Segmenting the stream of consciousness: the psychological correlates of temporal structures in the time series data of a continuous performance task

Using principal component analysis, we examined whether structural properties in the time series of response time would identify different mental states during a continuous performance task. We examined whether it was possible to identify regular patterns which were present in blocks classified as lacking controlled processing, either behaviourally (as a failure to withhold a response to a target) or subjectively (as an off task report at a thought probe). Principal component analysis identified three components present in response times accounting for 58.8% of the variance in the data. Of these components, the second largest factor showed two features that implied it was a marker for mind wandering. First, it was stronger under slow relative to fast stimulus presentation conditions, and so paralleled the distribution of mind wandering reports. Second, it was more powerful prior to behaviour markers of mind wandering (failures in response inhibition) and less powerful prior to reports of task focused thinking (on task reports). Taken together, the use of principal components analysis on response times seem a viable tool for differentiating different mental states and so could help identify the neural substrates which underpin mind wandering and other subjective states.     

Subjective valuation and asymmetrical motivational systems: implications of scope insensitivity for decision making

Studies using the Iowa Gambling Task have revealed individual differences in performance on the task. In this study, we tested the hypothesis that approach and avoidance motivations influence decision making through the process of subjective valuation. We examined the implications of a high sensitivity to gains or losses from two perspectives which we labeled scalar multiplication and valuation by feeling. Using two versions of the Iowa Gambling Task, we find evidence supporting the view that asymmetry in the systems regulating approach and avoidance leads to systematic biases that translate to differences in performance. Specifically, we find that high sensitivity in the Behavioral Activation System (BAS) translates to valuation by feeling and insensitivity to scope in the domain of gains, while high sensitivity in the Behavioral Inhibition System (BIS) translates to valuation by feeling and insensitivity to scope in the domain of losses. The basis for these findings is discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

平衡秤任务复杂性的事前与事后分析

任务复杂性的分析和评估是心理测量学和认知心理学都非常关注的重要主题。以264名小学四、五、六年级儿童为被试,平衡秤任务为研究材料,考察任务在未旋转时第一个因素上的载荷(事后分析)能否作为评价任务复杂性的一个指标,以及关系-表征复杂性模型对平衡秤任务复杂性分析(事前分析)的有效性两个问题。结果表明:平衡秤任务施测后所得所有项目的因素载荷与其难度之间没有显著正相关,即因素载荷的高低没有反映平衡秤任务复杂性的大小;而基于关系-表征复杂性模型对任务的事前分析所确定的任务等级复杂性和知识经验对任务难度的解释率为95.0%,可见,关系-表征复杂性模型提供的分析任务复杂性的思路和方法是较为合理的。     

Contexts and control operations used in accessing list-specific, generalized, and semantic memories

The human ability to focus memory retrieval operations on a particular list, episode or memory structure has not been fully appreciated or documented. In Experiment 1-3, we make it increasingly difficult for participants to switch between a less recent list (multiple study opportunities), and a more recent list (single study opportunity). Task performance was good, although there was a cost associated with switching. In Experiment 4, list-specific learning experiences were used to create a generalized memory as a step towards semantic memory. List-specific memories intruded during attempts to retrieve the generalized memory and the generalized memory enhanced list-specific performance. The generalized memory also intruded in a free-association task. We propose that a hierarchy of contexts and control operations underlie the human ability to access different memory structures and that there is no sharp discontinuity in the control operations needed to access list-specific, generalized, and semantic memories.     

Cyclic variations in sustained human performance

Biological rhythms play a prominent role in the modulation of human physiology and behavior. [Smith, K., Valentino, D., & Arruda, J. (2003). Rhythmic oscillations in the performance of a sustained attention task. Journal of Clinical and Experimental Neuropsychology, 25, 561-570] suggested that sustained human performance may systematically fluctuate in a cyclic manner with periods of 1.5 min and 5.2 min. The current series of investigations sought to manipulate those periodicities by altering task difficulty, administering caffeine, and testing on a more ecologically valid task. Strong evidence of a 1.5 min periodicity was found across studies. Most participants did not demonstrate the 5.2 min periodicity. Moreover, the 1.5 min periodicity was resistant to task manipulations and appeared in similar levels across conditions in all three experiments. These rhythms may be indicative of an endogenous system that modulates sustained attention in humans. Evidence supporting this idea and implications of the research are discussed.     

The influence of perceptual and semantic categorization on inhibitory processing as measured by the N2–P3 response

In daily activities, humans must attend and respond to a range of important items and inhibit and not respond to unimportant distractions. Our current understanding of these processes is largely based on perceptually simple stimuli. This study investigates the interaction of conceptual-semantic categorization and inhibitory processing using Event Related Potentials (ERPs). Participants completed three Go–NoGo tasks that increased systematically in the degree of conceptual-semantic information necessary to respond correctly (from single items to categories of objects and animals). Findings indicate that the N2 response reflects inhibitory processing but does not change significantly with task difficulty. The P3 NoGo amplitude, on the other hand, is attenuated by task difficulty. Further, the latency of the peak of the P3 NoGo response elicited by the most difficult task is significantly later than are the peaks detected during performance of the other two tasks. Thus, the level of complexity of conceptual-semantic representations influences inhibitory processing in a systematic way. This inhibition paradigm may be a key for investigating inhibitory dysfunction in patient populations.     

When simple things are meaningful: Working memory strength predicts children’s cognitive flexibility

People often perseverate, repeating outdated behaviors despite correctly answering questions about rules they should be following. Children who perseverate are slower to respond to such questions than children who successfully switch to new rules, even after controlling for age and processing speed. Thus, switchers may have stronger working memory strength than perseverators, with stronger rule representations supporting both flexible switching and faster responses to questions. Alternatively, better inhibitory abilities may support switchers’ faster responses by helping to resolve conflict. The current study tested these accounts using a new one-dimensional card sort. Even with all possible sources of conflict removed, switchers still responded faster than perseverators to questions about rules, supporting the graded working memory account.     

Knowledge about the distribution of information and group decision making: When and why does it work?

Research has shown that decision-making groups with distributed information perform better when group members know which member is knowledgeable about what. Thus far research has been unable to identify the process responsible for this effect. In the present study, we propose that group members’ task representations mediate the effect of knowledge about the distribution of information on decision performance. Building on this proposition, we also propose that reflection about the task moderates the effect of knowledge about distributed information through its effect on task representations. These hypotheses were put to the test in an experimental study of decision-making groups (N = 125). As predicted, knowledge of distributed information interacted with reflection to affect decision quality. Findings confirmed the proposed mediating role of task representations and information elaboration.     

Young children's affective decision-making in a gambling task: Does difficulty in learning the gain/loss schedule matter?

This research investigated the development of affective decision-making (ADM) during early childhood, in particular role of difficulty in learning a gain/loss schedule. In Experiment 1, we administrated the Children's Gambling Task (CGT) to 60 Chinese children aged 3 and 4, replicating the results obtained by Kerr and Zelazo [Kerr, A., & Zelazo, P. D. (2004). Development of “hot” executive function: The Children's Gambling Task. Brain and Cognition, 55, 148–157]. In Experiment 2, the CGT was modified to make it easier for young children to learn the gain/loss schedule by increasing delayed loss frequency and magnitude in the disadvantageous deck, and a larger sample (181 children aged 3–5) was assessed. Age-differences between 3- and 4-year-olds, rather than 4- and 5-year-olds, showed that ADM develops rapidly between 3 and 4 years. The reduction of the difficulty in learning the gain/loss schedule provides the basis for an account of the development of young children's AMD.     

收益—风险并存情境中海洛因戒除者的行为冲动性

以64名男性生理脱瘾后处于不同康复阶段的海洛因戒除者和30名男性无毒品依赖行为的社会招募人员为被试,采用Iowa赌博任务探讨了收益-风险并存情境中海洛因戒除者的冲动性行为模式。结果发现,相对于正常人群,海洛因戒除者表现出"即时收益优先"的决策模式和对高风险的耐受性,且该特征不随戒除期的延长而改善。该研究为解释海洛因戒除者不顾其潜在的严重不利后果仍维持其复吸行为的现象提供了实验证据。