跨通道情境下双任务范式与计时中断范式中的效应比较*

为了探讨跨通道情境下同一种刺激序列中双任务范式与计时中断范式中位置效应和间断效应的异同,研究设计了实验1和实验2。实验1以2500 ms和4500 ms为目标时距,采用相同的刺激序列(视觉呈现时距信号,听觉呈现干扰信号或中断信号),要求3组被试分别在控制、干扰及中断条件下完成相应任务,结果发现不管2500 ms或4500 ms时,中断条件较干扰条件和控制条件的间断效应更明显;同时发现在2500 ms时,不管控制、干扰还是中断条件下均发现了位置效应,而4500 ms时仅在中断条件下出现了位置效应,这可能由于实验1的控制及干扰任务中的4500 ms时的“晚”位置的时间确定性较高,以致掩盖了位置效应。为了降低“晚”位置出现的确定性,更好地对比两种范式中的效应,实验2将目标时距设置为1500 ms和2500 ms,结果发现在1500 ms或2500 ms时,不管控制、干扰还是中断条件下均发现了位置效应,且中断条件较干扰条件和控制条件下间断效应更明显。上述结果意味着跨通道情境下同一种刺激序列中双任务范式与计时中断范式中位置效应是否相同局限在一定时间范畴;计时中断范式中的中断效应对计时的消弱较双任务范式干扰效应更显著。     

期望中断效应的注意共享解释-来自ERP的证据

以1700毫秒和2300毫秒为考察时距,采用时距复制任务,对编码阶段的中断位置进行操纵,并记录了14名大学生在进行时距复制任务时编码阶段的事件相关电位(ERP).行为结果发现:分别就1700毫秒和2300毫秒而言,中断位置越靠后,复制时距越短.脑电结果发现:无中断条件的(控制任务1)编码阶段在350～550毫秒和350～1150毫秒的CNV平均波幅分别较中断位置为550毫秒的条件和中断位置为1150毫秒条件显著更高;无中断条件的(控制任务2)编码阶段在350～750毫秒和350～1550毫秒的CNV平均波幅分别较中断位置为750毫秒的条件和中断位置为1550毫秒条件显著更高.这说明了间断编码的时间复制任务中存在期望中断效应且以注意共享机制解释期望中断效应得到了电生理学证据的直接支持.     

面孔-词Stroop范式中的情绪冲突效应研究

为探究面孔-词Stroop范式中的情绪冲突效应,本实验给被试呈现两种时长（150ms或1500ms）的刺激,令其分别完成对面孔-词Stroop范式中的“面孔任务”和“词任务”。结果发现：只有“面孔任务”中出现Stroop效应,产生情绪冲突,而在“词任务”中未出现Stroop效应;当呈现时间为150ms时,情绪词影响情绪面孔加工从而引发个体的情绪冲突,出现Stroop效应;当呈现时间为1500ms时,“面孔任务”中的Stroop效应消失。这提示了呈现时间是影响面孔-词Stroop范式中情绪冲突效应的一个重要因素。     

时距估计年龄差异的认知机制

采用双任务的实验范式,通过对（5s、13s和26s）三个目标时距的产生法和复制法的结果来探讨时距估计年龄差异的认知机制。实验结果表明,在不同目标时距和不同的估计方法上均存在显著的年龄效应。年老被试在产生法上比年轻被试显著高估时距,存在非时间任务和年龄的交互作用,随着任务难度的增加年老被试会比年轻被试产生更长的时距。而在复制法上年老被试比年轻被试显著低估时距,但是只有在长时距条件下（26s）存在非时间任务和年龄的交互作用。本研究结果表明年老被试在产生法上对时距的高估可能与内部时钟减慢和注意资源减少有关,而在复制法上对时距的低估可能反映注意资源的减少。此外,对于长时距的时间复制,情节记忆的损伤也是导致时距估计年龄差异的一个可能原因。     

客体工作记忆任务中大脑皮层活动的记忆负荷效应

利用128导事件相关电位技术,采用延迟匹配任务的实验范式,测查了20名正常被试完成不同负荷客体任务时的皮层慢电位（slow cortical potentials,简称sp成分）,实验发现：背侧前额叶在刺激呈现后的700ms到1400ms出现记忆负荷效应,高负荷任务诱发的sp成分显著负于低负荷任务;低负荷任务诱发的sp成分在左前额区（500~1800ms）、左前额-中央区（700~1800ms）、左中央-顶叶区（1000~1400s和1800~4800ms）、右前额区（1800~4800ms）和右前额-中央区（1400~4800ms）显著负于高负荷任务,出现记忆负荷效应,但这种负荷效应在左右大脑半球所反映的心理意义可能不同     

标量计时模型的影响因素及发展

标量计时模型为人类时间知觉的研究提供了理论框架和研究范式, 它采用信息加工的观点, 包含时钟、记忆和决策三个阶段。时间二分任务是在标量计时模型的框架下研究时间知觉和加工的理想范式。它要求被试对时距进行与标量计时模型相对应的多阶段操作, 包含了时间知觉所涉及的各个过程, 能有效测量主观时距和时间敏感性的变化。通过这个范式, 研究者发现, 除了任务参数, 年龄和疾病都会影响人的主观时距和/或时间敏感性。这些时间二分任务的实验结果促进了标量计时模型的发展, 最近提出的两阶段决策模型和差别模型分别以不同的方式对标量计时模型进行了修正, 并解释了参数设置的影响和计时的个体差异。     

线索提示对表征动量的影响

研究结合线索提示和表征动量范式,实验1、2均采用2有无线索(有线索,无线索)×4诱导期间时距(1250ms,1750ms,2250ms,2750ms)混合实验设计,探讨线索呈现的加工阶段和时距对表征动量的影响。实验1恒定保持间隔时距,在不同时距的诱导期间呈现线索,发现线索主效应不显著,但表征动量呈减小趋势;时距主效应不显著。实验2变化诱导时距,在恒定的保持间隔呈现线索,发生向后偏移现象,线索主效应显著;时距主效应不显著。研究结果表明,随着注意的增加,表征动量效应减小;注意时距不显著影响表征动量,而注意阶段显著影响表征动量。研究结果为表征动量的双加工理论提供了实证支持。     

中英双语者情绪注意偏向中的双语优势效应

采用改进的点–探测范式，考察熟练双语者在情绪注意偏向中对情绪信息加工的优势效应及该效应产生的原因。采用2（熟练双语者和非熟练双语者）×3（靶刺激与消极词汇出现的位置一致、不一致和中性条件）×2（线索呈现时间为100 ms和400 ms）的混合实验设计，记录被试对靶子的按键反应时和错误率。结果发现：线索呈现100 ms和400 ms时，两组被试在注意定向分数上无显著差异；线索呈现100 ms时，两组被试的注意解除分数无显著差异；线索呈现400 ms时，熟练双语者的注意解除分数显著小于非熟练双语者。结果表明，在情绪注意偏向任务中，熟练双语者比非熟练双语者表现出了对情绪词汇信息更好的注意抑制控制能力，体现出对情绪信息加工的双语优势效应，产生这一优势效应的原因是熟练双语者在注意的晚期阶段比非熟练双语者具有更好的情绪信息注意解除能力。     

非平衡双语者Stroop效应的时间进程

运用Stroop任务的SOA范式,考察中-英双语者干扰和易化效应的时间进程及程度,比较双语者认知控制和词汇通达的差异。结果发现,在中文条件下,干扰效应的峰值发生在SOA为-200ms时,在英文条件下,最大的干扰效应发生在SOA为-300 ms时,由此可见,干扰效应时间出现了负转换。在英文条件下,-400ms SOA引发了最大的易化效应,而中文条件下最大的易化效应发生在-300ms SOA。该研究表明,双语者没有表现出认知优势,在Stroop任务中受到了词汇通达的影响。     

重复知盲效应产生的机制——来自汉语叠词加工的证据

以汉语中的叠词为实验材料,对重复知盲产生机制的类型标记个体化理论和建构理论进行检验。采用RSVP研究范式,在两个实验中让178名被试口头报告列表中出现的所有汉字（全部报告）或列表中最后两个字（部分报告）。结果发现：（1）在呈现速率为128ms和198ms时,完全重复的汉字在全部报告和部分报告任务中均存在RB效应,但在部分报告任务下出现的RB相比全部报告任务的减少了,符合建构理论的假设。（2）在全部报告条件下,不仅重复刺激的正确报告率会降低,而且与重复刺激相关的非重复刺激的正确报告率也会降低。研究表明建构理论比类型标记个体化理论更能解释RB效应的产生机制。     

Timing processes in motor imagery

Previous research shows inconsistencies in the timing of imagined and actual actions. Little is known about the timing in imagery, or how it relates to other forms of timing. Two studies examined whether imagery timing followed Weber's law, where variations in judgements grow linearly as the interval duration increases, or Vierordt's law, where short durations are overestimated and longer durations underestimated. In Study 1 participants (n=22) mentally walked and estimated journey times for flat paths and stairways, with and without a load. The timing patterns that emerged did not conform to Weber's law. In Study 2 participants (n=20) completed imagery, reproduction, production, and estimation timing tasks. Timing errors for imagery along a straight path, reproduction, estimation, and production all showed “Vierordt-like” effects. However, when imagining walking in a square participants consistently overestimated. It was concluded that imagery and interval timing processes are similar, but imagery timing is task dependent.     

How emotional auditory stimuli modulate time perception

Emotional and neutral sounds rated for valence and arousal were used to investigate the influence of emotions on timing in reproduction and verbal estimation tasks with durations from 2 s to 6 s. Results revealed an effect of emotion on temporal judgment, with emotional stimuli judged to be longer than neutral ones for a similar arousal level. Within scalar expectancy theory (J. Gibbon, R. Church, & W. Meck, 1984), this suggests that emotion-induced activation generates an increase in pacemaker rate, leading to a longer perceived duration. A further exploration of self-assessed emotional dimensions showed an effect of valence and arousal. Negative sounds were judged to be longer than positive ones, indicating that negative stimuli generate a greater increase of activation. High-arousing stimuli were perceived to be shorter than low-arousing ones. Consistent with attentional models of timing, this seems to reflect a decrease of attention devoted to time, leading to a shorter perceived duration. These effects, robust across the 2 tasks, are limited to short intervals and overall suggest that both activation and attentional processes modulate the timing of emotional events.     

Complexity of interruptions: Evidence supporting a non-interruption-based theory

Interruptions are known to be pervasive and harmful for concentration. It is also known that many factors can influence their effect, such as the complexity of the interrupting task. Less, however, is known about the processes underlying the resumption of the primary task, especially if the interrupting task is complex. Many hypotheses have been proposed but, as yet, it has not been possible to distinguish between their various qualities. In the current study, we carried out two experiments in which we manipulated the complexity of the interrupting task (either simple or complex) and the time between the end of the interrupting task and the resumption of the primary task (i.e., a break). Results showed that complex interrupting tasks led to longer resumption lags (RL) when there was no break, as has already been shown many times. However, while RL after simple interrupting tasks did not change as the break before resumption lengthened up to 1,500 ms, those after complex interrupting tasks decreased. Moreover, after a break of 3,000 ms, RL were longer overall. These results can only support the hypothesis based on task-switching theories, but not hypotheses derived from interruption-based models. Our findings therefore provide empirical evidence in support of explanations of complexity effects and the implications for research and application are discussed.     

Time Reproduction in Children With ADHD: Motivation Matters

The primary goal of this study was to examine whether children with ADHD have a true deficit in subjective time sense, or whether their impairment reflects a motivational deficit. Thirty children with ADHD and 30 matched control children completed two versions of a time reproduction paradigm (“Regular” and “Enhanced”) in which motivational level was manipulated by the addition of positive sham feedback and the prospect of earning a reward. A secondary goal was to investigate performance on measures of working memory and behavioural inhibition, and how those constructs relate to time reproduction in the context of Barkley’s (1997a) model of ADHD. Children with ADHD performed significantly better on the motivating ‘Enhanced’ versus the Regular time reproduction paradigm, although they continued to perform significantly worse than controls on both tasks. Control children exhibited no reliable change in performance between versions of the task. Significant group differences were also observed on the working memory and behavioural inhibition tasks. We discuss the impact of motivation, working memory, and behavioural inhibition on time reproduction performance.     

右侧背外侧前额叶皮质在时间知觉中的作用:基于经颅磁刺激的研究

将10 Hz的重复经颅磁刺激(r TMS)施加于右背外侧前额叶皮质(r DLPFC),探讨该区域在时间加工模型中的作用。实验一采用时间复制任务,通过比较基线和后测条件下时间估计行为的差异,探究高频r TMS离线施加于r DLPFC之后对时间知觉的影响。实验二采用毫秒和秒两种范围的时距,探究r DLPFC在不同范围的时间知觉中的作用。结果发现r TMS施加于r DLPFC导致对1.5 s高估,对600 ms的估计无显著影响,提示r DLPFC在涉及工作记忆加工过程的秒范围的时间知觉中有重要作用。     

Timing and executive function: Bidirectional interference between concurrent temporal production and randomization tasks

A review of interference effects in concurrent temporal/nontemporal dual-task studies suggests that prospective timing may be related to executive cognitive functions. Executive processes play a supervisory role in behavior by controlling attention, coordinating information, and scheduling actions. In the present research, a timing task was paired with an established executive task in a dual-task paradigm. The timing task required subjects t o generate a series o f 5-sec temporal productions,and the executive task was random number generation. These tasks were performed both separately and concurrently. Comparisons of single-task and dual-task conditions showed that (1) the randomization task interfered with timing by making temporal productions more variable and longer and (2) concurrent timing disrupted randomization performance by making responses less random. This pattern of bidirectional interference supports the idea that timing relies on the same attentional resources used by other executive-level tasks.     

Basal ganglia, dopamine and temporal processing: performance on three timing tasks on and off medication in Parkinson's disease

A pervasive hypothesis in the timing literature is that temporal processing in the milliseconds and seconds range engages the basal ganglia and is modulated by dopamine. This hypothesis was investigated by testing 12 patients with Parkinson's disease (PD), both 'on' and 'off' dopaminergic medication, and 20 healthy controls on three timing tasks. In a seconds range (30-120 s) time production task, patients tested 'on' medication showed a significantly different accuracy profile compared to controls and when tested 'off' medication. However, no group or on vs off medication differences in accuracy were found on a time reproduction task and a warned reaction time task requiring temporal processing within the 250-2000 ms range. Variability was measured using the coefficient of variation, with the performance of the patient group on the time reproduction task violating the scalar property, suggesting atypical temporal processing mechanisms. The data suggest that the integrity of the basal ganglia is necessary for 'typical' time production in the seconds range as well as for time reproduction at shorter intervals. Exploratory factor analysis suggested that the time production task uses neural mechanisms distinct from those used in the other two timing tasks. The dissociation of the effects of dopaminergic medication and nature of task on performance in PD raises interesting questions about the pharmacological mediation and task-specificity of deficits in temporal processing.     

How do changes in speed affect the perception of duration?

Six experiments investigated how changes in stimulus speed influence subjective duration. Participants saw rotating or translating shapes in three conditions: constant speed, accelerating motion, and decelerating motion. The distance moved and average speed were the same in all three conditions. In temporal judgment tasks, the constant-speed objects seemed to last longer than the decelerating objects, which in turn seemed to last longer than the accelerating stimuli. In temporal reproduction tasks, the difference between accelerating and decelerating stimuli disappeared; furthermore, watching an accelerating shape lengthened the apparent duration of the subsequent (static) display. These results (a) suggest that temporal judgment and reproduction can dissociate for moving stimuli because the stimulus influences the apparent duration of the subsequent interval, and (b) constrain theories of time perception, including those which emphasize memory storage, those which emphasize the existence of a pacemaker-accumulator timing system, and those which emphasize the division of attention between temporal and non-temporal information processing.     

Attentional resources in timing: Interference effects in concurrent temporal and nontemporal working memory tasks

Three experiments examined interference effects in concurrent temporal and nontemporal tasks. The timing task in each experiment required subjects to generate a series of 2- or 5-sec temporal productions. The nontemporal tasks were pursuit rotor tracking (Experiment 1), visual search (Experiment 2), and mental arithmetic (Experiment 3). Each nontemporal task had two levels of difficulty. All tasks were performed under both single- and dual-task conditions. A simple attentional allocation model predicts bidirectional interference between concurrent tasks. The main results showed the classic interference effect in timing. That is, the concurrent nontemporal tasks caused temporal productions to become longer (longer productions represent a shortening of perceived time) and/or more variable than did timing-only conditions. In general, the difficult version of each nontemporal task disrupted timing more than the easier version. The timing data also exhibited a serial lengthening effect, in which temporal productions became longer across trials. Nontemporal task performance showed a mixed pattern. Tracking and visual search were essentially unaffected by the addition of a timing task, whereas mental arithmetic was disrupted by concurrent timing. These results call for a modification of the attentional allocation model to incorporate the idea of specialized processing resources. Two major theoretical frameworks—multiple resource theory and the working memory model—are critically evaluated with respect to the resource demands of timing and temporal/ nontemporal dual-task performance.     

Time reproduction in children with ADHD: motivation matters.

The primary goal of this study was to examine whether children with ADHD have a true deficit in subjective time sense, or whether their impairment reflects a motivational deficit. Thirty children with ADHD and 30 matched control children completed two versions of a time reproduction paradigm ("Regular" and "Enhanced") in which motivational level was manipulated by the addition of positive sham feedback and the prospect of earning a reward. A secondary goal was to investigate performance on measures of working memory and behavioural inhibition, and how those constructs relate to time reproduction in the context of Barkley's (1997a) model of ADHD. Children with ADHD performed significantly better on the motivating 'Enhanced' versus the Regular time reproduction paradigm, although they continued to perform significantly worse than controls on both tasks. Control children exhibited no reliable change in performance between versions of the task. Significant group differences were also observed on the working memory and behavioural inhibition tasks. We discuss the impact of motivation, working memory, and behavioural inhibition on time reproduction performance.