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.     

错误相关负波的神经起源及其影响因素

与个体做出错误反应相伴的错误相关ERP成分叫错误相关负波 (error-related negativity, ERN),当前冲突监控理论、表征失匹配理论和强化学习理论从不同的角度对ERN的神经机制进行解释,各理论间并非完全相互排斥。目前大部分研究认为ERN定位于扣带回,部分研究则出现其它脑区的激活,然而,扣带回与其它脑区存在复杂的神经功能联系,ERN 电位很可能是多个脑区电活动在头颅的综合表现,而非某一脑区的单独表现。ERN的神经机制受到实验任务、被试年龄及其意识水平等因素的影响。未来要推动实验室研究走向临床应用,发现与诊断脑电波异常的病人和毒品易复吸人群。     

Monitor yourself! Deficient error-related brain activity predicts real-life self-control failures

Despite their immense relevance, the neurocognitive mechanisms underlying real-life self-control failures (SCFs) are insufficiently understood. Whereas previous studies have shown that SCFs were associated with decreased activity in the right inferior frontal gyrus (rIFG; a region involved in cognitive control), here we consider the possibility that the reduced implementation of cognitive control in individuals with low self-control may be due to impaired performance monitoring. Following a brain-as-predictor approach, we combined experience sampling of daily SCFs with functional magnetic resonance imaging (fMRI) in a Stroop task. In our sample of 118 participants, proneness to SCF was reliably predicted by low error-related activation of a performance-monitoring network (comprising anterior mid-cingulate cortex, presupplementary motor area, and anterior insula), low posterror rIFG activation, and reduced posterror slowing. Remarkably, these neural and behavioral measures predicted variability in SCFs beyond what was predicted by self-reported trait self-control. These results suggest that real-life SCFs may result from deficient performance monitoring, leading to reduced recruitment of cognitive control after responses that conflict with superordinate goals.     

情绪的动机强度与工作记忆任务类型的协调性对自我控制任务的影响

考察趋近动机强度不同的积极情绪和回避动机强度不同的消极情绪与工作记忆的协调性对自我控制任务的影响。结果发现,与高趋近动机的积极情绪、高回避动机的消极情绪以及中性情绪相比,在低趋近动机的积极情绪下完成言语工作记忆以及在低回避动机的消极情绪下完成空间工作记忆,工作记忆成绩提高,而Stroop分数降低,这表明情绪与工作记忆的协调性受到情绪动机强度的影响。     

Stress regulation and cognitive control: evidence relating cortisol reactivity and neural responses to errors

In this study, we tested the relationship between error-related signals of cognitive control and cortisol reactivity, investigating the hypothesis of common systems for cognitive and emotional self-regulation. Eighty-three participants completed a Stroop task while electroencephalography (EEG) was recorded. Three error-related indices were derived from the EEG: the error-related negativity (ERN), error positivity (Pe), and error-related alpha suppression (ERAS). Pre- and posttask salivary samples were assayed for cortisol, and cortisol change scores were correlated with the EEG variables. Better error–correct differentiation in the ERN predicted less cortisol increase during the task, whereas greater ERAS predicted greater cortisol increase during the task; the Pe was not correlated with cortisol changes. We concluded that an enhanced ERN, part of an adaptive cognitive control system, predicts successful stress regulation. In contrast, an enhanced ERAS response may reflect error-related arousal that is not adaptive. The results support the concept of overlapping systems for cognitive and emotional self-regulation.     

Mindful awareness of feelings increases neural performance monitoring

Mindfulness has been associated with enhanced performance monitoring; however, little is known about the processes driving this apparent neurocognitive benefit. Here, we tested whether focusing present-moment awareness toward the nonjudgmental experience of emotion facilitates rapid neural responses to negative performance outcomes (i.e., mistakes). In particular, we compared whether directing present-moment awareness toward emotions or thoughts would enhance the neurophysiological correlates of performance monitoring: the error-related negativity (ERN) and the error positivity (Pe). Participants were randomly assigned to either a thought-focused or an emotion-focused group, and first they completed a preinduction go/no-go task. Subsequently, the groups followed inductions that promoted mindful attention toward either thoughts or emotions, before completing a final postinduction go/no-go session. The results indicated that emotion-focused participants demonstrated higher neural sensitivity to errors in the time course of the ERN, whereas focusing on thoughts had no effect on performance monitoring. In contrast, neither induction procedure altered the amplitude of the later Pe component. Although our manipulations also induced changes in behavior, the ERN effects remained significant after controlling for performance. Thus, our results suggest that mindfulness meditation boosts early neural performance monitoring (ERN amplitude), specifically through meditation’s influence on affective processing.     

Performance costs when emotion tunes inappropriate cognitive abilities: implications for mental resources and behavior

Emotion tunes cognition, such that approach-motivated positive states promote verbal cognition, whereas withdrawal-motivated negative states promote spatial cognition (Gray, 2001). The current research examined whether self-control resources become depleted and influence subsequent behavior when emotion tunes an inappropriate cognitive tendency. In 2 experiments, either an approach-motivated positive state or a withdrawal-motivated negative state was induced, and then participants completed a verbal or a spatial working memory task creating conditions of emotion-cognition alignment (e.g., approach/verbal) or misalignment (e.g., approach/spatial). A control condition was also included. To examine behavioral costs due to depleted self-control resources, participants completed either a Stroop task (Stroop, 1935; Experiment 1) or a Black/White implicit association test (IAT; Greenwald, McGhee, & Schwartz, 1998; Experiment 2). Participants in the misalignment conditions performed worse on the Stroop task, and they were worse at controlling their implicit attitude biases on the IAT. Thus, when emotion tunes inappropriate cognitive tendencies for one's current environment, self-control resources become depleted, impairing behavioral control.     

Preverbal error-monitoring in stutterers and fluent speakers

This study was designed to characterize the brain system that monitors speech in people who stutter and matched controls. We measured two electrophysiological peaks associated with action-monitoring: the error-related negativity (ERN) and the error positivity (Pe). Both the ERN and Pe were reliably observed after errors in a rhyming task and a nonverbal flanker task, replicating previous reports of a language-monitoring ERN and demonstrating that the Pe can also be elicited by phonological errors. In the rhyming task, stutterers showed a heightened ERN peak regardless of whether they actually committed an error. Similar results, though only marginally significant, were obtained from the flanker task. These results support the vicious cycle hypothesis, which posits that stuttering results from over-monitoring the speech plan. The elevation of the ERN in stutterers and the similarity of the results between the flanker and rhyming tasks implies that speech-monitoring may rely on the same neural substrate as action-monitoring.     

选择损耗自我控制资源:取舍效应还是信息加工难度效应?

研究以自我控制的资源模型为理论框架,从选择难度特征的视角出发,通过两项实验考察选择损耗自我控制资源的成因。结果发现,高取舍冲突组被试的stroop任务成绩显著低于低取舍冲突组被试,高、低阅读难度组被试的stroop任务成绩差异不显著;为自己做选择组被试的stroop任务成绩显著低于为他人做选择组被试,完成3选项和4选项任务组被试的stroop任务成绩差异不显著。研究表明,选择损耗效应是由选择的取舍难度而非信息加工难度造成。。     

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。     

Counter-regulation triggered by emotions: Positive/negative affective states elicit opposite valence biases in affective processing

The present study investigated whether counter-regulation in affective processing is triggered by emotions. Automatic attention allocation to valent stimuli was measured in the context of positive and negative affective states. Valence biases were assessed by comparing the detection of positive versus negative words in a visual search task (Experiment 1) or by comparing interference effects of positive and negative distractor words in an emotional Stroop task (Experiment 2). Imagining a hypothetical emotional situation (Experiment 1) or watching romantic versus depressing movie clips (Experiment 2) increased attention allocation to stimuli that were opposite in valence to the current emotional state. Counter-regulation is assumed to reflect a basic mechanism underlying implicit emotion regulation.     

Error detection and posterror behavior in depressed undergraduates

This study examined the influence of depression on error-monitoring and behavioral compensation after errors, two important aspects of cognitive control. Undergraduates differing in self-reported depression levels completed a modified Stroop task while error-related scalp potentials were recorded. Behaviorally, participants with higher depression scores were disproportionately slower and less accurate after errors in a task condition that included negative emotional words. Physiological results indicated that the amplitudes of the error-related negativity (ERN) and error positivity (Pe), two indices of error detection, were not correlated with depression score. ERN amplitudes predicted behavioral slowdown after errors, but only among more depressed participants in the negative-word condition. Together, the results imply that depression is associated not with an error detection deficit, but rather with alterations in subsequent performance changes, once errors have been identified.     

Effects of Stroop task duration on subsequent cognitive and physical performance

The strength model of self-control purports to explain why brief cognitive response inhibition tasks impair subsequent isometric handgrip endurance. According to the model, ego depleting tasks requiring self-control resources impair performance on subsequent tasks that also require self-control resources. However, several lines of evidence challenge this model, including evidence of improved exercise performance following longer cognitive tasks. Our study investigated the effects of cognitive task duration on (1) subsequent physical endurance performance, (2) concurrent cognitive task performance, and (3) subsequent novel cognitive task performance. Adopting an experimental design, with Stroop task type (incongruent, congruent) and duration (5, 10, 20 min) as between-participant factors, participants (N = 180) completed a color word Stroop task, an isometric handgrip to exhaustion task, and a novel 5-min incongruent number word Stroop task. In the handgrip task, endurance performance was worse following incongruent word Stroop than congruent word Stroop for 10-min tasks but not 5-min and 20-min tasks. In the word Stroop task, accuracy was lower and speed was slower following incongruent word Stroop than congruent word Stroop. Importantly, reaction times improved with longer task durations. In the novel number Stroop task, accuracy was higher following incongruent word Stroop than congruent word Stroop. In conclusion, the finding that the ego depletion effect was moderated by cognitive task duration is better explained by the expected value of control model than the strength model.     

Dealing efficiently with emotions: acceptance-based coping with negative emotions requires fewer resources than suppression

Previous studies have consistently shown that changing or avoiding emotions requires resources and therefore leads to impaired performance on a subsequent self-control task. The aim of the present study was to investigate the extent to which acceptance-based coping requires regulatory resources. Participants who accepted their emotions during exposure to a sad video performed better on a subsequent self-control task than participants who were instructed to suppress their emotions and a control group who received no instructions. These findings suggest that acceptance is an efficient strategy in terms of resources.     

An independent component analysis of fMRI data of grapheme-colour synaesthesia

The independent component analysis (ICA) method was applied to fMRI data from two synaesthetes and their matched controls while they performed the coloured-word Stroop task and the single-letter (synaesthetic) Stroop task. ICA identified an 'attention' network, a 'perceptual' network as well as a 'conflict monitoring' network. Increased activity was observed in right V4 during the single-letter Stroop task for synaesthetes only. The finding confirms that the same neural substrate that is known to support the experience of physical colours also supports the experience of synaesthetic colours.     

工作记忆广度与自我损耗的关系

以往研究表明,工作记忆能力高的个体在自我控制方面也表现得更好,通过考察工作记忆广度（working memory span, WMS）与自我损耗的关系,有助于揭示这种现象的内在机制。66名被试随机分为损耗组和控制组,采用自动化操作广度测验测量WMS。双任务实验中,任务一为情绪抑制任务,任务二为Stroop任务。结果发现,损耗组的Stroop效应明显高于控制组。进一步分析显示,损耗组中高WMS被试的自我损耗效应要强于低WMS被试,此结果表明：高WMS个体在自我控制任务中表现得更好并不是因为固有的自我控制能量水平更高,而是因为他们倾向于在自我控制过程中投入更多能量。     

自我损耗促进冲动决策：来自行为和ERPs的证据

该研究以自我控制资源模型为理论框架, 采用行为实验和ERPs技术考察自我损耗对冲动决策的影响。实验1采用Stroop任务操纵自我控制资源并采用延迟折扣任务考察被试的决策冲动性, 实验2采用同样的实验任务并同时采用ERPs技术记录高、低自我损耗者在随后决策任务中的脑电成分。行为结果发现, 在控制心境、特质自我控制水平以及风险偏好等无关变量后, 高损耗者比低损耗者在延迟折扣任务上的折扣程度更大。ERPs结果发现, 不论延迟金额大小, 高损耗者在左侧额区诱发的N1波幅显著小于低损耗者; 高损耗者在右半球诱发的P2波幅显著大于低损耗者。研究表明, 自我损耗抑制决策早期左侧额区的激活水平, 个体因而无法识别冲突以及抵制即时满足的诱惑, 这促使他们采用直觉启发式进行决策, 最终导致冲动决策的产生。     

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.     

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.     

Can implementation intentions help to overcome ego-depletion?

Research on ego-depletion suggests that the ability to self-regulate one’s behavior is limited: Exerting self-control on an initial task reduces performance on a subsequent task that also requires self-control. Two experiments tested whether forming implementation intentions could prevent ego-depletion and/or offset the effects of ego-depletion. Experiment 1 found that participants who formed implementation intentions during an initial ego-depleting task subsequently showed greater persistence on an unsolvable puzzles task compared to participants who did not form implementation intentions. Experiment 2 found that among participants who had been ego-depleted during an initial task, forming implementation intentions improved subsequent performance on a Stroop task to the level exhibited by non-depleted controls. Thus, implementation intentions help to enhance people’s ability to self-regulate their behavior.