Balance deficits in Chronic Fatigue Syndrome with and without fibromyalgia

OBJECTIVE

Chronic Fatigue Syndrome (CFS) is a disorder of unknown etiology associated with debilitating fatigue. One symptom commonly reported is disequilibrium. The goal of this study was to determine if CFS patients demonstrated verified balance deficits and if this was effected by comorbid fibromyalgia (FM).

METHODS

Twenty-seven patients with CFS (12 with comorbid FM) and 22 age and gender matched controls performed posturography.

RESULTS

Balance scores were significantly correlated with physical functional status in the CFS group (R2 = 0.43, P < 0.001), which was not found for mental functional status (R2 = 0.06, P > 0.5). CFS patients (regardless of FM) had significantly higher anxiety subscale of the vertigo symptom scale scores. CFS patients, regardless of FM status, demonstrated significantly lower overall composite balance scores (Controls - 78.8±1.5; CFS - 69.0±1.4, P < 0.005) even when controlling for anxiety and also had worse preference scores, indicating they relied on visual information preferentially even when visual information was incorrect. Interestingly, the CFS+FM group, not CFS only, demonstrated significantly worse vestibular scores (Controls - 70.2±2.4; CFS only - 67.9±3.8; CFS with FM - 55.4±4.6, P = 0.013).

INTERPRETATION

The major findings are that poor balance may be associated with poorer self-reported physical health. In addition, CFS patients seemed to rely preferentially on visual inputs, regardless of whether it was correct. The finding that vestibular function may be impaired in patients with CFS+FM but not in those with CFS alone suggests that the pathophysiology of CFS+FM may differ as has been suggested by some.

Vegetarians' and omnivores' affective and physiological responses to images of food

Many vegetarians report that meat is unpleasant, but little else is known about their affective responses to meat and non-meat foods. Here we explored affective responses to food images in vegetarians and omnivores and tested the hypothesis that vegetarians have global differences in affective processing (e.g., increased disgust sensitivity). We presented pictures of different food items and recorded participants' affective experience while we recorded peripheral physiology. We found that vegetarians' self-reported experience of meat meal images was less pleasant than omnivores', but that other food images were equally pleasant across the two groups. Moreover, vegetarians and omnivores had strikingly similar physiological responses to all food images - including meat meals. We interpret these results from a psychological constructionist perspective, which posits that individuals conceptualize changes in their bodily states in ways that match their beliefs, such that increased sympathetic nervous system activity may be conceptualized as an experience of excitement about a delicious meat meal for omnivores but as an experience of displeasure for a vegetarian who believes meat is cruel, wasteful, impure, or unhealthy. This interpretation is consistent with emerging neuroscience evidence that the brain constructs experience by predicting and making meaning of internal sensations based on past experience and knowledge.

Longitudinal relationship between onset of physical symptoms and functional impairment

Patients with chronic physical symptoms (e.g., chronic pain) often have significant functional impairment (i.e., disability). The fear avoidance model is the dominant theoretical model of how the relationship between chronic physical symptoms and functional impairment develops and proposes a cyclical/bidirectional relationship. There has never been a definitive test of the proposed bi-directional relationship. The current study followed 767 Operation Enduring Freedom/Operation Iraqi Freedom soldiers from pre-deployment, when they were relatively healthy, to 1 year after deployment, when it was anticipated that symptoms would increase or develop. Over the four assessment time points, physical symptom severity consistently predicted worse functional impairment at the subsequent time point. Functional impairment did not show a consistent relationship with worsening of physical symptom severity. These findings suggest that changes to functional impairment do not have a short-term impact on physical symptom severity.

Emotion fingerprints or emotion populations? A meta-analytic investigation of autonomic features of emotion categories

The classical view of emotion hypothesizes that certain emotion categories have a specific autonomic nervous system (ANS) "fingerprint" that is distinct from other categories. Substantial ANS variation within a category is presumed to be epiphenomenal. The theory of constructed emotion hypothesizes that an emotion category is a population of context-specific, highly variable instances that need not share an ANS fingerprint. Instead, ANS variation within a category is a meaningful part of the nature of emotion. We present a meta-analysis of 202 studies measuring ANS reactivity during lab-based inductions of emotion in nonclinical samples of adults, using a random effects, multilevel meta-analysis and multivariate pattern classification analysis to test our hypotheses. We found increases in mean effect size for 59.4% of ANS variables across emotion categories, but the pattern of effect sizes did not clearly distinguish 1 emotion category from another. We also observed significant variation within emotion categories; heterogeneity accounted for a moderate to substantial percentage (i.e., I2 ≥ 30%) of variability in 54% of these effect sizes. Experimental moderators epiphenomenal to emotion, such as induction type (e.g., films vs. imagery), did not explain a large portion of the variability. Correction for publication bias reduced estimated effect sizes even further, increasing heterogeneity of effect sizes for certain emotion categories. These findings, when considered in the broader empirical literature, are more consistent with population thinking and other principles from evolutionary biology found within the theory of constructed emotion, and offer insights for developing new hypotheses to understand the nature of emotion. (PsycINFO Database Record

Seeing What You Feel: Affect Drives Visual Perception of Structurally Neutral Faces

Affective realism, the phenomenon whereby affect is integrated into an individual's experience of the world, is a normal consequence of how the brain processes sensory information from the external world in the context of sensations from the body. In the present investigation, we provided compelling empirical evidence that affective realism involves changes in visual perception (i.e., affect changes how participants see neutral stimuli). In two studies, we used an interocular suppression technique, continuous flash suppression, to present affective images outside of participants' conscious awareness. We demonstrated that seen neutral faces are perceived as more smiling when paired with unseen affectively positive stimuli. Study 2 also demonstrated that seen neutral faces are perceived as more scowling when paired with unseen affectively negative stimuli. These findings have implications for real-world situations and challenge beliefs that affect is a distinct psychological phenomenon that can be separated from cognition and perception.

Less Engagement in Pleasure Activities is associated with poorer quality of life for Veterans with Comorbid Post-Deployment Conditions

Objective

The presence of multiple comorbid conditions is common after combat deployment and complicates treatment. A potential treatment approach is to target shared mechanisms across conditions that maintain poorer health-related quality of life (HRQOL). One such mechanism may be decrements in pleasurable activities. Impairment in pleasurable activities frequently occurs after deployment and may be associated with poorer HRQOL.

Method

In this brief report, we surveyed 126 Veterans who had previously sought an assessment at a Veterans Affairs post-deployment health clinic and assessed pleasurable activities, HRQOL, and post-deployment health symptoms.

Results

Forty-three percent of Veterans met our criteria for all three post-deployment conditions (PTSD, depression and chronic wide-spread physical symptoms). Greater engagement in pleasurable activities was associated with better HRQOL for all Veterans regardless of type or level of post-deployment health symptoms.

Conclusion

Future research should study if interventions that encourage Veterans with post-deployment health conditions to engage in pleasurable activities are effective rehabilitation strategies.

Simple, Transparent, and Flexible Automated Quality Assessment Procedures for Ambulatory Electrodermal Activity Data

OBJECTIVE

Electrodermal activity (EDA) is a noninvasive measure of sympathetic activation often used to study emotions, decision making, and health. The use of "ambulatory" EDA in everyday life presents novel challenges-frequent artifacts and long recordings-with inconsistent methods available for efficiently and accurately assessing data quality. We developed and validated a simple, transparent, flexible, and automated quality assessment procedure for ambulatory EDA data.

METHODS

A total of 20 individuals with autism (5 females, 5-13 years) provided a combined 181 h of EDA data in their home using the Affectiva Q Sensor across 8 weeks. Our procedure identified invalid data using four rules: First, EDA out of range; second, EDA changes too quickly; third, temperature suggests the sensor is not being worn; and fourth, transitional data surrounding segments identified as invalid via the preceding rules. We identified invalid portions of a pseudorandom subset of our data (32.8 h, 18%) using our automated procedure and independent visual inspection by five EDA experts.

RESULTS

Our automated procedure identified 420 min (21%) of invalid data. The five experts agreed strongly with each other (agreement: 98%, Cohen's κ: 0.87) and, thus, were averaged into a "consensus" rating. Our procedure exhibited excellent agreement with the consensus rating (sensitivity: 91%, specificity: 99%, accuracy: 92%, κ: 0.739 [95% CI = 0.738, 0.740]).

CONCLUSION

We developed a simple, transparent, flexible, and automated quality assessment procedure for ambulatory EDA data.

SIGNIFICANCE

Our procedure can be used beyond this study to enhance efficiency, transparency, and reproducibility of EDA analyses, with free software available at http://www.cbslab.org/EDAQA.

High healthcare utilization near the onset of medically unexplained symptoms

OBJECTIVE

Patients with medically unexplained syndromes (MUS) often do not receive appropriate healthcare. A critical time for effective healthcare is the inception of MUS. The current study examined data from a prospective longitudinal study of Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF) soldiers to understand the relationship of increasing physical symptom burden to healthcare utilization.

METHODS

Data was examined from a prospective study of OEF/OIF soldiers assessed before and one year after deployment (n=336). Physical symptom burden was measured with the Patient Health Questionnaire (PHQ-15). Analyses were conducted with polynomial regression and response surface analysis (RSA).

RESULTS

Increases in physical symptom burden predicted greater healthcare utilization one year after deployment: primary care practitioner (slope=-0.26, F=4.07, p=0.04), specialist (slope=-0.43, F=8.67, p=0.003), allied health therapy (e.g., physical therapy) (slope=-0.41, F=5.71, p=0.02) and mental health (slope=-0.32, F=4.04, p=0.05). There were no significant difference in utilization between those with consistently high levels and those with increases in physical symptom burden.

CONCLUSION

This is the first prospective study to examine, and show, a relationship between onset of clinically significant physical symptoms and greater healthcare utilization. Our data suggest that patients with increasing physical symptom burden have the same level of healthcare as patients with chronic physical symptom burden. Needed next steps are to better understand the quality of care at inception and determine how to intervene so that recommended approaches to care are provided from the onset.

Salience Network Connectivity Modulates Skin Conductance Responses in Predicting Arousal Experience

Individual differences in arousal experience have been linked to differences in resting-state salience network connectivity strength. In this study, we investigated how adding task-related skin conductance responses (SCR), a measure of sympathetic autonomic nervous system activity, can predict additional variance in arousal experience. Thirty-nine young adults rated their subjective experience of arousal to emotionally evocative images while SCRs were measured. They also underwent a separate resting-state fMRI scan. Greater SCR reactivity (an increased number of task-related SCRs) to emotional images and stronger intrinsic salience network connectivity independently predicted more intense experiences of arousal. Salience network connectivity further moderated the effect of SCR reactivity: In individuals with weak salience network connectivity, SCR reactivity more significantly predicted arousal experience, whereas in those with strong salience network connectivity, SCR reactivity played little role in predicting arousal experience. This interaction illustrates the degeneracy in neural mechanisms driving individual differences in arousal experience and highlights the intricate interplay between connectivity in central visceromotor neural circuitry and peripherally expressed autonomic responses in shaping arousal experience.

Evidence for a Large-Scale Brain System Supporting Allostasis and Interoception in Humans

Large-scale intrinsic brain systems have been identified for exteroceptive senses (e.g., sight, hearing, touch). We introduce an analogous system for representing sensations from within the body, called interoception, and demonstrate its relation to regulating peripheral systems in the body, called allostasis. Employing the recently introduced Embodied Predictive Interoception Coding (EPIC) model, we used tract-tracing studies of macaque monkeys, followed by two intrinsic functional magnetic resonance imaging samples (N = 280 and N = 270) to evaluate the existence of an intrinsic allostatic/interoceptive system in the human brain. Another sample (N = 41) allowed us to evaluate the convergent validity of the hypothesized allostatic/interoceptive system by showing that individuals with stronger connectivity between system hubs performed better on an implicit index of interoceptive ability related to autonomic fluctuations. Implications include insights for the brain's functional architecture, dissolving the artificial boundary between mind and body, and unifying mental and physical illness.

Resilience during war: Better unit cohesion and reductions in avoidant coping are associated with better mental health function after combat deployment

OBJECTIVE

The majority of individuals who endure traumatic events are resilient; however, we do not yet understand why some individuals are more resilient than others. We used data from a prospective longitudinal study Army National Guard and Reserve personnel to examine how unit cohesion (military-specific social support) and avoidant coping relate to resilience over the first year after return from deployment.

METHOD

Soldiers (N = 767) were assessed at 4 phases: predeployment (P1), immediately postdeployment (P2), 3 months' postdeployment (P3), and 1-year postdeployment (P4).

RESULTS

After controlling for predeployment avoidant coping and overall social support, higher unit cohesion was associated with a reduction in avoidant coping (from P1 to P3). This reduction in avoidant coping (from P1 to P3) mediated the relationship between unit cohesion (P2) and improvement in mental health function (from P1 to P3).

CONCLUSIONS

The results are consistent with the hypothesis that higher unit cohesion may mitigate increases in avoidant coping in military personnel after a combat deployment and in turn may improve mental health function. (PsycINFO Database Record

Iraq and Afghanistan Veterans report symptoms consistent with chronic multisymptom illness one year after deployment

Many Veterans returning from service in Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) experience chronic pain. What is not known is whether for some OIF/OEF Veterans this pain is part of a larger condition of diffuse multisystem symptoms consistent with chronic multisymptom illness (CMI). We use data from a prospective longitudinal study of OIF/OEF Veterans to determine the frequency of CMI. We found that 1 yr after deployment, 49.5% of OIF/OEF Veterans met criteria for mild to moderate CMI and 10.8% met criteria for severe CMI. Over 90% of Veterans with chronic pain met criteria for CMI. CMI was not completely accounted for either by posttraumatic stress disorder or by predeployment levels of physical symptoms. Veterans with symptoms consistent with CMI reported significantly worse physical health function than Veterans who did not report symptoms consistent with CMI. This study suggests that the presence of CMI should be considered in the evaluation of OIF/OEF Veterans. Further, it suggests the pain management for these Veterans may need to be tailored to take CMI into consideration.

An active inference theory of allostasis and interoception in depression

In this paper, we integrate recent theoretical and empirical developments in predictive coding and active inference accounts of interoception (including the Embodied Predictive Interoception Coding model) with working hypotheses from the theory of constructed emotion to propose a biologically plausible unified theory of the mind that places metabolism and energy regulation (i.e. allostasis), as well as the sensory consequences of that regulation (i.e. interoception), at its core. We then consider the implications of this approach for understanding depression. We speculate that depression is a disorder of allostasis, whose myriad symptoms result from a 'locked in' brain that is relatively insensitive to its sensory context. We conclude with a brief discussion of the ways our approach might reveal new insights for the treatment of depression.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.

Comparison of the functional health limitations of Iraq or Afghanistan Veterans to Desert Shield/Storm Veterans with chronic fatigue syndrome

Initial evidence suggests some Operation Enduring/Iraqi Freedom (OEF/OIF) veterans suffer from significant physical symptoms. It is not known if other medical conditions may explain these symptoms or if they are causing functional limitations. We compared OEF/OIF veterans with CFS to Desert Shield/Storm veterans with CFS seen at a post-deployment VA clinic soon after their respective deployments. We found 17.6% of OEF/OIF veterans met criteria for CFS. Compared to Desert Shield/Storm veterans with CFS, the OEF/OIF veterans with CFS demonstrated worse mental health function and similar physical health function.

Methodological recommendations for a heartbeat detection-based measure of interoceptive sensitivity

Heartbeat detection tasks are often used to measure cardiac interoceptive sensitivity-the ability to detect sensations from one's heart. However, there is little work to guide decisions on the optimum number of trials to use, which should balance reliability and power against task duration and participant burden. Here, 174 participants completed 100 trials of a widely used heartbeat detection task where participants attempt to detect whether presented tones occurred synchronously or asynchronously with their heartbeats. First, we quantified measurement reliability of the participant's accuracy derived from differing numbers of trials of the task using a correlation metric; we found that at least 40-60 trials were required to yield sufficient reliability. Next, we quantified power by simulating how the number of trials influenced the ability to detect a correlation between cardiac interoceptive sensitivity and other variables that differ across participants, including a variable measured from our sample (body mass index) as well as simulated variables of varying effect sizes. Using these simulations, we quantified the trade-offs between sample size, effect size, and number of trials in the heartbeat detection task such that a researcher can easily determine any one of these variables at given values of the other two variables. We conclude that using fewer than 40 trials is typically insufficient due to poor reliability and low power in estimating an effect size, although the optimal number of trials can differ by study.

Decision making from economic and signal detection perspectives: development of an integrated framework

Behavior is comprised of decisions made from moment to moment (i.e., to respond one way or another). Often, the decision maker cannot be certain of the value to be accrued from the decision (i.e., the outcome value). Decisions made under outcome value uncertainty form the basis of the economic framework of decision making. Behavior is also based on perception-perception of the external physical world and of the internal bodily milieu, which both provide cues that guide decision making. These perceptual signals are also often uncertain: another person's scowling facial expression may indicate threat or intense concentration, alternatives that require different responses from the perceiver. Decisions made under perceptual uncertainty form the basis of the signals framework of decision making. Traditional behavioral economic approaches to decision making focus on the uncertainty that comes from variability in possible outcome values, and typically ignore the influence of perceptual uncertainty. Conversely, traditional signal detection approaches to decision making focus on the uncertainty that arises from variability in perceptual signals and typically ignore the influence of outcome value uncertainty. Here, we compare and contrast the economic and signals frameworks that guide research in decision making, with the aim of promoting their integration. We show that an integrated framework can expand our ability to understand a wider variety of decision-making behaviors, in particular the complexly determined real-world decisions we all make every day.

A shift in perspective: Decentering through mindful attention to imagined stressful events

Ruminative thoughts about a stressful event can seem subjectively real, as if the imagined event were happening in the moment. One possibility is that this subjective realism results from simulating the self as engaged in the stressful event (immersion). If so, then the process of decentering--disengaging the self from the event--should reduce the subjective realism associated with immersion, and therefore perceived stressfulness. To assess this account of decentering, we taught non-meditators a strategy for disengaging from imagined events, simply viewing these events as transient mental states (mindful attention). In a subsequent neuroimaging session, participants imagined stressful and non-stressful events, while either immersing themselves or adopting mindful attention. In conjunction analyses, mindful attention down-regulated the processing of stressful events relative to baseline, whereas immersion up-regulated their processing. In direct contrasts between mindful attention and immersion, mindful attention showed greater activity in brain areas associated with perspective shifting and effortful attention, whereas immersion showed greater activity in areas associated with self-processing and visceral states. These results suggest that mindful attention produces decentering by disengaging embodied senses of self from imagined situations so that affect does not develop.

Using the common sense model of self-regulation to understand the relationship between symptom reporting and trait negative affect

BACKGROUND/PURPOSE

Based on the Common Sense Model of Self-Regulation, we examined if the relationship of trait NA to physical symptom reporting was moderated by life events and illness representations.

METHODS

This relationship was examined using a cross-sectional dataset of 554 elderly adults.

RESULTS

A significant three-way interaction demonstrated that individuals who reported the greatest severity of physical symptoms were higher in trait NA, and reported more life events and a chronic illness history.

CONCLUSIONS

The results of this study are consistent with the hypothesis that individual high on trait NA who have a history of a chronic illness have illness representations with both disease specific physical symptoms and symptoms from other causes, such as emotional distress. This may complicate the care of medical conditions for these patients.

Threat perception after the Boston Marathon bombings: The effects of personal relevance and conceptual framing

We examined how the Boston Marathon bombings affected threat perception in the Boston community. In a threat perception task, participants attempted to "shoot" armed targets and avoid shooting unarmed targets. Participants viewing images of the bombings accompanied by affectively negative music and text (e.g., "Terror Strikes Boston") made more false alarms (i.e., more errors "shooting" unarmed targets) compared to participants viewing the same images accompanied by affectively positive music and text (e.g., "Boston Strong") and participants who did not view bombing images. This difference appears to be driven by decreased sensitivity (i.e., decreased ability to distinguish guns from non-guns) as opposed to a more liberal bias (i.e., favouring the "shoot" response). Additionally, the more strongly affected the participant was by the bombings, the more their sensitivity was reduced in the negatively framed condition, suggesting that this framing was particularly detrimental to the most vulnerable individuals in the affected community.

Attention network test: assessment of cognitive function in chronic fatigue syndrome

Information processing difficulties are common in patients with chronic fatigue syndrome (CFS). It has been shown that the time it takes to process a complex cognitive task, rather than error rate, may be the critical variable underlying CFS patients' cognitive complaints. The Attention Network Task (ANT) developed by Fan and colleagues may be of clinical utility to assess cognitive function in CFS, because it allows for simultaneous assessment of mental response speed, also called information processing speed, and error rate under three conditions challenging the attention system. Comparison of data from two groups of CFS patients (those with and without comorbid major depressive disorder; n = 19 and 22, respectively) to controls (n = 29) consistently showed that error rates did not differ among groups across conditions, but speed of information processing did. Processing time was prolonged in both CFS groups and most significantly affected in response to the most complex task conditions. For simpler tasks, processing time was only prolonged in CFS participants with depression. The data suggest that the ANT may be a task that could be used clinically to assess information processing deficits in individuals with CFS.

Self-reported stressors of National Guard women veterans before and after deployment: the relevance of interpersonal relationships

BACKGROUND

With their rapidly expanding roles in the military, women service members experience significant stressors throughout their deployment experience. However, there are few studies that examine changes in women Veterans' stressors before and after deployment.

OBJECTIVE

This study examines the types of stressors women Veterans report before deployment, immediately after deployment, 3 months after deployment, and 1 year post-deployment.

DESIGN

Descriptive data on reported stressors was collected at four time points of a longitudinal study (HEROES Project). Open-ended responses from the Coping Response Inventory (CRI) were coded into six possible major stressor categories for analysis.

PARTICIPANTS

Seventy-nine Army National Guard and Reserve female personnel deploying to Operation Enduring Freedom (OFF)/Operation Iraqi Freedom (OIF) were surveyed prior to deployment. Of these participants, 35 women completed Phase 2, 41 completed Phase 3, and 48 completed Phase 4 of the study.

KEY RESULTS

We identified six major stressor categories: (1) interpersonal (i.e., issues with family and/or friends), (2) deployment-related and military-related, (3) health concerns, (4) death of a loved one, (5) daily needs (i.e., financial/housing/transportation concerns), and (6) employment or school-related concerns. At all time points, interpersonal issues were one of the most common type of stressor for this sample. Daily needs concerns increased from 3 months post-deployment to 1 year post-deployment.

CONCLUSIONS

Interpersonal concerns are commonly reported by women Veterans both before and after their combat experience, suggesting that this is a time during which interpersonal support is especially critical. We discuss implications, which include the need for a more coordinated approach to women Veterans' health care (e.g., greater community-based outreach), and the need for more and more accessible Veterans Affairs (VA) services to address the needs of female Veterans.

What pre-deployment and early post-deployment factors predict health function after combat deployment?: a prospective longitudinal study of Operation Enduring Freedom (OEF)/Operation Iraqi Freedom (OIF) soldiers

Background

Physical and mental function are strong indicators of disability and mortality. OEF/OIF Veterans returning from deployment have been found to have poorer function than soldiers who have not deployed; however the reasons for this are unknown.

Methods

A prospective cohort of 790 soldiers was assessed both pre- and immediately after deployment to determine predictors of physical and mental function after war.

Results

On average, OEF/OIF Veterans showed significant declines in both physical (t=6.65, p<.0001) and mental function (t=7.11, p<.0001). After controlling for pre-deployment function, poorer physical function after deployment was associated with older age, more physical symptoms, blunted systolic blood pressure reactivity and being injured. After controlling for pre-deployment function, poorer mental function after deployment was associated with younger age, lower social desirability, lower social support, greater physical symptoms and greater PTSD symptoms.

Conclusions

Combat deployment was associated with an immediate decline in both mental and physical function. The relationship of combat deployment to function is complex and influenced by demographic, psychosocial, physiological and experiential factors. Social support and physical symptoms emerged as potentially modifiable factors.

Older adults' hemodynamic responses to an acute emotional stressor: short report

BACKGROUND/STUDY CONTEXT: Vascular and myocardial activation can each increase blood pressure responses to stressors, but vascular responses are uniquely associated with negative affect, pernicious coping processes, and cardiovascular risk. These hemodynamic correlates of coping in response to acute stressors have not been well characterized in older adults.

METHODS

Adults 65 to 97 years of age (N = 74) either engaged in written disclosure about a distressing event (acute stressor) or wrote objectively about a neutral topic (control). Blood pressure, impedance cardiography, and affect measures were assessed at baseline and in response to writing. Moderating effects of age on affect, blood pressure, and vascular and myocardial responses to the acute stressor were tested using multiple linear regression models.

RESULTS

Follow-up tests of Age × Writing Group interactions indicated that the expected effects of written disclosure on systolic and diastolic blood pressure responses were diminished with increasing age. Regardless of age, compared with neutral writing, written disclosure increased negative affect and vascular responses, but not myocardial responses.

CONCLUSION

Blood pressure responses to an acute, emotionally evocative stressor were indistinguishable from blood pressure responses to a control condition among the eldest older adults in our sample. In contrast, characterizing the hemodynamic mechanisms of blood pressure responses revealed notable vascular effects of the acute, emotional stressor across a wide age range. Such characterization may be particularly useful for clarifying the psychophysiological pathways to older adults' cardiovascular health.

The hundred-year emotion war: are emotions natural kinds or psychological constructions? Comment on Lench, Flores, and Bench (2011)

For the last century, there has been a continuing debate about the nature of emotion. In the most recent offering in this scientific dialogue, Lench, Flores, and Bench (2011) reported a meta-analysis of emotion induction research and claimed support for the natural kind hypothesis that discrete emotions (e.g., happiness, sadness, anger, and anxiety) elicit specific changes in cognition, judgment, behavior, experience, and physiology. In this article, we point out that Lench et al. (2011) is not the final word on the emotion debate. First, we point out that Lench et al.'s findings do not support their claim that discrete emotions organize cognition, judgment, experience, and physiology because they did not demonstrate emotion-consistent and emotion-specific directional changes in these measurement domains. Second, we point out that Lench et al.'s findings are in fact consistent with the alternative (a psychological constructionist approach to emotion). We close by appealing for a construct validity approach to emotion research, which we hope will lead to greater consensus on the operationalization of the natural kind and psychological construction approaches, as well as the criteria required to finally resolve the emotion debate.

A retrospective cohort study of U.S. service members returning from Afghanistan and Iraq: is physical health worsening over time?

Background

High rates of mental health disorders have been reported in veterans returning from deployment to Afghanistan (Operation Enduring Freedom: OEF) and Iraq (Operation Iraqi Freedom: OIF); however, less is known about physical health functioning and its temporal course post-deployment. Therefore, our goal is to study physical health functioning in OEF/OIF veterans after deployment.

Methods

We analyzed self-reported physical health functioning as physical component summary (PCS) scores on the Veterans version of the Short Form 36 health survey in 679 OEF/OIF veterans clinically evaluated at a post-deployment health clinic. Veterans were stratified into four groups based on time post-deployment: (1Yr) 0 – 365 days; (2Yr) 366 – 730 days; (3Yr) 731 – 1095 days; and (4Yr+) > 1095 days. To assess the possibility that our effect was specific to a treatment-seeking sample, we also analyzed PCS scores from a separate military community sample of 768 OEF/OIF veterans evaluated pre-deployment and up to one-year post-deployment.

Results

In veterans evaluated at our clinic, we observed significantly lower PCS scores as time post-deployment increased (p = 0.018) after adjusting for probable post-traumatic stress disorder (PTSD). We similarly observed in our community sample that PCS scores were lower both immediately after and one year after return from deployment (p < 0.001) relative to pre-deployment PCS. Further, PCS scores obtained 1-year post-deployment were significantly lower than scores obtained immediately post-deployment (p = 0.02).

Conclusion

In our clinical sample, the longer the duration between return from deployment and their visit to our clinic, the worse the Veteran’s physical health even after adjusting for PTSD. Additionally, a decline is also present in a military community sample of OEF/OIF veterans. These data suggest that, as time since deployment length increases, physical health may deteriorate for some veterans.

Rumination moderates the associations between PTSD and depressive symptoms and risky behaviors in U. S. veterans

Risky behaviors, including unsafe sex, aggression, rule breaking, self-injury, and dangerous substance use have become a growing issue for U.S. veterans returning from combat deployments. Evidence in nonveteran samples suggests that risky behaviors reflect efforts to cope with and alleviate depressive and/or anxious symptoms, particularly for individuals with poor emotion-regulation skills. These associations have not been studied in veterans. Rumination, or repeated thoughts about negative feelings and past events, is a coping strategy that is associated with several psychopathologies common in veterans. In this cross-sectional study, 91 recently returned veterans completed measures of trait rumination, self-reported risky behaviors, and symptoms of posttraumatic stress disorder (PTSD) and depression. Analyses revealed that veterans with more depressive and PTSD symptoms reported more risky behaviors. Moreover, rumination significantly interacted with PTSD symptoms and depressive symptoms (both β = .21, p < .05), such that psychiatric symptoms were associated with risky behaviors only for veterans with moderate to high levels of rumination. Although cross-sectional, these findings support theory that individuals with poor coping skills may be particularly likely to respond to negative mood states by engaging in risky behaviors. Implications include using rumination-focused interventions with veterans in order to prevent engagement in risky behaviors.

The impact of self-monitoring of blood glucose on a behavioral weight loss intervention for patients with type 2 diabetes

PURPOSE

The purpose of the study was to examine the association of self-monitoring of blood glucose (SMBG) to weight loss and A1C among participants in a behavioral weight loss intervention.

METHODS

Multivariate analyses were employed to evaluate the relationship between SMBG and changes in patient weight and A1C levels. Bootstrapping was used to determine whether there was an indirect effect of SMBG on weight loss through diet adherence and an indirect effect of SMBG on A1C through weight loss.

RESULTS

The relationship between increased SMBG and greater weight loss was mediated by better adherence to diet. The relationship of increased SMBG and greater reductions in A1C were mediated by greater weight loss.

CONCLUSIONS

Results of the study were consistent with the hypothesis that SMBG leads to an increased adherence to dietary recommendations. For patients who are taught to use their diet to lose weight, increased adherence to dietary recommendations is associated with increased weight loss and subsequently better glucose control. SMBG may be of value as an adjunctive intervention in behavioral programs for type 2 diabetes.

Association between self-monitoring of blood glucose and diet among minority patients with diabetes

BACKGROUND

Self-monitoring of blood glucose (SMBG) is used to regulate glucose control. It is unknown whether SMBG can motivate adherence to dietary recommendations. We predicted that participants who used more SMBG would also report lower fat and greater fruit and vegetable consumption.

METHODS

The present study was a cross-sectional study of 401 primarily minority individuals living with diabetes in East Harlem, New York. Fat intake and fruit and vegetable consumption were measured with the Block Fruit/Vegetable/Fiber and Fat Screeners.

RESULTS

Greater frequency of SMBG was associated with lower fat intake (r(s) = -0.15; P < 0.01), but not fruit and vegetable consumption. The effects of SMBG were not moderated by insulin use; thus, the relationship was significant for those individuals both on and not on insulin. A significant interaction was found between frequency of SMBG and changing one's diet in response to SMBG on total fat intake. The data suggest that participants who use SMBG to guide their diet do not have to monitor multiple times a day to benefit.

CONCLUSION

The present study found that the frequency of SMBG was associated with lower fat intake. Patients are often taught to use SMBG to guide their self-management. This is one of the first studies to examine whether SMBG is associated with better dietary intake.

Chronic widespread pain, mental health, and physical role function in OEF/OIF veterans

OBJECTIVE

Describe the associations among pain, mental health concerns, and function in veterans of Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF).

DESIGN

Retrospective review of self-reported, standardized clinical intake surveys.

SETTING

A multidisciplinary deployment health clinic at a Veterans Affairs (VA) medical center.

PATIENTS

The first 429 veterans of OEF/OIF presenting for clinical evaluation at a deployment health clinic.

OUTCOME MEASURES

Function, measured with the Role Physical (RP) scale of the Veterans RAND (VR)-36 survey, was compared for veterans with and without chronic widespread pain (CWP).

RESULTS

After controlling for age, sex, and positive screens for depression and post-traumatic stress disorder (PTSD), the presence of CWP had a significant, clinically relevant, and independent effect on VR-36 RP (-6.2 points, DeltaR(2) = 0.052, P < 0.001). Mean VR-36 RP normed score was 43.3 (standard deviation 11.9). CWP was common (29%), as were positive mental health screens (PTSD 53%, depression 60%, alcohol misuse 63%).

CONCLUSIONS

In this sample of OEF/OIF veterans, the majority of whom reported good or better general health, CWP was common and related to poorer physical role function, independent of comorbid mental health concerns.

Exploratory behavior in mice selectively bred for developmental differences in aggressive behavior

The development and expression of exploratory behavior was assessed in the Cairns lines of Institute for Cancer Research (ICR) mice that were selectively bred for differences in aggressive behavior, with a high-aggressive 900 line, low-aggressive 100 line, and control 500 line. Four paradigms were employed. Developmental changes were evident in the complex novel arena, with older males faster to contact a novel object, and ambulating more than young males. Within the control 500 line, older males showed longer latency to emerge from the home cage, and shorter latency to contact novel objects. In the 900 line, younger males showed this same pattern. R. B. Cairns proposed that line differences in aggressive behavior arise through alterations in developmental timing [Cairns et al. [1983] Life-span developmental psychology (Vol. 5). New York: Academic Press; Gariépy et al. [2001] Animal Behaviour 61: 933-947]. The early appearance of mature patterns of exploratory behavior in 900 line males supports this interpretation. The 900 line males also appear to be behaviorally inhibited in novel settings such as the light-dark box and the neohypophagia paradigm, compared to the 500 and 100 lines (Experiments 1, 2, and 4). Moreover, in the most complex apparatus, the novel arena, 900 line males were slowest to exit the home cage, and fastest to contact a novel object. The apparent contrast in these parameters of exploratory behavior is discussed in relation to T. C. Schneirla's [1965 Advances in the study of behavior (Vol. 1). New York: PN Academic] approach-withdrawal theory.

Continuous measurement of BRSI in chronic fatigue syndrome

This paper discusses the development of a system to measure continuous cardiac baroreceptor measurement during a 45-minute 70-degree head-up tilt (HUT) of five groups of subjects suffering the following: chronic fatigue syndrome (CFS), CFS with fibromyalgia (CFS-FM), CFS with postural orthostatic tachycardia syndrome (CFS-POTS), controls with POTS (CON-POTS), and controls (CON). The duration of the test was 56-minutes, which included a five-minute supine baseline, a 45-minute HUT and a six-minute recovery period. The system was developed in LabView, and can provide a comparative time analyses of weighted BRSI averages. Baroreflex effectiveness index (BEI) was also investigated over the course of lags 0, 1 and 2 as well as an assessment of overall BEI performance between groups.

A comparative validation of sympathetic reactivity in children and adults

This study provides comparative data on cardiac reactivity to common laboratory tasks in preschool children (ages 4.5-5.5 years) and young adults. We used a series of tasks (an emotionally evocative video, interview, reaction time task, and cold forehead pressor) to examine whether pre-ejection period, a common estimate of sympathetic cardiac activity in adults, provides a comparable measure of sympathetic reactivity to these tasks in preschool children. Our results demonstrate that the cardiac reactivity (pre-ejection period, respiratory sinus arrhythmia, and heart period) to such tasks in children and young adults is similar, but with smaller sympathetic reactivity in children. The consistency of the reactivity across tasks within individuals and consistency of reactivity across children and young adults suggests that pre-ejection period is a reasonable estimate of sympathetic activity in children.

Locus of control predicts appraisals and cardiovascular reactivity to a novel active coping task

These two studies investigated the influence of dispositional locus of control (LOC) on subjective and physiological responses to a novel laboratory stressor task. Across two studies, 64 healthy undergraduate students, ages 18-22, completed Levenson's (LOC) scales for internal, powerful others, and chance prior to performing a video-game task. Participants rated pretask and posttask stressfulness and coping ability (i.e., measures of primary and secondary appraisal). Cardiovascular measures (heart period, HP; preejection period, PEP; respiratory sinus arrhythmia, RSA; cardiac output, CO; systolic blood pressure, SBP; diastolic blood pressure, DBP & total peripheral resistance, TPR) were recorded during 4-minute baseline and 4-minute stressor task periods. The internal LOC factor predicted pretask reports of coping ability as well as posttask reports of stressfulness. In contrast, the powerful-others LOC factor predicted cardiac changes (HP, PEP, and RSA) during the task but not cardiac output or any other vascular change measure. These results underscore the importance of using the three subscales of the Levenson LOC to assess relationships between dispositional LOC and the response to stressors because self-reported appraisals of a task are predicted by a different component of dispositional LOC than are task-related cardiovascular functions.

Cardiovascular Measures of Attention to Illusory and Nonillusory Visual Stimuli

This study was an extension of the Berntson, Cacioppo, and Fieldstone (1996) study that found that attending to visual illusions presented with text (usually a question directing attention to the illusory property) lengthened heart period via uncoupled vagal activation. Eighty participants were assigned to one of four groups that received either the original Berntson et al. illusions or a modification formed by the factorial combination of whether the illusion and its related text were present or absent. Participants also performed the same serial-subtraction mental-arithmetic task from Berntson et al. During the mental-arithmetic task heart period (HP) shortened, respiratory sinus arrhythmia (RSA) was reduced, and preejection period (PEP) shortened, which indicated a reciprocally coupled sympathetic activation and parasympathetic inhibition mode of cardiac control. Although idiographic analyses found this to be the most common control mode, all other modes were also obtained – especially the nonreciprocal modes of coactivation and coinhibition. During the visual task, PEP lengthened for all groups indicating uncoupled sympathetic inhibition while attending to the stimuli; however, HP differed depending upon the illusion factor. HP lengthened when illusions were absent, but unlike Berntson et al. it shortened when illusions were present. Idiographic analyses found that although most participants showed sympathetic inhibition, approximately equal numbers of participants showed parasympathetic activation and inhibition. Variation in response stereotypy may mask cardiac responses elicited by subtle cognitive phenomena such as the processing of visual illusions, especially in passive viewing tasks. We also suggest that individual differences in mental effort needed to integrate top-down and bottom-up perceptual processes, or personality variables such as the need for cognition, may contribute to response variability in the visual task.

Development of the baroreflex in the young rat

The baroreceptor-heart period reflex was assessed in conscious, freely behaving rat pups on postnatal days 6 and 14. The baroreceptor-heart period reflex was elicited using the alpha1-adrenergic agonist phenylephrine to increase blood pressure and the vasodilator, sodium nitroprusside, to decrease blood pressure. The autonomic effects of the baroreceptor manipulations were determined using pharmacological autonomic blockade. The data demonstrate that vasoconstriction produces a potent baroreflex-mediated bradycardia as early as postnatal day 6, which had previously been demonstrated only in anesthetized pups. In the anesthetized pup, the bradycardia is mediated by vagal activation, while we demonstrate that both vagal activation and sympathetic withdrawal occur in unanesthetized animals. In addition, the results replicate previous findings in rats demonstrating minimal cardiac sympathetic activation or vagal withdrawal following vasodilation during the first week of life, but substantial baroreflex-mediated tachycardia by the second week.

Postural stability index is a more valid measure of stability than equilibrium score

Researchers, therapists, and physicians often use equilibrium score (ES) from the Sensory Organization Test, a key test in the NeuroCom EquiTest System (a dynamic posturography system) to assess stability. ES reflects the overall coordination of the visual, proprioceptive, and vestibular systems for maintaining standing posture. In our earlier article, we proposed a new measure of anterior-posterior (A-P) postural stability called the Postural Stability Index (PSI), which accounts for more biomechanical aspects than ES. This article showed that PSI provides a clinically important adjunct to ES. In the present article, we show that PSI can provide an acceptable index even if a person falls during the trial, whereas ES assigns a zero score for any fall. We also show that PSI decreases as ankle stiffness increases, which is intuitive, while ES exhibits the opposite behavior. Ankle stiffness is generally recognized as an indicator of postural stability. These results suggest that PSI is a more valid measure of A-P stability than ES.

Use of time-frequency analysis to investigate temporal patterns of cardiac autonomic response during head-up tilt in chronic fatigue syndrome

Although a number of studies have reported alterations in cardiac autonomic nervous system function in chronic fatigue syndrome (CFS), the results are not consistent across studies. Reasons for these discrepancies include (1) the use of a heterogeneous patient sample that included those with orthostatic postural tachycardia (POTS), a condition with an autonomic changes, and (2) the use of frequency domain techniques which require a stationary signal and averaging data across relatively long epochs. To deal with these shortcomings, we used the smoothed pseudo-Wigner-Ville transform (SPWVT) to analyze heart rate variability (HRV) and blood pressure variability (BPV) during head-up tilt (HUT) by separating CFS patients into those with and without POTS. SPWVT has the advantage of providing instantaneous information about autonomic function under nonstable physiological conditions. We studied 18 CFS patients without POTS, eight CFS patients with POTS and 25 sedentary healthy controls during supine rest and during the first 10 min after HUT. While we found significant effects of postural change in both groups for all autonomic variables, there were significant group x time interactions between CFS without POTS and controls for only instant center frequency (ICF) within the low frequency region both from HRV (p=0.02) and from BPV (p=0.01). Although the physiological meaning of ICF still remains unknown, the data suggest that even CFS patients without POTS may have a subtle underlying disturbance in autonomic function.

Interoceptive sensitivity and self-reports of emotional experience

People differ in the extent to which they emphasize feelings of activation or deactivation in their verbal reports of experienced emotion, termed arousal focus (AF). Two multimethod studies indicate that AF is linked to heightened interoceptive sensitivity (as measured by performance on a heartbeat detection task). People who were more sensitive to their heartbeats emphasized feelings of activation and deactivation when reporting their experiences of emotion over time more than did those who were less sensitive. This relationship was not accounted for by several other variables, including simple language effects. Implications for the role of interoception in experienced emotion and the validity of self-reported emotion are discussed.

Measures of postural stability

Dynamic posturography has become an important tool for understanding standing balance in clinical settings. A key test in the NeuroCom International (Clackamas, Oregon) dynamic posturography system, the Sensory Organization Test (SOT), provides information about the integration of multiple components of balance. The SOT test leads to an outcome measure called the "equilibrium score" (ES), which reflects the overall coordination of the visual, proprioceptive, and vestibular systems for maintaining standing posture. Researchers, therapists, and physicians often use the ES from the SOT as a clinically relevant measure of standing balance. We discuss here the formula used for evaluating the ES and propose an additional measure of postural stability, called the Postural Stability Index (PSI), that accounts for shear force and individual anthropomorphic measures. We propose that this new measure provides a clinically important adjunct to the current SOT and can be calculated from data already collected by the NeuroCom forceplate during the SOT.

Relationship between temporal changes in cardiac parasympathetic activity and motion sickness severity

Chemotherapy-induced nausea has been associated with a time-related decrease in cardiac parasympathetic activity. We tested the hypothesis that a time-related decrease in cardiac parasympathetic activity would also be associated with nausea and other motion sickness symptoms during illusory self-motion (vection). Fifty-nine participants (aged 18-34 years: 25 male) were exposed to a rotating optokinetic drum to induce vection. Symptoms of motion sickness and an estimate of cardiac parasympathetic activity (respiratory sinus arrhythmia; RSA) were obtained at baseline and throughout a drum-rotation period. As expected, motion sickness symptoms increased and RSA decreased over time during drum rotation. Moreover, greater decreases in RSA over time correlated with greater motion sickness severity. These results suggest that a time-related decrease in cardiac parasympathetic activity may be an important correlate of nausea and motion sickness across different evocative contexts.

Influence of control and physical effort on cardiovascular reactivity to a video game task

This study investigated the influences of both perceived control and physical effort on cardiovascular reactivity. Undergraduates (N = 32) played a video game task interrupted by aversive noise. Perceived control of the noise was manipulated by instructions indicating the presence or absence of a contingency between performance and noise presentations. Physical effort was manipulated by controlling the physical force required to perform the task. There was a significant main effect of control on systolic blood pressure (SBP) and total peripheral resistance (TPR), with both increasing more during low than high control conditions. The results suggest that high perceived control over aversive noise in an effortful task reduces SBP and TPR reactivity relative to low perceived control. The results are consistent with the idea that control buffers the reactivity associated with task performance under aversive conditions.

Cardiovascular patterns associated with threat and challenge appraisals: a within-subjects analysis

Previous studies demonstrated distinct cardiovascular patterns associated with threat and challenge appraisals for groups of participants. We extend these results by assessing whether appraisals continue to be associated with these cardiovascular response patterns within an individual as appraisals change. Participants completed four verbal mental arithmetic tasks for which they made appraisals before and after each task. Cardiac reactivity and total peripheral resistance (TPR) were calculated for the first and last minutes of each task, and the number of responses and percent correct were measured for each task. In line with our prediction, pretask appraisals were related to some task-related cardiac responses across the four tasks. In addition, task-related cardiovascular reactivity and behaviors both influenced appraisals following the task. Our findings suggest that an idiographic analysis of appraisals, cardiovascular physiology, and task-related behaviors provides a richer understanding of the appraisal process and reveals sex differences deserving further assessment.