Individual Differences In Tolerance Research Articles

Sometimes I feel the fear of uncertainty: How intolerance of uncertainty and trait anxiety impact fear acquisition, extinction and the return of fear

It is hypothesized that the ability to discriminate between threat and safety is impaired in individuals with high dispositional negativity, resulting in maladaptive behavior. A large body of research investigated differential learning during fear conditioning and extinction protocols depending on individual differences in intolerance of uncertainty (IU) and trait anxiety (TA), two closely-related dimensions of dispositional negativity, with heterogenous results. These might be due to varying degrees of induced threat/safety uncertainty. Here, we compared two groups with high vs. low IU/TA during periods of low (instructed fear acquisition) and high levels of uncertainty (delayed non-instructed extinction training and reinstatement). Dependent variables comprised subjective (US expectancy, valence, arousal), psychophysiological (skin conductance response, SCR, and startle blink), and neural (fMRI BOLD) measures of threat responding. During fear acquisition, we found strong threat/safety discrimination for both groups. During early extinction (high uncertainty), the low IU/TA group showed an increased physiological response to the safety signal, resulting in a lack of CS discrimination. In contrast, the high IU/TA group showed strong initial threat/safety discrimination in physiology, lacking discriminative learning on startle, and reduced neural activation in regions linked to threat/safety processing throughout extinction training indicating sustained but non-adaptive and rigid responding. Similar neural patterns were found after the reinstatement test. Taken together, we provide evidence that high dispositional negativity, as indicated here by IU and TA, is associated with greater responding to threat cues during the beginning of delayed extinction, and, thus, demonstrates altered learning patterns under changing environments.

Event-related potentials to acoustic startle probes during unpredictable threat are associated with individual differences in intolerance of uncertainty

Individual differences in sensitivity to unpredictable threat may be a critical mechanism for internalizing psychopathology phenotypes. The present study examined whether the startle probe-elicited N100 and P300 during unpredictable threat – two event-related potentials indexing early and elaborative attentional processing of unpredictable threat – may be endophenotypes for internalizing psychopathology, including fear and distress/misery disorders and intolerance of uncertainty (IU), a clinical trait that is transdiagnostically associated with internalizing disorders. A large sample of adult siblings (N = 375) completed the no, predictable, and unpredictable threat task, during which the N100 and P300 were recorded. Relative to the no threat condition, N100 was more strongly enhanced in anticipation of unpredictable than predictable threat while P300 was suppressed to both predictable and unpredictable threat. While neither N100 enhancement nor P300 suppression to unpredictable threat was associated with fear or distress/misery disorders, they were negatively linked to inhibitory IU (a facet of IU). Thus, individuals high in inhibitory IU showed reduced attentional engagement with the threatening context when it was unpredictable. Further, N100 enhancement and, to a lesser degree, P300 suppression to unpredictable threat showed familial aggregation – a key criterion for determining whether a biomarker is an endophenotype. In sum, N100 enhancement and P300 suppression to unpredictable threat may be endophenotypes for dimensional measures of internalizing psychopathology.

Cryopreservation of dog semen in a Tris extender with two different 1% soybean preparations compared with a Tris egg yolk extender.

Egg yolk is widely used as a cryoprotectant in dog semen extenders, but there is a risk of contamination with animal pathogens. In addition, egg yolk may vary in composition, making it difficult to standardize the extender. Lecithin is an animal protein‐free alternative to egg yolk for semen cryopreservation. Recently, it was shown that 1% of soybean lecithin type II‐S was better than 2% for freezing canine semen. The aim of the study was to compare two different types of soybean lecithin, with egg yolk as a control. Ejaculates from eight dogs were divided into three equal parts and diluted with a Tris‐based extender, containing either 20% egg yolk, 1% soybean lecithin Type II‐S or 1% soybean lecithin Type IV‐S. The samples were then frozen. Sperm motility was evaluated by computer‐assisted sperm analysis (CASA), acrosome integrity (FITC‐PNA/PI) and sperm membrane integrity (SYBR‐14/PI) post‐thaw, as well as after 2 and 4 hr incubation at 37°C. Post‐thaw sperm chromatin structure assay and plasma membrane integrity were evaluated by flow cytometry. Total motility, sperm plasma membrane integrity and acrosome integrity were significantly better in the egg yolk extender than in the two soybean lecithin‐based extenders. Individual motility post‐thaw differed more than in the fresh samples, illustrating individual differences in tolerance to the cryostress. The DNA Fragmentation Index (% DFI) was significantly lower in the Tris egg yolk (TEY) extender compared to any of the soybean‐based extenders. The number of high green stained spermatozoa were significantly higher in Type IV‐S compared to the control TEY extender. In conclusion, egg yolk was superior to the two lecithin‐based extenders to cryopreserve canine semen.

Intolerance of uncertainty, and not social anxiety, is associated with compromised extinction of social threat

Extinction-resistant threat is regarded as a central hallmark of pathological anxiety. However, it remains relatively under-studied in social anxiety. Here we sought to determine whether self-reported trait social anxiety is associated with compromised threat extinction learning and retention. We tested this hypothesis within two separate, socially relevant conditioning studies. In the first experiment, a Selective Extinction Through Cognitive Evaluation (SECE) paradigm was used, which included a cognitive component during the extinction phase, while experiment 2 used a traditional threat extinction paradigm. Skin conductance responses and subjective ratings of anxiety (experiment 1 and 2) and expectancy (experiment 2) were collected across both experiments. The findings of both studies demonstrated no effect of social anxiety on extinction learning or retention. Instead, results from experiment 1 indicated that individual differences in Intolerance of Uncertainty (IU) were associated with the ability to use contextual cues to decrease a conditioned response during SECE. However, during extinction retention, high IU predicted greater generalisation across context cues. Findings of experiment 2 revealed that higher IU was associated with impaired extinction learning and retention. The results from both studies suggest that compromised threat extinction is likely to be a characteristic of high levels of IU and not social anxiety.

Habituation is not neutral or equal: Individual differences in tolerance suggest an overlooked personality trait.

In behavioral studies, observer effects can be substantial, even for habituated animals, but few studies account for potential observer-related phenomenon empirically. We used wild, habituated chacma baboons to explore two key assumptions of behavioral ecology (i) that observers become a "neutral" stimulus and (ii) that habituation is "equal" across group members. Using flight initiation distance (FID) methods within a personality paradigm, the behavioral responses of baboons suggested that observers were not perceived as neutral but instead viewed as a high-ranking social threat. Habituation was also not equal across group members, with repeatable individual differences more important than contextual factors (e.g., habitat) in determining the distance at which baboons visually oriented or displaced from observers. A strong correlation between individual visual tolerance and displacement tolerance (i.e., convergent validity) indicated a personality trait. We offer several suggestions for how to account for these factors and minimize potential bias in future studies.

Measuring aniseikonia tolerance range for stereoacuity - a tool for the refractive surgeon.

ObjectiveNo method exists to measure aniseikonia tolerance in stereoacuity. The brain can compensate for 2%–3% aniseikonia (i.e. 2–3 dioptres of anisometropia) without impairing stereoacuity; however, a substantial proportion of anisometropic patients experience problems caused by disruptions of sensory fusion due to surgically induced aniseikonia. We hypothesized that individual differences in tolerance to aniseikonia exist and sought to develop a method to measure aniseikonia tolerance.MethodsA total of 21 eye‐healthy phakic individuals older than 50 years of age and 11 patients awaiting clear lens extraction were included. Patients were tested with best corrected near and distance visual acuity, cover/uncover test, eye dominance test, stereoacuity threshold (TNO test), slit lamp examination and ocular coherence tomography. The stereoacuity threshold was determined with aniseikonia induced by different size lenses ranging from 1% to 9% magnification of both eyes in increments of 1%. The aniseikonia tolerance range (ATR) was defined as the percentage aniseikonia in which the stereoacuity threshold was maintained.ResultsWe examined 32 patients with a median age of 65 (95% CI: 62–66 years), CDVA better than 6/7.5 (0.1 logMAR), and median near visual acuity better than 6/6 (0.0 logMAR). The median stereoacuity threshold was 60 arcsec (maximum 30, minimum 120). We observed large inter‐individual differences in ATR: 6/31 (19%) participants had an ATR of ≤1%, 1/31 (3%) had an ATR of 1‐5%, 7/31 (22%) had an ATR of 5‐10%, and 17/31 (54%) had an ATR of >10%.ConclusionWe present a reliable method for measuring the amount of aniseikonia that a person can tolerate without impairing stereopsis. We report large inter‐individual differences in tolerance of aniseikonia.

The role of threat level and intolerance of uncertainty in extinction

Recent evidence suggests that individual differences in intolerance of uncertainty (IUS) are associated with disrupted threat extinction. However, it is unknown what maintains the learned threat association in high IUS individuals: is it the experienced uncertainty during extinction or the combination of experienced uncertainty with potential threat during extinction? Here we addressed this question by running two independent experiments with uncertain auditory stimuli that varied in threat level (Experiment 1, aversive human scream (n = 30); Experiment 2, neutral tone (n = 47) and mildly aversive tone (n = 49)). During the experiments, we recorded skin conductance responses and subjective ratings to the learned cues during acquisition and extinction. In experiment 1, high IUS was associated with heightened skin conductance responding to the learned threat vs. safe cue during extinction. In experiment 2, high IUS was associated only with larger skin conductance responding to the learned cues with more threatening properties during extinction i.e. mildly aversive tone. These findings suggest that uncertainty in combination with threat, even when mild, disrupts extinction in high IUS individuals. Such findings help us understand the link between IUS and threat extinction, and its relevance to anxiety disorder pathology.

What do I do now? Intolerance of uncertainty is associated with discrete patterns of anticipatory physiological responding to different contexts.

Heightened physiological responses to uncertainty are a common hallmark of anxiety disorders. Many separate studies have examined the relationship between individual differences in intolerance of uncertainty (IU) and physiological responses to uncertainty during different contexts. Despite this, there is a scarcity of research examining the extent to which individual differences in IU are related to shared or discrete patterns of anticipatory physiological responding across different contexts. Anticipatory physiological responses to uncertainty were assessed in three different contexts (associative threat learning and extinction, threat uncertainty, decision-making) within the same sample (n=45). During these tasks, behavioral responses (i.e., reaction times, choices), skin conductance, and corrugator supercilli activity were recorded. In addition, self-reported IU and trait anxiety were measured. IU was related to both skin conductance and corrugator supercilii activity for the associative threat learning and extinction context and decision-making context. However, trait anxiety was related to corrugator supercilii activity during the threat uncertainty context. Ultimately, this research helps us to further tease apart the role of IU on different aspects of anticipation (i.e., valence and arousal) across contexts, which will be relevant for future IU-related models of psychopathology.

Minimizing Mistreatment by Female Adults: The Influence of Gender-Based Social Categories and Personality Differences on Attitudes about Child Sexual Abuse

We investigated the effects of gender-based social categories (i.e., men, women, boys, and girls) on attitudes about child sexual abuse and individual differences in the use of such categories. In four experiments, we systematically varied perpetrators’ sex and victims’ sex. In three investigations, we assessed personality variables potentially related to participants’ use of these social categories. Across these four experiments, we varied perpetrator-victim relationships (teacher-student, neighbors) and victims’ ages. In experiment one, individuals had the least negative attitude about child sexual abuse involving adult female neighbors and eighth grade male neighbors. In experiment two, we replicated this effect with fifth grade victims and demonstrated that attitudes were moderated by individual differences in intolerance of ambiguity. In experiment three, we again replicated the aforementioned effect while (a) extending this finding to teacher-student relationships with eighth grade adolescent victims and (b) demonstrating the need for cognition was a moderator. In experiment four, we again replicated (a) our perpetrator sex/victim sex interactive effect and (b) need for cognition moderation while also demonstrating that these effects were applicable to fifth grade victims. Methodological limitations as well as clinical and policy implications (e.g., attenuating the underreporting incidents of child sexual abuse) are discussed.

Reliability and Validity of a Brief Version of the Intolerance of Uncertainty Scale in Outpatients with Psychosis

Individual differences in intolerance of uncertainty are hypothesized to play a role in certain difficulties and distress in individuals with psychosis. However, the few studies that have directly explored this have yielded mixed results, which are difficult to interpret because measures of intolerance of uncertainty have not been formally validated for use with this population. To this end, the primary goal of the present study was to validate a brief (9-item) version of the Intolerance of Uncertainty Scale (Freeston et al. Personality and Individual Differences, 17, 791–802 1994) in an outpatient sample of 252 adults with psychosis. Results showed strong evidence for reliability (internal consistency and 6-month test-retest), as well as concurrent, predictive, and discriminant validity. Scores from the brief IUS were significantly correlated with emotional distress (e.g., anxiety, depression, hopelessness), quality of life, global functioning, and delusions, but not hallucinations. Further, these scores predicted changes in levels of general anxiety over time. Notably, intolerance of uncertainty was associated with symptoms/distress and functioning above and beyond pertinent cognitive variables (e.g., defeatist beliefs, asocial beliefs), suggesting this brief scale has incremental validity. Overall, results suggest it is a promising tool for future research on psychosis, and possibly clinical work with this population.

Brains after hours: shift work’s impact on the effectiveness of employees’ cognitive abilities

Various sources point out that shift work (especially night shifts) has a negative influence on peoples’ health and their everyday functioning. This article strives to start a discussion about the current state of knowledge on the impact of shift work on workers’ cognitive functioning, on the basis of studies, which used objective diagnostic methods. It also covers individual differences in tolerance to shift work and prevention of cognitive impairments due to shift work.

If or when? Uncertainty's role in anxious anticipation.

Uncertainty is often associated with subjective distress and a potentiated anxiety response. Occurrence uncertainty, or the inability to predict if a threat will occur, has rarely been compared experimentally with temporal uncertainty, or the inability to predict when a threat will occur. The current study aimed to (a) directly compare the anxiogenic effects of anticipating these two types of uncertain threat, as indexed by the eyeblink startle response, and (b) assess the relationship between startle response to occurrence and temporal uncertainty and individual differences in self-reported intolerance of uncertainty and anxiety. The findings indicated that anticipation during occurrence uncertainty elicited a larger startle response than anticipating a certain threat, but anticipation during temporal uncertainty was superior at potentiating startle blink overall. Additional analyses of the effects of order and habituation further highlighted temporal uncertainty's superiority in eliciting greater startle responding. This suggests that, while uncertainty is physiologically anxiety provoking, some level of certainty that the threat will occur enhances the robustness of the physiological anxiety response. However, self-reported anxiety was equivalent for temporal and occurrence uncertainty, suggesting that, while defensive responding may be more affected by temporal uncertainty, people perceive both types of uncertainty as anxiogenic. Individual differences in the intolerance of uncertainty and other anxiety measures were not related to anticipatory startle responsivity during any of the conditions.

Distress intolerance modulation of neurophysiological markers of cognitive control during a complex go/no-go task.

Distress intolerance (DI), a trait-like individual difference reflective of the inability to endure aversive affective states, is relevant to multiple forms of psychopathology, but its relations to theoretically relevant neurobiological systems have received little attention. Altered cognitive control-related neurobiology has been theorized to underlie individual differences in DI, but little empirical work has been conducted. To test this hypothesis, baseline data from a large community sample with elevated high levels of emotional psychopathology and comorbidity was utilized (N = 256). Participants completed a complex go/no-go task while EEG was recorded, and P2, N2, and P3 amplitudes were measured. Based upon prior findings on the relations between these components and response inhibition, a core cognitive control function, we hypothesized that DI would predict reduced no-go N2 and P3 amplitude while controlling for current anxious/depressive symptom severity (i.e., negative affect). Peak amplitudes from the raw data and principal components analysis were used to quantify amplitude of ERP components. Partially consistent with predictions, high DI was independently associated with reduced no-go N2 peak amplitude in the raw ERP data, and was significantly related to a frontal positivity factor in the N2 time window across no-go and go trials. Contrary to predictions, no relations between DI and the P3 were found. Overall, results support the theorized relevance of cognitive control-linked neurobiology to individual differences in tolerance of distress over and above distress severity itself, and suggest specific relations between DI and alterations in early controlled attention/conflict-monitoring but not response inhibition or response inhibition-related sequelae. (PsycINFO Database Record

I don’t know where to look: the impact of intolerance of uncertainty on saccades towards non-predictive emotional face distractors

ABSTRACTAttentional bias to uncertain threat is associated with anxiety disorders. Here we examine the extent to which emotional face distractors (happy, angry and neutral) and individual differences in intolerance of uncertainty (IU), impact saccades in two versions of the “follow a cross” task. In both versions of the follow the cross task, the probability of receiving an emotional face distractor was 66.7%. To increase perceived uncertainty regarding the location of the face distractors, in one of the tasks additional non-predictive cues were presented before the onset of the face distractors and target. We did not find IU to impact saccades towards non-cued face distractors. However, we found IU, over Trait Anxiety, to impact saccades towards non-predictive cueing of face distractors. Under these conditions, IU individuals’ eyes were pulled towards angry face distractors and away from happy face distractors overall, and the speed of this deviation of the eyes was determined by the combination of the cue and emotion of the face. Overall, these results suggest a specific role of IU on attentional bias to threat during uncertainty. These findings highlight the potential of intolerance of uncertainty-based mechanisms to help understand anxiety disorder pathology and inform potential treatment targets.

Nothing is safe: Intolerance of uncertainty is associated with compromised fear extinction learning

Extinction-resistant fear is considered to be a central feature of pathological anxiety. Here we sought to determine if individual differences in Intolerance of Uncertainty (IU), a potential risk factor for anxiety disorders, underlies compromised fear extinction. We tested this hypothesis by recording electrodermal activity in 38 healthy participants during fear acquisition and extinction. We assessed the temporality of fear extinction, by examining early and late extinction learning. During early extinction, low IU was associated with larger skin conductance responses to learned threat vs. safety cues, whereas high IU was associated with skin conductance responding to both threat and safety cues, but no cue discrimination. During late extinction, low IU showed no difference in skin conductance between learned threat and safety cues, whilst high IU predicted continued fear expression to learned threat, indexed by larger skin conductance to threat vs. safety cues. These findings suggest a critical role of uncertainty-based mechanisms in the maintenance of learned fear.

The impact of an unpredictable context and intolerance of uncertainty on the electrocortical response to monetary gains and losses.

There is growing evidence that unpredictability and uncertainty can alter reward system functioning. The present study examined the impact of (1) a task-irrelevant unpredictable relative to predictable context and (2) individual differences in intolerance of uncertainty (IU) on the reward-related positivity (RewP), an event-related potential (ERP) response to monetary gains relative to losses. Specifically, 64 participants listened to predictable and unpredictable tone sequences while electroencephalography was recorded during a monetary gambling task. Participants also completed the Intolerance of Uncertainty Scale, which measures both cognitive distress (prospective IU) and behavioral inhibition (inhibitory IU) elicited by uncertainty, in addition to the Depression Anxiety Stress Scale-21 and Penn State Worry Questionnaire. Results indicated that the RewP was reduced during the unpredictable relative to the predictable context. Greater self-reported anxiety elicited by the unpredictable context was associated with a decreased RewP, and a decreased RewP was associated with poorer lose-shift behavioral adjustment. Furthermore, the RewP mediated the relationship between self-reported anxiety elicited by the unpredictable context and lose-shift behavioral adjustment. The IU subscales demonstrated the opposite relationship with the RewP across both contexts-inhibitory IU was associated with an attenuated RewP and prospective IU was associated with an enhanced RewP. In contrast, anxiety, depression, stress, and worry symptomatology were not associated with the RewP. This is the first study to demonstrate that an unpredictable context and individual differences in the degree to which people cannot tolerate uncertainty impact an ERP measure of reward system functioning.

Recommendations for the safe administration of donepezil.

# {#article-title-2} Safe administration of a medicine depends on individual differences in tolerance and appropriate, consistent instructions from the physician, pharmacist, and package directions. When patients receive written and oral dosing directions that disregard individual differences and are inconsistent, the therapeutic benefits of the medication may be reduced and adverse effects may result. A specific example occurs with the written and oral directions to patients (and caregivers) for the administration of donepezil. The Aricept Patient Package Insert (paper) under the section “How should the patient take ARICEPT?” instructs as follows: “Give ARICEPT one time each day. ARICEPT can be taken with or without food.”1 In the same package, the second larger insert reads: “Full Prescribing Information, 2) Dosage and Administration”: “ARICEPT should be taken in the …

Berufliche Belastungen in der Anästhesiologie – Belastungen und gesundheitliche Störungen durch Schichtarbeit

In Germany aprox. 15% of all employees have irregular or flexible working hours. Disturbed sleep and/or hypersomnia are direct consequences of shift work and therefore described as shift work disorder. Beyond this, shift work can also be associated with specific pathological disorders. There are individual differences in tolerance to shift work. Optimization of both shift schedules and sleep to "non-physiological" times of the day are measures to counteract the negative effects of shift work. There is still not enough evidence to recommend drugs for routine use in shift workers.

Individual differences in tolerance to shift work – A systematic review

Shift work tolerance is a term describing the ability to adapt to shift work without adverse consequences. In this paper we systematically review literature published investigating the relation between individual differences such as age, gender, personality, morningness/eveningness as well as biological variables and different measures of shift work tolerance from 1998 till 2009. A total of 60 articles were included in this review, of which ten studies were classified as longitudinal, while the rest were classified as cross-sectional. Overall, the studies indicate that young age, male gender, low scores on morningness, high scores on flexibility and low scores on languidity, low scores on neuroticism, high scores on extraversion and internal locus of control and some genetic dispositions are related to higher shift work tolerance. More longitudinal studies, especially concerning personality, are needed to make conclusions about the predictive power of individual differences for shift work tolerance.

Managing jet lag: Some of the problems and possible new solutions

Jet lag is due to the misalignment of the internal circadian clock(s) with external time cues. For short stopovers (1-2 days) adapting the circadian system is not advised, and at present immediate circadian adaptation is virtually impossible. The use of short-term measures such as judicious naps, caffeine and short acting hypnotics to maintain alertness and sleep is preferred. For intermediate length stays (3-5 days) a phase position with the circadian nadir situated within the sleep period is desirable but difficult to achieve. For longer stays (more than 4-5 days) strategies to hasten adaptation include timed exposure to and avoidance of light. The use of artificial light enriched with short wavelengths may be beneficial. The American Academy of Sleep Medicine recommends the timed use of the chronobiotic melatonin to hasten adaptation. Large individual differences in rate and direction of adaptation make timing treatment according to individual circadian phase difficult. Individual differences in tolerance to the sleep deprivation of jet lag may relate to a length polymorphism in the human clock gene PER3. The maximum efficacy for jet lag avoidance is by pre-flight adaptation, however, this requires time and commitment.