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Circadian mismatch and cardiovascular response to a performance challenge: Larks in morning and evening work sessions
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We offer thoughts pertaining to purported conceptual and replication crises that have been discussed in relation to the limited-resource model (LRM) of self-control, functioning as crisis outsiders who have been conducting related research concerned with determinants and cardiovascular correlates of effort. Guiding analyses in our laboratory convey important lessons about experimental generation of the now-classic LRM self-regulatory-fatigue effect on control. They do so by drawing attention to conditions that must be met in fatigue-induction and fatigue-influence phases of relevant experiments. One fundamental lesson is that even highly standardized fatigue-induction protocols cannot be expected to consistently allow definitive tests of this effect. Another is that the effect might emerge consistently only in a behavioral-restraint “sweet spot” of sorts—a multidimensional motivational space wherein rested study participants view restraint as possible and worthwhile and fatigued participants do not. Implications are identified and discussed.
This article addresses recent controversy surrounding the limited resource model of self-control developed by Baumeister and colleagues. It does so focusing on certain concerns that have been raised and drawing from an emerging analysis of fatigue influence on behavioral restraint that is guiding current research in our laboratory. The concerns pertain to elements of the relevant research literature that present an uncertain fit with one of the model’s key propositions, regarding performance resource depletion—that is, fatigue—influence on inhibitory strength and control. They have led some investigators to question the proposition, suggesting that related control findings might have been generated by a mechanism or set of mechanisms alternative to fatigue. Our emerging analysis of fatigue influence goes against this grain. It suggests that the fatigue proposition remains viable but could benefit from informed elaboration regarding the role fatigue plays in determining how intensively people resist unwanted behavioral urges. In light of the analysis, the literature elements of concern are not only understandable, but to be expected.
Although individual athletic performance generally tends to peak in the evening, individuals who exhibit a strong diurnal preference perform better closer to their circadian peak. Time-of-day performance effects are influenced by circadian phenotype (diurnal preference and chronotype—sleep-wake patterns), homeostatic energy reserves and, potentially, genotype, yet little is known about how these factors influence physiological effort. Here, we investigate the effects of time of day, diurnal preference, chronotype, and PER3 (a circadian clock gene) genotype on both effort and performance in a population of Division I collegiate swimmers (n = 27). Participants competed in 200m time trials at 7:00 and 19:00 and were sampled pre- and post-trial for salivary α-amylase levels (as a measure of physiological effort), allowing for per-individual measures of performance and physiological effort. Hair samples were collected for genotype analysis (a variable-number tandem-repeat (VNTR) and a single nucleotide polymorphism (SNP) in PER3). Our results indicate significant and parallel time-of-day by circadian phenotype effects on swim performance and effort; evening-type swimmers swam on average 6% slower with 50% greater α-amylase levels in the morning than they did in the evening, and morning types required 5–7 times more effort in the evening trial to achieve the same performance result as the morning trial. In addition, our results suggest that these performance effects may be influenced by gene (circadian clock gene PER3 variants) by environment (time of day) interactions. Participants homozygous for the PER34,4 length variant (rs57875989) or who possess a single G-allele at PER3 SNP rs228697 swam 3–6% slower in the morning. Overall, these results suggest that intra-individual variation in athletic performance and effort with time of day is associated with circadian phenotype and PER3 genotype.
Objectives
Based on the Implicit-Affect-Primes-Affect (IAPE) model (Gendolla 2012, 2015), we investigated the effect of affect primes’ visibility on effort-related cardiac response.
Methods
Participants worked on a cognitive “parity task” with integrated pictures of sad vs. angry faces that were briefly flashed (25 ms) vs. clearly visible (780 ms). We recorded cardiac pre-ejection period (PEP) to assess effort mobilization.
Results
As expected, PEP reactivity in the sadness-prime condition was stronger than in the anger-prime condition when the primes were briefly flashed, while the opposite pattern occurred when the affect primes were clearly visible. However, these effects only occurred for men, but not for women, as indicated by a significant prime x prime visibility x gender interaction.
Conclusions
These findings provide new evidence for the role of prime visibility as a moderator of automatic effort mobilization—and suggest that this moderator effect applies especially to men.
Human circadian rhythmicity is driven by a circadian clock comprised of two distinct components: the central clock, located in the suprachiasmatic nucleus (SCN) within the hypothalamus, and the peripheral clocks, located in almost all tissues and organ systems in the body. Entrainment, or alignment, of circadian rhythmicity is dependent upon time of day and can occur through environmental influences such as light cues and physical activity exerted on skeletal muscle. Entrainment of the circadian clock through exercise has been reported to improve health by reducing risk of conditions such as cardiovascular disease (CVD), but further research is still needed. The purpose of this review is to discuss the effects exercise has on the regulation of circadian rhythmicity, specifically with respect to CVD risk factors – including hormonal levels, sleep/wake cycles, blood pressure, and heart rate. Additionally, the impact of exercise-induced circadian entrainment is discussed relative to hormone regulation, nocturnal blood pressure dipping, post-exercise hypotension, and overall cardiovascular health.
We describe an emerging analysis of fatigue influence on behavioral restraint and consider its potential significance for two central concerns of contemporary restraint investigators: (1) adverse health effects of restraint, and (2) fatigue influence on self-control. Regarding health, the analysis provides a conceptual framework for anticipating
restraint intensity and therefore possible risk. It also draws attention to a pathological pathway through which restraint could generate some adverse health outcomes. Regarding self-control, the analysis conveys a perspective that could markedly improve our prediction of relevant outcomes and has focused significance for crises that have been identified in relation to the influential limited resource analysis of self-control developed by Baumeister and colleagues. Crisis concerns have led some to conclude that the limited resource analysis should be discarded. The present behavioral restraint analysis goes against this grain, suggesting that the limited resource analysis might wisely be retained and afforded the chance to mature – among other things, incorporating elaborated effort components.
The aim of this study was to investigate the influence of chronotype on mood state and ratings of perceived exertion (RPE) before and in response to acute high intensity interval exercise (HIIE) performed at different times of the day. Based on the morningness–eveningness questionnaire, 12 morning-types (M-types; N = 12; age 21 ± 2 years; height 179 ± 5 cm; body mass 74 ± 12 kg) and 11 evening-types (E-types; N = 11; age 21 ± 2 years; height 181 ± 11 cm; body mass 76 ± 11 kg) were enrolled in a randomized crossover study. All subjects underwent measurements of Profile of Mood States (POMS), before (PRE), after 12 (POST12) and 24 h (POST24) the completion of both morning (08.00 am) and evening (08.00 p.m.) training. Additionally, Global Mood Disturbance and Energy Index (EI) were calculated. RPE was obtained PRE and 30 min POST HIIE. Two-way ANOVA with Tukey’s multiple comparisons test of POMS parameters during morning training showed significant differences in fatigue, vigor and EI at PRE and POST24 between M-types and E-types. In addition, significant chronotype differences were found only in POST12 after the evening HIIE for fatigue, vigor and EI. For what concerns Borg perceived exertion, comparing morning versus evening values in PRE condition, a higher RPE was observed in relation to evening training for M-types (P = 0.0107) while E-types showed higher RPE values in the morning (P = 0.008). Finally, intragroup differences showed that E-types had a higher RPE respect to M-types before (P = 0.002) and after 30 min (P = 0.042) the morning session of HIIE. No significant changes during the evening training session were found. In conclusion, chronotype seems to significantly influence fatigue values, perceived exertions and vigor in relation to HIIE performed at different times of the day. Specifically, E-types will meet more of a burden when undertaking a physical task early in the day. Practical results suggest that performing a HIIE at those times of day that do not correspond to subjects’ circadian preference can lead to increased mood disturbances and perceived exertion. Therefore, an athlete’s chronotype should be taken into account when scheduling HIIE.
Trial registration:
ACTRN12617000432314, registered 24 March 2017, “retrospectively registered”.
Web address of trial:
https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371862&showOriginal=true&isReview=true
The purpose of this study was to evaluate if the time of the day (8.00 a.m. vs 8.00 p.m.) and chronotype could influence autonomic cardiac control in soccer players in relation to an acute session of high-intensity interval training. The morningness-eveningness questionnaire was administered to recruit Morning-type and Evening-type collegiate male soccer players. Therefore, 24 players (12 Morning-types and 12 Evening-types) were randomly assigned, to either morning (n = 12; age 23 ± 3 years; height 1.75 ± 0.07 m; body mass 73 ± 10 kg; weekly training volume 8±2 hours), or evening (n = 12; age 21 ± 3 years; height 1.76 ± 0.05 m; body mass 75 ± 11 kg; weekly training volume 8 ± 3 hours) training. Heart Rate Variability vagal and sympa-tho/vagal indices were calculated in time, frequency and complexity domains at rest, before, after 12 and 24 hours of high-intensity interval training. Before evening training session, a higher resting heart rate was observed which was determined by a marked parasympathetic withdrawal with a sympathetic predominance. Moreover, Evening-type subjects during morning training session, present a significant higher heart rate that corresponded to significant higher vagal indices with a significant lower parasympathetic tone that returned to the rest values after 24 hours of the cessation of high-intensity interval training exercise. On the contrary, Morning-type subjects did not reveal any significant differences with Evening-Type subjects during evening high-intensity interval training session. Stress response of high-intensity interval training is influenced by both the time of the day and by the chronotype. Understanding the Heart Rate Variability response to high-intensity interval training can be an additional important procedure for evaluating of cardiovascular recovery in soccer players. Moreover, these results suggest that an athlete’s chronotype should be taken into account when scheduling a high-intensity interval training exercise.
Background
Many variables related to sport have been shown to have circadian rhythms. Chronotype is the expression of circadian rhythmicity in an individual, and three categories of chronotype are defined: morning types (M-types), evening types (E-types), and neither types (N-types). M-types show earlier peaks of several psychophysiological variables during the day than E-types. The effect of chronotype on athletic performance has not been extensively investigated. Objective
The objective of the present review was to study the effect of chronotype on athletic performance and the psychophysiological responses to physical activity. Methods
The present review adheres to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) reporting guidelines. We searched PubMed, Scopus, and Web of Science for scientific papers using the keywords “chronotype”, “circadian typology”, “morningness”, and “eveningness” in combination with each of the words “sport”, “performance”, and “athletic.” Relevant reference lists were inspected. We limited the search results to peer-reviewed papers published in English from 1985 to 2015. ResultsTen papers met our inclusion criteria. Rating of perceived exertion and fatigue scores in relation to athletic performances are influenced by chronotype: M-types perceived less effort when performing a submaximal physical task in the morning than did N- and E-types. In addition, M-types generally showed better athletic performances, as measured by race times, in the morning than did N- and E-types. Other results concerning chronotype effect on physiological responses to physical activity were not always consistent: heterogeneous samples and different kinds of physical activity could partially explain these discrepancies. Conclusions
Sports trainers and coaches should take into account the influence of both the time of day and chronotype effect when scheduling training sessions into specific time periods.
Figure 1. Motivational intensity theory's predictions for tasks with known and fixed difficulty (Panels A and B) and for tasks with unknown and unfixed difficulty (Panel C).
Recent behavioral and biomedical research has suggested that psychophysiologic responsiveness (reactivity) to emotional stress may be a marker of processes involved in the development of cardiovascular disorders. The assessment of reactivity focuses on acute changes in functioning as opposed to the sole assessment of resting levels of variables. This article reviews evidence linking behaviorally induced cardiovascular and endocrine changes to coronary heart disease and essential hypertension. Particular attention is given to methodologic issues involving measurement. It is concluded that reactivity to stress is a construct with multiple dimensions: Different tasks and situations appear to elicit different patterns of physiologic responses. Further, an evaluation of evidence reveals that reactivity per se should currently not be regarded as a proven risk factor.Promising evidence does, however, justify continued laboratory and naturalistic, hypothesis-testing research. Recommended are methodologic studies to identify(a) the psychologic dimensions of stimuli that elicit reactivity in different subject groups, and (b) the patterns of physiologic responses produced. Such research would set the stage for epidemiologic studies to further examine relations between behavior and disease processes.
To suggest that a person has control over an outcome is to suggest that the person can affect the outcome—that is, impact its presence, quality, or the like—through action (e.g., see Skinner, 1996). There are various determinants of perceived control, including the appraised character of activity that must be carried out to alter an outcome (easy versus difficult), the appraised effectiveness of that activity in accomplishing its purpose, and the appraised ability (or efficacy, Bandura, 1986) of the performer to do what must be done. In this chapter, I focus on the latter determinant of perceived control and consider its relation to cardiovascular (CV) responsivity (i.e., CV elevation above baseline).
I sketch here an analysis of fatigue influence on effort and apply it to the phenomenon of self-regulatory restraint, construing such restraint as resistance against a behavioral urge or impulse. The analysis suggests that fatigue does not have a single influence, but rather a multifaceted one dependent on the difficulty of the task at hand and the importance of accomplishing it. Application to self-regulatory restraint offers a novel and potentially significant understanding of how the phenomenon works. A key implication is that restraint intensity should vary proximally with the magnitude of the urge resisted. Another is that fatigue and other restraint ability factors should have different influences on restraint intensity depending on the magnitude of an urge and the importance of resisting it. Cardiovascular results from ability and fatigue studies attest to the validity of the fatigue analysis and support its application in the self-regulatory context.
This chapter deals with the psychological process that determines effort intensity in instrumental behavior. According to motivation intensity theory, effort should be proportional to experienced task difficulty as long as success is possible and justified and low when success is impossible or excessively difficult, given the available benefit. When task difficulty is unspecified or unknown, effort should be proportional to the importance of success. We report a program of experimental studies that have operationalized effort intensity as cardiovascular reactivity during task performance and used multiple manipulations of variables influencing subjective task difficulty (e.g., performance standards, ability, mood) and the amount of justified effort (e.g., material incentive, instrumentality, evaluation). The empirical evidence is in clear support of the principles of motivation intensity theory and challenges a number of other theoretical accounts. Directions for future research are discussed.
Abstract A recent study found that South African endurance athletes are likely to be morning-types and carry the PER3(5) allele, which has been associated with a preference for mornings. The aim of this study was to measure the response of morning-type cyclists to a standardised bout of exercise performed at different times of the day. Participants ncluded 20 trained male cyclists (age: 39.8 ± 7.7 years, VO2max: 51.0 ± 7.0 ml · kg(-1) · min(-1), training: 166 ± 98 km · wk(-1)), categorised as morning-types (mean Horne-Östberg score: 68.3 ± 5.5) and carrying the PER3(5) allele. They completed a 17-min sub-maximal cycling test at 60%, 80% and 90% of maximum heart rate (HRmax) at 06h00, 10h00, 14h00, 18h00 and 22h00. These morning-type cyclists reported higher ratings of perceived exertion when cycling at 60% (P = 0.044), 80% (P < 0.001) and 90% (P < 0.001) of HRmax during the evening (18h00 and 22h00) compared to the other sessions (0600, 10h00 and 14h00). This was despite absolute power output, speed and cadence displaying no time-of-day differences. Thus, morning-type cyclists perceive the same relative intensity workload to be harder in the evening compared to the morning. This may have implications for both training and competition scheduling, and highlights the importance of considering individual chronotype in sports in which diurnal variation may be relevant to training and competition.
Two studies assessed the circadian variation of cardiovascular responses to stress in healthy and coronary artery disease (CAD) populations. In within-subjects designs, stressors were administered to healthy male subjects and male CAD patients both in the morning and afternoon, and subjects were classified as either morning or evening types using the Morningness-Eveningness Questionnaire (Horne & Östberg, 1976, International Journal of Chronobiology, 4, 97–110). No consistent circadian variation in blood pressure or heart rate responses was observed in the aggregate sample of either healthy subjects or CAD patients. However, there were significant interactions between circadian type and time of day. In both populations, morning, subjects exhibited higher cardiovascular levels during the morning session, and evening subjects exhibited higher levels during the afternoon session. Analyses of cardiovascular reactivity revealed less consistent evidence for this interaction. Self-reports of stress revealed interactions between time of day and and morningness/eveningness only in CAD sample. In CAD patients, preliminary analysis of myocardial wall function, an index of myocardial ischemia, did not reveal a significant interaction between morningness/eveningness and time of day, perhaps due to small sample size. The presence of differing circadian patterns in stress response based on individual differences in morningness/eveningness is discussed in teerms of its methodological implications for psychophysiological research and in terms of the role of stress as an acute trigger of CAD.
When subjects judge whether a test symbol is contained in a short memorized sequence of symbols, their mean reaction-time
increases linearly with the length of the sequence. The linearity and slope of the function imply the existence of an internal
serial-comparison process whose average rate is between 25 and 30 symbols per second.
Female undergraduates performed an easy (fatigue low) or difficult (fatigue high) scanning task and then were presented mental arithmetic problems with instructions that they would earn a high or low chance of winning a prize if they did as well as or better than 50% of those who had performed previously. As expected, blood pressure responses in the second work period rose or tended to rise with fatigue where the chance of winning was high. By contrast, the responses tended weakly to decline with fatigue where the chance of winning was low. The pressure findings support the suggestion of a recent fatigue analysis that success importance should moderate fatigue influence on CV responses to a challenge so long as fatigued performers view success as possible. They also conceptually replicate previous fatigue results and provide a special class of evidence that fatigue influence on CV response is mediated by effort.
An English language self-assessment Morningness-Eveningness questionnaire is presented and evaluated against individual differences in the circadian vatiation of oral temperature. 48 subjects falling into Morning, Evening and Intermediate type categories regularly took their temperature. Circadian peak time were identified from the smoothed temperature curves of each subject. Results showed that Morning types and a significantly earlier peak time than Evening types and tended to have a higher daytime temperature and lower post peak temperature. The Intermediate type had temperatures between those of the other groups. Although no significant differences in sleep lengths were found between the three types, Morning types retired and arose significantly earlier than Evening types. Whilst these time significatly correlated with peak time, the questionnaire showed a higher peak time correlation. Although sleep habits are an important déterminant of peak time there are other contibutory factors, and these appear to be partly covered by the questionnaire. Although the questionnaire appears to be valid, further evaluation using a wider subject population is required.
A study was conducted to assess the relative impact of partial sleep deprivation (restriction to 4 h sleep before testing) and full sleep deprivation (no sleep on the night before testing) on 2 h of simulated driving, compared with an alcohol treatment (mean blood alcohol content = 0.07%). Data were collected from the 64 male participants on the primary driving task, psychophysiology (0.1 Hz heart rate variability), and subjective self-assessment. The results revealed that the full sleep deprivation and alcohol group exhibited a safety-critical decline in lane-keeping performance. The partial sleep deprivation group exhibited only noncritical alterations in primary task performance. Both sleep-deprived groups were characterized by subjective discomfort and an awareness of reduced performance capability. These subjective symptoms were not perceived by the alcohol group. The findings are discussed with reference to the development of systems for the online diagnosis of driver fatigue. Potential applications of this research include the formulation of performance criteria to be encompassed within a driver impairment monitoring system.
Psychosocial characteristics predict the development and course of coronary heart disease (CHD). In this review, the authors discussed human and animal research on psychophysiological mechanisms influencing coronary artery disease and its progression to CHD. They then reviewed literature on personality and characteristics of the social environment as risk factors for CHD. Hostility confers increased risk, and a group of risk factors involving depression and anxiety may be especially important following myocardial infarction. Social isolation, interpersonal conflict, and job stress confer increased risk. Psychosocial interventions may have beneficial effects on CHD morbidity and mortality, although inconsistent results and a variety of methodological limitations preclude firm conclusions. Finally, they discussed implications for clinical care and the agenda for future research.
What determines effort intensity in instrumental behavior? According to motivation intensity theory, effort should be proportional to experienced task difficulty as long as success is possible and justified and low when success is impossible or excessively difficult, given the available benefit. When task difficulty is unspecified or unknown, effort should be proportional to the importance of success. This chapter reports an extensive program of research that has operationalized effort intensity as cardiovascular reactivity during task performance and used multiple manipulations of variables influencing subjective task difficulty (e.g., performance standards, instrumentality, ability, fatigue, mood, depressive symptoms, implicit affect, implicit and biological aging) and the amount of justified effort (e.g., material incentive, instrumentality, needs, personal and social evaluation, mortality salience). In the second edition of this handbook, this chapter focuses on recent empirical evidence for the principles of motivation intensity theory and discusses challenges for other theoretical accounts.
Motivation and volition play an important role in sports. Professional athletes benefit from a strong achievement motivation, while findings on recreational sport show the importance of the affiliation motive. Sport psychological research has developed a large body of evidence on the conditions of motivation and volition in sports, including specific instruments for the measurement of motives as well as factors of motivation and volition. The distinction between implicit and explicit motives has only recently gained more attention. Through processes of self-regulation, volition is an essential component for persisting during training or succeeding in emotionally and physically exhausting competitions. Sport psychological interventions are primarily related to self-regulation.
Participants first completed a state affect checklist that included a fatigue (energy-tiredness) index and a measure of mental sharpness. They then were presented a simple memory challenge. In the first minute of the two-minute work period, heart rate responses (1) rose with values on the fatigue index, and (2) fell with values on the measure of mental sharpness. In the second minute of the work period, the responses were unrelated to fatigue index and mental sharpness values. Follow-up analysis indicated mental sharpness mediation of fatigue influence on heart rate in Minute 1. First minute findings add substantively to the body of evidence supporting recent suggestions that fatigue can lead people to try harder and experience stronger cardiovascular responses when confronted with simple challenges. They also support the suggestion that fatigue might exert its influence on cardiovascular responses to a mental challenge by diminishing cognitive clarity, that is, by obscuring thought. Second minute findings are contrary to the fatigue suggestions, but could indicate that memorization was accomplished in the first minute. A practical implication of the first minute results is that real-world fatigue could elevate health risk by enhancing CV responses to mundane daily tasks.
Motivational intensity theory predicts that energy investment in goal pursuit is governed by the motivation to conserve resources and that it should consequently be a function of task demand: Trying to avoid wasting resources, individuals should invest only the energy that is required for task success and should disengage if success is impossible. Three experiments tested this hypothesis assessing the force exerted in an isometric handgrip task as indicator of energy investment. The results provided mixed evidence for motivational intensity theory. Supporting the theory, exerted force increased as a function of task demand if task success was possible and was low if success was impossible. However, exerted force exceeded required force in all possible conditions and participants did not disengage if task success was impossible. A meta-analysis of published studies involving disengagement conditions revealed that preceding research on motivational intensity theory also failed to provide support for the disengagement hypothesis. Our findings demonstrate the importance of task demand for energy investment but also challenge the assumption that energy investment is primarily driven by energy conservation concerns.
Participants were presented a moderately- or impossibly difficult cumulative mental addition task with instructions that they could win a traditionally feminine- or masculine incentive if they achieved a 90 percent success rate. When the incentive was feminine, systolic blood pressure responses during the task period were stronger under moderately difficult conditions among women, but low irrespective of difficulty among men - creating a gender difference only when difficulty was moderate. By contrast, when the incentive was masculine, systolic-, mean arterial- and, to a lesser degree, diastolic blood pressure responses during the task period were stronger under moderately difficult conditions irrespective of gender. The former finding confirmed expectations and adds substantively to the body of evidence favoring a recent effort analysis of gender influence on CV response to performance challenge. The latter findings conflict with what was first expected, but can be understood in terms of post hoc reasoning extended in light of participants' ratings of the masculine incentive.
Copyright © 2015. Published by Elsevier B.V.
A solution is suggested for an old unresolved social psychological problem.
This chapter provides an overview of the broader social psychological research community, the integrative cardiovascular (CV) response analysis and the body of evidence supporting it. The chapter also presents updates about previous reviews of evidence relevant to the integrative view; considers the motivational process in circumstances, involving challenges that are characterized as unfixed; and contrasts the integrative CV response perspective with some popular alternative CV response views. Furthermore, the chapter focuses on certain unresolved issues, analyzes the CV influence of specific social variables in the integrative terms, and identifies some social psychological studies that can be benefited by including CV measures in their research protocols. Over the years, the two themes that have been dominant concerning the psychological determination of CV response include firstly, where behavioral contingencies are positive, CV responsivity is proportional to the perceived value of incentives driving behavior; and secondly where at least some behavioral contingencies are negative; CV responsivity is proportional to subjective threat.
Undergraduate volunteers performed an easy (fatigue low) or difficult (fatigue high) counting task and then were presented a difficult scanning task with instructions that the task was or was not diagnostic of an important ability (low- versus high ego-involvement, respectively). As expected, systolic blood pressure responses in the second work period were positively proportional to fatigue where ego-involvement (and, thus, success importance) was high, but not where ego-involvement (and, thus, importance) was low. The pressure findings provide fresh support for the suggestion of a recent fatigue analysis that importance should moderate fatigue influence on effort-related CV responses to a performance challenge so long as fatigued performers view success as possible, conceptually replicating and extending effects from a previous fatigue experiment.
Conscious feelings have traditionally been viewed as a central and necessary ingredient of emotion. Here we argue that emotion also can be genuinely unconscious. We describe evidence that positive and negative reactions can be elicited subliminally and remain inaccessible to introspection. Despite the absence of subjective feelings in such cases, subliminally induced affective reactions still influence people’s preference judgments and even the amount of beverage they consume. This evidence is consistent with evolutionary considerations suggesting that systems underlying basic affective reactions originated prior to systems for conscious awareness. The idea of unconscious emotion is also supported by evidence from affective neuroscience indicating that subcortical brain systems underlie basic ‘‘liking’’ reactions. More research is needed to clarify the relations and differences between conscious and unconscious emotion, and their underlying mechanisms. However, even under the current state of knowledge, it appears that processes underlying conscious feelings can become decoupled from processes underlying emotional reactions, resulting in genuinely unconscious emotion.
This editorial offers and provides preliminary support for the hypothesis that sex differences exist in physiological responses to acute behavioral stress, which may aid in understanding the enormous sex differences in risk for coronary heart disease. Epidemiological data regarding the differential sex experience of coronary heart disease morbidity and mortality are discussed, followed by a meta-analytic review of available psychophysiological data on sex differences in stress-induced cardiovascular and neuroendocrine responses. The implications of the meta-analysis for conceptual and methodological issues in psychophysiological research are highlighted.
Research is reviewed concerning the interrelationships among cardiodynamics, blood pressure control mechanisms, somatic activity, and the stimulus parameter of active vs passive coping. Emerging evidence suggests that with passive coping such as classical aversive conditioning, the heart is more under vagal control which is directionally linked with somatic activity, while blood pressure is more dominated by vascular processes. With active coping such as shock avoidance, the heart is under greater sympathetic control which is directionally independent of concomitant somatic activity, while cardiac influences on blood pressure become more dominant. Several current psycho physiological issues are discussed including the possible significance of these effects for cardiovascular disease processes.
The statistical parameters that influence the reliability of delta and residualized change were examined in the context of the assessment of cardiovascular reactivity. A comparison of the relative reliabilities of these two quantification methods was performed using systolic blood pressure, diastolic blood pressure, and heart rate data from two samples of 134 and 109 subjects observed during baseline and either two or four behavioral challenges. The results indicated that both delta and residualized change scores can yield reliable measures of blood pressure and heart rate reactivity to behavioral challenges, and that their reliabilities will be comparable under the conditions observed in laboratory reactivity studies. Correlations between baseline and delta did not indicate that these two measures were systematically related. Finally, delta scores are more appropriate than residuals when assessing the generalizability of responses across a variety of tasks.
This article introduces a new theory about implicit affect's influence on resource mobilization-the implicit-affect-prime-effort (IAPE) model-and discusses a series of experiments testing its predictions. The theory posits that affect primes (e.g., facial expressions or emotion words) implicitly activate mental representations of the respective affective states, containing information about ease and difficulty. This in turn influences the extent of subjective task demand during performance. A series of experiments assessing implicit affect's impact on effort-related cardiovascular response in cognitive tasks (especially cardiac pre-ejection period) supports this idea: (1) sadness primes processed during task performance led to stronger cardiovascular responses than both happiness and anger primes. (2) Affect primes moderated the effect of objective task difficulty: compared with sadness primes, both anger and happiness primes led to weaker response for easy tasks but to stronger response for difficult tasks. (3) The effort deficit of people primed with sadness during a difficult task could be compensated by high success incentive. Perspectives for future research on implicit affect and motivation are discussed.
This paper presents a cognitive-energetical framework for the analysis of effects of stress and high workload on human performance. Following Kahneman's (1973) model, regulation of goals and actions is assumed to require the operation of a compensatory control mechanism, which allocates resources dynamically. A two-level compensatory control model provides the basis for a mechanism of resource allocation through an effort monitor, sensitive to changes in the level of regulatory activity, coupled with a supervisory controller which can implement different modes of performance-cost trade-off. Performance may be protected under stress by the recruitment of further resources, but only at the expense of increased subjective effort, and behavioural and physiological costs. Alternatively, stability can be achieved by reducing performance goals, without further costs. Predictions about patterns of latent decrement under performance protection are evaluated in relation to the human performance literature. Even where no primary task decrements may be detected, performance may show disruption of subsidiary activities or the use of less efficient strategies, as well as increased psychophysiological activation, strain, and fatigue after-effects. Finally, the paper discusses implications of the model for the assessment of work strain, with a focus on individual-level patterns of regulatory activity and coping.
Inter-individual differences in the circadian period of physical and mental functions can be described on the dimension of morningness/eveningness. Previous findings support the assumption that eveningness is related to greater impulsivity and susceptibility to stress than morningness. Heart rate variability (HRV) serves as a physiological correlate of self- and emotional regulation and has not yet been investigated in relation to chronotypes. The study explores differences in HRV and other cardiovascular measures in morning- and evening-types at rest and under stress at different times of day (8-11 a.m. or 4-7 p.m.). Students (N=471) were screened for chronotype and n=55 females (27 morning- and 28 evening-types) were recruited for testing. These participants performed a mental arithmetic task while heart rate (HR) and blood pressure (BP) were recorded. Spectral components and a time-domain measure of HRV were calculated on HR data from resting and mental stress periods. Evening-types had significantly higher HR and systolic BP, but lower HRV than morning-types both at baseline and during stress. Stress induced in the evening had a significantly stronger impact on absolute and baseline corrected physiological measures in both chronotypes. The interaction of chronotype and testing time did not reach the level of significance for any of the dependent variables. The enhanced physiological arousal in evening-types might contribute to increased vulnerability to psychological distress. Hence, previous behavioral findings are supported by the physiological data of this study.
Continuous non-invasive arterial pressure measured with CNAP (CNAP) has been shown to be superior to intermittent oscillometric measurements during procedural sedation and spinal anaesthesia. We assessed the performance of CNAP during general anaesthesia by analysis of agreement with invasive measurements of arterial pressure (AP).
Eighty-eight patients undergoing elective abdominal surgery, cardio-, or neurosurgery were included in the study. Systolic, diastolic, and mean AP measured by an intra-arterial catheter in the radial artery (IAP) were compared with those obtained by CNAP from the same arm. Data were analysed to determine the precision (i.e. measurement error) and accuracy (i.e. systematic error) of beat-to-beat CNAP values with respect to IAP. Also, we compared the frequency of fast changes in AP (FCAP) and hypotension (IOH) by both methods.
CNAP precision of 4.5, 3.1, and 3.2 mm Hg (systolic, diastolic, and mean AP, respectively) was not significantly different from IAP precision, and CNAP accuracy was +6.7, -5.6, and -1.6 mm Hg. The frequency of AP pairs having a difference within the calculated limits of agreement was 81%, 64%, and 76% for systolic, diastolic, and mean AP, respectively. The calculated limits of agreement were +/-17.6, +/-11.4, and +/-12.0 mm, Hg, respectively. CNAP and IAP detected simultaneously to 82.1% FCAP and to 84.6% IOH.
CNAP provides real-time estimates of arterial pressure comparable with those generated by an invasive intra-arterial catheter system during general anaesthesia.
Active coping enhances cardiovascular response presumably by beta-adrenergically mediated myocardial activation. This study examined impedance-derived hemodynamic parameters underlying blood pressure response to two laboratory tasks requiring active coping, performed either with or without an appetitive (i.e., monetary) incentive.
Forty-eight healthy, young men completed the Stroop Color-Word Test and Mirror Tracing. Half received no incentive, whereas half were provided with a monetary incentive as an active coping manipulation. Task-related changes in blood pressure, heart rate, systolic time intervals, and hemodynamic parameters were monitored. Psychological responses to the tasks were also obtained.
On average, incentive virtually doubled blood pressure response to both Stroop and Mirror Tracing. The change in blood pressure was explained predominantly by a concomitant increase in total peripheral resistance. Heart rate response was also enhanced substantially with incentive. Individuals in the incentive condition reported greater interest in the task, but less perceived control, than persons in the no-incentive condition.
The incentive-related increase in total peripheral resistance, combined with an absence of enhanced stroke volume, cardiac output, or preejection period response, indicates that active coping may, under certain conditions, elevate blood pressure via increased systemic resistance, presumably reflecting alpha-adrenergic activation. Furthermore, the enhanced heart rate associated with incentive may reflect a withdrawal of parasympathetic influence.
This study examined further cardiovascular effects of energy resource depletion. Participants performed initially an easy counting task (Task A easy) or a hard counting task (Task A difficult) for 5 min. Shortly thereafter, they were provided the chance to earn a modest incentive by attaining a low performance standard (Task B easy) or a high performance standard (Task B difficult) on a mental arithmetic task. As expected, the Task A difficulty factor combined with the Task B difficulty factor to determine blood pressure responses during the second performance period. Whereas Task A easy participants evinced relatively stronger responses when Task B was difficult than when Task B was easy, Task A difficult participants evinced relatively stronger responses when Task B was easy than when Task B was difficult. These cardiovascular results partially replicate cardiovascular results from a prior depletion study using a cognitive, as opposed to a motor, challenge. They also extend the cardiovascular results from the prior study by demonstrating that the cardiovascular influence of energy depletion depends on the difficulty of the challenge with which people are confronted.