How can reward contribute to efficient self-control? Reinforcement of task-defined responses diminishes ego-depletion

We examined whether reinforcement learning of habitual actions diminishes ego depletion after a cognitive control task. Participants performed the Stroop task after a card selection task, in which one group was reinforced to respond to colors in the Stroop task (Stroop-color group) while another group was reinforced to respond to colors not in the Stroop task (non-Stroop-color group). We measured ego depletion in terms of decrement in endurance on an isometric handgrip task after the Stroop task. The Stroop-color group exhibited less decrease in their isometric handgrip endurance compared to the non-Stroop-color group. These results suggest that the former needed less effort for cognitive control during conflict processing, as reinforcement learning make task-defined response habitual. This finding provides a new perspective on the role of reward in cognitive control.     

Resource depletion does not influence prospective memory in college students

This paper reports an experiment designed to investigate the potential influence of prior acts of self-control on subsequent prospective memory performance. College undergraduates (n = 146) performed either a cognitively depleting initial task (e.g., mostly incongruent Stroop task) or a less resource-consuming version of that task (e.g., all congruent Stroop task). Subsequently, participants completed a prospective memory task that required attentionally demanding monitoring processes. The results demonstrated that prior acts of self-control do not impair the ability to execute a future intention in college-aged adults. We conceptually replicated these results in three additional depletion and prospective memory experiments. This research extends a growing number of studies demonstrating the boundary conditions of the resource depletion effect in cognitive tasks.     

Self-control exertion and glucose supplementation prior to endurance performance

ObjectivesCompletion of a task requiring self-control may negatively impact on subsequent self-regulatory efforts. This study explored a) whether this effect occurs during a well-practiced endurance task, b) the potential for glucose supplementation to moderate this effect, and c) whether this effect differed over time.MethodFourteen trained cyclists completed four simulated 16 km time trials on an electromagnetically braked cycle ergometer. Prior to each time trial, participants completed a congruent Stroop task or an incongruent Stroop task that required self-control. They also received either a glucose-based drink or placebo. Participants' performance time and heart rate were recorded throughout the time trials.ResultsMultilevel growth curve analysis revealed a significant three-way interaction between self-control, glucose, and time (b = −0.91; p = 0.02). When participants did not exert self-control (congruent Stroop) or consume glucose (placebo drink) they were slowest during the early stages of the time trial but quickest over the full distance. No differences were found in heart rate across the four conditions.ConclusionsFindings suggest that pacing may explain why self-control exertion interferes with endurance performance. Moreover, the debate revolving around depletion of self-control must consider that any observed effects may be dependent on the timing of performance inspection.     

Prior self-control exertion and perceptions of pain during a physically demanding task

ObjectivesExertion of self-control has been associated with impaired performance on subsequent physical tasks also requiring self-control, but it remains unknown why this occurs. This study, therefore, explored whether a) prior self-control exertion reduces subsequent persistence on a physically demanding task, and b) whether any observed performance decrements could be explained by changes in perceptions of pain.MethodIn a within-subject design, sixty-three individuals completed an easy (congruent) Stroop task or a difficult (incongruent) Stroop task that required self-control. Participants were then required to remain in a physically demanding posture (i.e., a ‘wall-sit’) until voluntary exhaustion and their perception of pain was recorded during the task.ResultsWhen participants completed the difficult Stroop task, they quit the wall-sit sooner. This decrement in performance was explained by greater perceptions of pain at the beginning of the wall-sit.ConclusionsPerceptions of pain may, therefore, be an important attentional mechanism explaining why self-control use interferes with subsequent persistence during physically effortful tasks.     

Boredom,motivation, and perceptions of pain: Mechanisms to explain the effects of self-control exertion on subsequent physical performance

ObjectivesPrior self-control exertion has been shown to have a detrimental effect on subsequent physical performance. However, some potential underpinning mechanisms of the effect have yet to be examined. The present study explored whether exerting self-control reduces subsequent physical performance; and also examines the role of boredom, motivation, perceptions of pain, and sustained attention as mechanisms to explain these performance effects.MethodsIn a within-subjects order-balanced crossover design, 63 participants completed a self-control exertion task (incongruent Stroop) and non-self-control exertion task (congruent Stroop) for 4 min. Immediately after, participants completed a wall-sit task until volitional exhaustion. Task-specific boredom was measured following the Stroop task and following the wall-sit task. Participants’ perceptions of pain and motivation were measured every 30 s during the wall sit task. Upon completion of the wall-sit, participants completed a test of sustained attention.ResultsFollowing the self-control exertion task, participant’s wall-sit performance time was reduced (136 ± 62 s), compared to when they completed the non-self-control exertion task (144 ± 57 s, p = 0.05, d = 0.14). Participant’s task related boredom was significantly higher during the non-self-control exertion task (4.30 ± 1.23), compared to the self-control exertion task (3.82 ± 1.22) (p < 0.001, d = 0.39); but boredom was not different during the wall-sit task (p = 0.79). Prior self-control exertion also led to increased overall perceptions of pain (p = 0.02) and reduced overall (p = 0.01) and initial (p = 0.02) motivation during the wall-sit task. However, no differences in initial perceptions of pain (p = 0.16) or sustained attention (response time, p = 0.99; response accuracy, p = 0.78) were observed. Additional within-subjects mediation analysis revealed that differences in wall-sit performance time could not be explained by differences in task related boredom during the Stroop task, overall perceptions of pain, or overall and initial motivation (all p > 0.05).ConclusionsThe prior exertion of self-control resulted in a decrement in subsequent physical performance. Furthermore, individuals’ perceptions of task related boredom were higher during the non-self-control exertion (congruent Stroop) task, whilst overall perceptions of pain were higher, and initial and overall motivation were lower, following the self-control exertion (incongruent Stroop) task. However, mediation analysis revealed that these mechanisms did not explain the difference in wall sit performance time between the conditions.     

“Pay the piper”: It helps initially,but motivation takes a toll on self-control

ObjectiveTo investigate the aftereffects of anticipating future self-control and motivation on self-control strength depletion patterns.DesignSingle blind, randomized 2 (autonomy-supportive motivation/controlling motivation) × 2 (anticipation/no anticipation) factorial.MethodParticipants (N = 72) performed four sequential self-control strength challenges: an initial endurance handgrip squeeze followed by the Stroop task and two additional endurance handgrip squeezes. A sequential randomization procedure was used to allocate participants to one of four conditions: anticipation/autonomy-supportive motivation (n = 19), anticipation/controlling motivation (n = 17), no anticipation/autonomy-supportive motivation (n = 18), and no anticipation/controlling motivation (n = 18).ResultsParticipants who anticipated future self-control depletion conserved resources on the second task by completing fewer words on a Stroop task compared to controls. Participants who received autonomy-supportive instructions performed significantly better than controls on a third task (endurance handgrip squeeze), but worse than controls on the fourth task (another endurance handgrip squeeze). There were no significant interactions between anticipation and motivation (p > .05).ConclusionsResults support previous findings reflecting conservation and motivation effects on self-control strength. This was the first study to show that autonomy-supportive instructions may assist self-control performance in the short term but ultimately depletes self-control strength and impairs performance in the long term.     

Self-control exertion and caffeine mouth rinsing: Effects on cycling time-trial performance

ObjectivesThe exertion of self-control has been associated with impaired performance on subsequent physical tasks also requiring self-control. However, the effect in well-trained individuals, and of nutritional intervention strategies to reduce the impact of self-control exertion are unknown. This study, therefore, explored the effect of self-control exertion on endurance performance, and pacing strategies, in well-trained individuals. A further aim was to examine the potential for a caffeine mouth rinse to attenuate any decrements in performance due to self-control exertion.MethodFollowing familiarization, fifteen trained male cyclists completed four simulated 10 km cycling time-trials on a cycle ergometer. Prior to each time-trial, participants completed a congruent Stroop task, or an incongruent Stroop task, to manipulate self-control. They also received either a caffeine (containing 40 mg of dissolved caffeine) or placebo mouth-rinse prior to, and every 2 km during, the cycling time-trial. The participants' performance time, subjective measures (perceived pain, motivation, task importance, and RPE), heart rate, and blood lactate concentration were recorded throughout the time-trials. Data were analysed using three-way (self-control*caffeine*split time) repeated measures ANOVA.ResultsThere was no effect of self-control or caffeine on overall 10 km performance time (all p > 0.05). However, following self-control exertion, split time was significantly slower at 3 km (p = 0.031) and 5 km (p = 0.034), and tended to be slower at 1 km (p = 0.088) and 7 km (p = 0.078). There was no effect of the caffeine mouth rinse, nor did this interact with self-control, to affect split times (all p > 0.05). Prior self-control exertion and a caffeine mouth rinse did not influence perceptions of pain, motivation, and task importance in well-trained individuals (all p > 0.05).ConclusionsFindings suggest that prior self-control exertion affects self-regulatory pacing strategies during the first 7 km of a 10 km cycling time-trial, in well-trained individuals. However, caffeine mouth rinsing does not attenuate the effects of self-control exertion on subsequent endurance performance.     

How am I doing? Performance feedback mitigates the effects of mental fatigue on endurance exercise performance

Mental fatigue induced by an earlier cognitive task can impair performance on a subsequent physical task. The current study investigated whether such performance impairment could be mitigated by performance feedback. In an experimental sequential-task design, 63 sport science students completed a series of three tasks: 5-min physical (pre-test), 20-min cognitive, 5-min physical (post-test). Participants were randomly allocated to one of three groups: feedback (n = 23), no feedback (n = 20), control (n = 20). The physical tasks, which assessed force production during a self-paced rhythmic handgrip task as a measure of physical endurance performance, were performed with (feedback group) or without (no feedback group, control group) visual performance feedback. The cognitive tasks involved either completing a 2-back memory task to induce mental fatigue (feedback and no feedback groups) or watching a didactic film (control group). Self-report measures (fatigue, exertion, vigor, motivation) were collected throughout. The 2-back cognitive task increased mental fatigue, mental exertion and general fatigue in the feedback and no feedback groups compared to the control group. Relative to the pre-test physical task, post-test endurance performance declined in the no feedback group (−14.4%) but did not change in the control (−2.6%) and feedback (−2.4%) groups. This mitigation of performance effect was not accompanied by parallel changes in fatigue, exertion, vigor, or motivation. In conclusion, visual performance feedback mitigates the negative effects of mental fatigue on physical endurance performance.     

A reach-to-touch investigation on the nature of reading in the Stroop task

In a Stroop task, participants can be presented with a color name printed in color and need to classify the print color while ignoring the word. The Stroop effect is typically calculated as the difference in mean response time (RT) between congruent (e.g., the word RED printed in red) and incongruent (GREEN in red) trials. Delta plots compare not just mean performance, but the entire RT distributions of congruent and incongruent conditions. However, both mean RT and delta plots have some limitations. Arm-reaching trajectories allow a more continuous measure for assessing the time course of the Stroop effect. We compared arm movements to congruent and incongruent stimuli in a standard Stroop task and a control task that encourages processing of each and every word. The Stroop effect emerged over time in the control task, but not in the standard Stroop, suggesting words may be processed differently in the two tasks.     

Effect of acute aerobic exercise on cognitive performance: Role of cardiovascular fitness

ObjectivesTo determine whether fitness and cognitive task type moderate the relationship between acute exercise and cognition.MethodsThirty-six healthy college-aged adults completed a maximal graded exercise test and were categorized as low, moderate, or high in cardiovascular fitness. Participants then performed the Stroop Test prior to and after an acute bout of cycling exercise that consisted of a 5-min warm-up, 20 min of exercise at moderate intensity (65% VO_2max), and a 5-min cool-down.ResultsIndividuals of all fitness levels improved in cognitive performance following exercise. With regards to fitness, while no differences were observed on the congruent condition as a function of fitness, high fit individuals showed the longest response time on the Stroop incongruent condition.ConclusionThe beneficial relationship between performance of an acute bout of exercise and cognitive performance were observed for both cognitive task types and for participants of all fitness levels. However, a curvilinear relationship was observed between fitness and cognitive task type performance such that participants who were moderately fit performed the best on the incongruent trials, implying that maintaining fitness at a moderate level is associated with better executive function.     

自我损耗的视听通道效应

采用双任务实验范式,通过两个实验探讨了自我损耗的通道效应。实验1考察了完成视听工作记忆任务对执行手柄任务（非视听任务）的影响,结果发现,完成视觉损耗任务导致手柄任务的成绩显著地变差,完成听觉损耗任务、视听非损耗任务均对手柄任务的成绩没有影响。实验2考察了完成视听工作记忆任务对执行Stroop任务（视觉任务）的影响,结果发现,完成视觉损耗任务导致Stroop任务的成绩显著地变差,完成听觉损耗任务、视听非损耗任务对Stroop任务的成绩没有影响。研究结果表明同一自我控制任务通过视听通道完成对随后另一自我控制任务的影响不同,证实了自我损耗的视听通道效应。     

自我损耗促进冒险行为

基于自我控制资源模型,本研究探讨了自我损耗对冒险行为的影响以及生理能量补充在其中的缓解作用。实验1和实验2分别通过“Stroop”和“非利手写作”任务操纵被试的自我损耗,两个实验均用气球模拟风险决策任务考察被试的冒险行为,并且通过摄入含有或不含有葡萄糖的柠檬水来操纵生理能量水平。结果发现,在排除无关变量后,高损耗者比低损耗者尽可能多地对气球进行充气以寻求奖赏(实验1和实验2),但饮用含葡萄糖的柠檬水能够有效降低这种反应(实验2)。该研究证实了自我损耗促进冒险行为,补充生理能量能有效缓解该效应。     

冲突控制是领域一般性的还是领域特殊性的?

本研究采用整合交叉范式整合了Stroop任务和Simon任务,在双重认知控制的框架下探讨冲突控制是领域一般性的还是领域特殊性的问题。结果发现:序列一致性效应只出现在任务内,不出现于任务间,显示对冲突的反应性控制具有领域特殊性;比例一致性效应不仅出现在同种任务中,而且扩展到不同任务中,显示对冲突的主动性控制具有领域一般性。本研究结果对于理解认知控制的本质和机制具有重要意义。     

Individual differences in ego depletion: The role of sociotropy-autonomy

In his cognitive theory of depression, Beck (1987) suggested that highly sociotropic individuals have a strong need for social acceptance whereas highly autonomous individuals have an excessive need for achievement. Research by Baumeister (2000) has suggested that a phenomenon known as ego depletion, the weakening of performance on tasks following active self-control, occurs because it depletes a limited inner resource. The present study examined whether individuals who are highly sociotropic or autonomous would respond differently when faced with tasks requiring self-control. Participants completed the Sociotropy-Autonomy Scale (Clark et al. 1995) and engaged in two active self-control tasks. The results revealed that sociotropy levels were negatively correlated with persistence on tasks that require self-control whereas autonomy was positively correlated to persistence on the same task. In addition, the results suggested that, following a task requiring self-control, highly sociotropic individuals expend less effort, whereas highly autonomous individuals expend more effort on subsequent tasks requiring self-control.     

无意识自我控制目标启动对自我损耗的补偿效应

本研究基于对无意识目标启动的研究,采用阈上、阈下启动方式探讨无意识目标启动对自我损耗的补偿作用。实验1发现,阈上无意识目标启动能够有效提高自我控制,促进自控表现。实验2发现,阈下无意识目标启动对自我损耗存在补偿效应。上述结果提示,通过无意识启动方式激活自我控制目标,可以克服自我损耗的不良效应,且无需意识参与。     

Contextual adjustments in cognitive control across tasks

Does encountering information-processing conflict recruit general mechanisms of cognitive control or change only the representations of specific cues and responses? In the present experiments, a flanker task elicited responses to symbolic information (arrow meaning), whereas Stroop-like tasks elicited responses to nonsymbolic information (color of a letter or location of a target box). Despite these differences, when participants performed the flanker and Stroop tasks intermittently in randomized orders, the extent of information-processing conflict encountered on a particular trial modulated performance on the following trial. On across-task trial pairs, increases in response time to incongruent relative to congruent stimulus arrays were smaller immediately following incongruent trials than immediately following congruent trials. The degree of cognitive control exerted on a particular task thus appears to reflect not only the quality, but also the quantity, of recent experiences of information-processing conflict.     

RETRACTED ARTICLE: Losing control: Mostly incongruent lists postpone,but do not eliminate,the Stroop effect

Identifying the color (e.g., red) of a color word that is incongruent (e.g., “BLUE”) can be remarkably difficult. The Stroop effect is a measure of the interference between activity from word and color pathways. The efficacy of these pathways is thought to be highly contingent on the frequency of incongruent trials within a block. A block of trials with mostly incongruent (MI) trials typically results in a smaller Stroop effect than a block with mostly congruent (MC) trials. This reduction of the Stroop effect has been largely attributed to the strategic list-wide control of the word pathway. Here, the time course of the Stroop effect was explored using speed-accuracy tradeoff functions (SATfs) in tasks with 50 % congruent, MC, and MI trials. In the MC and 50 % congruent condition, color-word congruency affected the rate parameter of the SATf. In the MI condition, however, congruency affected the asymptote. This evidence is consistent with the idea that the strategic control of the word pathway is an effortful, temporary phenomenon, prone to buckle if responding is held in check.     

What Stroop tasks can tell us about selective attention from childhood to adulthood

A rich body of research concerns causes of Stroop effects plus applications of Stroop. However, several questions remain. We included assessment of errors with children and adults (N = 316), who sat either a task wherein each block employed only trials of one type (unmixed task) or where every block comprised of a mix of the congruent, neutral, and incongruent trials. Children responded slower than adults and made more errors on each task. Contrary to some previous studies, interference (the difference between neutral and incongruent condition) showed no reaction time (RT) differences by group or task, although there were differences in errors. By contrast, facilitation (the difference between neutral and congruent condition) was greater in children than adults, and greater on the unmixed task than the mixed task. After considering a number of theoretical accounts, we settle on the inadvertent word‐reading hypothesis, whereby facilitation stems from children and the unmixed task promoting inadvertent reading particularly in the congruent condition. Stability of interference RT is explained by fixed semantic differences between neutral and incongruent conditions, for children versus adults and for unmixed versus mixed task. We conclude that utilizing two tasks together may reveal more about how attention is affected in other groups.     

List-wide control is not entirely elusive: Evidence from picture–word Stroop

Stroop interference is attenuated in mostly incongruent lists, as compared with mostly congruent ones. This finding is referred to as the list-wide proportion congruence effect. The traditional interpretation refers to the strategic biasing of attention via list-wide control. In mostly incongruent lists, attention is biased away from the irrelevant words, whereas in mostly congruent lists, words are more fully processed. According to the item-specific account, the list-wide proportion congruence effect reflects stimulus-driven mechanisms, and not list-wide control. The unambiguous evidence available to date strongly favors the item-specific account. Using a picture–word Stroop task, we demonstrate a list-wide proportion congruence effect for 50% congruent items that are embedded in mostly incongruent and mostly congruent lists. This novel finding illustrates that the list-wide proportion congruence effect is not entirely dependent on item-specific contributions and supports the list-wide control account. We discuss factors impacting the emergence of list-wide control in Stroop tasks.