eyeblink response. In particular, we examined the extent to which trait anger, which is negative in valence, would be associated with a pattern of approach motivation in startle eyeblink responses to appetitive stimuli. Self-reported trait emotions were compared with emotion-modulated startle eyeblink responses to auditory probes during appetitive, aversive, and neutral pictures. Results revealed that trait anger, enjoyment, and surprise were each associated with greater blink inhibition to appetitive pictures, indicating an approach motivational response. No other trait emotions were associated with startle eyeblink responses to appetitive or aversive pictures. These results support the idea that trait anger, although experienced as a negative emotion, is associated with an approach-related motivational response to appetitive stimuli at basic, reflexive levels of processing.     

Spectral frequency and the modulation of the acoustic startle reflex by background noise

The rat's (Long-Evans) acoustic startle reflex to a high-frequency tone burst (10.5 kHz) was depressed by intense high-frequency band-pass noise (8-16 kHz) but enhanced by low frequency noise (1-2 kHz). However, contrary to the hypothesis that the depression of startle in intense background noise is produced by sensory masking, the reflex to a low-frequency tone burst (at 1 kHz) was depressed by both high- and low-frequency band-pass noise. Two additional hypotheses are offered to supplement sensory masking in order to explain the asymmetry in these data. The first is that the intratympanic reflex, which acts as a high pass filter on acoustic input, is elicited in intense backgrounds. The second is that acoustic startle reflexes elicited by intense low-frequency tones are in part elicited by their high-frequency distortion products and that these distortion products are then masked by high-frequency background noise.     

Reliving emotional personal memories: affective biases linked to personality and sex-related differences

Although available evidence suggests that the emotional valence and recollective properties of autobiographical memories (AMs) may be influenced by personality- and sex-related differences, overall these relationships remain poorly understood. The present study investigated these issues by comparing the effect of general personality traits (extraversion and neuroticism) and specific traits linked to emotion regulation (ER) strategies (reappraisal and suppression) on the retrieval of emotional AMs and on the associated postretrieval emotional states, in men and women. First, extraversion predicted recollection of positive AMs in both men and women, whereas neuroticism predicted the proportion of negative AMs in men and the frequency of rehearsing negative AMs in women. Second, reappraisal predicted positive AMs in men, and suppression predicted negative AMs in women. Third, while reliving of positive memories had an overall indirect effect on postretrieval positive mood through extraversion, reliving of negative AMs had a direct effect on postretrieval negative mood, which was linked to inefficient engagement of suppression in women. Our findings suggest that personality traits associated with positive affect predict recollection of positive AMs and maintenance of a positive mood, whereas personality traits associated with negative affect, along with differential engagement of habitual ER strategies in men and women, predict sex-related differences in the recollection and experiencing of negative AMs. These findings provide insight into the factors that influence affective biases in reliving AMs, and into their possible link to sex-related differences in the susceptibility to affective disorders.     

Individual differences in the activation and control of affective race bias as assessed by startle eyeblink response and self-report

The activation and control of affective race bias were measured using startle eyeblink responses (Study 1) and self-reports (Study 2) as White American participants viewed White and Black faces. Individual differences in levels of bias were predicted using E. A. Plant and P. G. Devine's (1998) Internal and External Motivation to Respond Without Prejudice scales (IMS/EMS). Among high-IMS participants, those low in EMS exhibited less affective race bias in their blink responses than other participants. In contrast, both groups of high-IMS participants exhibited less affective race bias in self-reported responses compared with low-IMS participants. Results demonstrate individual differences in implicit affective race bias and suggest that controlled, belief-based processes are more effectively implemented in deliberative responses (e.g., self-reports).     

Gratitude in intermediate affective terrain: links of grateful moods to individual differences and daily emotional experience

Two studies were conducted to explore gratitude in daily mood and the relationships among various affective manifestations of gratitude. In Study 1, spiritual transcendence and a variety of positive affective traits were related to higher mean levels of gratitude across 21 days. Study 2 replicated these findings and revealed that on days when people had more grateful moods than was typical for them, they also reported more frequent daily episodes of grateful emotions, more intense gratitude per episode, and more people to whom they were grateful than was typical for them. In addition, gratitude as an affective trait appeared to render participants' grateful moods somewhat resistant to the effects of discrete emotional episodes of gratitude.     

Gender differences in implicit and explicit processing of emotional facial expressions as revealed by event-related theta synchronization

Emotion information processing may occur in 2 modes that are differently represented in conscious awareness. Fast online processing involves coarse-grained analysis of salient features and is not represented in conscious awareness; offline processing takes hundreds of milliseconds to generate fine-grained analysis and is represented in conscious awareness. These processing modes may be studied using event-related electroencephalogram theta synchronization as a marker of emotion processing. Two experiments were conducted that differed on the mode of emotional information presentation. In the explicit mode, subjects were explicitly instructed to evaluate the emotional content of presented stimuli; in the implicit mode, their attention was directed to other features of the stimulus. In the implicit mode, theta synchronization was most pronounced in the early processing stage, whereas in the explicit mode, it was more pronounced in the late processing stage. The early processing stage was more pronounced in men, whereas the late processing stage was more pronounced in women. Implications of these gender differences in emotion processing for well-documented differences in social behavior are discussed.     

Individual differences in hedonic capacity,depressed mood,and affective states predict emotional reactivity

Identifying factors that contribute to inter-individual differences in emotional reactivity is central to understanding the basic mechanisms that give rise to adaptive emotion reactivity and to disruptions that may occur in psychopathology. The current study related emotional reactivity in an unselected young adult sample (N?=?101) to individual difference factors relevant to emotional functioning and mood pathology, specifically anhedonia, depressed mood, and current affective state. To assess emotional reactivity, participants rated their emotional responses to 100 pictures from the International Affective Picture System. Increased self-reported anhedonia (i.e. reduced hedonic capacity) predicted blunted emotional reactivity to both positive and negative images, relative to neutral images, while elevated depressed mood predicted potentiated emotional reactivity to negative vs. neutral images. Anhedonia also accounted for far greater variance in emotional reactivity than depressed mood. Further, more positive affective state predicted potentiated reactivity to positive versus neutral images while more negative affective state predicted potentiated reactivity to negative versus neutral images beyond effects of anhedonia and depressed mood. The current study identified separable effects of anhedonia, depressed mood, and current affect on emotional reactivity.     

Processing deceptive information in sports: Individual differences for responding to head fakes depends on the attentional capability of the observer

In team sports, players sometimes try to deceive their opponents by providing misleading information in order to gain a temporal advantage. Head-fakes are often applied when a player gazes in one direction, while passing/shooting the ball in another direction. The opponent is challenged to focus attention on the relevant information (i.e., pass direction), while ignoring the conflicting information (i.e., gaze direction). The present study aimed to identify the link between attentional capabilities and the effectiveness of head fakes. Twenty-seven novices performed in a basketball-specific head-fake task and in the attention-window task. A correlation between performances in both tasks revealed that participants with higher attentional capabilities were better able to focus their attention on the relevant feature (pass direction), when judging basketball situations, than participants with lower attentional capabilities. The results emphasize the relevance of high attentional capabilities in team sports and indicate that focusing one’s attention to the pass direction poses a possibility of reducing the effects of head fakes.     

Mood-induced shifts in attentional bias to emotional information predict ill- and well-being

Previous research has suggested that biased attention toward emotional (typically threatening) stimuli contributes to ill-being (e.g., high levels of anxiety), but its contribution to well-being is less clear. The researchers assessed naturalistic shifts in attentional bias toward threatening and pleasant schematic face cues in response to five induced mood states in college students. They also assessed state anxiety and satisfaction with life concurrently and 3 weeks later. Controlling for concurrent anxiety, a fear-induced shift in attention to threatening cues was associated with increased levels of later anxiety. Controlling for concurrent life satisfaction, a happiness-induced shift in attention to emotional cues (both threatening and pleasant) was associated with increased levels of later life satisfaction. These results suggest that mood-induced changes in deployment of attention to emotional information may accumulate in ways that impact psychological functioning, yet these effects depend on mood state and the emotional cues afforded by the context.     

Components of attentional bias to threat in high trait anxiety: Facilitated engagement, impaired disengagement, and attentional avoidance

There is a wealth of evidence demonstrating enhanced attention to threat in high trait anxious individuals (HTA) compared with low trait anxious individuals (LTA). In two experiments, we investigated whether this attentional bias is related to facilitated attentional engagement to threat or difficulties disengaging attention from threat. HTA and LTA undergraduates performed a modified exogenous cueing task, in which the location of a target was correctly or incorrectly cued by neutral, highly and mildly threatening pictures. Results indicate that at 100 ms picture presentation, HTA individuals more strongly engaged their attention with and showed impaired disengagement from highly threatening pictures than LTA individuals. In addition, HTA individuals showed a stronger tendency to attentional avoidance of threat at the 200 and 500 ms picture presentation. These data provide evidence for differential patterns of anxiety-related biases in attentive processing of threat at early versus later stages of information processing.     

Personal and cultural differences in responding to criticism in three countries

The present study investigated whether verbal aggression, argument approach, argument avoidance or assertiveness had any effect on how participants in three countries responded to criticism. Consistent with the first hypothesis, men were significantly more aggressive, assertive, less avoidant, and approached argument more than women. However, men did not respond more assertively to criticism. As predicted in the second hypothesis, US Americans responded more assertively to criticism than did Japanese and Chinese. The third hypothesis predicted that verbal aggression, argument approach, argument avoidance and assertiveness would be associated with a more assertive response to criticism. The data obtained were only partially consistent with the third hypothesis. While only a small number of participants in this study indicated that they would respond to criticism with silence, US Americans used silence to mean anger while for Chinese silence showed personal embarrassment. Very few Japanese selected silence as an option for responding to a neighbor's criticism. The implications of these results are discussed.     

Individual differences in emotional reactivity moderate the strength of the relationship between attentional and implicit-memory biases towards threat-related stimuli

The study investigated whether the strength of the relationship between attentional and implicit-memory biases for threat-related material can be moderated by individual differences in temperament and personality. A spatial cueing task, where task-irrelevant angry, happy, and neutral faces acted as spatial cues preceding a target, was immediately followed by an unexpected “old/new” task involving previously presented faces. Temperament-based emotional reactivity (ER; one's typical response strength to emotional stimuli) predicted improved memory performance for angry faces in the “old/new” task. Critically, the relationship between the attentional bias towards threat (indexed by a cue validity index, i.e., a difference in response times on trials where cues with angry expression were presented in the same versus different location to the subsequent target) and enhanced implicit-memory for previously presented task-irrelevant threat-related information was found to be moderated by ER. The current findings provide the first evidence that temperament traits can offer novel insights into the mechanisms enhancing cognitive biases towards threat in the typical population.     

The role of extinction and reinstatement in attentional bias to threat: a conditioning approach

We investigated the effects of extinction and reinstatement on attentional bias to fear-conditioned signals in healthy individuals using an emotional modification of a spatial cueing paradigm. Spatial cues were emotionally modulated using differential conditioning. The CS+ was sometimes followed by an aversive electrocutaneous stimulus (UCS), whereas the CS- was never followed by the UCS. During a subsequent extinction phase no UCS was presented anymore. The reinstatement phase started with one or four unpredicted UCS-only trials for half of the participants (reinstatement group). For the other half there were no additional UCS presentations (control group). We found that attention was biased to threat signals during acquisition. This biased attention largely disappeared during extinction. During the reinstatement phase attentional bias to threat signals re-emerged in the reinstatement group, but not in the control group.     

Hemispheric differences in split-brain monkeys viewing and responding to videotape recordings

Eight split-brain monkeys were tested for hemispheric differences in their viewing of and responses to colored videotape recordings of monkeys, people, animals, and scenery. The number of facial expressions elicited from the right hemisphere was significantly greater than the number made when using the left hemisphere. Monkeys also tended to look longer when viewing with their right hemispheres than when viewing with the left.