Effects of intolerance of uncertainty on subjective and psychophysiological measures during fear acquisition and delayed extinction

Individuals who score high in self-reported Intolerance of Uncertainty (IU) tend to find uncertainty unacceptable and aversive. In recent years, research has shed light on the role of IU in modulating subjective (i.e. expectancy ratings) and psychophysiological responses (i.e. skin conductance) across different classical fear conditioning procedures, particularly that of immediate extinction. However, there remain gaps in understanding how IU, in comparison to other negative emotionality traits (STAI-T), impact different types of subjective and psychophysiological measures during different classical fear conditioning procedures. Here, we analyzed IU, STAI-T, subjective (i.e. fear ratings) and psychophysiological (i.e. skin conductance, auditory startle blink) data recorded during fear acquisition training and 24h-delayed extinction training (n = 66). Higher IU, over STAI-T, was: (1) significantly associated with greater fear ratings to the learned fear cue during fear acquisition training, and (2) at trend associated with greater fear ratings to the learned fear versus safe cue during delayed extinction training. Both IU and STAI-T were not related to skin conductance or auditory startle blink during fear acquisition training and delayed extinction training. These results add to and extend our current understanding of the role of IU on subjective and physiological measures during different fear conditioning procedures, particularly that of delayed extinction training. Implications of these findings and future directions are discussed.

New insights on the correspondence between subjective affective experience and physiological responses from representational similarity analyses

Classical views suggest that experienced affect is related to a specific bodily response (Fingerprint hypothesis), whereas recent perspectives challenge this view postulating that similar affective experiences rather evoke different physiological responses. To further advance this debate in the field, we used representational similarity analysis to investigate the correspondence between subjective affect (arousal and valence ratings) and physiological reactions (skin conductance response [SCR], startle blink response, heart rate and corrugator activity) across various emotion induction contexts (picture viewing task, sound listening task and imagery task). Significant similarities were exclusively observed between SCR and arousal in the picture viewing task. However, none of the other physiological measures showed a significant relation with valence and arousal ratings in any of the tasks. These findings tend to support the populations hypothesis, suggesting that there is no clear match between the evoked physiological responses and the experienced subjective affect between individuals.

Examining the role of thin-ideal internalization in the relationship between reactions to high- and low-calorie food and eating pathology

Motivational responses to both body and food stimuli are relevant for eating disorders (EDs). Thin-ideal internalization, a socio-cognitive factor implicated in EDs, has been associated with approach responses toward thin bodies and avoidant responses to overweight bodies. Research examining reactions to food in EDs has been mixed, with some studies reporting enhanced approach and others observing avoidant responses to food. Thin-ideal internalization may help to explain these mixed findings, as individuals with eating pathology may experience food as a threat to internalized ideals of thinness, despite its inherently appetitive qualities. In the present study, physiological reflexes measuring aversive (startle blink reflex) and appetitive (postauricular reflex) responding as well as self-report ratings were recorded while 87 women with and without eating pathology viewed images of high- and low-calorie food. Greater global eating pathology, but not thin-ideal internalization, was associated with negative self-report valence ratings and lower craving ratings of high-calorie food. Thin-ideal internalization was related to more positive self-report ratings of low-calorie food, and low-calorie food ratings were related to eating pathology indirectly through thin-ideal internalization. Overall, thin-ideal internalization may represent a higher-order factor that influences conscious reactions to food.

I told you it was safe: Associations between intolerance of uncertainty and different types of uncertainty during instructed threat of shock

Background and Objectives. Intolerance of Uncertainty (IU) is a dispositional tendency to find uncertainty aversive. There is a lack of research on how IU modulates physiological responding to different types of uncertainty. Methods. Here, we conducted exploratory secondary analyses on an existing data set (n = 45) to examine whether IU is related to a particular type of uncertainty during instructed threat of shock (i.e. certain shock, certain safety from shock, outcome uncertainty of shock, temporal uncertainty of shock). Results. Analyses revealed that IU was associated with larger auditory startle blink during the anticipatory period for the certain safety from shock condition, relative to the certain shock condition. Limitations. The sample was relatively small. Conclusions. Individuals higher in IU may be more inclined to generalize threat to safety cues in the context of instructed threat of shock with multiple types of uncertainty

Your guess is as good as mine: Assessing physiological markers of fear and anxiety to the unknown in individuals with varying levels of intolerance of uncertainty

Individuals who score high in Intolerance of Uncertainty (IU) have a tendency to find uncertainty and the unknown aversive. However, there is a dearth of literature on the extent to which known vs. unknown threat induce fear and anxiety in individuals with high IU. Here we seek to address this question by varying the level of known and unknown threat using a modified version of the NPU-threat test. We will use the standard instructed conditions of the NPU-threat test (known unpredictable shock, known predictable shock and known no shock), as well as an uninstructed condition (unknown threat). We propose to measure ratings, skin conductance response, pupil dilation, orbicularis occuli (startle blink reflex) and corrugator supercilii activity during the modified NPU-threat test (n = 93). This work will further our understanding of the impact of known and unknown threat upon physiological markers of fear and anxiety in IU. Ultimately, this research will inform future models of IU and clinical treatments of anxiety and stress disorders.

The effect of Parkinson's disease on learning-related slow potentials and emotion

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The dopaminergic reward system is the focus of intensive research because of its relevance to disorders such as addiction, obesity, Parkinson's disease (PD), schizophrenia, and depression. One purpose of the current study was to test whether learning effects on a measure of reward expectancy, the Stimulus-Preceding Negativity (SPN), are dopamine mediated. We compared changes in SPN amplitude across trials as healthy people and people whose dopamine system had been damaged by PD learned a series of probabilistic categorization tasks, in which they were required to find out which of two doors was usually followed by a pleasant picture and which by an unpleasant one. We also assessed dopamine effects in the two groups using a behavioral assay, resting spontaneous eye-blink rate. The second purpose of the study was to test the involvement of dopamine in emotions triggered by positive and negative feedback displays via measures of the late positive potential (LPP), startle blink reflex, post-auricular reflex (PAR), and self-report. Results showed that SPN learning effects seen in the control group were absent in the patient group. These effects did not vary as a function of spontaneous blink rate. Changes in SPN topography suggested that patients might have compensated for impairments in their dopamine-dependent reinforcement learning system by switching to declarative memory. Confirming prior findings, participants with Parkinson's disease were less responsive to negative feedback as indicated by LPP. Patients with low spontaneous blink rate tended to exhibit reduced affective modulation of startle blink. Dopamine plays an important role in both anticipation and receipt of task feedback.

The Postauricular Reflex as a Measure of Attention and Positive Emotion

The postauricular reflex is a muscular reaction that occurs behind the ear in response to short, abrupt sounds. Its magnitude increases with louder eliciting sounds, rotating the eyes in the direction of the eliciting sound, and flexing the head forward. The reflex exhibits prepulse inhibition, especially during attention to complex foreground stimuli. Its magnitude is larger (or potentiated) during pleasant than during neutral pictures, sounds, and videos that are highly arousing. This pattern is particularly evident for erotic, food, and nurturant scenes, suggesting it assesses more than just appetitive processing. This reflex’s potentiation varies across development; positively correlates with personality traits associated with well-being; and negatively correlates with such psychopathologies as depression, schizophrenia, and opioid dependence. It appears distinct from and uncorrelated with the startle blink reflex. New data suggest that activity in left frontal areas generates postauricular reflex potentiation during pleasant versus neutral pictures.

The effect of Parkinson's disease on learning-related slow potentials and emotion

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The dopaminergic reward system is the focus of intensive research because of its relevance to disorders such as addiction, obesity, Parkinson's disease (PD), schizophrenia, and depression. One purpose of the current study was to test whether learning effects on a measure of reward expectancy, the Stimulus-Preceding Negativity (SPN), are dopamine mediated. We compared changes in SPN amplitude across trials as healthy people and people whose dopamine system had been damaged by PD learned a series of probabilistic categorization tasks, in which they were required to find out which of two doors was usually followed by a pleasant picture and which by an unpleasant one. We also assessed dopamine effects in the two groups using a behavioral assay, resting spontaneous eye-blink rate. The second purpose of the study was to test the involvement of dopamine in emotions triggered by positive and negative feedback displays via measures of the late positive potential (LPP), startle blink reflex, post-auricular reflex (PAR), and self-report. Results showed that SPN learning effects seen in the control group were absent in the patient group. These effects did not vary as a function of spontaneous blink rate. Changes in SPN topography suggested that patients might have compensated for impairments in their dopamine-dependent reinforcement learning system by switching to declarative memory. Confirming prior findings, participants with Parkinson's disease were less responsive to negative feedback as indicated by LPP. Patients with low spontaneous blink rate tended to exhibit reduced affective modulation of startle blink. Dopamine plays an important role in both anticipation and receipt of task feedback.

Moral Identity and Emotion in Athletes

The purpose of this study was to investigate the effects of moral identity on physiological responses to affective pictures, namely, the startle blink reflex and pain-related evoked potential. Male (n = 48) and female (n = 46) athletes participating in contact team sports were randomly assigned to either a moral identity group or a non-moral identity group and viewed a series of unpleasant, neutral, and pleasant sport-specific pictures. During picture viewing, a noxious electrocutaneous stimulus was delivered as the startle probe and the startle blink and pain-related evoked potential were measured. Upon completion of physiological measures, participants reviewed the pictures and rated them for valence and arousal. ANOVAs revealed that participants in the moral identity group displayed larger startle blinks and smaller pain-related potentials than did those in the non-moral identity group across all picture valence categories. However, the difference in the magnitude of startle blinks between the moral and non-moral identity groups was larger in response to unpleasant than pleasant and neutral pictures. Our findings suggest that moral identity affects physiological responses to sport-specific affective pictures, thereby providing objective evidence for the link between moral identity and emotion in athletes.

Further Evidence for the Independent Reflex-Eliciting and Reflex-Inhibiting Effects of a Startle-Blink Eliciting Stimulus

A small change in the environment (a prepulse) that just precedes a startle-eliciting stimulus can reduce the size of the elicited reflex, but a prepulse does not appear to diminish the ability of the startle-eliciting stimulus to depress a startle response elicited a little later. The reflex-eliciting and reflex-modifying effects of startle stimuli seem to be independent. However, most support for this observation rests on a failure to reject the null hypothesis, and relatively little of this research has employed the acoustic startle blink in human beings. The purpose of the present study was to provide additional evidence on this issue. Participants (n = 20) encountered trials in which a prepulse (p) and two 103 dB(A) blink-eliciting noise bursts (S1 and S2) were given in succession. The prepulse (a synchronous word and tone) occurred 150 ms prior to S1. The prepulse inhibited the startle blink to S1, and S1 depressed the blink elicited 1.5 s later by S2. However, regardless of whether p inhibited the blink to S1, S1 maintained the same capacity to depress the blink to S2. In contrast, a softer S1 (88 dB(A); S1attenuated), which produced a blink nearly matching the size of the prepulse-inhibited blink, did not significantly depress the response to S2. Participants also judged the loudness of S1 and S2. The prepulse reduced the perceived intensity of S1, but much less so than caused by reducing the actual intensity of S1, and proportionally much less so than the prepulse reduced the blink to S1. These results provide further evidence for independent reflex-eliciting and reflex-modifying effects of a startle-eliciting stimulus and argue against the notion that prepulses strongly reduce the general sensory impact of the startle stimulus.