Task difficulty effects on cardiac activity

An Integrated Perspective of Effort and Perception of Effort

Effort and the perception of effort (PE) have been extensively studied across disciplines, resulting in multiple definitions. These inconsistencies block scientific progress by impeding effective communication between and within fields. Here, we present an integrated perspective of effort and PE that is applicable to both physical and cognitive activities. We define effort as the energy utilized to perform an action. This definition can be applied to biological entities performing various voluntary or involuntary activities, irrespective of whether the effort contributes to goal achievement. Then, we define PE as the instantaneous experience of utilizing energy to perform an action. This definition builds on that of effort without conflating it with other subjective experiences. We explore the nature of effort and PE as constructs and variables and highlight key considerations in their measurement. Our integrated perspective aims to facilitate a deeper understanding of these constructs, refine research methodologies, and promote interdisciplinary collaborations.

A Multimodal Approach to Measuring Listening Effort: A Systematic Review on the Effects of Auditory Task Demand on Physiological Measures and Their Relationship

OBJECTIVES

Listening effort involves the mental effort required to perceive an auditory stimulus, for example in noisy environments. Prolonged increased listening effort, for example due to impaired hearing ability, may increase risk of health complications. It is therefore important to identify valid and sensitive measures of listening effort. Physiological measures have been shown to be sensitive to auditory task demand manipulations and are considered to reflect changes in listening effort. Such measures include pupil dilation, alpha power, skin conductance level, and heart rate variability. The aim of the current systematic review was to provide an overview of studies to listening effort that used multiple physiological measures. The two main questions were: (1) what is the effect of changes in auditory task demand on simultaneously acquired physiological measures from various modalities? and (2) what is the relationship between the responses in these physiological measures?

DESIGN

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, relevant articles were sought in PubMed, PsycInfo, and Web of Science and by examining the references of included articles. Search iterations with different combinations of psychophysiological measures were performed in conjunction with listening effort-related search terms. Quality was assessed using the Appraisal Tool for Cross-Sectional Studies.

RESULTS

A total of 297 articles were identified from three databases, of which 27 were included. One additional article was identified from reference lists. Of the total 28 included articles, 16 included an analysis regarding the relationship between the physiological measures. The overall quality of the included studies was reasonable.

CONCLUSIONS

The included studies showed that most of the physiological measures either show no effect to auditory task demand manipulations or a consistent effect in the expected direction. For example, pupil dilation increased, pre-ejection period decreased, and skin conductance level increased with increasing auditory task demand. Most of the relationships between the responses of these physiological measures were nonsignificant or weak. The physiological measures varied in their sensitivity to auditory task demand manipulations. One of the identified knowledge gaps was that the included studies mostly used tasks with high-performance levels, resulting in an underrepresentation of the physiological changes at lower performance levels. This makes it difficult to capture how the physiological responses behave across the full psychometric curve. Our results support the Framework for Understanding Effortful Listening and the need for a multimodal approach to listening effort. We furthermore discuss focus points for future studies.

Engagement of mental effort in response to mental fatigue: A psychophysiological analysis

Acute mental fatigue, characterized by a transient decline in cognitive efficiency during or following prolonged cognitive tasks, can be managed through adaptive effort deployment. In response to mental fatigue, individuals can employ two main behavioral patterns: engaging a compensatory effort to limit performance decrements, or disengaging effort, leading to performance deterioration. This study investigated the behavioral pattern used by participants in mental fatigue conditions. Fifty participants underwent a sequential-task protocol with counterbalanced sessions who took place in two separate sessions: a 30-min incongruent Stroop task (fatiguing session) or a 30-min documentary viewing task (control session), followed by a time-to-exhaustion (TTE) handgrip task at 13 % of maximal voluntary contraction. Psychophysiological measures included the preejection period, heart rate variability, blood pressure, and respiration. Behavioral results showed deteriorated TTE handgrip performance after the Stroop task compared to after the documentary viewing task. During the Stroop task participants were more conservative and prioritized accuracy over speed. Self-reported fatigue was greater after the Stroop task. Psychophysiological data revealed a gradual decrease in sympathetic activity over time in both tasks, with the Stroop task showing a more pronounced decrease. Taken together, these findings suggest a disengagement of effort for a large proportion of participants (49 %) that could be partly attributed to a habituation to the demands of the Stroop task. This study illustrates the interplay of behavioral patterns of effort investment in the context of mental fatigue and underscores the role of disengagement as a dominant response to this phenomenon among healthy participants.

Personal task choice attenuates implicit happiness effects on effort: A study on cardiovascular response

Research on the Implicit-Affect-Primes-Effort model (Gendolla, 2012) found that priming happiness or anger in challenging tasks results in stronger sympathetically mediated cardiovascular responses, reflecting effort, than priming sadness or fear. Recent studies on action shielding revealed that personal task choice can attenuate affective influences on action execution (e.g., Gendolla et al., 2021). The present experiment tested if this action shielding effect also applies to affect primes' influences on cardiovascular response. Participants (N = 136) worked on a cognitive task with integrated briefly flashed and backward masked facial expressions of sadness vs. happiness. Half of the participants could ostensibly choose whether they wanted to work on an attention or on a memory task, while the other half was assigned to one task. Our findings revealed effects on cardiac pre-ejection period (PEP), which align with the expected outcomes for a task of unfixed difficulty where participants establish their own performance standard. Most importantly, task choice shielded against the implicit affective influence on PEP that was evident when the task was externally assigned. Effects on systolic blood pressure (SBP) reactivity largely corresponded to those of PEP.

Analysing experienced and inexperienced cyclists' attentional focus and self-regulatory strategies during varying intensities of fixed perceived effort cycling: A mixed method study

Using a think aloud approach during fixed perceived effort exercise is a unique method to explore the decision-making processes that guide the self-regulation of perceived effort during endurance-based activity. In a two-part study, authors investigated the attentional focus and self-regulatory strategies associated with: Part A - perceived effort corresponding to (RPEGET) and above gas exchange threshold (RPE+15%GET); Part B - between experienced and inexperienced cyclists during fixed perceived effort cycling tasks. Eighteen (15 male, 3 female) healthy, active individuals completed three visits (visit 1 - ramped incremental test and familiarisation, visit 2 and 3-30-min fixed perceived effort cycling). During which, power output, heart rate, lactate, think aloud, and perceptual markers were taken. Random-intercepts linear mixed-effects models assessed the condition, time, and condition × time interactions on all dependent variables. Power output, heart rate, lactate and instances of internal sensory monitoring (t195=2.57,p=.011,β=0.95[0.23,1.68]) and self-regulation (t195=4.14,p=.001,β=1.69[0.89,2.49]) were significantly higher in the RPE+15%GET versus RPEGET trial. No significant differences between inexperienced and experienced cyclists for internal sensory monitoring (t196=-1.78,p=.095,β=-1.73[-3.64,0.18]) or self-regulatory thoughts (t196=-0.39,p=.699,β=-1.06[-6.32,4.21]) were noted but there were significant condition × time interactions for internal monitoring (t196=2.02,p=.045,β=0.44[0.01,0.87]) and self-regulation (t196=3.45,p=.001,β=0.85[0.37,1.33]). Seemingly, experienced athletes associatively attended to internal psychophysiological state and subsequently self-regulate their psychophysiological state at earlier stages of exercise than inexperienced athletes. This is the first study to exhibit the differences in attentional focus and self-regulatory strategies that are activated based on perceived effort intensity and experience level in cyclists.

Task-evoked pulse wave amplitude tracks cognitive load

Cognitive load is a crucial factor in mentally demanding activities and holds significance across various research fields. This study aimed to investigate the effectiveness of pulse wave amplitude (PWA) as a measure for tracking cognitive load and associated mental effort in comparison to heart rate (HR) during a digit span task. The data from 78 participants were included in the analyses. Participants performed a memory task in which they were asked to memorize sequences of 5, 9, or 13 digits, and a control task where they passively listened to the sequences. PWA and HR were quantified from photoplethysmography (PPG) and electrocardiography (ECG), respectively. Pupil dilation was also assessed as a measure of cognitive load. We found that PWA showed a strong suppression with increasing memory load, indicating sensitivity to cognitive load. In contrast, HR did not show significant changes with task difficulty. Moreover, when memory load exceeded the capacity of working memory, a reversal of the PWA pattern was observed, indicating cognitive overload. In this respect, changes in PWA in response to cognitive load correlated with the dynamics of pupil dilation, suggesting a potential shared underlying mechanism. Additionally, both HR and PWA demonstrated a relationship with behavioral performance, with higher task-evoked HR and lower PWA associated with better memory performance. Our findings suggest that PWA is a more sensitive measure than HR for tracking cognitive load and overload. PWA, measured through PPG, holds significant potential for practical applications in assessing cognitive load due to its ease of use and sensitivity to cognitive overload. The findings contribute to the understanding of psychophysiological indicators of cognitive load and offer insights into the use of PWA as a non-invasive measure in various contexts.

Can personal task choice shield against fear and anger prime effects on effort? A study on cardiac response

This experiment tested whether personal task choice can shield against implicit affective influences on sympathetically mediated cardiovascular response, reflecting effort. Participants were N = 121 healthy university students who completed a moderately difficult memory task with integrated briefly flashed and masked fear vs. anger primes. Half of the participants believed they could choose between an attention and a memory task, while the other half was automatically assigned to the task. Replicating previous research, we expected an influence of the affect primes on effort when the task was externally assigned. By contrast, when participants were given a task choice, we predicted strong action shielding and thus a weak implicit affect effect on resource mobilization. As expected, participants in the assigned task condition showed stronger cardiac pre-ejection period reactivity when exposed to fear primes than when processing anger primes. Importantly, this affect prime effect disappeared when participants could ostensibly choose the task. These findings add to other recent evidence for action shielding by personal task choice and importantly extend this effect to implicit affective influences on cardiac reactivity during task performance.

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.

How Long Is Long Enough? Controlling for Acute Caffeine Intake in Cardiovascular Research

Caffeine substantially affects cardiovascular functioning, yet wide variability exists in caffeine control procedures in cardiovascular reactivity research. This study was conducted in order to identify a minimal abstention duration in habitual coffee consumers whereby cardiovascular reactivity is unconfounded by caffeine; Six hours (caffeine's average half-life) was hypothesized. Thirty-nine subjects (mean age: 20.9; 20 women) completed a repeated measures study involving hand cold pressor (CP) and memory tasks. Caffeinated and decaffeinated coffee were administered. The following cardiovascular indices were acquired during pre-task, task, and post-task epochs prior to coffee intake, 30 min-, and six hours post-intake: Heart rate (HR), high-frequency heart rate variability (HF-HRV), root mean squared successive differences (RMSSD), systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), pre-ejection period (PEP), left ventricular ejection time (LVET), systemic vascular resistance (SVR), systemic vascular resistance index (SVRI). Results support the adequacy of a six-hour abstention in controlling for caffeine-elicited cardiovascular changes. The current study offers a suggested guideline for caffeine abstention duration in cardiovascular research in psychophysiology. Consistent practice in caffeine abstention protocols would promote validity and reliability across such studies.

A randomized controlled trial assessing behavioral, cognitive, emotional and physiological changes resulting from a communication skills training in physicians caring for cancer patients

OBJECTIVE

This randomized study assesses behavioral, cognitive, emotional and physiological changes resulting from a communication skills training (CST) for physicians caring for cancer patients.

METHODS

Medical specialists (N = 90) were randomly assigned in groups to complete a manualized 30-h CST or to a waiting list. Assessments included behavioral (communication skills), cognitive (self-efficacy, sense of mastery), emotional (perceived stress) and physiological (heart rate) measures. Assessments were made at baseline (both groups), after CST program (training group), and four months after (waiting list group). All assessments were conducted before, during, and after a complex communication task with an advanced-stage cancer simulated patient (SP).

RESULTS

Trained physicians had higher levels of communication skills (from RR=1.32; p = .003 to RR=41.33; p < .001), self-efficacy (F=9.3; p = .003), sense of mastery (F=167.9; p < .001) and heart rate during the SP encounter (from F=7.4; p = .008 to F=4; p = .050) and same levels of perceived stress (F=3.1; p = .080).

CONCLUSION

A learner-centered, skills-focused and practice-oriented manualized 30-h CST induced multilevel changes indicating physician engagement in a learning process.

PRACTICE IMPLICATIONS

Trainers should consider the CST multilevel benefits (behavioral, cognitive, emotional and physiological) before, during and after a complex communication simulated task as an innovative way to assess the efficacy of a communication skills learning process.

Avoidant Personality Disorder Symptoms and Cardiovascular Reactivity to Psychological Stress Tasks With Increasing Cognitive Demands

Abstract. This study aimed to investigate whether and how avoidant personality disorder symptoms are related to cardiovascular reactivity to stress tasks with different levels of cognitive demands. The revised Chinese edition of the avoidant personality disorder subscale of Personality Diagnosed Questionnaire-4+ (PDQ-4+) was administered to 222 undergraduate students randomly assigned to psychological stress tasks (i.e., mental arithmetic tasks) with low, moderate, or high cognitive demands (manipulated by task difficulty), during which their physiological data were continuously collected. Results showed that avoidant personality disorder symptoms and cognitive demands of tasks interactively predicted systolic blood pressure (SBP) and diastolic blood pressure (DBP) reactivity. In specific, avoidant personality disorder symptoms were not associated with SBP reactivity under the low- and moderate-demand conditions and DBP reactivity under the low-demand condition but were associated with blunted SBP reactivity under the high-demand condition and blunted DBP reactivity under the moderate- and high-demand conditions. These findings indicate that the association between avoidant personality disorder symptoms and cardiovascular reactivity to psychological stress is contingent on the cognitive demands of tasks, which have potential implications for physical health.

Virtual Reality Adaptation Using Electrodermal Activity to Support the User Experience

Virtual reality is increasingly used for tasks such as work and education. Thus, rendering scenarios that do not interfere with such goals and deplete user experience are becoming progressively more relevant. We present a physiologically adaptive system that optimizes the virtual environment based on physiological arousal, i.e., electrodermal activity. We investigated the usability of the adaptive system in a simulated social virtual reality scenario. Participants completed an n-back task (primary) and a visual detection (secondary) task. Here, we adapted the visual complexity of the secondary task in the form of the number of non-player characters of the secondary task to accomplish the primary task. We show that an adaptive virtual reality can improve users’ comfort by adapting to physiological arousal regarding the task complexity. Our findings suggest that physiologically adaptive virtual reality systems can improve users’ experience in a wide range of scenarios.

Training Willpower: Reducing Costs and Valuing Effort

The integrative model of effortful control presented in a previous article aimed to specify the neurophysiological bases of mental effort. This model assumes that effort reflects three different inter-related aspects of the same adaptive function. First, a mechanism anchored in the salience network that makes decisions about the effort that should be engaged in the current task in view of costs and benefits associated with the achievement of the task goal. Second, a top-down control signal generated by the mechanism of effort that modulates neuronal activity in brain regions involved in the current task to filter pertinent information. Third, a feeling that emerges in awareness during effortful tasks and reflects the costs associated with goal-directed behavior. The aim of the present article is to complete this model by proposing that the capacity to exert effortful control can be improved through training programs. Two main questions relative to this possible strengthening of willpower are addressed in this paper. The first question concerns the existence of empirical evidence that supports gains in effortful control capacity through training. We conducted a review of 63 meta-analyses that shows training programs are effective in improving performance in effortful tasks tapping executive functions and/or self-control with a small to large effect size. Moreover, physical and mindfulness exercises could be two promising training methods that would deserve to be included in training programs aiming to strengthen willpower. The second question concerns the neural mechanisms that could explain these gains in effortful control capacity. Two plausible brain mechanisms are proposed: (1) a decrease in effort costs combined with a greater efficiency of brain regions involved in the task and (2) an increase in the value of effort through operant conditioning in the context of high effort and high reward. The first mechanism supports the hypothesis of a strengthening of the capacity to exert effortful control whereas the second mechanism supports the hypothesis of an increase in the motivation to exert this control. In the last part of the article, we made several recommendations to improve the effectiveness of interventional studies aiming to train this adaptive function."Keep the faculty of effort alive in you by a little gratuitous exercise every day."James (1918, p. 127).

Inter-Individual Variability in tDCS Effects: A Narrative Review on the Contribution of Stable, Variable, and Contextual Factors

Due to its safety, portability, and cheapness, transcranial direct current stimulation (tDCS) use largely increased in research and clinical settings. Despite tDCS’s wide application, previous works pointed out inconsistent and low replicable results, sometimes leading to extreme conclusions about tDCS’s ineffectiveness in modulating behavioral performance across cognitive domains. Traditionally, this variability has been linked to significant differences in the stimulation protocols across studies, including stimulation parameters, target regions, and electrodes montage. Here, we reviewed and discussed evidence of heterogeneity emerging at the intra-study level, namely inter-individual differences that may influence the response to tDCS within each study. This source of variability has been largely neglected by literature, being results mainly analyzed at the group level. Previous research, however, highlighted that only a half—or less—of studies’ participants could be classified as responders, being affected by tDCS in the expected direction. Stable and variable inter-individual differences, such as morphological and genetic features vs. hormonal/exogenous substance consumption, partially account for this heterogeneity. Moreover, variability comes from experiments’ contextual elements, such as participants’ engagement/baseline capacity and individual task difficulty. We concluded that increasing knowledge on inter-dividual differences rather than undermining tDCS effectiveness could enhance protocols’ efficiency and reproducibility.

Pulse arrival time as a surrogate of blood pressure

Various models have been proposed for the estimation of blood pressure (BP) from pulse transit time (PTT). PTT is defined as the time delay of the pressure wave, produced by left ventricular contraction, measured between a proximal and a distal site along the arterial tree. Most researchers, when they measure the time difference between the peak of the R-wave in the electrocardiogram signal (corresponding to left ventricular depolarisation) and a fiducial point in the photoplethysmogram waveform (as measured by a pulse oximeter attached to the fingertip), describe this erroneously as the PTT. In fact, this is the pulse arrival time (PAT), which includes not only PTT, but also the time delay between the electrical depolarisation of the heart's left ventricle and the opening of the aortic valve, known as pre-ejection period (PEP). PEP has been suggested to present a significant limitation to BP estimation using PAT. This work investigates the impact of PEP on PAT, leading to a discussion on the best models for BP estimation using PAT or PTT. We conducted a clinical study involving 30 healthy volunteers (53.3% female, 30.9 ± 9.35 years old, with a body mass index of 22.7 ± 3.2 kg/m[Formula: see text]). Each session lasted on average 27.9 ± 0.6 min and BP was varied by an infusion of phenylephrine (a medication that causes venous and arterial vasoconstriction). We introduced new processing steps for the analysis of PAT and PEP signals. Various population-based models (Poon, Gesche and Fung) and a posteriori models (inverse linear, inverse squared and logarithm) for estimation of BP from PTT or PAT were evaluated. Across the cohort, PEP was found to increase by 5.5 ms ± 4.5 ms from its baseline value. Variations in PTT were significantly larger in amplitude, - 16.8 ms ± 7.5 ms. We suggest, therefore, that for infusions of phenylephrine, the contribution of PEP on PAT can be neglected. All population-based models produced large BP estimation errors, suggesting that they are insufficient for modelling the complex pathways relating changes in PTT or PAT to changes in BP. Although PAT is inversely correlated with systolic blood pressure (SBP), the gradient of this relationship varies significantly from individual to individual, from - 2946 to - 470.64 mmHg/s in our dataset. For the a posteriori inverse squared model, the root mean squared errors (RMSE) for systolic and diastolic blood pressure (DBP) estimation from PAT were 5.49 mmHg and 3.82 mmHg, respectively. The RMSEs for SBP and DBP estimation by PTT were 4.51 mmHg and 3.53 mmHg, respectively. These models take into account individual calibration curves required for accurate blood pressure estimation. The best performing population-based model (Poon) reported error values around double that of the a posteriori inverse squared model, and so the use of population-based models is not justified.

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.

Effort Mobilization and Healthy Aging

Healthy aging is in part dependent upon people's willingness and ability to mobilize the effort necessary to support behaviors that promote health and well-being. People may have the best information relating to health along with the best intentions to stay healthy (e.g., health-related goals), but positive outcomes will ultimately be dependent upon them actually investing the necessary effort toward using this information to achieve their goals. In addition, the influences on effort mobilization may vary as a function of physical, psychological, and social changes experienced by the individual across the life span. Building on the overall theme of this special issue, we explore the relationships between motivation, effort mobilization, and healthy aging. We begin by characterizing the relationship between motivation and effort, and identify the factors that influence effort mobilization. We then consider the factors associated specifically with aging that may influence effort mobilization (e.g., changes in cardiovascular and neural mechanisms) and, ultimately, the health and well-being of older adults. Finally, distinguishing between those influential factors that are modifiable versus intractable, we identify ways to structure situations and beliefs to optimize mobilization in support of healthy aging.

Proof-of-Concept and Test-Retest Reliability Study of Psychological and Physiological Variables of the Mental Fatigue Paradigm

This study provided a proof-of-concept and test–retest reliability of measures frequently used to assess a mental fatigue paradigm. After familiarization, 28 healthy men performed (40-min) the Rapid Visual Information Processing (RVP) test in a test–retest design, having mental fatigue sensation, motivation, emotional arousal, total mood disturbance, and electroencephalography (EEG) in the prefrontal cortex measured before and after the test. EEG was recorded during a 3-min rest so that the power spectral density of theta (3–7 Hz) and alpha (8–13 Hz) bands was calculated. Pre-to-post RVP test changes in psychological and physiological domains were compared (paired-T tests), and absolute (standard error of measurement (SEM) and minimal difference (MD)) and relative reliability (intraclass correlation coefficient (ICC)) were calculated. The RVP test induced an increase (p < 0.05) in mental fatigue sensation (120.9% (109.4; 132.4)) and total mood disturbance (3.5% (−6.3; 13.3)), and a decrease in motivation (−7.1% (−9.2; −5.1)) and emotional arousal (−16.2% (−19.1; −13.2)). Likewise, EEG theta (59.1% (33.2; 85.0); p < 0.05), but not alpha band, increased due to RVP test. All psychophysiological responses showed poor-to-moderate relative reliability. Changes in mental fatigue sensation and motivation were higher than SEM and MD, but changes in EEG theta band were higher only than SEM. Mental fatigue sensation, motivation, and EEG theta band were sensitive to distinguish a mental fatigue paradigm despite true mental fatigue effects on theta activity may be trivial.

Blunted cardiovascular reactivity may serve as an index of psychological task disengagement in the motivated performance situations

Challenge and threat models predict that once individuals become engaged with performance, their evaluations and cardiovascular response determine further outcomes. Although the role of challenge and threat in predicting performance has been extensively tested, few studies have focused on task engagement. We aimed to investigate task engagement in performance at the psychological and physiological levels. We accounted for physiological task engagement by examining blunted cardiovascular reactivity, the third possible cardiovascular response to performance, in addition to the challenge/threat responses. We expected that low psychological task engagement would be related to blunted cardiovascular reactivity during the performance. Gamers (N = 241) completed five matches of the soccer video game FIFA 19. We recorded psychological task engagement, heart rate reactivity, and the difference between goals scored and conceded. Lower psychological task engagement was related to blunted heart rate reactivity during the performance. Furthermore, poorer performance in the previous game was related to increased task engagement in the subsequent match. The findings extend existing literature by providing initial evidence that blunted cardiovascular reactivity may serve as the index of low task engagement.

Explicit achievement motive strength determines effort-related myocardial beta-adrenergic activity if task difficulty is unclear but not if task difficulty is clear

Work on physiological and other behavioral correlates of motives often assumes that motives exert a direct effect on behavior once activated. Motivational intensity theory, however, suggests that this does not always apply. In the context of task engagement, motive strength should exert a direct effect on myocardial beta-adrenergic activity if task difficulty is unclear, but not if task difficulty is known. The presented study tested this prediction for the impact of the explicit achievement motive on myocardial beta-adrenergic activity-assessed as pre-ejection period (PEP) reactivity during task performance. Seventy-eight participants performed one of two versions of a mental arithmetic task. After having completed the achievement motive scale of the Personality Research Form, participants were either informed about the difficulty of the task or not before working on it. Participants' PEP reactivity during task performance provided evidence for the predicted moderating impact of clarity of task difficulty: PEP reactivity increased with increasing achievement motive strength if task difficulty was unclear, but not if it was clear. These findings demonstrate that the explicit achievement motive impact on myocardial beta-adrenergic activity is moderated by clarity of task difficulty and suggest that motive strength does not always translate into direct effects on physiology and behavior.

Sympathetic involvement in time-constrained sequential foraging

Appraising sequential offers relative to an unknown future opportunity and a time cost requires an optimization policy that draws on a learned estimate of an environment’s richness. Converging evidence points to a learning asymmetry, whereby estimates of this richness update with a bias toward integrating positive information. We replicate this bias in a sequential foraging (prey selection) task and probe associated activation within the sympathetic branch of the autonomic system, using trial-by-trial measures of simultaneously recorded cardiac autonomic physiology. We reveal a unique adaptive role for the sympathetic branch in learning. It was specifically associated with adaptation to a deteriorating environment: it correlated with both the rate of negative information integration in belief estimates and downward changes in moment-to-moment environmental richness, and was predictive of optimal performance on the task. The findings are consistent with a framework whereby autonomic function supports the learning demands of prey selection.

The role of objective and subjective effort costs in voluntary task choice

Human beings tend to avoid effort, if a less effortful option is equally rewarding. However, and in sharp contrast to this claim, we repeatedly found that (a subset of) participants deliberately choose the more difficult of two tasks in a voluntary task switching (VTS) paradigm even though avoidance of the difficult task was allowed (Jurczyk et al., Motivation Science 5:295–313, 2019). In this study, we investigate to what extent the deliberate switch to the difficult task is determined by the actual objective or the subjective effort costs for the difficult task. In two experiments, participants (N = 100, each) first went through several blocks of voluntary task choices between an easy and a difficult task. After that, they worked through an effort discounting paradigm, EDT, (Westbrook et al., PLoS One 8(7):e68210, 2013) that required participants to make a series of iterative choices between re-doing a difficult task block for a fixed amount or an easy task block for a variable (lower) amount of money until the individual indifference point was reached. In Experiment 1, the EDT comprised the same tasks from the VTS, in Experiment 2, EDT used another set of easy vs. difficult tasks. Results showed that the voluntary switch to the difficult task was mostly predicted by the objective performance costs and only marginally be the subjective effort cost. The switch to the difficult task may thus be less irrational than originally thought and at its avoidance at least partially driven by economic considerations.

Social observation increases the cardiovascular response of hearing-impaired listeners during a speech reception task

Certain cardiovascular measures allow for distinction between sympathetic and parasympathetic nervous system activity. Applied during listening, these measures may provide a novel and complementary insight into listening effort. To date, few studies have implemented cardiovascular measures of listening effort and seldom have these included hearing-impaired participants. These studies have generally measured changes in cardiovascular parameters while manipulating environmental factors, such as listening difficulty. Yet, listening effort is also known to be moderated by individual factors, including the importance of performing successfully. In this study, we aimed to manipulate success importance by adding observers to the traditional laboratory set-up. Twenty-nine hearing-impaired participants performed a speech reception task both alone and in the presence of two observers. Auditory stimuli consisted of Danish Hearing in Noise Test (HINT) sentences masked by four-talker babble. Sentences were delivered at two individually adapted signal-to-noise ratios, corresponding to 50 and 80% of sentences correct. We measured change scores, relative to baseline, of pre-ejection period, two indices of heart rate variability, heart rate and blood pressure (systolic, diastolic, and mean arterial pressure). After each condition, participants rated their effort investment, stress, tendency to give up and preference to change the situation to improve audibility. A multivariate analysis revealed that cardiovascular reactivity increased in the presence of the observers, compared to when the task was performed alone. More specifically, systolic, diastolic, and mean arterial blood pressure increased while observed. Interestingly, participants' subjective ratings were sensitive only to intelligibility level, not the observation state. This study was the first to report results from a range of different cardiovascular variables measured from hearing-impaired participants during a speech reception task. Due to the timing of the observers' presence, we were not able to conclusively attribute these physiological changes to being task related. Therefore, instead of representing listening effort, we suggest that the increased cardiovascular response detected during observation reveals increased physiological stress associated with potential evaluation.

Effects of Transcranial Direct Current Stimulation on effort during a working-memory task

Transcranial Direct Current Stimulation (tDCS) has shown that stimulation of Dorsolateral Prefrontal Cortex (DLPFC) facilitates task performance in working-memory tasks. However, little is known about its potential effects on effort. This study examined whether tDCS affects effort during a working-memory task. Participants received anodal, cathodal and sham stimulation over DLPFC across three sessions before carrying out a 2-back task. During the task, effort-related cardiovascular measures were recorded-especially the Initial Systolic Time Interval (ISTI). Results showed that anodal stimulation produced a shorter ISTI, indicating a greater effort compared to cathodal and sham conditions, where effort was lower. These findings demonstrate that anodal stimulation helps participants to maintain engagement in a highly demanding task (by increasing task mastery), without which they would otherwise disengage. This study is the first to show that tDCS impacts the extent of effort engaged by individuals during a difficult task.

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.

Impact of pain on mental effort assessed as cardiovascular reactivity

Introduction

Pain typically impairs task performance, increases fatigue, and is associated with behavioral disengagement. Together, this suggests that pain impacts effort, defined as the mobilization of resources to carry out behavior. However, empirical evidence on this issue is lacking.

Objectives

Drawing on motivational intensity theory, this study investigated the impact of pain on effort mobilization during cognitive task performance.

Methods

We administered individually adjusted painful thermal stimulations during an easy memory task during which we measured effort as cardiovascular reactivity-a valid and objective measure. Control conditions included painful stimulations alone, the memory task alone, and the memory task with nonpainful heat stimulations. We expected pain to increase subjective difficulty due to additional demand on cognitive functioning, and in turn effort according to motivational intensity theory. Effort-related cardiovascular reactivity was predicted to increase along these conditions: pain-alone, task-alone, task with nonpainful stimulations, and the strongest effort when painful stimulations were administered during the task.

Results

Overall, the findings offered support to our hypotheses. As predicted, results showed that pain increased subjective task difficulty (P = 0.020). Moreover, most of the effort-related cardiovascular measures showed the expected pattern with the strongest reactivity when painful stimulations were administered during the task compared with the other conditions (p < 0.02).

Conclusion

These results are first evidence that pain impacts mental effort assessed as cardiovascular reactivity. We discuss how such extra effort might be related to the persistent feeling of fatigue and behavioral disengagement frequently observed in patients with chronic pain.

Physiological responses to a school task: The role of student-teacher relationships and students' emotional appraisal

BACKGROUND

To be successful, students must learn to deal with socially and cognitively demanding tasks. Much remains unknown about the effects of previous classroom experiences and of students' emotional appraisal of a task on their physiological adaptive responses to it.

AIMS

To investigate how children's physiological response to a social and cognitive task would be directly and interactively influenced by the perceived student-teacher relationship and by children's emotional appraisal of what reaction they expect to have while completing the task.

METHODS

One hundred and sixteen second and third graders took part in the study. Children completed a cognitive and social stress task. Before the task, they were interviewed on their emotional appraisal of the task and on student-teacher relationships. Children's cardiac activity was registered at rest and during the task to measure physiological activation (heart rate) and self-regulation (heart rate variability).

RESULTS

Heart rate variability during the task was positively correlated with the appraised emotional valence of the task and of being observed while doing it. Regression analyses showed that children's physiological self-regulation during the task was affected by the interaction between student-teacher relationships and appraised emotional valence of being observed. Only among children who had experienced negative student-teacher relationships, an active physiological self-regulation was observed in response to the task when they expected it to be positive compared to when they perceived it as negative.

CONCLUSIONS

Children's emotional appraisal of tasks and the quality of student-teacher relationships are important to promote a functional physiological response of self-regulation that underlies academic functioning and well-being at school.

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.

Ventromedial Prefrontal Cortex Activity and Sympathetic Allostasis During Value-Based Ambivalence

Anxiety is characterized by low confidence in daily decisions, coupled with high levels of phenomenological stress. Ventromedial prefrontal cortex (vmPFC) plays an integral role in maladaptive anxious behaviors via decreased sensitivity to threatening vs. non-threatening stimuli (fear generalization). vmPFC is also a key node in approach-avoidance decision making requiring two-dimensional integration of rewards and costs. More recently, vmPFC has been implicated as a key cortical input to the sympathetic branch of the autonomic nervous system. However, little is known about the role of this brain region in mediating rapid stress responses elicited by changes in confidence during decision making. We used an approach-avoidance task to examine the relationship between sympathetically mediated cardiac stress responses, vmPFC activity and choice behavior over long and short time-scales. To do this, we collected concurrent fMRI, EKG and impedance cardiography recordings of sympathetic drive while participants made approach-avoidance decisions about monetary rewards paired with painful electric shock stimuli. We observe first that increased sympathetic drive (shorter pre-ejection period) in states lasting minutes are associated with choices involving reduced decision ambivalence. Thus, on this slow time scale, sympathetic drive serves as a proxy for "mobilization" whereby participants are more likely to show consistent value-action mapping. In parallel, imaging analyses reveal that on shorter time scales (estimated with a trial-to-trial GLM), increased vmPFC activity, particularly during low-ambivalence decisions, is associated with decreased sympathetic state. Our findings support a role of sympathetic drive in resolving decision ambivalence across long time horizons and suggest a potential role of vmPFC in modulating this response on a moment-to-moment basis.

Effort investment in uncontrollable situations: The moderating role of motivation toward closure

According to the principle of energy-conservation principle, effort investment is usually reduced in situations that are perceived as uncontrollable. This is because when success is recognized as impossible, any effortful actions are no longer justified. However, we predicted that individual differences in uncertainty tolerance, i.e., the need for closure (NFC), may moderate effort investment in uncontrollable situations. We tested this prediction in two experimental studies in which we exposed participants with differing levels of NFC to uncontrollable events, and indexed effort through the assessment of systolic blood pressure (SBP) responses. As predicted, in the uncontrollability (vs. controllability) condition, effort investment decreased significantly among low- but not high-NFC participants. Since gaining certainty and achieving closure is not a critical epistemic goal for low-NFC individuals, exerting extra effort to gain certainty is therefore no longer justified. On the other hand, high-NFC participants do not withhold their efforts, as they are highly motivated to obtain certainty. These results may help to account for contradictory findings in effort-investment behaviour and add substantively to the literature concerning motivation toward closure.

Investigating the Influences of Task Demand and Reward on Cardiac Pre-Ejection Period Reactivity During a Speech-in-Noise Task

OBJECTIVES

Effort investment during listening varies as a function of task demand and motivation. Several studies have manipulated both these factors to elicit and measure changes in effort associated with listening. The cardiac pre-ejection period (PEP) is a relatively novel measure in the field of cognitive hearing science. This measure, which reflects sympathetic nervous system activity on the heart, has previously been implemented during a tone discrimination task but not during a speech-in-noise task. Therefore, the primary goal of this study was to explore the influences of signal to noise ratio (SNR) and monetary reward level on PEP reactivity during a speech-in-noise task.

DESIGN

Thirty-two participants with normal hearing (mean age = 22.22 years, SD = 3.03) were recruited at VU University Medical Center. Participants completed a Dutch speech-in-noise test with a single-interfering-talker masking noise. Six fixed SNRs, selected to span the entire psychometric performance curve, were presented in a block-wise fashion. Participants could earn a low (€0.20) or high (€5.00) reward by obtaining a score of ≥70% of words correct in each block. The authors analyzed PEP reactivity: the change in PEP measured during the task, relative to the baseline during rest. Two separate methods of PEP analysis were used, one including data from the whole task block and the other including data obtained during presentation of the target sentences only. After each block, participants rated their effort investment, performance, tendency to give up, and the perceived difficulty of the task. They also completed the need for recovery questionnaire and the reading span test, which are indices of additional factors (fatigue and working memory capacity, respectively) that are known to influence listening effort.

RESULTS

Average sentence perception scores ranged from 2.73 to 91.62%, revealing a significant effect of SNR. In addition, an improvement in performance was elicited by the high, compared to the low reward level. A linear relationship between SNR and PEP reactivity was demonstrated: at the lower SNRs PEP reactivity was the most negative, indicating greater effort investment compared to the higher SNRs. The target stimuli method of PEP analysis was more sensitive to this effect than the block-wise method. Contrary to expectations, no significant impact of reward on PEP reactivity was found in the present dataset. Also, there was no physiological evidence that participants were disengaged, even when performance was poor. A significant correlation between need for recovery scores and average PEP reactivity was demonstrated, indicating that a lower need for recovery was associated with less effort investment.

CONCLUSIONS

This study successfully implemented the measurement of PEP during a standard speech-in-noise test and included two distinct methods of PEP analysis. The results revealed for the first time that PEP reactivity varies linearly with task demand during a speech-in-noise task, although the effect size was small. No effect of reward on PEP was demonstrated. Finally, participants with a higher need for recovery score invested more effort, as shown by average PEP reactivity, than those with a lower need for recovery score.

Type D personality and blunted cardiovascular stress reactivity: Role of task engagement

OBJECTIVE

The underlying mechanisms for linking Type D personality to cardiovascular stress reactivity remain unknown. The present study explored the possible mediating role of cognitive appraisals of stress and/or motivational levels involved in stress in the association between Type D personality and cardiovascular stress reactivity.

DESIGN

Cross-sectional.

METHODS

Chinese version of Type D Scale-14 was administered to 154 undergraduate students who underwent psychosocial stress during which the physiological data were continuously monitored, and cognitive appraisals indexed by a ratio of perceived stress demands to perceived personal resources and motivational levels engaged in stress indexed by self-reported stress task engagement were immediately assessed after the stress exposure.

RESULTS

Results indicated that Type D personality was related to blunted HR, SBP, and DBP reactivity to stress. Self-reported stress task engagement mediated the relation between Type D personality and blunted cardiovascular stress reactivity. The mediation effect of cognitive appraisals on this link was non-significant.

CONCLUSIONS

These findings suggest that motivational disengagement in the psychosocial stress task might be an important pathway linking Type D personality to blunted cardiovascular stress reactivity.

Influence of common lighting conditions and time-of-day on the effort-related cardiac response

Melanopic stimuli trigger diverse non-image-forming effects. However, evidence of a melanopic contribution to acute effects on alertness and performance is inconclusive, especially under common lighting situations. Effects on cognitive performance are likely mediated by effort-related physiological changes. We assessed the acute effects of lighting in three scenarios, at two times of day, on effort-related changes to cardiac contraction as indexed by the cardiac pre-ejection period (PEP). In a within-subject design, twenty-seven participants performed a cognitive task thrice during a morning and a late-afternoon session. We set the lighting at 500 lux in all three lighting scenarios, measured horizontally at the desk level, but with 54 lux, 128 lux, or 241 lux melanopic equivalent daylight illuminance at the eye level. Impedance cardiography and electrocardiography measurements were used to calculate PEP, for the baseline and task period. A shorter PEP during the task represents a sympathetic heart activation and therefore increased effort. Data were analysed with linear mixed-effect models. PEP changes depended on both the light scene and time of day (p = 0.01 and p = 0.002, respectively). The highest change (sympathetic activation) occurred for the medium one of the three stimuli (128 lux) during the late-afternoon session. However, effect sizes for the singular effects were small, and only for the combined effect of light and time of day middle-sized. Performance scores or self-reported scores on alertness and task demand did not change with the light scene. In conclusion, participants reached the same performance most efficiently at both the highest and lowest melanopic setting, and during the morning session. The resulting U-shaped relation between melanopic stimulus intensity and PEP is likely not dependent solely on intrinsic ipRGC stimuli, and might be moderated by extrinsic cone input. Since lighting situations were modelled according to current integrative lighting strategies and real-life indoor light intensities, the result has implications for artificial lighting in a work environment.

A Curvilinear Effect of Mental Workload on Mental Effort and Behavioral Adaptability: An Approach With the Pre-Ejection Period

OBJECTIVE

We tested Hancock and Szalma's mental workload model, which has never been experimentally validated at a global level with the measure of the pre-ejection period (PEP), an index of beta-adrenergic sympathetic impact.

BACKGROUND

Operators adapt to mental workload. When mental workload level increases, behavioral and physiological adaptability intensifies to reduce the decline in performance. However, if the mental workload exceeds an intermediate level, behavioral and physiological adaptability will decrease to protect individuals from excessive perturbations. This decrease is associated with a change in behavioral strategies and disengagement.

METHOD

The experimental task was a modified Fitts' task used in Hancock and Caird. Five levels of task difficulty were computed. Behavioral and physiological adaptability was indexed by the performance with speed-accuracy trade-off and PEP reactivity.

RESULTS

A curvilinear effect of task difficulty on PEP reactivity was significant, with high reactivity at the intermediate level but low reactivity at other levels. We observed a linear effect of task difficulty on error rate and a curvilinear effect on movement time. A decline in performance was noted up to the intermediate level, with a speed-accuracy trade-off above this level showing a faster movement time.

CONCLUSION

We observed for the first time behavioral and physiological adaptability as a function of mental workload.

APPLICATION

The results have important implications for the modeling of mental workload, particularly in the context of the performance-sensitive domain (car driving and air traffic control). They can help guide the design of human-computer interaction to maximize adaptive behavior, that is, the "comfort zone."

Sympathetic arousal during the processing of dysphoric affect by youths at high and low familial risk for depression

Youths at high risk for depression have been shown to have problems in repairing their own sad mood. Given that sympathetic arousal has been implicated both in the experience and regulation of affect, an atypical pattern of arousal may be one of the factors that contribute to mood repair problems. In the current study, we measured sympathetic arousal of never-depressed youths at high (n = 56) and low (n = 67) familial risk for depression during sad mood induction and instructed mood repair. Sympathetic arousal was indexed by skin conductance level (SCL) and cardiac pre-ejection period (PEP); mood repair outcome was indexed by self-rated affect. High-risk youths demonstrated increased SCL during sadness induction, which persisted during mood repair; low-risk youths evidenced increased SCL only during mood repair. Shortened PEP was evident only among high-risk youths and only during mood repair. Furthermore, shortened PEP during mood induction predicted less successful mood repair in the low-risk but not in the high-risk group. The findings suggest that: (a) depression-prone youths differ from control peers in patterns of sympathetic responses to emotional stimuli, which may impair their ability to relieve sadness, and (b) activation patterns differ across subsystems (SCL vs. PEP) of sympathetic activity, in conjunction with depression risk status.

Losses Motivate Cognitive Effort More Than Gains in Effort-Based Decision Making and Performance

Human behavior is more strongly driven by the motivation to avoid losses than to pursue gains (loss aversion). However, there is little research on how losses influence the motivation to exert effort. We compared the effects of loss and gain incentives on cognitive task performance and effort-based decision making. In three experiments, participants performed a cognitively effortful task under gain and loss conditions and made choices about effort expenditure in a decision-making task. Results consistently showed significant loss aversion in effort-based decision making. Participants were willing to invest more effort in the loss compared to the gain condition (i.e., perform a longer duration task: Experiments 1 and 2; or higher task load: Experiment 3). On the other hand, losses did not lead to improved performance (sustained attention), or higher physiological effort (pupil diameter) in Experiments 1 and 2. In Experiment 3, losses did enhance working memory performance, but only at the highest load level. Taken together, these results suggest that loss aversion motivates higher effort investment in effort-based decision-making, while the effect of loss aversion during a performance may depend on the task type or effort level.

Mortality salience, effort, and cardiovascular response to a bar-press challenge: Remarkably nuanced effects of a death prime on heart performance

We presented participants with a bar-pressing challenge relevant to their identity after having exposed them to a prime that made their mortality more or less salient. For some participants, difficulty was low; for others, it was high; for the rest, it was unfixed. As expected, heart pre-ejection period responses-reflecting heart contraction force-were (a) stronger under high-salience conditions when difficulty was high and unfixed, but (b) low regardless of salience when difficulty was low. Findings bear out conceptually and extend results from a previous experiment. In doing so, they add substantively to a new line of support for terror management theory and document the predictive utility of a proposed blended analysis of associated effort processes. The blended analysis speaks to the way in which motives to manage existential terror should convert into active goal striving and to the impact that existential threat might have on aspects of autonomic arousal.

The Influence of Hearing Loss on Cognitive Control in an Auditory Conflict Task: Behavioral and Pupillometry Findings

Purpose The pupil dilation response is sensitive not only to auditory task demand but also to cognitive conflict. Conflict is induced by incompatible trials in auditory Stroop tasks in which participants have to identify the presentation location (left or right ear) of the words "left" or "right." Previous studies demonstrated that the compatibility effect is reduced if the trial is preceded by another incompatible trial (conflict adaptation). Here, we investigated the influence of hearing status on cognitive conflict and conflict adaptation in an auditory Stroop task. Method Two age-matched groups consisting of 32 normal-hearing participants (M _age = 52 years, age range: 25-67 years) and 28 participants with hearing impairment (M _age = 52 years, age range: 23-64 years) performed an auditory Stroop task. We assessed the effects of hearing status and stimulus compatibility on reaction times (RTs) and pupil dilation responses. We furthermore analyzed the Pearson correlation coefficients between age, degree of hearing loss, and the compatibility effects on the RT and pupil response data across all participants. Results As expected, the RTs were longer and pupil dilation was larger for incompatible relative to compatible trials. Furthermore, these effects were reduced for trials following incompatible (as compared to compatible) trials (conflict adaptation). No general effect of hearing status was observed, but the correlations suggested that higher age and a larger degree of hearing loss were associated with more interference of current incompatibility on RTs. Conclusions Conflict processing and adaptation effects were observed on the RTs and pupil dilation responses in an auditory Stroop task. No general effects of hearing status were observed, but the correlations suggested that higher age and a greater degree of hearing loss were related to reduced conflict processing ability. The current study underlines the relevance of taking into account cognitive control and conflict adaptation processes.

Too much or too little? Exploring effort perception in schizophrenia within the framework of motivational intensity theory

Introduction: To explain motivational difficulties in schizophrenia (SZ), attention has focused on the reward system and effort-based decision-making deficits. However, according to motivational intensity theory (MIT), effort is not directly determined by reward but by task difficulty. Moreover, no studies have examined the effort perception in the SZ. Therefore, this cross-sectional study compared effort perception in SZ group with healthy controls. Method: Task difficulty was manipulated by increasing the distance covered (from 8 to 48 metres). Walking speed, perceptions of difficulty and effort were assessed for all difficulty levels. Clinical and bodyweight variables were recorded. Results: As postulated by MIT, perceived effort and difficulty increased with task difficulty in both groups. Perceived effort and difficulty were higher in the SZ group. Perceptions of effort were positively correlated with BMI in SZ, but not with clinical variables. Importantly, although SZ patients perceived the task as more effortful, walking speed was similar between groups. Conclusions: Taken together, these results suggested that individuals with SZ perceived more strongly the effort and the difficulty of the task but could mobilise more effort to complete it. This observation may explain in part the decrease in engaging in physical demanding activities in daily life in SZ.

Non-invasive Neurophysiology in Learning and Training: Mechanisms and a SWOT Analysis

Although many scholars deem non-invasive measures of neurophysiology to have promise in assessing learning, these measures are currently not widely applied, neither in educational settings nor in training. How can non-invasive neurophysiology provide insight into learning and how should research on this topic move forward to ensure valid applications? The current article addresses these questions by discussing the mechanisms underlying neurophysiological changes during learning followed by a SWOT (strengths, weaknesses, opportunities, and threats) analysis of non-invasive neurophysiology in learning and training. This type of analysis can provide a structured examination of factors relevant to the current state and future of a field. The findings of the SWOT analysis indicate that the field of neurophysiology in learning and training is developing rapidly. By leveraging the opportunities of neurophysiology in learning and training (while bearing in mind weaknesses, threats, and strengths) the field can move forward in promising directions. Suggestions for opportunities for future work are provided to ensure valid and effective application of non-invasive neurophysiology in a wide range of learning and training settings.

An Integrative Model of Effortful Control

This article presents an integrative model of effortful control, a resource-limited top-down control mechanism involved in mental tasks and physical exercises. Based on recent findings in the fields of neuroscience, social psychology and cognitive psychology, this model posits the intrinsic costs related to a weakening of the connectivity of neural networks underpinning effortful control as the main cause of mental fatigue in long and high-demanding tasks. In this framework, effort reflects three different inter-related aspects of the same construct. First, effort is a mechanism comprising a limited number of interconnected processing units that integrate information regarding the task constraints and subject’s state. Second, effort is the main output of this mechanism, namely, the effort signal that modulates neuronal activity in brain regions involved in the current task to select pertinent information. Third, effort is a feeling that emerges in awareness during effortful tasks and reflects the costs associated with goal-directed behavior. Finally, the model opens new avenues for research investigating effortful control at the behavioral and neurophysiological levels.