Do depressive symptoms "blunt" effort? An analysis of cardiac engagement and withdrawal for an increasingly difficult task

Cognitive conflict does not always mean high effort: Task difficulty's moderating effect on cardiac response

This article presents an experiment (N = 127 university students) testing whether the previously found impact of conflict primes on effort-related cardiac response is moderated by objective task difficulty. Recently, it has been shown that primed cognitive conflict increases cardiac pre-ejection period (PEP) reactivity-an index of effort intensity-during the performance of relatively easy tasks. This effect could be attributed to conflict-related negative affect. Consequently, as it has been shown for other types of negative affect, we expected conflict primes' effect to be task-context dependent and thus to be moderated by objective task difficulty. In a between-persons design, we manipulated conflict via embedded pictures of conflict-related vs. non-conflict-related Stroop items in a memory task. We expected primed conflict to increase effort in a relatively easy version of the task but to lead to disengagement when task difficulty was objectively high. PEP reactivity corroborated our predictions. Rather than always increasing effort, cognitive conflict's effect on resource mobilization was context-dependent and resulted in weak responses in a difficult task.

Depressive symptoms, task choice, and effort: The moderating effect of personal control on cardiac response

Dysphoric individuals perceive mental tasks as more demanding and show increased cardiovascular responses during the performance of easy cognitive tasks. Recent research on action shielding indicates that providing individuals with personal control over their tasks can mitigate the effects of manipulated affective states on cardiovascular responses reflecting effort. We investigated whether the shielding effect of personal choice also applies to the effect of dispositional negative mood on effort. N = 125 university students with high (dysphoric) versus low (nondysphoric) depressive symptoms engaged in an easy cognitive task either by personal choice or external assignment. As expected, dysphoric individuals showed significantly stronger cardiac PEP reactivity during task performance when the task was externally assigned. Most importantly, this dysphoria effect disappeared when participants could ostensibly personally choose their task. Our findings show that the previously observed shielding effect of personal action choice against incidental affective stimulation also applies to dispositional negative affect.

Economic Choice and Heart Rate Fractal Scaling Indicate That Cognitive Effort Is Reduced by Depression and Boosted by Sad Mood

BACKGROUND

People with depression typically exhibit diminished cognitive control. Control is subjectively costly, prompting speculation that control deficits reflect reduced cognitive effort. Evidence that people with depression exert less cognitive effort is mixed, however, and motivation may depend on state affect.

METHODS

We used a cognitive effort discounting task to measure propensity to expend cognitive effort and fractal structure in the temporal dynamics of interbeat intervals to assess on-task effort exertion for 49 healthy control subjects, 36 people with current depression, and 67 people with remitted depression.

RESULTS

People with depression discounted more steeply, indicating that they were less willing to exert cognitive effort than people with remitted depression and never-depressed control subjects. Also, steeper discounting predicted worse functioning in daily life. Surprisingly, a sad mood induction selectively boosted motivation among participants with depression, erasing differences between them and control subjects. During task performance, depressed participants with the lowest cognitive motivation showed blunted autonomic reactivity as a function of load.

CONCLUSIONS

Discounting patterns supported the hypothesis that people with current depression would be less willing to exert cognitive effort, and steeper discounting predicted lower global functioning in daily life. Heart rate fractal scaling proved to be a highly sensitive index of cognitive load, and data implied that people with lower motivation for cognitive effort had a diminished physiological capacity to respond to rising cognitive demands. State affect appeared to influence motivation among people with current depression given that they were more willing to exert cognitive effort following a sad mood induction.

Relationship of cortisol and alpha amylase to behavioral engagement under three levels of negative evaluative psychosocial stress

Despite that behavioral engagement is integral to mental health, surprisingly little is known about the relationship of psychosocial stress and behavioral engagement. The current study developed an observer-rated measure of behavioral engagement for lab-based stress inductions, then examined its relationship with stress-responsive biomarkers and affect. Young adults (N = 109, Mage=19.4, SDage=1.59, 57% female) completed one of three Trier Social Stress Test (TSST) conditions-non-stressful Control, Intermediate, or an Explicit Negative Evaluative-and at four timepoints provided self-reports of positive and negative affect and saliva samples for cortisol and salivary alpha-amylase (sAA). Trained study staff (experimenters and TSST judges) completed a programmed questionnaire measure of the novel behavioral engagement measure after the participants completed the TSST. Psychometric review and EFA of the behavioral engagement items resulted in a final 8-item measure with good interrater reliability and well-fitting 2-factor structure, capturing Persistence (4 items; loadings=.41-.89), and Quality of Speech (4 items; loadings=.53-.92). Results indicated that the relationship of positive affect growth and biomarker level to behavioral engagement varied substantially as a function of context: As negative evaluation level strengthened, behavioral engagement became more tightly associated with relative preservation of positive affect. For both cortisol and sAA, the relationship between biomarker levels (but not reactivity) and behavioral engagement varied significantly by condition, such that under milder conditions and elevated levels of biomarkers, engagement was greater, but under Explicit Negative Evaluation, and elevated levels of biomarkers, engagement was less, suggesting behavioral withdrawal. Findings reveal the critical role of context-especially negative evaluation-in the relationship of biomarkers with behavioral engagement.

Effortful listening: Sympathetic activity varies as a function of listening demand but parasympathetic activity does not

Research on listening effort has used various physiological measures to examine the biological correlates of listening effort but a systematic examination of the impact of listening demand on cardiac autonomic nervous system activity is still lacking. The presented study aimed to close this gap by assessing cardiac sympathetic and parasympathetic responses to variations in listening demand. For this purpose, 45 participants performed four speech-in-noise tasks differing in listening demand-manipulated as signal-to-noise ratio varying between +23 dB and -16 dB-while their pre-ejection period and respiratory sinus arrythmia responses were assessed. Cardiac responses showed the expected effect of listening demand on sympathetic activity, but failed to provide evidence for the expected listening demand impact on parasympathetic activity: Pre-ejection period reactivity increased with increasing listening demand across the three possible listening conditions and was low in the very high (impossible) demand condition, whereas respiratory sinus arrythmia did not show this pattern. These findings have two main implications. First, cardiac sympathetic responses seem to be the more sensitive correlate of the impact of task demand on listening effort compared to cardiac parasympathetic responses. Second, very high listening demand may lead to disengagement and correspondingly low effort and reduced cardiac sympathetic response.

The Intensity Side of Volition

Abstract. Attaining sports or health goals requires not only high motivation but also the willpower to translate sport-behavior intentions into successful action. This volitional regulation calls for the mobilization of effort to overcome obstacles in the pursuit of goals. The present article provides a theoretical and empirical overview of motivation intensity theory ( Brehm & Self, 1989 ) – a conceptual framework that makes clear and testable predictions about effort mobilization in various contexts. First, we present the guiding principles of this theory and its operationalizations by measures of effort-related cardiovascular reactivity and physical handgrip force. Second, we review a selection of empirical tests of the basic assumptions of this theory and the impact of psychological moderator variables such as affect, fatigue, pain, and personality on effort mobilization. Finally, we discuss important implications of these findings for the sports and health domains and make suggestions for future research.

RZ Interval as an Impedance Cardiography Indicator of Effort-Related Cardiac Sympathetic Activity

Research on effort and motivation commonly assesses how the sympathetic branch of the autonomic nervous system affects the cardiovascular system. The cardiac pre-ejection period (PEP), assessed via impedance cardiography, is a common outcome, but assessing PEP requires identifying subtle points on cardiac waveforms. The present research examined the psychometric value of the RZ interval (RZ), which has recently been proposed as an indicator of sympathetic activity, for effort research. Also known as the initial systolic time interval (ISTI), RZ is the time (in ms) between the ECG R peak and the dZ/dt Z peak. Unlike PEP, RZ involves salient waveform points that are easily and reliably identified. Data from two experiments evaluated the suitability of RZ for effort paradigms and compared it to a popular automated PEP method. In Studies 1 (n = 89) and 2 (n = 71), participants completed a standard appetitive task in which each correct response earned a small amount of cash. As expected, incentives significantly affected PEP and RZ in both experiments. PEP and RZ were highly correlated (all rs ≥ 0.89), and RZ consistently yielded a larger effect size than PEP. In Study 3, a quantitative synthesis of the experiments indicated that the effect size of RZ's response to incentives (Hedges's g = 0.432 [0.310, 0.554]) was roughly 15% larger than PEP's effect size (g = 0.376 [0.256, 0.496]). RZ thus appears promising for future research on sympathetic aspects of effort-related cardiac activity.

Appetitive Motivation in Depressive Anhedonia: Effects of Piece-Rate Cash Rewards on Cardiac and Behavioral Outcomes

Deficits in self-regulation and motivation are central to depression. Using motivational intensity theory (Brehm & Self, 1989), the present research examined how depressive anhedonia influences effort during a piece-rate appetitive task. In piece-rate tasks, people can work at their own pace and are rewarded for each correct response, so they can gain rewards more quickly by expending more effort. A sample of community adults (n = 78) was evaluated for depressive anhedonia using a structured clinical interview, yielding depressive anhedonia and control groups. Participants completed a self-paced cognitive task, and each correct response yielded a cash reward (3 cents or 15 cents, manipulated within-person). Using impedance cardiography, effort-related physiological activity was assessed via the cardiac pre-ejection period (PEP). The results indicated lower reward responsiveness in the anhedonia group. Compared to the control group, the depressive anhedonia group showed significantly less baseline-to-task change in PEP, and they performed marginally worse on the task. The experiment supports the predictions made by applying motivational intensity theory to depression and offers a useful paradigm for evaluating anhedonic effects on effort while people are striving for appealing rewards.

Conscientiousness and Effort-Related Cardiac Activity in Response to Piece-Rate Cash Incentives

Although conscientiousness predicts many aspects of motivation, from delay of gratification to higher achievement, its relationship to responses to monetary incentives is surprisingly inconsistent. Several studies have found null or relationships between conscientiousness and behavioral performance in piece-rate, pay-for-performance tasks, in which people earn money for each unit of work completed. In the present study, we examined the role of conscientiousness in effort-related cardiac activity and behavioral performance during a pay-for-performance task. People worked on a self-paced, piece-rate cognitive task in which they earned 1 cent or 5 cents, manipulated within-person, for each correct response. Conscientiousness predicted greater physiological effort (i.e., shorter pre-ejection period [PEP] reactivity) as incentives increased but had no effect on behavioral performance. The findings suggest that conscientiousness is significantly related to effort for piece-rate tasks, and they reinforce a core idea in motivational intensity theory: effort, performance, and persistence are distinct outcomes that often diverge, so drawing conclusions about effort from performance can be complex.

Psychopathology, everyday behaviors, and autonomic activity in daily life: An ambulatory impedance cardiography study of depression, anxiety, and hypomanic traits

Discrepancies regarding the link between autonomic nervous system (ANS) activity and psychopathology may be due in part to inconsistent measurement of non-psychological factors, including eating, drinking, activity, posture, and interacting with others. Rather than sources of noise, behaviors like being active and being with others may be the behavioral pathways that connect psychopathology symptoms to autonomic activity. The present study examined whether behaviors mediate the association of depression, anxiety, and hypomanic traits with ANS by using experience sampling methodology and ambulatory impedance cardiography. Participants (n = 49) completed measures of affect and one day of experience sampling and ambulatory impedance cardiography. The association of hypomanic traits with heart rate variability and heart rate was mediated by physical activity, and social activity mediated the association of depressive symptoms and respiration. These results highlight the importance of considering the pathways between psychopathology and ANS and the mediating role that everyday behaviors play.

Association Between Depression, Anxiety, and Antidepressant Use With T-Wave Amplitude and QT-Interval

Objectives: Cardiac repolarization may be affected by psychiatric disorders and/or antidepressant use, but evidence for this is inconclusive. This study examined the relationship between depressive and anxiety disorder and use of antidepressants with T-wave amplitude (TWA) and QT-interval.

Methods: Data was obtained from the Netherlands Study of Depression and Anxiety (n = 1,383). Depression/anxiety was diagnosed with the DSM-IV based Composite International Diagnostic Interview. The use of tricyclic antidepressants (TCAs), selective serotonin and noradrenalin reuptake inhibitors (SNRIs), and selective serotonin reuptake inhibitors (SSRIs) was established. T-wave amplitude and QT-interval corrected for heart rate (QTc) were obtained from an ECG measured in a type II axis configuration.

Results: Compared to controls, persons with depression or anxiety disorders did not show a significantly different TWA (p = 0.58; Cohen's d = 0.046) or QTc (p = 0.48; Cohen's d = −0.057). In spite of known sympathomimetic effects, TCA use (p = 0.26; Cohen's d = −0.162) and SNRI use (p = 0.70; Cohen's d = −0.055) were not significantly associated with a lower TWA. TCA use (p = 0.12; Cohen's d = 0.225) and SNRI use (p = 0.11; Cohen's d = 0.227) were also not significantly associated with a prolonged QTc.

Conclusion: We did not find evidence that either depressive/anxiety disorder or antidepressant use is associated with abnormalities in TWA or QTc. Earlier found sympathomimetic effects of TCAs and SNRIs are not evident in these measures of cardiac repolarization.

The cortisol reactivity threshold model: Direction of trait rumination and cortisol reactivity association varies with stressor severity

Various internalizing risk factors predict, in separate studies, both augmented and reduced cortisol responding to lab-induced stress. Stressor severity appears key: We tested whether heightened trait-like internalizing risk (here, trait rumination) predicts heightened cortisol reactivity under modest objective stress, but conversely predicts reduced reactivity under more robust objective stress. Thus, we hypothesized that trait rumination would interact with a curvilinear (quadratic) function of stress severity to predict cortisol reactivity. Evidence comes from 85 currently non-depressed emerging adults who completed either a non-stressful control protocol (n = 29), an intermediate difficulty Trier Social Stress Test (TSST; n = 26), or a robustly stressful negative evaluative TSST (n = 30). Latent growth curve models evaluated relationships between trait rumination and linear and quadratic effects of stressor severity on the change in cortisol and negative affect over time. Among other findings, a significant Trait Rumination x Quadratic Stress Severity interaction effect for cortisol's Quadratic Trend of Time (i.e., reactivity, B = .125, p = .017) supported the hypothesis. Rumination predicted greater cortisol reactivity to intermediate stress (r_p = .400, p = .043), but blunted reactivity to more robust negative evaluative stress (r_p = -0.379, p = 0.039). Contrasting hypotheses, negative affective reactivity increased independently of rumination as stressor severity increased (B = .453, p = 0.044). The direction of the relationship between an internalizing risk factor (trait rumination) and cortisol reactivity varies as a function of stressor severity. We propose the Cortisol Reactivity Threshold Model, which may help reconcile several divergent reactivity literatures and has implications for internalizing psychopathology, particularly depression.

Get Going! Self-focused Attention and Sensitivity to Action and Inaction Effort Primes

Implicit action primes and inaction primes can directly affect effort in some circumstances. The present research examined if people high in trait self-focused attention were more strongly affected by action and inaction primes. Past work has found that self-focus makes people more likely to encode implicit primes as self-relevant, thus increasing the effects of primes. As a result, we expected that people high in trait self-focus would be more strongly affected when primed with action and inaction concepts. A group of young adults completed a self-paced parity task in which most trials primed words related to action or inaction. Effort was measured as baseline-to-task change in the cardiac pre-ejection period (PEP), a measure of sympathetic autonomic influence on the heart. Trait self-focus significantly interacted with the priming manipulation. People high in self-focus were more sensitive to the action primes, shown in greater PEP reactivity, but not to the inaction primes. The findings extend the growing literature on how priming influences effort and support models of how self-focused attention shapes motivational processes.

Predicting Motivation: Computational Models of PFC Can Explain Neural Coding of Motivation and Effort-based Decision-making in Health and Disease

Human behavior is strongly driven by the pursuit of rewards. In daily life, however, benefits mostly come at a cost, often requiring that effort be exerted to obtain potential benefits. Medial PFC (MPFC) and dorsolateral PFC (DLPFC) are frequently implicated in the expectation of effortful control, showing increased activity as a function of predicted task difficulty. Such activity partially overlaps with expectation of reward and has been observed both during decision-making and during task preparation. Recently, novel computational frameworks have been developed to explain activity in these regions during cognitive control, based on the principle of prediction and prediction error (predicted response-outcome [PRO] model [Alexander, W. H., & Brown, J. W. Medial prefrontal cortex as an action-outcome predictor. Nature Neuroscience, 14, 1338-1344, 2011], hierarchical error representation [HER] model [Alexander, W. H., & Brown, J. W. Hierarchical error representation: A computational model of anterior cingulate and dorsolateral prefrontal cortex. Neural Computation, 27, 2354-2410, 2015]). Despite the broad explanatory power of these models, it is not clear whether they can also accommodate effects related to the expectation of effort observed in MPFC and DLPFC. Here, we propose a translation of these computational frameworks to the domain of effort-based behavior. First, we discuss how the PRO model, based on prediction error, can explain effort-related activity in MPFC, by reframing effort-based behavior in a predictive context. We propose that MPFC activity reflects monitoring of motivationally relevant variables (such as effort and reward), by coding expectations and discrepancies from such expectations. Moreover, we derive behavioral and neural model-based predictions for healthy controls and clinical populations with impairments of motivation. Second, we illustrate the possible translation to effort-based behavior of the HER model, an extended version of PRO model based on hierarchical error prediction, developed to explain MPFC-DLPFC interactions. We derive behavioral predictions that describe how effort and reward information is coded in PFC and how changing the configuration of such environmental information might affect decision-making and task performance involving motivation.

Perfectionism and Effort-Related Cardiac Activity: Do Perfectionists Try Harder?

Do perfectionists try harder? Previous research on perfectionism and effort has used self-report items and task performance as indicators of effort. The current study investigated whether individual differences in perfectionism predicted effort-related cardiac activity during a mental effort task. Based on past research that suggests adaptive perfectionism is associated with higher effort, it was hypothesized that self-oriented perfectionism (SOP) would predict increased effort on the task. One hundred and eleven college students completed the Multidimensional Perfectionism Scale (MPS) and a self-paced parity task in which they received a small cash reward (3 cents) for each correct response. Impedance cardiography was used to assess autonomic reactivity, and regression models tested whether SOP and socially prescribed perfectionism (SPP) explained autonomic reactivity. Overall, participants showed both sympathetic (faster pre-ejection period; PEP) and parasympathetic activation (elevated high-frequency heart rate variability; HRV) during the task, reflecting higher effort and engagement. Contrary to predictions, individual differences in perfectionism did not moderate cardiac reactivity. These findings draw attention to the importance of assessing physiological components of effort and motivation directly rather than inferring them from task performance or self-reported effort.