奖惩对行为抑制能力和自主生理活动影响的时效性

将45名被试随机分配为奖励组、惩罚组和对照组, 实验进程按时间发展过程被分为五阶段, 采用停止信号任务探讨奖惩刺激对行为抑制能力和自主生理活动影响的时效性。结果显示：奖惩刺激对行为反应时和抑制失败率影响仅在第二、三阶段差异显著, 对心率影响的显著差异在第三阶段结束、而对皮电和指温影响的显著差异仍持续到第五阶段。结果表明：奖惩刺激对行为的抑制作用具有时效性, 有效时间内表现为仅奖励能提高行为抑制能力; 奖惩刺激对心率的影响具有时效性, 但对其它生理指标的影响则未显示出时效性。     

奖惩对行为抑制及程序阶段中自主生理反应的影响

采用停止信号任务探讨奖惩条件对行为抑制和程序阶段中自主生理反应的影响。结果显示：(1)奖惩组的反应时显著高于控制组, 抑制失败率则显著低于控制组; (2)奖励组与其它两组相比表现出心率显著增加和皮肤电活动显著降低; (3)各生理指标在准备、工作和奖惩阶段中的奖惩差异性显著(4)奖惩条件下皮肤电活动呈现出一致性程序阶段变化。结果表明：奖惩条件均对行为具有抑制作用, 但在自主生理反应上则有显著差异; 各生理指标在准备、工作和奖惩阶段的情绪效价显著; 皮肤电活动的程序阶段变化显著, 但其奖惩效价较为稳定, 很少接受程序阶段变化的影响。     

奖励和惩罚在注意控制过程中的优化和分离：眼动研究

通过两个眼动实验考察金钱奖励和惩罚引起的动机对个体在不同空间线索条件下注意控制加工的影响。实验1采用朝向/反向眼跳范式, 被试通过内源性线索提供心理准备的情况下做出简单的朝向眼跳以及需要抑制优势反应的反向眼跳。结果发现, 相比无奖惩条件, 奖励条件下朝向眼跳任务的正确率更高, 惩罚条件下反向眼跳任务的正确率更高; 两种眼跳任务中有奖惩条件下的眼跳峰速度均比无奖惩条件高。实验2采用Go/No-go任务, 进一步探讨了由副中央凹加工外源性边缘线索从而不能提供充分心理准备的情况下奖励和惩罚对注意控制的影响。结果发现, 奖励条件下Go反应的眼跳潜伏期更短, 惩罚条件下No-go反应正确率更高, 眼跳峰速度在两种条件下均比无奖惩条件高。以上结果表明, 奖励和惩罚均能够促进个体的注意控制, 但二者的加工过程是分离的, 奖励能够改善趋近行为, 惩罚则能够显著促进抑制控制行为, 且奖励和惩罚在注意控制加工过程中具有不同的作用模式, 奖励能够更早唤醒注意控制系统从而更快地促进行为的发生与执行, 惩罚则能够通过调节注意资源促进以目标为导向的行为中对优势反应的抑制。     

不同趋近动机强度积极情绪对认知控制的影响

情绪的动机维度模型认为, 积极情绪对认知加工的影响受其趋近动机强度的调节, 高、低趋近动机积极情绪对认知加工的影响不同。本研究运用情绪图片诱发被试高、低趋近动机积极情绪, 采用停止信号任务和任务转换作业考察了不同趋近动机强度积极情绪对认知控制的影响。结果发现：(1)与中性条件相比, 高趋近动机积极情绪促进了停止信号任务中Go任务和任务转换作业中重复任务的反应执行。(2)在停止信号任务中, 相对于中性条件, 低趋近动机积极情绪条件下的停止信号反应时显著缩短; 在任务转换作业中, 低趋近动机积极情绪条件下的反应时转换损失和错误率转换损失均显著降低, 而高趋近动机积极情绪条件下的反应时转换损失显著增加。因此, 积极情绪对认知控制的影响受其趋近动机强度的调节, 即低趋近动机积极情绪增强认知灵活性, 提高停止反应与任务转换的速度; 而高趋近动机积极情绪增强认知稳定性, 加快停止信号任务中Go任务和任务转换作业中重复任务的反应执行, 增加了反应时转换损失。     

自我信息的反应抑制优势：来自神经振荡的证据

为探明个体对自我信息的反应抑制神经机制,记录了被试在完成面孔识别的停止信号任务时的脑电信号。神经振荡结果显示,反应任务中,加工自我面孔引发了更大的同步化δ节律和去同步化β节律;停止任务中,自我面孔引发了更大的去同步化β节律,特别在大脑前额区和中线上。表明,自我信息的反应抑制优势发生在抑制控制阶段,在于增强的β节律的去同步化促进了运动准备,提高了后续的动作抑制的速度。     

阈下奖励调节认知控制的权衡

本研究采用奖励版的AX-CPT任务, 通过控制奖励线索和反馈的呈现方式, 设置出基线、阈上奖励、阈下奖励三种条件, 考察习得的奖励联结和奖励动机能否以潜意识的方式影响认知任务的表现和认知控制的权衡。结果显示：奖励线索只在阈上呈现时提高AX序列的任务表现; 与基线条件相比, 阈上和阈下奖励条件下认知控制的权衡均偏向主动性控制, 且这种偏向在两者间无显著差异。这表明习得的阈下奖励线索可以调节认知控制的权衡, 使被试像阈上奖励时那样偏向主动性控制。     

药物相关线索干扰海洛因戒断者的刷新能力

研究采用n-back任务,检验药物相关线索对海洛因戒断者工作记忆刷新的影响,旨在探究海洛因戒断者由于长期药物使用造成的认知损伤和药物相关线索之间的关系。结果显示:（1）无论在1-back任务中还是在2-back任务中,相对于正常人,海洛因戒断者反应时长更长。（2）相对于中性线索条件,海洛因戒断者在药物相关线索条件下的反应时更长;（3）相对于2-back任务,正常人与海洛因戒断者在1-back任务中的正确率更高。这可能表明长期的药物使用会使海洛因成瘾戒断者的工作记忆刷新能力受损,而药物相关线索会进一步干扰这种认知损伤。     

人格特质对选择性加工偏向的影响

采用词性辨别和注意探测任务,考察了神经质和外倾性对选择性加工偏向的影响。结果表明：（1）放试在选择信息时存在特质一致性倾向;（2）在单一刺激条件下,当刺激词呈现时间为0．5s时,高神经质对所有效价词的RT均快于低神经质;而当呈现时间为1．0s时,外倾者比内倾者的反应潜伏期更短4（3）双重刺激条件下的选择性加工偏向比单一刺激条件更明显;（4）在词性辨别任务中．刺激词呈现时间只影响了神经质被试对情绪词的RT;在注意探测任务中,呈现时间对内外倾被试的加工偏向影响不显著。     

两种亚型ADHD儿童在停止信号任务中的反应抑制

采用停止信号任务,操纵其中的反应冲突,探查两种亚型（注意缺陷型和混合型）ADHD儿童在不同抑制功能——反应冲突和反应停止上的表现,以及儿童在内源性和外源性两种注意条件下反应抑制的表现。结果发现,与正常儿童相比,ADHD儿童在两种反应抑制上都有不同程度的缺损,不仅冲突效应量更大,反应停止的错误率也更高;但在控制年龄因素后,未观察到两种亚型ADHD儿童之间在反应冲突和反应停止能力上有明显差异。研究还发现,儿童在内源性和外源性两种注意条件下反应抑制的表现模式相似,说明反应冲突和反应停止可能存在某些共同的神经机制,两种亚型ADHD儿童在这些机制的功能缺损上有类似之处。     

辣食渴求者抑制控制能力的行为和ERP研究

采用事件相关电位(ERP)技术,探讨一般线索Go/Nogo和辣食线索Go/Nogo任务过程中,辣食渴求者和非辣食渴求者的抑制控制能力。（1）行为结果显示,两组被试辣食线索的反应时和错误率无显著差异,均在任务类型上有差异,即对辣食线索的反应更慢;（2）ERP结果显示,在辣食相关线索Go/Nogo任务中辣食渴求者的N2b和P3波幅都显著小于非辣食渴求者,N2a没有差异;在一般线索Go/Nogo任务中,ERP成分没有发现显著差异。结果提示,辣食渴求者只在辣食相关线索的抑制控制能力弱于非辣食渴求者,这可能意味着他们对辣食线索抑制反应的缺失。     

Extroversion-related differences in speed of premotor and motor processing as revealed by lateralized readiness potentials

To further elucidate extroversion-related differences in speed of sensorimotor processing, the authors obtained behavioral and psychophysiological measures as participants (16 introverts and 16 extroverts) performed a visual go/no-go task. Although no extroversion-related differences in reaction time emerged, introverts showed faster premotor processing but slower central and peripheral motor processing--as indicated by latencies of the lateralized readiness potential (LRP) and electromyographic (EMG) data, respectively--than extroverts did. Additional regression analyses revealed that stimulus-locked LRP latency, response-locked LRP latency, and Nl EMG amplitude accounted for 40% of overall variability in individual extroversion scores. On the basis of the present results, the authors introduce a compensation hypothesis that accounts for the common failure of researchers to demonstrate extroversion-related differences in reaction time. The present results challenge J. Brebner and C. Cooper's (1985) model of extroversion in which stimulus analysis is not slower in introverts than in extroverts. However, the present findings support the assumption of faster motor processing in extroverts.     

The influence of introversion/extraversion on the skin conductance response to stress and stimulus intensity

A series of studies compared skin conductance level (SCL) for introverts and extraverts during a series of tones varying in both stimulus intensity (SI) and the amount of stress preceding the tones. When a difficult paired-associate task preceded the tones, both groups were about the same for 83 dB tones but extraverts were much higher at 103 dB, introverts failing to show an increase as a function of SI. There were no differences between the two groups following a simple paired-associate task, both groups showing a similar increase with increased SI. Finally, SCL was higher for introverts than extraverts during tones preceded by a rest period, and this was especially true for the early trials and for lower SI (75 and 83 dB compared with 100 and 103 dB). Taken together, these results suggest that SCL is higher for extraverts at higher levels of arousal but that the reverse is true for lower levels of arousal. This relationship is consistent with the theory that introverts have a “weak nervous system” which develops transmarginal or protective inhibition under stress.     

Electrodermal measures of attention and effort to stimulus onset and offset for intramodal and intermodal tasks.

Two experiments were designed to assess the relationship between task difficulty and arousal. Electrodermal measures of tonic and phasic arousal to four levels of task difficulty at stimulus onset and offset were studied in college students for intramodal and intermodal tasks. The students were presented for 18 trails with visual-auditory or visual-visual stimuli with either 2.0-, 0.2-, or 0.02-sec difference between stimuli onset or offset, and asked to judge which stimulus came on or went off first or merely to observe the stimuli. Both frequency and amplitude of skin conductance responses reliably differentiated the levels of task difficulty for both the intramodal and the intermodal task. None of the measures of tonic level of arousal was reliable. Electrodermal measures of phasic responses accurately reflected the task demands.     

The effects of emotional stimuli on target detection: indirect and direct resource costs

The present study was designed to explore the performance costs of negative emotional stimuli in a vigilance task. Forty participants (20 women) performed a vigilance task in two conditions: one with task-irrelevant negative-arousing pictures and one with task-irrelevant neutral pictures. In addition to performance, we measured subjective state (energetic arousal, tense arousal, task-related and task-unrelated thoughts) and frontal cerebral activity with near infrared spectroscopy. Overall performance in the negative picture condition was lower than in the neutral picture condition and the negative picture condition had elevated levels of energetic arousal, tense arousal and task-related thoughts. Moreover, there was a significant relationship between the impact of the negative pictures on tense arousal and task-related thoughts and the impact of the negative pictures on performance (in comparison to the neutral picture stimuli task). These results provide support for indirect cost models of negative emotional stimuli on target detection performance.     

Exploring the mechanism of dishabituation

In this study we explored elicitation and habituation of the orienting reflex (OR) in the context of indifferent and significant stimuli, particularly aiming to clarify the mechanism driving dishabituation. An in-depth analysis of the mechanisms of electrodermal habituation and dishabituation was conducted, focusing on the role of state measures as determinants of the phasic response profile. Twenty-four young adult participants completed an auditory dishabituation task while electrodermal activity was recorded. Participants listened to a series of 10 innocuous tones of the same frequency (standards), followed by a deviant tone of a different frequency, and succeeded by 2-4 tones of the same frequency as the initial 10 stimuli. All stimuli had a random stimulus onset asynchrony of 5-7 s. Participants completed an indifferent condition in which there was no task in relation to the stimuli, and a significant condition where instruction was given to count the stimuli silently; order was counterbalanced between participants. As predicted, both skin conductance responses (SCRs) and skin conductance levels (SCLs) were larger for the significant than the indifferent condition. The initial phasic ORs were dependent on pre-stimulus arousal level, and there were significant decreases in both SCR and SCL over the first 10 standards in both conditions. Phasic response recovery was apparent to the deviant stimulus, and dishabituation to the following standard stimulus; both effects were enhanced in the significant condition. Sensitisation was apparent in SCL following the initial and deviant stimuli, but the extent of this was confounded with incomplete resolution of the preceding phasic OR in the significant condition. In the indifferent condition, dishabituation was independent of deviant-related sensitisation; this could not be tested in the significant condition. These findings suggest that dishabituation is not a process of sensitisation, but rather, a disruption of the habituation process.     

The influence of musical distraction of varying complexity on the cognitive performance of extroverts and introverts

This study examined the effects of complexity in background music on the performance of four cognitive tasks by extroverts and introverts. In the presence of either ‘complex’ or ‘simple’ musical distraction or in silence, 24 introverts and 24 extroverts carried out a reading comprehension test, an observation test, and a memory test (in which recall was measured both immediately and after a six‐minute delay). An interaction was predicted such that increasing‐complexity musical distraction would result in the increase of extroverts', and the decrease of introverts', cognitive‐task performance. A significant interaction was obtained for three of the four tests: the observation test and both memory tests. These findings are discussed with regard to Eysenck's theory of personality. Copyright © 1999 John Wiley & Sons, Ltd.     

Neuroticism, extroversion, and response to stress

The study evaluated the role of dispositional determinants in the mediation of response to stress. Thirty-five undergraduate females were assigned to one of four groups according to scores on the neuroticism and extroversion scales of the Eysenck Personality Inventory. The Induced Affect research paradigm was adapted as a stress analog procedure and, following a baseline phase, subjects were run in alternating relaxation and arousal phases. Both univariate and multivariate analyses were completed. Neurotic introverts tended to label IA generated arousal as fear whereas neurotic extroverts tended to label arousal as anger.     

Do emotional stimuli interfere with response inhibition? Evidence from the stop signal paradigm

Participants performed a stop signal task in which an emotional picture preceded a neutral stimulus. They were asked to respond on the basis of the identity of the neutral stimulus unless an auditory tone was presented, in which case participants should try to withhold their response. In Experiment 1, we used positive, neutral and negative pictures. Results demonstrated that the presentation of an emotional stimulus prolonged both response and stopping latencies regardless of the valence of the emotional stimulus. This suggested that the degree of arousal could modulate the interference effect. In Experiment 2, high- and low-arousing pictures with a positive or negative valence were used. In line with the arousal hypothesis, high-arousal pictures interfered more with responding and stopping than low-arousing pictures whereas the valence of the pictures had little or no effect. These findings support the hypothesis that emotional stimuli interrupt ongoing cognitively controlled activities because they attract attention away from these ongoing activities.     

Television distraction and the performance of introverts and extroverts

An experiment was run to test the effect on reading comprehension of distraction by a television programme, which was presented while reading took place. Respondents, classified in terms of extroversion or introversion, carried out two reading comprehension tests in silence and in the presence of a television drama programme. As predicted, extroverts and introverts both performed better in silence, but there was a significant interaction that showed that extroverts performed better than introverts in the presence of television distraction. The findings are discussed in relation to previous research on this subject.     

One-trial learning and superior resistance to extinction of autonomic responses conditioned to potentially phobic stimuli.

Human subjects were exposed to pictures of potentially phobic (snakes) and supposedly neutral (houses) objects as conditioned stimuli (CSs) in a Pavlovian conditioning experiment with shock as unconditioned stimulus (US), and skin conductance and finger pulse volume as dependent variables. The skin conductance responses conditioned to phobic stimuli were acquired after one CS-US pairing, and showed practically no extinction, whereas the responses to neutral stimuli showed very little resistance to extinction after both 1 and 5 reinforcements. The superior resistance to extinction of the phobic condition was interpreted to be a specific associative effect. In general, the skin conductance acquisition data showed tendencies similar to those during extinction. For finger pulse volume responses, however, there were very weak conditioning effects, and no effect of stimulus.