High Trait Anxious Individuals Research Articles

Fear-Conditioning Mechanisms Associated with Trait Vulnerability to Anxiety in Humans

SummaryInvestigations of fear conditioning in rodents and humans have illuminated the neural mechanisms underlying cued and contextual fear. A critical question is how personality dimensions such as trait anxiety act through these mechanisms to confer vulnerability to anxiety disorders, and whether humans' ability to overcome acquired fears depends on regulatory skills not characterized in animal models. In a neuroimaging study of fear conditioning in humans, we found evidence for two independent dimensions of neurocognitive function associated with trait vulnerability to anxiety. The first entailed increased amygdala responsivity to phasic fear cues. The second involved impoverished ventral prefrontal cortical (vPFC) recruitment to downregulate both cued and contextual fear prior to omission (extinction) of the aversive unconditioned stimulus. These two dimensions may contribute to symptomatology differences across anxiety disorders; the amygdala mechanism affecting the development of phobic fear and the frontal mechanism influencing the maintenance of both specific fears and generalized anxiety.

Is there a mutual relationship between opposite attentional biases underlying anxiety?

Current models that account for attentional processes in anxiety have proposed that high-trait anxious individuals are characterized by a hypervigilant-avoidant pattern of attentional biases to threat. We adopted a laboratory conditioning procedure to induce concomitant hypervigilance and avoidance to threat, emphasizing a putative relationship between lower-level reactive and upper-level controlled attentional mechanisms as the core account of attentional processes involved in the development and maintenance of anxiety. Eighty high- and low-trait anxious participants underwent Pavlovian conditioning to a human face. Eye tracking was used to monitor attentional changes to the conditioned stimulus (CS+) face and the neutral stimulus (CS-) face, presented at 200, 500, and 800 ms durations. The high-anxious participants developed the expected attentional bias toward the CS+ at 200 ms presentation time and attentional avoidance at 500 and 800 ms durations. Hypervigilance to aversive stimuli at 200 ms and later avoidance to the same stimuli at 500 and 800 ms were associated with higher levels of galvanic skin conductance to the CS+. The low-anxious individuals developed the opposite attentional pattern with an initial tendency to orient attention away from the aversive stimuli in the 200 ms condition and to orient attention toward aversive stimuli in the remaining time. The differential modulation between hypervigilance and avoidance elicited in the two groups by the conditioning procedure suggests that vulnerability to anxiety is characterized by a latent relationship between diverse attentional mechanisms. Within this relationship, hypervigilance and avoidance to threat operate at different stages of information processing suggesting fuzzy boundaries between early reactive and later-strategic processing of threat.

Trait anxiety affects the orofacial nociceptive response in rats

The aims of the present study were to assess the influence of: a) trait anxiety on orofacial pain; and b) orofacial pain on state anxiety. Forty-four rats were initially exposed to the free-exploratory paradigm for the evaluation of their anxiety profiles. In accordance to the parameter "Percentage of time in the novel side", the animals were considered as presenting high or low levels of trait anxiety when presenting values below the 1st quartile, or above the 3rd quartile, respectively. A week later, formalin-1.5% was injected into the upper lip of each animal. The behavioural nociceptive response, characterized by increased orofacial rubbing (OR), was quantified for 30 minutes, as follows: Total time OR (0-30 minutes: total pain), 1st phase OR (0-6 minutes: neurogenic pain), and 2nd phase OR (12-30 minutes: inflammatory pain). Immediately after this test, but still under the effect of formalin, the rats were submitted to the Elevated Plus-maze test (EPM). The results showed that the high trait anxiety individuals presented higher frequency of OR than the low trait anxiety ones, except during the neurogenic pain period. However, no correlation was found between OR frequency and levels of state anxiety presented on the EPM. In conclusion, the animals presenting higher anxiety profiles were the most susceptible to orofacial pain, nevertheless, orofacial pain did not influence state anxiety.

Processing efficiency in anxiety: Evidence from eye-movements during visual search

It is generally held that anxiety is characterized by an attentional bias for threatening information. In recent years there has been an important debate whether these biases reside at the level of attentional selection (threat detection) or attentional processing after threat detection (attentional disengagement). In a visual search task containing emotional facial expressions, eye-movements were examined before and after threat detection in high and low trait anxious individuals to further elucidate the temporal unfolding of attentional bias. Results indicated that high-anxious individuals neither showed facilitated orienting to threat nor impaired disengagement of visual attention from threat. Interestingly, the presence of threat in the visual search display was associated with increased decision times in high-anxious individuals. These results challenge some of the current views on attentional bias to threat but indicate that emotional information reduces processing efficiency in anxiety.

Selective attention for masked and unmasked emotionally toned stimuli: Effects of trait anxiety, state anxiety, and test order

We investigated selective attention for masked and unmasked, threat, and positively valenced words, in high trait anxious (HTA) and low trait anxious (LTA) individuals using the emotional Stroop colour-naming task. State anxiety was varied within participants through the threat of electric shock. To investigate whether the sequencing of the state anxiety manipulation affected colour-naming latencies, the ordering of the shock threat and shock safe conditions was counterbalanced across participants. The results indicated that the ordering of the state anxiety manipulation moderated masked and unmasked threat bias effects. Specifically, relative to LTA individuals, HTA individuals showed a threat interference effect, but this effect was limited to those who performed under the threat of shock in the later stages of the experiment. Irrespective of exposure mode and state anxiety status, all individuals showed interference for threat in the early stages of the experiment, relative to a threat facilitation effect in the later stages of the experiment. For the unmasked trials alone, the data also revealed a significant threat interference effect for the HTA group relative to the LTA group in the shock threat condition, and this effect was evident irrespective of shock threat order. The results are discussed with respect to the automatic nature of emotional processing in anxiety.

Effects of an acute α-lactalbumin manipulation on mood and food hedonics in high- and low-trait anxiety individuals

Serotonergic hypofunction is associated with a depressive mood state, an increased drive to eat and preference for sweet (SW) foods. High-trait anxiety individuals are characterised by a functional shortage of serotonin during stress, which in turn increases their susceptibility to experience a negative mood and an increased drive for SW foods. The present study examined whether an acute dietary manipulation, intended to increase circulating serotonin levels, alleviated the detrimental effects of a stress-inducing task on subjective appetite and mood sensations, and preference for SW foods in high-trait anxiety individuals. Thirteen high- (eleven females and two males; anxiety scores 45.5 (sd 5.9); BMI 22.9 (sd 3.0)kg/m(2)) and twelve low- (ten females and two males; anxiety scores 30.4 (sd 4.8); BMI 23.4 (sd 2.5) kg/m(2)) trait anxiety individuals participated in a placebo-controlled, two-way crossover design. Participants were provided with 40 g alpha-lactalbumin (LAC; l-tryptophan (Trp):large neutral amino acids (LNAA) ratio of 7.6) and 40 g casein (placebo) (Trp:LNAA ratio of 4.0) in the form of a snack and lunch on two test days. On both the test days, participants completed a stress-inducing task 2 h after the lunch. Mood and appetite were assessed using visual analogue scales. Changes in food hedonics for different taste and nutrient combinations were assessed using a computer task. The results demonstrated that the LAC manipulation did not exert any immediate effects on mood or appetite. However, LAC did have an effect on food hedonics in individuals with high-trait anxiety after acute stress. These individuals expressed a lower liking (P = 0.012) and SW food preference (P = 0.014) after the stressful task when supplemented with LAC.

Anxiety and feedback negativity

It has been suggested that anxious individuals are more prone to feel that negative outcomes are particularly extreme and to interpret ambiguous outcomes as negative compared to nonanxious individuals. Previous studies have demonstrated that the feedback negativity (FN) component of event-related brain potential (ERP) is sensitive to outcome evaluation and outcome expectancy. Hence, we predicted that the FN should be different between high trait-anxiety (HTA) and low trait-anxiety (LTA) individuals. To test our hypothesis, the ERPs were recorded during a simple monetary gambling task. The FN was measured as a difference wave created across conditions. We found that the amplitude of the FN indicating negative versus positive outcomes was significantly larger for LTA individuals compared to HTA individuals. However, there was no significant difference in the FN between groups in response to ambiguous versus positive outcomes. The results indicate that there is a relationship between the FN and individual differences in anxiety. We suggest that these results reflect the impact of anxiety on outcome expectation. Our results challenge the reinforcement learning theory of error-related negativity, which proposes that ERN and FN reflect the same cognitive process.

Selective attention for masked and unmasked threatening words in anxiety: Effects of trait anxiety, state anxiety and awareness

We investigated the effects of awareness on selective attention for masked and unmasked verbal threat material using a computerised version of the emotional Stroop. Participants were assigned to the high trait anxious (HTA) and low trait anxious (LTA) groups on the basis of questionnaire scores, and state anxiety was manipulated within participants through the threat of electric shock. To investigate the effects of awareness on responses to threat, the mode of exposure was blocked such that half the participants received masked trials before the unmasked trials, whereas the other half received the reverse order. The results revealed that there was no difference between the HTA and LTA groups in responses to threat for those who received the masked trials before the unmasked trials. However, when unmasked trials were presented before the masked trials HTA individuals were significantly slower to respond to both masked and unmasked threat words compared to the LTA group, and these effects were not further modified by participants' state anxiety status. The results are discussed in terms of the automatic nature of threat processing in anxiety.

An electrophysiological investigation into the automaticity of emotional face processing in high versus low trait anxious individuals

To examine the extent of automaticity of emotional face processing in high versus low trait anxious participants, event-related potentials (ERPs) were recorded to emotional (fearful, happy) and neutral faces under varying task demands (low load, high load). Results showed that perceptual encoding of emotional faces, as reflected in P1 and early posterior negativity components, was unaffected by the availability of processing resources. In contrast, the postperceptual registration and storage of emotion-related information, as reflected in the late positive potential component at frontal locations, was influenced by the availability of processing resources, and this effect was further modulated by level of trait anxiety. Specifically, frontal ERP augmentations to emotional faces were eliminated in the more demanding task for low trait anxious participants, whereas ERP enhancements to emotional faces were unaffected by task load in high trait anxious participants. This result suggests greater automaticity in processing affective information in high trait anxious participants.

Reduced recollective memory about negative items in high trait anxiety individuals: An ERP study

The present study investigated whether trait anxiety reduce the contribution of episodic retrieval to recognizing negative words. Behavioral and electrophysiological responses in anxious individuals were measured during an exclusion recognition task to compare with a previous report about control participants (Inaba et al., 2007). At test, participants were asked to respond “old” when an item had been included in a target study list. According to the process-dissociation framework, the difference in the waveforms for the “old” responses between target and non-target items is considered to be a measurement of recollection. It was shown to be the difference in the slow waves. As with the behavioral estimate of recollection, the difference in the slow waves at left-parietal area was smaller for negative items compared to other items in the anxiety group. This result was in contrast to a greater difference in the slow positivity for negative words in the control group. These findings suggest that excess old judgments for negative items in the anxious group might be associated with less recollective memory.

Regulation of negative emotions in high trait anxious individuals: An ERP study.

Literature has shown that failures in the ability to down-regulate negative emotions are the core substrate of anxiety disorders. Previous studies have investigated this issue by encouraging individuals to voluntarily change how they think about a situation in order to decrease its emotional impact. The majority of studies has demonstrated that explicit instructions to reduce negative affect in anxious individuals are usually ineffective. Thus, the goal of the present study was to investigate whether an implicit regulation strategy would modulate electrophysiological activity (Late Positive Potential) associated to affective picture viewing. The Late Positive Potential (LPP) is a sustained positive deflection in the event-related potential that is larger following the presentation of emotional compared to neutral visual stimuli. Participants (low trait anxious - LTA and high trait anxious - HTA individuals) performed an attention task (bar orientation discrimination) while emotional distractive pictures were presented. The task was performed in two different contexts: in the Real context, participants were informed that the distractive pictures had been obtained from real life situations, whereas in the Fictitious context they were told that the pictures had been obtained from movie scenes. In this vein, we encouraged participants to change how they appraised the pictures. Results showed that HTA individuals exhibited larger Late Positive Potential (LPPs) when mutilation pictures were presented in the Real context. Importantly, during the Fictitious one (regulation strategy) the LPP was reduced even in HTA individuals, emphasizing its importance to psychotherapeutic interventions. The present results indicate that HTA individuals are susceptible to modifications in affective contexts.

Trait anxiety and impoverished prefrontal control of attention

Many neurocognitive models of anxiety emphasize the importance of a hyper-responsive threat-detection system centered on the amygdala, with recent accounts incorporating a role for prefrontal mechanisms in regulating attention to threat. Here we investigated whether trait anxiety is associated with a much broader dysregulation of attentional control. Volunteers performed a response-conflict task under conditions that posed high or low demands on attention. High trait-anxious individuals showed reduced prefrontal activity and slower target identification in response to processing competition when the task did not fully occupy attentional resources. The relationship between trait anxiety and prefrontal recruitment remained after controlling for state anxiety. These findings indicate that trait anxiety is linked to impoverished recruitment of prefrontal attentional control mechanisms to inhibit distractor processing even when threat-related stimuli are absent. Notably, this deficit was observed when ongoing task-related demands on attention were low, potentially explaining the day-to-day difficulties in concentration that are associated with clinical anxiety.

Attentional Bias of High Trait Anxious Individuals

Previous literatures demonstrate that clinically anxious patients are very sensitive to threatening stimuli.Further,it is easier for them to be engaged in threatening stimuli,after which they find it hard to shift their attention to other kinds of stimuli in the situation.However,not many studies have been conducted to demonstrate the attentional bias of high trait anxious(HTA)individuals,which was the subject of the present study.Are these individuals more sensitive to threat? Is it easy for them to be engaged in threat,and is it hard to distract their attention? What is the underlying mechanism in such cases of attentional bias? Two experiments were designed according to the paradigm "odd-one-out search task" to test whether HTA individuals are more vigilant to threats or whether it is hard to distract their attention from the threat.In experiment 1,20 HTA individuals and 20 low trait anxious(LTA)individuals selected from among 400 college students by using the Chinese version of the State-Trait Anxiety Inventory(STAI-T)1983,developed by Spielberger et al.They participated in the test under peaceful conditions(no anxiety-eliciting task).The participants were asked to ascertain whether there was any different face in the square containing 12 faces as soon as possible.In order to test attentional sensitivity to threatening(or unthreatening)stimuli,the participants were required to discriminate an angry face(or a happy face)from among 12 faces in a square(1 emotional face with 11 neutral faces).In order to test attentional distraction from threatening(or unthreatening)stimuli,the participants were required to discriminate a neutral face from among 12 faces in a square(1 neutral face with 11 angry or happy faces).The experiment measured the time of judgment and emotional change in the meanwhile.In experiment 2,19 HTA and 19 LTA participants selected from among 300 college students by using the STAI-T were tested through the "odd-one-out search task" after an anxiety-eliciting task.The results revealed the following.(1)Under peaceful conditions,both the HTA and LTA groups were found to be more susceptible to a happy face than to an angry face.It was difficult to distract both groups from angry faces.However,as compared to the LTA group,it was more difficult to disengage the attention of the HTA group from angry faces.(2)It was more difficult to disengage the HTA group's attention from the angry faces than from happy faces when they were in highly anxious mood.On the other hand,it was harder to disengage the attention of the LTA group from the happy faces than from the anger faces.There was no significant difference in the HTA group's attentional sensitivity to happy and angry faces;meanwhile,the LTA group was more sensitive to happy face than to anger face.It can be concluded that HTA individuals were not particularly attention-sensitive to threatening stimulus,but they were much more difficult to disengage their attention from threatening stimuli.Meanwhile,the LTA individuals were more attention-sensitive to pleasant stimuli and were easily engaged in pleasant stimuli.The study further suggested that a higher degree of anxiety and the fact that is easier to elicit an anxious mood in HTA subjects would play a key role in the attentional bias.

Trait anxiety and reasoning under uncertainty

We explored the relationship between trait anxiety and reasoning under conditions of uncertainty. In our opinion, high trait anxious individuals (HTA) could have an implicit goal of uncertainty reduction. According to this, we predicted that in reasoning tasks HTA individuals would try to shorten the length of uncertain states by gathering less evidence prior to deciding, compared to low trait anxious ones (LTA). In Study 1 we employed several probabilistic reasoning tasks to examine the amount of data requested before making a decision. In Study 2, we investigated how evidence is weighed up and how hypotheses are tested. Results confirmed our prediction: HTA individuals gathered fewer pieces of evidence, thus jumping to conclusions, compared to LTA individuals. Groups did not differ in their reasoning if evidence was at their disposal from the start. Furthermore, the HTA group jumped to conclusions and provided incorrect answers in the hypothesis-testing task. We suggest that HTA individuals are particularly concerned with reducing uncertainty, even at the expense of correctness.

The role of effort in moderating the anxiety – performance relationship: Testing the prediction of processing efficiency theory in simulated rally driving

We tested some of the key predictions of processing efficiency theory using a simulated rally driving task. Two groups of participants were classified as either dispositionally high or low anxious based on trait anxiety scores and trained on a simulated driving task. Participants then raced individually on two similar courses under counterbalanced experimental conditions designed to manipulate the level of anxiety experienced. The effort exerted on the driving tasks was assessed though self-report (RSME), psychophysiological measures (pupil dilation) and visual gaze data. Efficiency was measured in terms of efficiency of visual processing (search rate) and driving control (variability of wheel and accelerator pedal) indices. Driving performance was measured as the time taken to complete the course. As predicted, increased anxiety had a negative effect on processing efficiency as indexed by the self-report, pupillary response and variability of gaze data. Predicted differences due to dispositional levels of anxiety were also found in the driving control and effort data. Although both groups of drivers performed worse under the threatening condition, the performance of the high trait anxious individuals was affected to a greater extent by the anxiety manipulation than the performance of the low trait anxious drivers. The findings suggest that processing efficiency theory holds promise as a theoretical framework for examining the relationship between anxiety and performance in sport.

Attention to Threat in Anxiety-prone Individuals: Mechanisms Underlying Attentional Bias

Cognitive views on anxiety have proposed that attentional biases towards threatening information in high trait anxious individuals play an important role in the maintenance of anxiety and may even cause the development of clinical anxiety disorders. However, the precise nature of these attentional biases is under debate. In a pictorial version of the dot probe task, two accounts of attention to threat were contrasted and the components of attention involved in orienting to threat were assessed. Overall, the results support the view that all individuals orient to highly threatening pictures, with high trait anxious individuals orienting more strongly to moderately threatening pictures than the low trait anxious individuals. Attentional bias to threat in high trait anxious individuals was caused by attentional disengagement from threat. These results are discussed in relation to cognitive models of attention to threat.

The interactive role of worried mood and trait anxiety in the selective processing of subliminally presented threat words

The purpose of the present study was threefold: (a) to replicate the finding by MacLeod and Rutherford (1992) that low trait-anxious individuals, in contrast to high trait-anxious individuals, show a selective attention away from subliminally presented threat words at elevated levels of stress; (b) to test the hypothesis that this effect is due to individuals with repressive coping-style rather than true low trait-anxious individuals; and (c) to study the stability of Stroop interference over time. Both social threat and physical threat words were used. Although some support was found for the first hypothesis, there was no evidence that this effect was due to individuals with repressive coping-style. Finally, Stroop interference showed very little test–retest stability from the first to the second testing session, indicating that it is heavily influenced by temporary cognitive-emotional states, and that it should not be treated as a trait variable. Unexpectedly, high defensiveness predicted a decrease in worried mood from session 1 to session 2.

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.

Repeating the stimulus exposure to investigate what happens after initial selective attention to threatening pictures

This study investigated whether individuals with a high trait anxiety (HTA) rating retain attentional bias towards threatening pictures when such pictures are repeatedly presented. Subjects rated high ( n = 20) and low ( n = 20) on an anxiety scale participated in a forced-choice reaction time version of a modified dot-probe task. Picture pairs were presented in four exposure blocks. On each exposure, the attentional bias to the threatening pictures was measured. HTA individuals showed more selective attention to the high threatening pictures than individuals with low trait anxiety (LTA). However, HTA individuals did not maintain attentional bias. On the fourth block, the attentional bias to threatening pictures disappeared. Theoretical and methodological implications of these findings are discussed.

The effects of acute psychological stress on immune function in college students with different trait-anxiety

目的 探讨急性心理应激对不同特质焦虑大学生免疫功能的影响.方法用状态-特质焦虑问卷(STAI)对120名大学生自愿者进行测试,筛选出高、低焦虑组各22名,再对高、低焦虑组随机分为应激组和对照组;应激后用放射免疫法测定其血清白介素-2、白介素-6和皮质醇的含量.结果高、低焦虑组大学生血清中皮质醇浓度应激组[分别为(203.69±29.60)μg/L,(244.57±53.96)μg/L]高于对照组[分别为(164.60±49.77)μg/L,(131.71±56.85)μg/L](P＜0.05,P＜0.01).高焦虑组大学生血清中白介素-2、白介素-6浓度应激组[分别为(1.35±0.29)μg/L,(154.95±32.23)ng/L]低于对照组[分别为(2.65±0.82)μg/L,(204.33±58.57)μg/L](P＜0.01,P＜0.05);低焦虑组大学生血清中白介素-2的浓度应激组(1.83±0.53)μg/L低于对照组(2.81±1.23)μg/L(P＜0.05).结论急性心理应激对高焦虑组个体血清白介素-2、白介素-6浓度变化的影响较低焦虑个体大,特质焦虑人格是影响急性心理应激导致免疫功能改变的因素之一。