High trait anxiety in healthy subjects is associated with low neuroendocrine activity during psychosocial stress

Altered stress responsiveness has been repeatedly related to mood and anxiety disorders. In a traditional view, a reduction of the stress response has been thought favorable. The goal of the present study was to verify the hypothesis that high anxiety is accompanied by enhanced hormone release during stress. Healthy subjects at the upper (anxious, n=15) and lower (non-anxious, n=12) limits of the normal range of a trait anxiety scale (State trait anxiety inventory) were exposed to psychosocial stress procedure based on public speech. Hormone levels, cardiovascular activation and skin conductance were measured. Exposure to psychosocial stress was associated with significant increases of all parameters measured. During the stress procedure, subjects with high trait anxiety exhibited lower levels of hormones of the hypothalamo–pituitary–adrenocortical axis, namely ACTH and cortisol in plasma, as well as cortisol in saliva. Similarly, the stress-induced activation of epinephrine, norepinephrine and prolactin secretion was significantly lower in anxious subjects in comparison with that in non-anxious subjects. Thus, in contrast to the traditional view, high anxiousness was not associated with exaggerated stress response. Our findings suggest that high trait anxiety may be associated with an inability to respond with adequate hormone release to acute stress stimuli.     

Saliva cortisol responses to unpleasant film stimuli differ between high and low trait anxious subjects.

The present study, which aims to investigate effects of low and high trait anxiety on saliva cortisol secretion, was performed on 64 healthy male volunteers. They were assigned either to an unpleasant or a control film. Furthermore, subjects were divided within each film group by median split of their anxiety ratings into high and low trait anxious groups, resulting in four equal-sized groups. Saliva cortisol and mood ratings were the dependent variables. In contrast to the low anxious, the high anxious subjects responded with a diminished saliva cortisol response.     

The role of trait anxiety in the recognition of emotional facial expressions

Previous work has suggested that elevated levels of trait anxiety are associated with an increased ability to accurately recognize the facial expression of fear. However, to date, recognition has only been assessed after viewing periods of 10s, despite the fact that the process of emotion recognition from faces typically takes a fraction of this time. The current study required participants with either high or low levels of non-clinical trait anxiety to make speeded emotional classification judgments to a series of facial expressions drawn from seven emotional categories. Following previous work it was predicted that recognition of fearful facial expressions would be more accurate in the high-trait anxious group compared with the low-trait anxious group. However, contrary to this prediction, no anxiety-related differences in emotion perception were observed across all seven emotions. This suggests that anxiety does not influence the perception of fear as has been previously proposed.     

Neuroendocrine responses to psychological stress in adolescents with anxiety disorder

Neurotransmitter-neuroendocrine and cardiovascular responses to the administration of a psychologically stressful mixed-model test (Mental Arithmetic, Stroop Color Word Interference Task, Trier Social Stress Test) were examined in 20 male peripubertal subjects affected by anxiety disorder (group A: 14 with generalized anxiety disorder, 6 with generalized anxiety disorder and separation anxiety disorder) and 20 junior school adolescents, matched for age, without overt psychological disorders (group B). Plasma levels of norepinephrine (NE), epinephrine (EPI), adrenocorticotropic hormone (ACTH), beta-endorphin (beta-EP), cortisol (CORT), growth hormone (GH), prolactin (PRL) and testosterone (Te) were measured immediately before the beginning of the tests and 30 min later at their end. Mean prestress values of GH, PRL, beta-EP and ACTH were significantly higher in anxious subjects than in controls. There was no difference in NE, EPI, CORT and Te prestress levels in the two groups. After the psychological stress session NE, GH and Te concentrations increased significantly in anxious subjects (A), but not in controls. In contrast, beta-EP and PRL decreased significantly during the psychological stress session in anxious subjects, and were unaffected by stress in the subjects without anxiety. No significant changes were found in ACTH, CORT and EPI during the challenge either in anxious subjects or in controls, which may be attributed to the late time of poststress blood sampling. In contrast to controls, heart rate and systolic blood pressure increased significantly in anxious subjects after psychological stress testing. Our data support the hypothesis that the hyperactivity of the noradrenergic system in response to stress is associated with anxiety disorders in adolescents and might influence the responses of GH and Te. High prestress basal values of stress hormones seem to be induced in anxious subjects by the anticipation of the task or by a persistent hyperactivity of the noradrenergic system. Further studies are needed to investigate in more detail the involvement of the HPA axis in anxious adolescents by a more refined resolution of time points of blood sampling.     

Mediators of the relationship between social anxiety and post-event rumination

A variety of cognitive and attentional factors are hypothesised to be associated with post-event rumination, a key construct that has been proposed to contribute to the maintenance of social anxiety disorder (SAD). The present study aimed to explore factors contributing to post-event rumination following delivery of a speech in a clinical population. 121 participants with SAD completed measures of trait social anxiety a week before they undertook a speech task. After the speech, participants answered several questionnaires assessing their state anxiety, self-evaluation of performance, perceived focus of attention and probability and cost of expected negative evaluation. One-week later, participants completed measures of negative rumination experienced over the week. Results showed two pathways leading to post-event rumination: (1) a direct path from trait social anxiety to post-event rumination and (2) indirect paths from trait social anxiety to post-event rumination via its relationships with inappropriate attentional focus and self-evaluation of performance. The results suggest that post event rumination is at least partly predicted by the extent to which socially anxious individuals negatively perceive their own performance and their allocation of attentional resources to this negative self-image. Current findings support the key relationships among cognitive processes proposed by cognitive models.     

Brain response to unexpected novel noises in children with low and high trait anxiety

The behavioral inhibition system [Gray, J. A. The neuropsychology of anxiety: An enquiry into the functions of the septo-hippocampal system. Oxford: Oxford University Press, 1982] proposes that anxiety is associated with the processing of novel stimuli. We aimed to explore this relationship by recording auditory event-related potentials associated with unexpected novel noises in typically developing children. Children aged 10-14 years with low (n = 12) and high (n = 11) self-report trait anxiety were assessed using a novelty oddball task. The N1 associated with novel stimuli, specifically the "N1c" component maximal at temporal lobe sites, was of significantly longer latency (p = .014) and greater amplitude (p = .004) in the high compared with the low anxious group. This group difference was supported by linear correlations between N1c amplitude and trait anxiety scores. There was no effect of anxiety on the later novelty P3. These data suggest a subtle moderating role of trait anxiety on brain response to novelty, and further research with clinically anxious children is indicated.     

Study of the stress response: role of anxiety, cortisol and DHEAs

AIM OF THE STUDY: Several studies have exhibited the psychological processes that are implied in the stress response and have shown, according to Selye's research, the participation of the hypothalamic-pituitary-adrenal axis and the major role of cortisol. The possible action of another adrenal stero?d, dehydroepiandrosterone (DHEA), is increasingly documented. The beneficial effect of the latter and his antistress role would be related to an antagonistic action to that of cortisol. The aim of our study was, first to assess biological and psychological aspects of the stress response, then to define the relationships that exist between these two processes. POPULATION AND METHODOLOGY: 40 subjects (21 women) aged 42 +/- 12 years, who consulted within a clinic of stress (CITES Prevert, Liege, Belgium) were studied. They all felt stressed but, according to DSM IV, were without mental disorders and drug free when examined. Subjects were asked to accomplish simple cognitive tasks: 1 - to distinguish two different auditory stimulations. The first one was a high-pitched sound of 1 470 Hz, which was presented unfrequently (20%). The second one, a low frequency tone of 800 Hz, was presented more frequently (80%). The interval between both stimuli was 1 s. The subject had to press a button when the rare stimulus was recognized. 2 - to extinguish a light after a warning tone of 64 dB, 50 ms and 1 000 Hz. The light, which followed one second later the tone, consisted of a series of flashes of 18 c/s that the subject had to stop by pressing a button. The purpose of this second procedure was that the subject was warned and had to prepare and anticipate the most rapid response. After that, subjects were submitted to self-evaluation psychological tests. The impact of psychosocial factors was assessed by Amiel-Lebigre life events questionnaire. Personality features and emotional response (state anxiety, related to experimental situation) were assessed by Spielberger inventory (STAI: State and Trait Anxiety Inventory). Psychological tests are practised immediately after experimental situation. Cortisol and DHEAs (dehydroepiandrosterone sulfate) were measured in blood samples taken before (t1) and after (t2) the experimental test. Cortisol was measured by radio-immunology and expressed as ng/ml of plasma. DHEAs was measured by radio-immunoassay and expressed as g/liter of plasma. RESULTS AND DISCUSSION: The majority of subjects displayed high scores of trait anxiety (37 subjects had a score>42) and life events impact (35 subjects had a score>200). These data confirmed that the subjects were fragile and were obviously stressed. In response to the cognitive tasks, that constituted for each subject a new event with which it was necessary to cope, 25 subjects exhibited high level of state anxiety (score>42) and an increase of cortisol plasmatic concentrations occurred solely in 11 persons. Ten among them were in the group of subjects which displayed a score of state anxiety>42 (p=0,0223, Chi square). Base on these data three types of stress response were identified: 1 - the experimental situation was experienced without anxiety ( psychological silence ) and without any increase in cortisol level ( biological silence ). There was no stress and these subjects were, despite their vulnerability, close to a normal health state . 2 - high emotional reaction (high level of state anxiety) was observed. This response reveals a psychological vulnerability that can be considered as the expression of a consecutive psychological distress induced by a threatening experimental situation. There were no biological manifestations ( biological silence ). 3 - high state anxiety and increased plasma cortisol levels were observed. The corresponding subjects were obviously more vulnerable. CONCLUSION: These results allow us to propose that the emergence of state anxiety is the first stress response and the primary protest . Up to a certain level, a plateau level, anxiety remains stable. Then, nature of the stress response changes and takes a biological aspect. Increased of cortisol plasma levels, the secondary protest , is observed and gives evidence of an intensified and sustained stress response. Such a gradual phenomenon is particularly reported in elevated psychological distress which is associated with loss of control. It is important to note that identical scores of state anxiety (Mann Whitney test) were observed in anxious subjects with or without rise of plasma cortisol levels. DHEAs was also implied in the stress response. The enhancement of plasma levels of DHEAs were dependent on cortisol, as shown by the close correlation between both hormones (r=0,433, p=0,0033, Spearman test). The hypothesis of an antagonism between these two hormones is based on the fact that DHEAs opposes the action of cortisol and exerts a true anticortisol effect. This antagonism might be related to a competition in their synthesis and release by the adrenal gland. In the present case, high level of anxiety (state and trait) was associated with an increase of cortisol, while low level (of anxiety) was related to an exclusive rise of DHEAs. Intermediate anxious score was observed in subjects who showed increases of both cortisol and DHEAs (p=0,0225, Kruskall Wallis test). Furthermore, a close relationship (negative correlation: Spearman test), was observed between increases in DHEAS and scores of state anxiety (r=- 0,382, p=0,06) and trait anxiety (r=- 0,0097, p=0,527). This means that the worriness and the underlying anxious ruminations and negative anticipations, which characterize trait anxiety, were less important in subjects who increased plasma DHEAs levels. In addition, emotional tension and uneasiness, which accompanies state anxiety, were also less marked. There are no studies reporting a relation between DHEA(s) and state or trait anxiety. Nevertheless, many authors have proposed a beneficial action of DHEA on the feeling of well-being. This beneficial role could be related to a double action of DHEA: a direct effect provided by its transformation into sexual hormones, an indirect one mediated by its competition with cortisol, of which the synthesis and consequently the activity decrease.     

The moderating impact of emotional intelligence on free cortisol responses to stress

The construct of trait emotional intelligence (trait EI) refers to the individual differences in the perception, processing, regulation and utilization of emotional information. Several studies have found that trait EI was a significant moderator of subjective responses (e.g., mood deterioration, emotional intensity, action tendencies, bodily sensations) to both natural and laboratory stressors. The present study aims at extending these findings by examining whether trait EI also moderates the biological (i.e., cortisol) response to stress. To this end, 56 participants were assigned to either a neutral or a stressful condition (public speech task) and psychological and cortisol reactivity were examined. Results revealed that higher trait EI scores were associated with significantly lower reactivity to stress at both psychological (i.e., mood deterioration) and biological (i.e., salivary cortisol) levels. Additional analyses revealed that trait EI had incremental validity to predict stress reactivity over and above social desirability, alexithymia and the five-factor model of personality.     

Associations of anxiety-related symptoms with reported history of childhood sexual abuse in schizophrenia spectrum disorders

OBJECTIVE: Research suggests that persons with schizophrenia tend to experience significant levels of anxiety and that history of childhood sexual abuse may predispose some with schizophrenia to experience significant levels of persistent anxiety. It is unclear whether childhood sexual abuse is more closely linked to specific forms of anxiety including symptoms of post-traumatic stress disorder (PTSD). METHOD: Data were gathered from April 2004 through November 2004 on trauma history, PTSD symptoms, social anxiety, and state and trait anxiety from 45 men with a SCID-I-confirmed diagnosis of schizophrenia or schizoaffective disorder and 11 with a SCID-I-confirmed diagnosis of PTSD with no history of psychosis. Participants with schizophrenia spectrum disorders (schizophrenia group) were divided into those with and without history of childhood sexual abuse. Five participants in the schizophrenia group with a history of adult but not childhood sexual assault were excluded from analyses. RESULTS: Analysis of variance comparing the childhood sexual abuse (N = 21) and non-abused (N = 19) schizophrenia groups and the PTSD group on all anxiety assessments revealed that the sexually abused schizophrenia group had significantly higher levels of dissociation, intrusive experiences, and state and trait anxiety than the non-abused schizophrenia group. The schizophrenia groups did not differ statistically on levels of anxious arousal, defensive avoidance, or social anxiety. When compared with participants with PTSD and no psychosis, the sexually abused schizophrenia group had significantly lower levels of state anxiety, anxious arousal, intrusive experiences, and fearful social avoidance but failed to differ statistically on other scores. CONCLUSION: These results, if replicated, could lead to identification of those at risk for anxiety and PTSD and to targeted interventions.     

Attentional capture and trait anxiety: Evidence from inhibition of return

Attentional biases regarding attentional capture by threat-related stimuli in anxious people were investigated by using a standard spatial cueing procedure suitable to measure inhibition of return (IOR). In two experiments, participants categorized the emotional valence of either emotional (positive and negative words) or non-emotional (neutral words in both experiments and sets of ‘xxx’ in Experiment 1) targets that were preceded by a peripheral non-predictive cue. The typical IOR effect (slower responses for words presented at previously cued locations) was observed for non-emotional and positive stimuli, with similar results being observed for both low and high trait anxiety groups. For negative stimuli, however, the high trait anxiety group did not show the IOR effect, while it was present in the low trait anxiety group. This general pattern of results suggests that, in individual with high trait anxiety, threatening stimuli can capture attention at the locations whether attentional capture is hindered by other cognitive effects such as IOR.     

The effect of positive and negative evaluation on state anxiety and repetitive negative thinking in social evaluative situations: An experimental study

The Bivalent Fear of Evaluation (BFOE) Model suggests that fears of negative and positive evaluation are core cognitive vulnerability and maintenance factors for social anxiety disorder The aim of this study was to experimentally assess cognitive and emotional effects of positive and negative feedback in social anxiety. False positive or negative feedback (vs no feedback) was provided following a speech task to high and low socially anxious individuals to investigate impacts on state anxiety and repetitive negative thinking (N = 152, M_age = 22.13, 69 % female). Measures were completed prior to the speech and after the false feedback but prior to an anticipated discussion with the group about participants’ feedback and performance. High socially anxious participants reporting higher state anxiety and repetitive negative thinking than low socially anxious participants. There were no feedback type by group interactions, indicating that high socially anxious individuals experienced heightened social anxiety and repetitive negative thinking regardless of feedback type (or the absence of feedback). Exploratory analyses revealed that state fear of negative evaluation but not state fear of positive evaluation uniquely predicted both outcomes. Implications for theory and clinical practice are discussed.     

Psychophysiological arousal and biased perception of bodily anxiety symptoms in socially anxious children and adolescents: a systematic review

Cognitive models of social anxiety [Clark and Wells, Social phobia: Diagnosis, assessment, and treatment, Guilford Press, New York, 1995], diagnostic criteria and studies on adult samples suggest that both an overestimation of bodily anxiety symptoms and psychophysiological abnormalities play an important role in social anxiety. To date, less is known about such a perception bias and physiological characteristics in children and adolescents with social anxiety. We performed a systematic review of the literature in the electronic databases Medline, PsycINFO, and PSYNDEX. Additional studies were identified by hand search using the ancestry approach. We identified 1,461 studies, screened their titles and abstracts, viewed 94 papers, and included 28 of these. Study samples were heterogeneous and consisted of socially phobic, high socially anxious, shy and test anxious children and adolescents. Regarding a biased perception, most studies in the review suggest that bodily symptoms of anxiety were overestimated by children and adolescents across the social anxiety spectrum when compared with control groups. An elevated psychophysiological reactivity to social stress was present in samples of high social anxiety, shyness, and test anxiety. In clinical samples with social phobia, by contrast, no differences or an even lower physiological responding compared with healthy control groups were reported. In addition, some evidence for a chronic psychophysiological hyperarousal was found across all sample types. The results are discussed with regard to current models of social anxiety, psychophysiological theories, and treatment implications.     

Anticipatory processing in social anxiety: two pilot studies

Two studies investigating the cognitive processes associated with anticipatory social anxiety are reported. Study 1 used a semi-structured interview to compare high and low socially anxious individuals (n=20 per group) in terms of their reported mental processes during periods of anticipatory social anxiety. Study 2 investigated the anxiety inducing effects of the mental processes that were shown to be characteristic of high socially anxious individuals in Study 1. Prior to giving a speech, high and low socially anxious individuals (n=20 per group) either engaged in these processes or performed a distraction task. The results of Study 1 were broadly consistent with Clark and Wells’ (In: R.G. Heimberg, M. Liebowitz, D.A. Hope, F.R. Schneier (Eds.), Social phobia: Diagnosis, Assessment and Treatment (pp. 69–93). New York: Guilford Press, 1995) hypotheses about the nature of anticipatory processing in social anxiety. Study 2 showed that, compared to distraction, engaging in the mental processes characteristic of high socially anxious individuals was associated with sustained elevations of anticipatory anxiety in both high and low socially anxious individuals, and led to higher levels of peak anxiety during the speech. The findings suggest that high and low socially anxious individuals show systematic differences in their mental processes prior to a stressful social event, and are consistent with the suggestion that these differences play an important role in sustaining anticipatory anxiety.     

Clinical anxiety and the selective encoding of threatening information

Trait vulnerability to anxiety is a dimension of individual difference which is continuously distributed within the normal population. However, while clinically anxious patients are typically high trait anxious individuals, the severity of symptoms observed in the anxiety disorders often seems to be quite discontinuous with the levels of anxiety encountered in the normal population. Also, despite certain commonalities, each of the various anxiety disorders is characterized by a rather different pattern of specific symptoms. Consequently, any comprehensive theoretical account of pathological anxiety must attempt to explain the similarities and differences between trait anxiety and clinical anxiety, and between the various classes of anxiety disorders. There is an increasing evidence that such issues may be illuminated by considering the patterns of information processing associated with anxiety vulnerability. On the basis of the current review of this literature, it is proposed that general vulnerability to anxiety may reflect an automatic tendency to selectively encode emotionally threatening information. Additionally, it is suggested that certain specific characteristics of this encoding bias may distinguish high trait anxious normals from clinically anxious patients, and may discriminate those patients suffering from different categories of anxiety disorders     

Emotional stability, anxiety, and natural killer activity under examination stress.

This study was performed to evaluate the relation between a stable personality trait, a mood state and immune response to an examination stress. A self-reported measure of emotional stability (BFQ-ES scale) was obtained in a sample (n = 39) randomly selected from 277 cadets; this personality trait was also investigated by completing a neuroticism scale (Eysenck personality inventory) and a trait-anxiety scale (STAI). Natural killer (NK) cell activity was measured at baseline, long before the examination time and the examination day. The state-anxiety scale evaluated the response to the stressful stimulus. Taking subjects all together, the academic task did not result in significant modification over baseline in NK cell activity. Subjects were then divided into three groups based on emotional stability and state-anxiety scores: high emotional stability/low anxiety, medium, and low emotional stability/high anxiety. Examination stress induced significant increases in NK cell activity in the high emotional stability/low anxiety group, no effect in the medium group, and significant decreases in the low emotional stability/high anxiety group. The repeated-measure ANOVA revealed a significant interaction of group x period (baseline vs. examination) for both lytic units and percent cytolysis. The results did not change after introducing coffee and smoking habits as covariates. Our findings suggest that the state-anxiety acts in concert with a stable personality trait to modulate NK response in healthy subjects exposed to a psychological naturalistic stress. The relation between anxiety and poor immune control has been already described, whereas the ability of emotional stability to associate with an immunoenhancement has not yet reported. The peculiarity of our population, a very homogeneous and healthy group for life style and habits, can have highlighted the role of emotional stability, and may account for the difference with other studies.     

Adaptation as a sensorial profile in trait anxiety: a study with virtual reality

Twenty-four volunteers were recruited on the basis of their trait anxiety scores (low trait anxiety [LTA] and high trait anxiety [HTA]) as assessed by the State-Trait Anxiety Inventory. Adaptation to conflicting visual-vestibular stimulation (VVS) was used to study integration of space-related multi-sensory information in trait anxiety. First, vestibular perception was assessed by rotating the blindfolded subjects about the vertical axis (horizontal plane rotations) on a remote-controlled mobile robot. The subjects were asked to indicate the perceived rotation by use of an angular pointer. Subjects were then immersed into the center of a visual virtual square room by means of a head-mounted display. They were asked to control the robot with a joystick in order to perform 90 degrees rotations in the virtual room. However, a gain of 0.5 was introduced between visual scene and robot rotation so that the subjects were submitted to a conflict situation in which the 90 degrees rotational visual input was concurrent with a 180 degrees vestibular input. After 45 min of training with the virtual reality display, subjects were tested again in total darkness in order to determine whether their vestibular system had been reset by the conflicting visual signals. We found significant differences in adaptation to VVS between HTA and LTA groups as well as between males and females. Subjects of the HTA group demonstrated larger adaptation than that of the LTA group. Males also showed a greater level of adaptation compared to females. Our results suggest greater visual dependence in HTA subjects. This might be important for understanding the mechanisms underlying pathological anxiety and particularly agoraphobia.     

Thyroid function in anxious and depressed patients

We measured serum thyroid hormone levels, and pre- and post-TRH administration serum thyrotropin (TSH) in 46 psychiatric inpatients with major depression (n = 20), anxiety disorder (n = 9), and anxious depression (n = 17), and in 56 healthy subjects. Basal serum triiodothyronine was lower in female patients with major depression and anxious depression than in healthy women (P less than 0.05). Basal serum thyroxine was lower in female patients with anxious depression than in controls; all patients showed lower basal serum TSH than controls. In healthy subjects, basal triiodothyronine and thyroxine, basal TSH, and delta TSH (the increment of TSH after TRH administration) correlated, whereas no correlation was found between triiodothyronine and thyroxine in male patients with major depression, or between TSH and delta TSH in female patients with major depression or anxious depression. In female patients, 45% with major depression, 25% with anxiety disorder, and 35% with anxious depression showed a blunted TSH response. We also investigated pre- and post-dexamethasone administration cortisol levels in these patients. The sensitivity obtained by the combination of the results of the TRH and dexamethasone suppression tests for major depression, anxiety disorder, and anxious depression was 45%, 55%, and 65%, respectively.     

Multisensory integration for spatial orientation in trait anxiety subjects: absence of visual dependence.

Studies suggest a greater reliance on visual information for maintaining balance in anxious subjects. Nevertheless, links between this supposed preferred visual processing and spatial orientation have not yet been evaluated. Two groups of subjects differing in their level of trait anxiety were formed. Equipped with a head-mounted visual display, they learned a virtual corridor using passive translation but active rotation, both with normal and with two different conflicting sensory conditions. After two visual navigation trials in the corridor, they were blindfolded and asked to reproduce the same trajectory from memory. In addition, subjects drew a map of the remembered corridor. Anxious subjects were comparable to non-anxious subjects when asked to reproduce the trajectory from memory, but exhibited a deficit when drawing a map of the corridor they were in. The results do not support the hypothesis that anxious subjects use preferentially one type of sensory cue over another for spatial orientation, but instead manifest difficulties in constructing more global representations of space.     

Cortisol responses of healthy volunteers undergoing magnetic resonance imaging

Self-reported anxiety is associated with various medical procedures, including structural and functional magnetic resonance imaging (MRI). The present study tested the hypothesis that MRI scanning would be associated with elevated cortisol levels in participants with no prior scanning experience. Baseline and post-scan cortisol levels, as well as measures of state and trait anxiety, were obtained from scanner-naive (n = 6) and scanner-experienced (n = 8) research participants. The anxiety scores and cortisol responses of the scanner-naive and scanner-experienced participants were compared. Subjects novel to MRI were no more anxious before the scan than were subjects familiar with the MRI examination, but the scanner-naive subjects manifested heightened post-scan cortisol secretion when compared to their pre-scan level and when compared to the scanner-experienced participants. The results are consistent with the hypothesis that the scanning environment can induce cortisol elevations and are congruent with the well-established effects of acute stressors on activity of the hypothalamic-pituitary-adrenal (HPA) axis. The implications for neuroimaging studies are discussed.     

The influence of emotional context on attention in anxious subjects: neurophysiological correlates

Several studies have shown the influence of threatening context on level of attention to target environmental stimuli. The present experiment explored the possibility that this influence of aversive context is particularly strong in anxious subjects, due to their known attentional bias towards negative information. Event-related potentials, that provide a direct index of attention-related cerebral processing, were recorded in 27 participants selected from a larger sample of 250, as a function of their trait anxiety scores (14 high, 13 low). State anxiety was also measured in selected subjects. Several contexts were presented: positive, negative, relaxing and neutral, and participants were instructed to attend, within these contexts, to a series of auditory stimuli. Threatening context triggered an increase in attention to these auditory stimuli only in conditions of high state anxiety, this increase being reflected in the greater amplitude of the P2 component, which is related to attentional processes. There were no significant differences in relation to trait anxiety. Data show that threatening context and high level of state anxiety in combination increase the quantity of attentional resources directed to the environment.