急性应激对工作记忆的影响受工作记忆负荷调节:来自电生理的证据

急性应激如何影响工作记忆还不清楚。采用电影片断诱发被试的急性应激或中性状态后,让其完成数字N-back任务并同时记录脑电。结果发现,低负荷工作记忆诱发的P3显著大于高负荷工作记忆;在0-back任务中,急性应激组诱发的P3显著大于控制组;而在2-back任务中,这种差异不显著。这些结果表明急性应激对工作记忆的影响受工作记忆负荷调节,支持了双竞争理论模型。     

网球运动专长对深度运动知觉影响的ERP研究

结合专家-新手范式与ERP技术,研究网球运动专长对个体深度运动知觉产生的影响。通过记录网球专家和新手各19名进行深度运动模式判断时的行为和ERP数据,比较两组个体深度运动知觉的行为反应差异和脑电特征。结果显示,网球专家组深度运动知觉的判断准确率高于新手组;新手组在球体靠近时P1(PO7点)的潜伏期比球体远离时的潜伏期长,专家组无显著性差异;专家组在球体靠近时的P2(Oz点)成分潜伏期长于球体远离时的潜伏期。结果表明,网球运动专家的深度运动知觉能力在准确性上较新手高;运动专长效应与选择性注意资源的调用以及模式识别有关;枕区P2成分可作为深度运动知觉的评价指标。     

Does preoccupation impair hazard perception? A simultaneous EEG and Eye Tracking study

The aim of this current study was to test the hypothesis that contemplating a recent mobile telephone conversation has a detrimental effect on measures of attentional processing in a driving situation. In this within-subjects design, hazard perception performance was compared between high and no cognitive load conditions (with or without a puzzle to solve). We tested 17 participants, all of whom were required to be in possession of a DVLA approved driving license and had completed the hazard perception portion of the British driving test. A novel dual-task paradigm, which did not require subjects to process or produce verbal information during the primary task, was employed to increase participants’ cognitive load. Participants were assessed on three categories of performance measures: behavioural, eye movements and cortical activity between both high and no cognitive load conditions whilst watching 20 clips from a hazard perception test. This study was run in a laboratory of the Psychology Research Wing at the University of Dundee. Behavioural findings from the hazard perception test indicate significantly increased reaction times to hazardous stimuli and significantly increased false alarm rates to non-hazardous stimuli in the high cognitive load condition (when contemplating a previous conversation). Analyses of eye movements indicated significant increases in blink frequencies, higher saccade peak velocities and a significant reduction in the spread of fixations along the horizontal axis. Results from EEG recordings showed a significant increase in frontal and a significant decrease in occipital theta activity within the high load condition. Findings were interpreted within the framework of Corbetta, Patel and Schulmann’s (2008) networks model of attention control. Our findings suggest that preoccupation with a recent conversation negatively influences the modulatory effect of the central executive on both the stimulus as well as goal-driven networks of the brain.     

压力下一搏：压力如何影响个体风险寻求

压力促使个体风险寻求已得到许多研究的验证和支持, 但对于该现象背后的根本机制缺乏深入探讨和整合。模型指出, 压力诱发认知资源损耗和心理需要失衡, 导致个体执行控制功能减弱, 奖赏寻求增加, 这两者引起对风险选项价值的高估、风险感知的降低和启发式决策策略的使用, 最终导致风险寻求。期望效用论、预期理论、双系统理论和风险敏感理论的视角能各有侧重地解析模型中的路径。最后, 基于模型梳理了边界条件, 并提出未来可关注压力下执行功能、认知和情绪的交互以及慢性压力的影响和调控。     

任务无关情绪刺激对工作记忆信息更新的影响:来自ERP的证据

任务无关的情绪刺激如何对工作记忆的信息更新过程产生影响还不清楚。本研究采用情绪N-back任务,结合事件相关电位技术调查情绪对工作记忆信息更新的影响。ERP结果显示,在0-back任务中,负性分心物诱发的P3显著小于中性分心物,表明其干扰了工作记忆信息更新过程;而在2-back任务中,负性分心物诱发的P3与中性分心物没有显著差异,表明其未对信息更新表现出干扰效应。该结果支持了情绪与认知加工的双竞争模型。     

The discrepant effect of acute stress on cognitive inhibition and response inhibition

This study aimed to investigate how acute stress impinges on individual’s cognitive inhibition and response inhibition abilities. Electroencephalography was adopted when 35 healthy adult females performing the No Go Flanker task before and after the Trier Social Stress Test. Both inhibition processes evoked N2 and P3 components, but only the response inhibition evoked the late positive potential (LPP), indicating the response inhibition needed continuous cognitive effort to inhibit the prepotent response. The N2 and the P3 amplitudes were decreased, while the LPP amplitudes were increased under acute stress. These results suggested that acute stress caused the detrimental effect by occupying cognitive resources. Contrastingly, individuals actively regulated and made more efforts to counteract the detrimental effect of acute stress on response inhibition. Thus, acute stress impaired cognitive inhibition but did not affect response inhibition.     

心理性应激的时间加工进程:来自ERP的证据*

采用有时间压力的算术题目诱发被试的心理性应激体验,并用事件相关电位技术(ERP)探讨心理性应激发生时大脑神经活动的时程变化。行为数据结果发现有时间压力下被试的反应时更短;脑电数据结果发现有时间压力组的容易题目比无时间压力组的容易题目诱发出更大的N1峰值、更长的P2潜伏期和更大的P300波幅;有时间压力组的困难题目比无时间压力组的困难题目同样诱发出更大的N1峰值、更长的P2潜伏期和更大的P300波幅,但这种组别主效应仅表现在部分电极点上。该研究结果表明心理性应激增加了早期知觉加工的负载,导致知觉加工速度减慢,在信息加工后期阶段需要占用更多的认知资源。     

任务转换中惯性激活对内隐记忆的影响：来自ERPs的证据

以往研究认为内隐记忆具有不受干扰影响的自动化加工特征,其证据主要来自于对内隐记忆编码过程的研究。最近已有多项研究发现,内隐记忆受提取过程中的干扰影响,但对这一现象的产生机制目前仍尚无定论。本研究根据任务转换相关理论,通过将go/no-go范式引入干扰任务,探讨提取过程中前置干扰对内隐记忆产生影响的内在机制。结果表明,前置的干扰任务产生惯性激活时,后续的内隐记忆任务会受到影响,即启动效应降低。对惯性激活进行抑制后,随后的内隐记忆则不受影响。并且,在内隐记忆相关的N400成分上得到了与行为数据一致的结果,即在no-go干扰下,获得的N400新旧效应,在go干扰下却未被发现。研究结果证明,提取干扰对内隐记忆的影响主要由干扰任务与内隐记忆任务对认知资源的竞争导致。     

Recognition of novel faces after single exposure is enhanced during pregnancy

Protective mechanisms in pregnancy include Nausea and Vomiting in Pregnancy (NVP) (Fessler, 2002; Flaxman and Sherman, 2000), increased sensitivity to health cues (Jones et al., 2005), and increased vigilance to out-group members (Navarette, Fessler, and Eng, 2007). While common perception suggests that pregnancy results in decreased cognitive function, an adaptationist perspective might predict that some aspects of cognition would be enhanced during pregnancy if they help to protect the reproductive investment. We propose that a reallocation of cognitive resources from nonessential to critical areas engenders the cognitive decline observed in some studies. Here, we used a recognition task disguised as a health rating to determine whether pregnancy facilitates face recognition. We found that pregnant women were significantly better at recognizing faces and that this effect was particularly pronounced for own-race male faces. In human evolutionary history, and today, males present a significant threat to females. Thus, enhanced recognition of faces, and especially male faces, during pregnancy may serve a protective function.     

Dopamine D1 receptors are responsible for stress-induced emotional memory deficit in mice

It is established that stress impairs spatial learning and memory via the hypothalamus-pituitary-adrenal axis response. Dopamine D1 receptors were also shown to be responsible for a stress-induced deficit of working memory. However, whether stress affects the subsequent emotional learning and memory is not elucidated yet. Here, we employed the well-established one-trial step-through task to study the effect of an acute psychological stress (induced by tail hanging for 5, 10, or 20?min) on emotional learning and memory, and the possible mechanisms as well. We demonstrated that tail hanging induced an obvious stress response. Either an acute tail-hanging stress or a single dose of intraperitoneally injected dopamine D1 receptor antagonist (SCH23390) significantly decreased the step-through latency in the one-trial step-through task. However, SCH23390 prevented the acute tail-hanging stress-induced decrease in the step-through latency. In addition, the effects of tail-hanging stress and/or SCH23390 on the changes in step-through latency were not through non-memory factors such as nociceptive perception and motor function. Our data indicate that the hyperactivation of dopamine D1 receptors mediated the stress-induced deficit of emotional learning and memory. This study may have clinical significance given that psychological stress is considered to play a role in susceptibility to some mental diseases such as depression and post-traumatic stress disorder.     

Amygdala functional connectivity is reduced after the cold pressor task

The amygdala forms a crucial link between central pain and stress systems. Previous research indicates that psychological stress affects amygdala activity, but it is less clear how painful stressors influence subsequent amygdala functional connectivity. In the present study, we used pulsed arterial spin labeling (PASL) to investigate differences in healthy male adults’ resting-state amygdala functional connectivity following a cold pressor versus a control task, with the stressor and control conditions being conducted on different days. During the period of peak cortisol response to acute stress (approximately 15–30 min after stressor onset), participants were asked to rest for 6 min with their eyes closed during a PASL scanning sequence. The cold pressor task led to reduced resting-state functional connectivity between the amygdalae and orbitofrontal cortex (OFC) and ventromedial prefrontal cortex, and this occurred irrespective of cortisol release. The stressor also induced greater inverse connectivity between the left amygdala and dorsal anterior cingulate cortex (ACC), a brain region implicated in the down-regulation of amygdala responsivity. Furthermore, the degree of poststressor left amygdala decoupling with the lateral OFC varied according to self-reported pain intensity during the cold pressor task. These findings indicate that the cold pressor task alters amygdala interactions with prefrontal and ACC regions 15–30 min after the stressor, and that these altered functional connectivity patterns are related to pain perception rather than cortisol feedback.     

Decline in executive control during acute bouts of exercise as a function of exercise intensity and fitness level

Studies on the effects of acute bouts of cardiovascular exercise on cognitive performances show contradictory findings due to methodological differences (e.g., exercise intensity, cognitive function assessed, participants’ aerobic fitness level, etc.). The present study assessed the acute effect of exercise intensity on cognition while controlling for key methodological confounds. Thirty-seven participants (M_age = 23. 8 years; SD = 2.6) completed a computerized modified-Stroop task (involving denomination, inhibition and switching conditions) while pedalling at 40%, 60% and 80% of their peak power output (PPO). Results showed that in the switching condition of the task, error rates increased as a function of exercise intensity (from 60% to 80% of PPO) in all participants and that lower fit individuals showed increased reaction time variability. This suggests that acute bouts of cardiovascular exercise can momentarily alter executive control and increase performance instability in lower fit individuals.     

Preliminary evidence that acute and chronic daily psychological stress affect sexual arousal in sexually functional women

It is assumed that psychological stress may inhibit sexual arousal in women. Research on the effect of (acute and chronic) psychological stressors on genital and subjective sexual arousal, however, is scarce. To investigate whether psychological stressors indeed inhibit sexual responding, sexually functional women were randomly assigned to an experimental condition (n=30) in which acute psychological stress was induced by a frustrating computer task or a control condition (n=29). After the acute psychological stress or control induction women were exposed to an erotic stimulus. Genital sexual arousal was assessed using vaginal photoplethysmography. Self-report ratings of subjective sexual arousal were collected after the erotic stimulus. Furthermore, women were post hoc divided into a 'low' and a 'high' chronic stress group, based on their pre-assessment scores on a chronic daily stress questionnaire. As predicted, it was found that women in the acute stress condition responded with lower levels of genital and subjective sexual arousal to an erotic stimulus than women in the control condition. In addition, women with high levels of chronic stress responded with lower levels of genital sexual arousal to an erotic stimulus than women with low levels of chronic stress. Chronic stress did not affect the level of subjective sexual arousal.     

Go no-go performance under psychosocial stress: beneficial effects of implementation intentions

Acute stress has been found to have negative and implementation intentions (IIs) to have positive effects on cognitive performance. This study was the first to examine the effects of IIs on executive action control under acute psychosocial stress. Forty-two male subjects aged 21-39 years were randomly assigned to the Trier Social Stress Test (TSST) versus a rest condition. In addition, the instruction to the executive task (a go no-go task) was manipulated (IIs versus standard instruction). After the stress test, a dual-task procedure including a go no-go task was conducted. The TSST resulted in increases in cortisol response, heart rate and state anxiety compared to the rest condition. Acute stress significantly impaired go no-go performance, but only in the group without IIs. We conclude that under acute stress conditions executive functioning is reduced, but the use of IIs can be an effective strategy to overcome this negative effect.     

The Effects of Acute Alcohol Intoxication on Person Memory: The Stereotypical Drunk1

Research has suggested that acute alcohol intoxication disrupts cognitive functioning by reducing the availability of executive resources for person perception. The present study tested the prediction that this effect would increase stereotype application during impression formation by reducing the encoding of nonstereotypical information. Participants were instructed to complete an impression-formation task following consumption of low, medium, or high doses of alcohol. This task involved the encoding of both stereotypical and neutral material. A subsequent free-recall test demonstrated that alcohol significantly decreased participants' encoding of neutral information, but did not affect the memorability of stereotypical information. These findings are discussed in relation to models of both stereotyping and alcohol intoxication.     

Regulating cognitive control through approach-avoidance motor actions

In two studies, the regulatory function of approach-avoidance cues in activating cognitive control processes was investigated. It was hypothesized that avoidance motor actions, relative to approach motor actions, increase the recruitment of cognitive resources, resulting in better performance on tasks that draw on these capacities. In Study 1, error rates on a verbal response mode version of the Stroop task were analyzed. On inconsistent Stroop trials, participants in the avoidance condition made significantly fewer errors than those in the approach condition. In Study 2, performance differences on a task switching paradigm were investigated. Crucially, approach and avoidance motor actions were manipulated within-subjects by alternating between approach and avoidance motor actions on 4 blocks of trials. Temporal switching costs were significantly lower while performing an avoidance, compared to an approach motor action. These results support our hypothesis that avoidance cues, relative to approach cues, lead to improved performance on cognitive control tasks.     

Intraindividual coupling of daily stress and cognition

Most psychological theories predict associations among processes that transpire within individuals. However, these theories are often tested by examining relationships at the between-persons (BP) rather than the within-persons (WP) level. The authors examined the WP and BP relationships between daily stress and daily variability in cognitive performance. Daily stress and cognitive performance were assessed on 6 occasions in 108 older adults and 68 young adults. WP variability in stress predicted WP variability in response times (RTs) on a 2-back working memory task in both younger and older adults. That is, RTs were slower on high-stress days compared with low-stress days. There was evidence of an amplified WP stress effect in the older adults on a serial attention task. There was no evidence of stress effects on simple versions of these tasks that placed minimal demands on working memory. These results are consistent with theories that postulate that stress-related cognitive interference competes for attentional resources.     

The effects of acute stress and perceptual load on distractor interference

Selective attention can be improved under conditions in which a high perceptual load is assumed to exhaust cognitive resources, leaving scarce resources for distractor processing. The present study examined whether perceptual load and acute stress share common attentional resources by manipulating perceptual and stress loads. Participants identified a target within an array of nontargets that were flanked by compatible or incompatible distractors. Attentional selectivity was measured by longer reaction times in response to the incompatible than to the compatible distractors. Participants in the stress group participated in a speech test that increased anxiety and threatened self-esteem. The effect of perceptual load interacted with the stress manipulation in that participants in the control group demonstrated an interference effect under the low perceptual load condition, whereas such interference disappeared under the high perceptual load condition. Importantly, the stress group showed virtually no interference under the low perceptual load condition, whereas substantial interference occurred under the high perceptual load condition. These results suggest that perceptual and stress related demands consume the same attentional resources.     

The effects of acute stress and perceptual load on distractor interference

Selective attention can be improved under conditions in which a high perceptual load is assumed to exhaust cognitive resources, leaving scarce resources for distractor processing. The present study examined whether perceptual load and acute stress share common attentional resources by manipulating perceptual and stress loads. Participants identified a target within an array of nontargets that were flanked by compatible or incompatible distractors. Attentional selectivity was measured by longer reaction times in response to the incompatible than to the compatible distractors. Participants in the stress group participated in a speech test that increased anxiety and threatened self-esteem. The effect of perceptual load interacted with the stress manipulation in that participants in the control group demonstrated an interference effect under the low perceptual load condition, whereas such interference disappeared under the high perceptual load condition. Importantly, the stress group showed virtually no interference under the low perceptual load condition, whereas substantial interference occurred under the high perceptual load condition. These results suggest that perceptual and stress related demands consume the same attentional resources.     

The relationship between aerobic activity and cognitive performance under stress

This study examined the relationship between regular aerobic activity and cognitive performance under stress when personality and inherent aptitude were statistically controlled. Aerobically conditioned subjects have been shown to mediate the physiological response to stress under physical challenge. Would aerobically conditioned subjects also respond more efficiently to psychological stress under cognitive challenge? Forty volunteers completed a battery of personality and aptitude measures and then completed two cognitive tasks (written tests of logic), one under a condition of no stress, the other while being verbally pressured by a test monitor. Heart rate and blood pressure were measured during and after each cognitive task. Contrary to the experimental hypothesis, aerobic activity was related to inferior cognitive performance and to elevated blood pressure under stress. Inherent cognitive aptitude and personality traits emerged as far more important correlates of cognitive performance under stress than did the level of exercise.