Changes In Arousal Research Articles

Decreased functional brain response to emotional arousal and increased psychiatric symptomology in FMR1 premutation carriers

The FMR1 premutation is an expansion of the CGG repeat island in the FMR1 gene to between 55 and 200 repeats. Evidence suggests that as well as conferring risk for neurodegeneration, the premutation is also associated with increased risk for autistic traits and psychiatric symptoms. An emotional processing fMRI task was used to examine the response to a change in emotional arousal in 17 male carriers and 17 matched controls. A psychiatric symptom checklist (SCL-90-R), autism spectrum and empathy quotients (AQ and EQ), and the Ekman Faces Test were used to investigate clinical symptoms and emotional processing. Carriers exhibited significantly lower activation compared to controls at the bilateral superior parietal lobe, bilateral Brodmann Area (BA) 17 (V1), right intraparietal area and right BA18 (V2) when comparing high and low arousal conditions. Group by age analyses were not significant. Assessments revealed that carriers displayed significantly worse symptoms of psychiatric symptoms and higher levels of autistic traits, as well as impaired facial emotion recognition. No measurements revealed an association with age. Here, we show significantly altered emotional processing in carriers which display stability over age, suggesting that, unlike degenerative aspects, emotional symptoms may be consistent over the lifespan in carriers.

A Psychophysiological and Behavioural Study of Slot Machine Near-Misses Using Immersive Virtual Reality.

During slot machine gambling, near-miss outcomes occur when the final winning icon lands one position off the pay-line. To understand how near-misses promote gambling behaviour in healthy populations, autonomic arousal is often used to index outcome response valence. Findings remain equivocal, possibly owing to the limited ecological validity of computer simulations. Relevant psychological traits, such as impulsivity, which increase the risk of problem gambling, are often not examined. Here, we used immersive virtual reality (VR) to investigate near-miss-induced changes in physiological arousal and VR gambling behaviour. Sixty adult participants with no history of problem gambling were immersed in a VR casino-bar where they engaged with a self-selected slot machine. Real-time heart rate (HR) data were acquired during immersion. Within-subjects analyses were conducted on HR and post-reinforcement pauses (PRPs; i.e., time taken to initiate next-spin) across wins, losses and near-misses. Significant HR acceleration occurred for both near-misses and losses compared to wins, indexing an initial orientation response. Both types of losses were associated with faster next-spin responses. Near-misses did not apparently have unique HR or PRP profiles from losses, although this may reflect our loss control condition, which in itself may have been a subtler near-miss outcome. Impulsivity measured by the SUPPS-P was not associated with near-miss responses. Losses may encourage gambling as participants experience more immediate HR acceleration (indexing arousal unique to losing) and initiate faster responses. Future studies should clarify this effect by investigating problem gambling cohorts and develop VR paradigms taking into consideration the current findings and limitations.

Detailed analysis of skin conductance responses during a gambling task: Decision, anticipation, and outcomes.

Physiological arousal is considered a key factor of gambling behavior. Hence, to understand gambling behavior it is important to study the arousal responses during gambling. Moreover, crucial mechanisms of action could be uncovered by detailing the situations that produce an arousal response. A gamble, or bet, can be partitioned into three distinct phases: (a) decision phase, during which the information concerning the gamble is presented, outcomes are appraised, and a decision is made on how to gamble; (b) anticipation phase, during which the result of the gamble is awaited; (c) outcome phase, during which the outcome of the gamble is presented. Previous research on arousal responses to gambling have mostly measured tonic changes in arousal, and when phasic responses have been measured, analyses have generally concentrated on one of the gamble phases. The aim of the present study was to map the arousal responses during gambling in more detail by measuring skin conductance responses (SCRs) during all three gamble phases of a simple card game. The anticipation phase was found to produce the largest arousal response, suggesting anticipation to be a major contributor to arousal during gambling behavior. Risk behavior during the gambling task was mirrored in self-reported risk taking in everyday life, and risk-takers displayed smaller SCRs compared to nonrisk-takers during decision making, suggesting this as a possible biomarker for risk-taking individuals.

Eye Tracking Effort Expenditure and Autonomic Arousal to Social and Circumscribed Interest Stimuli in Autism Spectrum Disorder.

The social communicative deficits and repetitive behaviours seen in Autism Spectrum Disorder (ASD) may be affected by altered stimulus salience and reward attribution. The present study used eye tracking and a behavioural measure to index effort expenditure, arousal, and attention, during viewing of images depicting social scenes and subject-specific circumscribed interests in a group of 10 adults with ASD (mean age 25.4years) and 19 typically-developing controls (mean age 20.7years) Split-plot and one-way repeated measures ANOVAs were used to explore results. A significant difference between the ASD and control group was found in the amount of effort expended to view social and circumscribed images. The ASD group also displayed significant differences in pupillary response to social and circumscribed images, indicative of changes in autonomic arousal. Overall, the results support the social motivation hypothesis in ASD (Chevallier et al., Trends Cogn Sci 16(4):231-239, 2012) and suggest a role for autonomic arousal in the ASD symptom dyad.

The impact of Yohimbine-induced arousal on facets of behavioural impulsivity

RationaleState-dependent changes in physiological arousal may influence impulsive behaviours.ObjectivesTo examine the relationship between arousal and impulsivity, we assessed the effects of yohimbine (an α2-adrenergic receptor antagonist, which increases physiological arousal via noradrenaline release) on performance on established laboratory-based impulsivity measures in healthy volunteers.MethodsForty-three participants received a single dose of either yohimbine hydrochloride or placebo before completing a battery of impulsivity measures. Blood pressure and heart rate were monitored throughout the study.ResultsParticipants in the yohimbine group showed higher blood pressure and better response inhibition in the Stop Signal Task, relative to the placebo group. Additionally, individual changes in blood pressure were associated with performance on Delay Discounting and Information Sampling tasks: raised blood pressure following drug ingestion was associated with more far-sighted decisions in the Delay Discounting Task (lower temporal impulsivity) yet reduced information gathering in the Information Sampling Task (increased reflection impulsivity).ConclusionsThese results support the notion that impulsive behaviour is dependent upon state physiological arousal; however, distinct facets of impulsivity are differentially affected by physiological changes.

Arousal changes and delirium in acute medically-ill male older patients with and without dementia: a prospective study during hospitalization

Objectives: Previous research has characterized the prevalence, natural course and outcomes of delirium superimposed in dementia but much less is known about the relation between preexisting dementia and the emergence of altered arousal (such as drowsiness, obtundation, stupor or agitation) during acute medical illness. This study aimed to determine the natural course of delirium and abnormal arousal states in acute medically-ill older patients with and without prior dementia during hospital stay.Methods: Observational prospective study in an acute male geriatric ward. Patients aged ≥ 65 years old were assessed by a psychiatrist within the first 72h of admission and in every other day until discharge to determine the level of arousal and the presence of delirium. Prior cognitive impairment, sociodemographic data, chronic comorbidities, psychotropic prescription and functional status were assessed at baseline.Results: 43.5% of participants in the final sample (n= 269) had dementia. Prior dementia was associated with higher rates of moderate/severe hypoarousal (29.9% vs. 4.6%; p<0.001) and delirium (20.5% vs. 7.2%; p<0.001) at admission. RASS ≤ -3 at admission predicted a 4-fold increased intra-hospital mortality risk and RASS ≠ 0 had a sensitivity of 82.8% and a specificity of85.9% for delirium.Conclusions: Moderate/severe hypoarousal is associated with adverse outcomes and should be assessed as part of delirium spectrum, particularly in subjects with prior dementia.

Intensity and workload related dose-response effects of acute resistance exercise on domain-specific cognitive function and affective response – A four-armed randomized controlled crossover trial

IntroductionPreliminary evidence indicates beneficial acute effects of resistance exercise on domain-specific cognitive function. Studies on dose response relationships and underlying mechanisms so far failed to deduce the impact of intensity and overall workload. ObjectiveTo analyze the impact of different intensities and workloads on effects of full body resistance training on cognitive attention, executive function performance, and affective response. MethodsTwenty-six volunteers (9 (35%) female, age 25.9 ± 4.0 years) participated in three workload-matched (60%, 75% and 90% one repetition maximum intensity (1RM) resistance exercise interventions (RE)) and one workload reduced but intensity matched (75% 1RM, 50% overall workload) RE. Order was randomized, REs were on separate days with ≥48 h washout in between. Stroop Test performance (Attention: word and color condition; Interference control: word color interference), self-perceived levels of arousal and ability to concentrate were assessed before and after each RE. ResultsWorkload-matched REs induced significant changes in attention and interference control. The workload reduced 75% 1RM RE induced changes in interference control, but no changes in attention performance. 75% 1RM exercise with full and 50% workload induced significant changes in arousal. Only 75% 1RM exercise with full workload significantly increased participants ability to concentrate. The repeated measures ANCOVA (Covariates: sex and fluid intelligence) indicated greater changes of interference control after 60% 1RM compared to 90% 1RM RE and greater changes of attention performance after 90% 1RM compared to 75% 1RM and 50% workload RE. DiscussionHigher cognitive functions such as interference control seem to particularly benefit from moderate intensity RE whereas lower cognitive functions may be stimulated by higher intensity and higher workload RE. Self-perceived subjective factors did not mediate these dose response relationships. Future studies could analyze changes in cortisol levels, oxygenation, blood flow or electrophysiological signals to deduce triggers for increased stimulus-driven brain response and more controlled brain function.

Facial expressiveness and physiological arousal in frontotemporal dementia: Phenotypic clinical profiles and neural correlates.

Early theories of emotion processing propose an interplay between autonomic function and cognitive appraisal of emotions. Patients with frontotemporal dementia show profound social cognition deficits and atrophy in regions implicated in autonomic emotional responses (insula, amygdala, prefrontal cortex), yet objective measures of facial expressiveness and physiological arousal have been relatively unexplored. We investigated psychophysiological responses (surface facial electromyography (EMG); skin conductance level (SCL)) to emotional stimuli in 25 behavioural-variant frontotemporal dementia (bvFTD) patients, 14 semantic dementia (SD) patients, and 24 healthy older controls, while viewing emotionally positive, neutral, or negative video clips. Voxel-based morphometry was conducted to identify neural correlates of responses. Unlike controls, patients with bvFTD did not show differential facial EMG responses according to emotion condition, whereas SD patients showed increased zygomaticus responses to both positive and neutral videos. Controls showed greater arousal (SCL) when viewing positive and negative videos; however, both bvFTD and SD groups showed no change in SCL across conditions. Regardless of group membership, right insula damage was associated with dampened zygomaticus responses to positive film stimuli. Change in arousal (SCL) was associated with lower integrity of the caudate, amygdala, and temporal pole. Our results demonstrate that while bvFTD patients show an overall dampening of responses, SD patients appear to show incongruous facial emotional expressions. Abnormal responding is related to cortical and subcortical brain atrophy. These results identify potential mechanisms for the abnormal social behaviour in bvFTD and SD and demonstrate that psychophysiological responses are an important mechanism underpinning normal socioemotional functioning.

Changes in brain arousal (EEG-vigilance) after therapeutic sleep deprivation in depressive patients and healthy controls

Depressed patients frequently exhibit a hyperstable brain arousal regulation. According to the arousal regulation model of affective disorders, the antidepressant effect of therapeutic sleep deprivation could be achieved by counter-acting this dysregulation. We investigated the impact of partial sleep deprivation (PSD) on EEG-vigilance (an indicator of brain arousal regulation) in depressed patients (n = 27) and healthy controls (n = 16). PSD was hypothesized to cause a more prominent destabilisation of brain arousal regulation in depressed patients (reflected by increased occurrence of lower EEG-vigilance stages). Furthermore, it was studied whether responders (n = 17) exhibit a more stable baseline brain arousal regulation and would show a more prominent arousal destabilisation after PSD than non-responders (n = 10). Before PSD, patients showed a more stable EEG-vigilance with less declines to lower vigilance stages compared to controls. Contrary to the hypothesis, a greater destabilisation of brain arousal after PSD was seen in controls. Within the patient sample, responders generally showed a less stable EEG-vigilance, especially after PSD when we found significant differences compared to non-responders. EEG-vigilance in non-responders showed only little change from baseline to after PSD. In summary, PSD had a destabilizing impact on brain arousal regulation in healthy controls whereas depressed patients reacted heterogeneously depending on the outcome of treatment.

New Insights on Emotional Contributions to Human Postural Control.

It has been just over 20 years since the effects of height-induced threat on human postural control were first investigated. Raising the height of the support surface on which individuals stood increased the perceived consequences of instability and generated postural control changes. Since this initial work, converging evidence has accumulated supporting the efficacy of using height-induced threat to study the effects of emotions on postural control and confirming a direct influence of threat-related changes in arousal, anxiety, and fear of falling on all aspects of postural control, including standing, anticipatory, and reactive balance. In general, threat-related postural changes promote a greater physical safety margin while maintaining upright stance. We use the static balance literature to critically examine the current state of knowledge regarding: (1) the extent to which threat-related changes in postural control are sensitive to threat-related changes in emotions; (2) the underlying neurophysiological and cognitive mechanisms that may contribute to explaining the relationship between emotions and postural control; and (3) the generalizability of threat-related changes across different populations and types of threat. These findings have important implications for understanding the neuromechanisms that control healthy balance, and highlight the need to recognize the potential contributions of psychological and physiological factors to balance deficits associated with age or pathology. We conclude with a discussion of the practical significance of this research, its impact on improving diagnosis and treatment of postural control deficits, and potential directions for future research.

Combined transcranial direct current stimulation with virtual reality exposure for posttraumatic stress disorder: Feasibility and pilot results

BackgroundFacilitating neural activity using non-invasive brain stimulation may improve extinction-based treatments for posttraumatic stress disorder (PTSD). Objective/hypothesisHere, we examined the feasibility of simultaneous transcranial direct current stimulation (tDCS) application during virtual reality (VR) to reduce psychophysiological arousal and symptoms in Veterans with PTSD. MethodsTwelve Veterans with PTSD received six combat-related VR exposure sessions during sham-controlled tDCS targeting ventromedial prefrontal cortex. Primary outcome measures were changes in skin conductance-based arousal and self-reported PTSD symptom severity. ResultstDCS + VR components were combined without technical difficulty. We observed a significant interaction between reduction in arousal across sessions and tDCS group (p = .03), indicating that the decrease in physiological arousal was greater in the tDCS + VR versus sham group. We additionally observed a clinically meaningful reduction in PTSD symptom severity. ConclusionsThis study demonstrates feasibility of applying tDCS during VR. Preliminary data suggest a reduction in psychophysiological arousal and PTSD symptomatology, supporting future studies.

Phasic locus coeruleus activity regulates cortical encoding of salience information

Phasic activation of locus coeruleus (LC)-norepinephrine (NE) neurons is associated with focused attention and behavioral responses to salient stimuli. We used cell-type-specific optogenetics and single-unit neurophysiology to identify how LC activity influences neural encoding of sensory information. We found that phasic, but not tonic, LC-NE photoactivation generated a distinct event-related potential (ERP) across cortical regions. Salient sensory stimuli (which innately trigger phasic LC activity) produced strong excitatory cortical responses during this ERP window. Application of weaker, nonsalient stimuli produced limited responses, but these responses were elevated to salient stimulus levels when they were temporally locked with phasic LC photoactivation. These results demonstrate that phasic LC activity enhances cortical encoding of salient stimuli by facilitating long-latency signals within target regions in response to stimulus intensity/salience. The LC-driven salience signal identified here provides a measure of phasic LC activity that can be used to investigate the LC's role in attentional processing across species.

The effects of breathing at a frequency of 0.1 Hz on affective state, the cardiovascular system, and adequacy of ventilation.

The present study aimed to investigate changes induced by breathing at 0.1Hz in affective state, cardiovascular activity, and adequacy of ventilation as well as the relation between changes in peripheral physiological processes and alteration of affect. Eighty-three participants were randomly assigned to one of three groups: Two groups doing paced breathing at 0.1Hz, one with and the other without a cover story hiding the goal of the experiment, and, as a control, paced breathing at 0.28Hz. We measured the effects of breathing at 0.1Hz on affective state (unpleasant and pleasant arousals), respiratory sinus arrhythmia (RSA), sympathetic control of the heart (preejection period, PEP), and adequacy of ventilation as measured by partial pressure of end-tidal CO2 (PetCO2 ). The use of a cover story did not influence the effects of paced breathing on the study outcomes. In the 0.1Hz groups, unpleasant arousal decreased only among men. Changes in RSA were not related to changes in affect. Respiratory frequency did not influence PEP. However, changes in PEP were inversely related to changes in pleasant arousal. PetCO2 decreased in all conditions, and a larger drop in PetCO2 predicted a greater decrease in unpleasant arousal. The results obtained corroborate previous findings showing that slow paced breathing may lead to moderate hyperventilation among untrained participants and suggest that hyperventilation during breathing at 0.1Hz is not deep enough to produce an increase in affective arousal.

Does Time of Day Affect Variety-Seeking?

Abstract Variety-seeking is a fundamental aspect of choice. But given circadian rhythms in chronobiology, might variety-seeking vary by time of day? Four studies, including an empirical analysis of millions of purchases, demonstrate diurnal variation in variety-seeking. Variety-seeking is lower in the morning than other times of day. People pick less varied flavors of yogurt, for example, when choosing in the morning. Further, the results demonstrate the underlying role of circadian changes in physiological stimulation and arousal. The effect is mediated by a physiological measure of arousal (i.e., body temperature) and moderated by factors that shape physiological arousal (i.e., sunlight and individual differences in circadian preferences). These findings shed light on drivers of variety-seeking and the biological basis of consumer behavior more generally.

Does the two-chair dialogue intervention facilitate processing of emotions more efficiently than basic Rogerian conditions?

ABSTRACTProcessing difficult emotions is assumed to be of importance in therapeutic change. In this study, we examine whether a two-chair dialogue in Emotion-focused Therapy (EFT) is associated with a change in emotional processing, measured as changes in emotional arousal and emotional experiencing. In a multiple baseline design, 20 clients in treatment for depression or anxiety first received five, seven or nine weekly sessions of baseline treatment providing Rogerian conditions and affect attunement. In the second phase, two-chair intervention was added for the five consecutive sessions. All sessions were subdivided into 2 min segments which were rated using the Client Emotional Arousal Scale III and the Experiencing Scale. Analyses indicated a significantly higher number of high-arousal segment in the latter phase. Individual clients’ change trajectories were not significantly steeper in the second phase. Experiencing increased throughout both phases of treatment. However, after introducing the two-chair dialogue the Experiencing change trajectory was not significantly steeper than in the baseline phase. Findings suggest that both the two-chair dialogue and the Rogerian conditions with affect attunement focus are effective in facilitating emotional processing. Results are consistent with previous research, suggesting that the two-chair dialogue is an emotionally evocative intervention. Implications and limitations are discussed.

Time-Series Prediction of Proximal Aggression Onset in Minimally-Verbal Youth with Autism Spectrum Disorder Using Physiological Biosignals.

It has been suggested that changes in physiological arousal precede potentially dangerous aggressive behavior in youth with autism spectrum disorder (ASD) who are minimally verbal (MV-ASD). The current work tests this hypothesis through time-series analyses on biosignals acquired prior to proximal aggression onset. We implement ridge-regularized logistic regression models on physiological biosensor data wirelessly recorded from 15 MV-ASD youth over 64 independent naturalistic observations in a hospital inpatient unit. Our results demonstrate proof-of-concept, feasibility, and incipient validity predicting aggression onset 1 minute before it occurs using global, person-dependent, and hybrid classifier models.

A Heart Rate Driven Kalman Filter for Continuous Arousal Trend Monitoring.

This paper proposes a continuous and unsupervised approach of monitoring the arousal trend of an individual from his heart rate using Kalman Filter. The state-space model of the filter characterizes the baseline arousal condition. Deviations from this baseline model are used to recognize the arousal trend. A publicly available dataset, DECAF, comprising the physiological responses of 30 subjects while watching 36 movie clips inducing different emotions, is used to validate the proposed technique. For each clip, annotations of arousal given by experts per second are used to quantify the ground truth of arousal change. Experimental results suggest that the proposed algorithm achieves a median correlation of 0.53 between the computed and expected arousal levels which is significantly higher than that achievable by the state-of-the-art technique.

A single dose of cocaine enhances prospective memory performance.

Background:Prospective memory is the ability to recall intended actions or events at the right time or in the right context. While cannabis is known to impair prospective memory, the acute effect of cocaine is unknown. In addition, it is not clear whether changes in prospective memory represent specific alterations in memory processing or result from more general effects on cognition that spread across multiple domains such as arousal and attention.Aims:The main objective of the study was, therefore, to determine whether drug-induced changes in prospective memory are memory specific or associated with more general drug-induced changes in attention and arousal.Methods:A placebo-controlled, three-way, cross-over study including 15 regular poly-drug users was set up to test the influence of oral cocaine (300 mg) and vaporised cannabis (300+150 ‘booster’ µg/kg bodyweight) on an event-based prospective memory task. Attentional performance was assessed using a divided attention task and subjective arousal was assessed with the Profile of Mood States questionnaire.Results:Results showed that cocaine enhanced prospective memory, attention and arousal. Mean performance of prospective memory and attention, as well as levels of arousal were lowest during treatment with cannabis as compared with placebo and cocaine as evinced by a significantly increased trend across treatment conditions. Prospective memory performance was only weakly positively associated to measures of attention and arousal.Conclusion:Together, these results indicate that cocaine enhancement of prospective memory performance cannot be fully explained by parallel changes in arousal and attention levels, and is likely to represent a direct change in the neural network underlying prospective memory.

Treatment Outcomes for Military Veterans With Posttraumatic Stress Disorder: Response Trajectories by Symptom Cluster.

Although effective posttraumatic stress disorder (PTSD) treatments are available, outcomes for veterans with PTSD are relatively modest. Previous researchers have identified subgroups of veterans with different response trajectories but have not investigated whether PTSD symptom clusters (based on a four-factor model) have different patterns of response to treatment. The importance of this lies in the potential to increase treatment focus on less responsive symptoms. We investigated treatment outcomes by symptom cluster for 2,685 Australian veterans with PTSD. We used Posttraumatic Stress Disorder Checklist scores obtained at treatment intake, posttreatment, and 3- and 9-month follow-ups to define change across symptom clusters.Repeated measures effect sizes indicated that arousal and numbing symptoms exhibited the largest changes between intake and posttreatment, dRM = -0.61 and dRM = -0.52, respectively, whereas avoidance and intrusion symptoms showed more modest reductions, dRM = -0.36 and dRM = -0.30, respectively. However, unlike the other symptom clusters, the intrusions cluster continued to show significant changes between posttreatment and 3-month follow-up, dRM = -0.21. Intrusion and arousal symptoms also showed continued changes between 3- and 9-month follow-ups although these effects were very small, dRM = -0.09. Growth curve model analyses produced consistent findings and indicated modest initial changes in intrusion symptoms that continued posttreatment. These findings may reflect the longer time required for emotional processing, relative to behavioral changes in avoidance, numbing, and arousal, during the program; they also reinforce the importance of prioritizing individual trauma-focused therapy directly targeting intrusions as the core component of programmatic treatment.

Locomotor activity modulates associative learning in mouse cerebellum.

Changes in behavioral state can profoundly influence brain function. Here we show that behavioral state modulates performance in delay eyeblink conditioning, a cerebellum-dependent form of associative learning. Increased locomotor speed in head-fixed mice drove earlier onset of learning and trial-by-trial enhancement of learned responses that were dissociable from changes in arousal and independent of sensory modality. Eyelid responses evoked by optogenetic stimulation of mossy fiber inputs to the cerebellum, but not at sites downstream, were positively modulated by ongoing locomotion. Substituting prolonged, low-intensity optogenetic mossy fiber stimulation for locomotion was sufficient to enhance conditioned responses. Our results suggest that locomotor activity modulates delay eyeblink conditioning through increased activation of the mossy fiber pathway within the cerebellum. Taken together, these results provide evidence for a novel role for behavioral state modulation in associative learning and suggest a potential mechanism through which engaging in movement can improve an individual’s ability to learn.