No evidence of risk-taking or impulsive behaviour in a person with episodic amnesia: Implications for the role of the hippocampus in future-regarding decision-making

Does advantageous decision-making require one to explicitly remember the outcome of a series of past decisions or to imagine future personal consequences of one's choices? Findings that amnesic people with hippocampal damage cannot form a clear preference for advantageous decks over many learning trials on the Iowa Gambling Task (IGT) have been taken to suggest that complex decision-making on the IGT depends on declarative (episodic) memory and hippocampal integrity. Alternatively, impaired IGT performance in amnesic individuals could be secondary to risk-taking and/or impulsive behaviour resulting from impaired episodic future thinking (i.e. prospection) known to accompany amnesia. We tested this possibility in the amnesic individual K.C. using the IGT and the Toronto Gambling Task (TGT), a novel task that dissociates impulsivity from risk-taking without placing demands on declarative memory. K.C. did not develop a preference for advantageous over disadvantageous decks on the IGT and, instead, showed a slight preference for short-term gains and an inability to acquire a more adaptive appreciation of longer-term losses. He also did not display impulsive or risk-taking behaviour on the TGT, despite a profound inability to imagine personal future experiences. These findings suggest that impaired decision-making on the IGT in amnesia is unlikely to reflect a predilection to act in the moment or failure to take future consequences into account. Instead, some forms of future-regarding decision-making may be dissociable, with performance on tasks relying on declarative learning or on episodic-constructive processes more likely to be impaired.     

风险取向类型与爱荷华赌博任务成绩的影响

神经科学领域的研究者们设计了测量情感决策的经典爱荷华赌博任务并提出了体细胞标记假说来解释其研究结果,但迄今为止这一假说还没有得到一致认可。许多研究提出了可能影响爱荷华赌博任务成绩的其他因素。本研究试图在前人研究的基础上采用实验法探讨风险取向类型这一人格因素是否影响正常个体的爱荷华赌博任务成绩。实验结果显示,不同风险取向类型的个体在爱荷华赌博任务中的成绩和表现截然不同。典型风险趋向型个体在爱荷华赌博任务中的表现类似于某些神经系统患者,倾向于更多地选择不利纸牌,其任务成绩显著差于典型风险回避型个体。这一研究结果表明：风险取向类型是影响正常个体爱荷华赌博任务成绩的重要因素之一。     

Positive feelings facilitate working memory and complex decision making among older adults

The impact of induced mild positive feelings on working memory and complex decision making among older adults (aged 63–85) was examined. Participants completed a computer administered card task in which participants could win money if they chose from “gain” decks and lose money if they chose from “loss” decks. Individuals in the positive-feeling condition chose better than neutral-feeling participants and earned more money overall. Participants in the positive-feeling condition also demonstrated improved working-memory capacity. These effects of positive-feeling induction have implications for affect theory, as well as, potentially, practical implications for people of all ages dealing with complex decisions.     

Emotion-based learning and central executive resources: an investigation of intuition and the Iowa Gambling Task

The role of emotion in complex decision-making can be assessed on the Iowa Gambling Task (IGT), a widely used neuropsychological measure that may tap a different aspect of executive function than that assessed by conventional measures. Most notably, the 'feeling' about which decks are good or bad, often described in relation to IGT performance, seems reminiscent of decision-making based on intuition-linked to a long history of research in decision-making contrasting the 'intuition' versus 'reasoning' styles of problem solving. To test the claim that the performance on the IGT relies more on emotion-based learning than conventional executive resources for normal performance, a group of participants completed the IGT simultaneously with one of two secondary-tasks, one of which (random number generation) is known to load executive resources. A third group performed the IGT with no secondary-task. If performance on the IGT requires the properties associated with intuitive operations, then participants should either show no disruption when completing a secondary-task, or at least show no selective disruption on a secondary-task that loads for executive function. The rate of learning in the three groups was not significantly different. This suggests that the sorts of cognitive resources loaded by traditional executive tasks such as random number generation do not overlap, in the cognitive architecture, with the emotion-based learning skills that are required for Iowa Gambling Task performance. The findings of the present study are also consistent with a previous claim of the Iowa group that emotion-based learning and working memory resources are doubly dissociable.     

Cognitive dissonance induced by writing a counterattitudinal essay facilitates performance on simple tasks but not on complex tasks that involve working memory

This article examines how performance is facilitated with simple tasks and is impaired with complex ones in individuals experiencing dissonance. Experiment 1 measured the performance of dissonance participants at a simple reaction time task. Reaction times were shortest in the dissonance condition. This facilitation effect was interpreted as resulting from increased arousal with dissonance. In Experiment 2, participants performed a more complex secondary memory task that required to memorize and to recall short and long series of numbers. Participants in the dissonance condition performed less well than participants in the no-dissonance condition only under a high memory load and did not differ with a low load. It is suggested that dissonance requires some working memory resources. Accordingly, it is assumed that the arousal properties of dissonance facilitate performance with simple task that do not involve working memory and require a dominant response, but that dissonance impairs performance with tasks that strongly involve working memory.     

Different working memory capacity in normal young adults for visual and tactile letter recognition task

Thirty-nine young adult participants performing the visual and tactile n-back working memory task were compared. In the visual task, letters were presented on a computer screen and in the tactile task, plastic letters embedded on a board were explored tactually. The amount of incorrect responses increased with increasing memory load in both tasks, but was significantly lower in the visual task. Subgrouping the participants with extreme performances into "skilled" and "poor" performers showed that the best performance was found among "skilled" visual performers, and the worst one among "poor" tactile performers. There was more interindividual variation among tactile than visual performance. We conclude that tactile working memory capacity, measured here by letter recognition and letter memory, is generally more limited and shows more variability than visual memory in normal sighted participants.     

A long‐term fatty fish intervention improved executive function in inpatients with antisocial traits and a history of alcohol and drug abuse

The aim of the present study was to investigate the effects of fatty fish consumption on cognitive functioning in a group of inpatients characterized by antisocial behavior. Eighty‐three male forensic inpatients participated in this study. Participants were randomly assigned into a Fish or a Control group (e.g., meat, chicken, pork). One decision‐making task, the Iowa Gambling Task (IGT), and one planning task, the Tower of Hanoi (ToH), were administered before (pre‐test) and at the end of the intervention period (post‐test). For the IGT the Fish group showed improved performance from pre‐ to post‐ test. Moreover, the Fish group showed significantly better performance than the Control group on the IGT at post‐test. The Fish group also demonstrated improved performance from pre‐ to post‐test on the ToH; however, this was limited to participants with a history of substance abuse. Further, the improvement was only significant for tasks with high working memory load (5–7 move problems), and not for tasks with low working memory load (1–4 move problems). The Control group showed no improvement on any of the tasks regardless of alcohol or drug abuse history. The present study suggests that regular fatty fish consumption may improve executive functions in forensic inpatients with antisocial traits and a history of substance abuse. Thus, the current results may have important implications with regard to health care interventions.     

Alexithymia, Cumulative Feedback, and Differential Response Patterns on the Iowa Gambling Task

ABSTRACT Although the role of emotional processing is central to contemporary models of risky decision making, to date the role of trait emotional understanding has not been explored experimentally in this context. The current experiment ( N =326) explores the role of alexithymia with respect to performance on the standard Iowa Gambling Task (IGT) and a version where cumulative financial feedback is obscured. Standard learning on the IGT was observed for those low in alexithymia. Those high in alexithymia learned to avoid disadvantageous decks over the first half of the task. However, over the later trials they showed a change in performance, shifting from advantageous to disadvantageous and back to advantageous decks again (termed an "explore-learn-change-return" strategy). It is argued that this is due to an inability to fully consolidate earlier learning and reduced sensitivity to losses. The absence of cumulative feedback independently resulted in reduced performance.     

Susceptibility of spatial and verbal working memory to demands of the central executive

We used a dual-task paradigm to examine the degree to which domain-specific spatial and verbal subsystems depend on the domain-general central executive. Forty participants were asked to retain spatial or verbal information while performing a concurrent secondary task related to simple arithmetic. The secondary tasks consisted of three cognitive processes: single-digit addition, a digit-carrying operation, and digit reading. The single-digit addition and carry operation include central executive functioning, while digit reading relies solely on the phonological loop. The single-digit addition caused a performance decrement on the spatial working memory task, while the digit reading impaired performance on the verbal working memory task. The carry operation interfered with recall accuracy on both working memory tasks. The spatial working memory task was significantly correlated with the verbal working memory task only when the secondary task was more demanding on the central executive. Our results suggest that spatial working memory rather than verbal working memory is susceptible to failure of central executive functioning and that the central executive plays an important role in regulating the cognitive demands of different domains.     

负荷越大，转换更难-来自数字大小交替比较的证据

工作记忆与认知灵活性是执行功能的两个核心成分,但两者之间的关系并不清晰。本研究在一个数字大小交替比较任务中操纵工作记忆负荷,考察转换代价在不同记忆负荷下的差异。结果显示与非转换条件相比,转换条件下的反应时更长,正确率更低。另外,高记忆负荷下的转换代价显著高于低记忆负荷下的转换代价。这些结果表明工作记忆负荷越大,转换越难,代价越大。     

Individual differences in event-based prospective memory: Evidence for multiple processes supporting cue detection

The multiprocess view proposes that different processes can be used to detect event-based prospective memory cues, depending in part on the specificity of the cue. According to this theory, attentional processes are not necessary to detect focal cues, whereas detection of nonfocal cues requires some form of controlled attention. This notion was tested using a design in which we compared performance on a focal and on a nonfocal prospective memory task by participants with high or low working memory capacity. An interaction was found, such that participants with high and low working memory performed equally well on the focal task, whereas the participants with high working memory performed significantly better on the nonfocal task than did their counterparts with low working memory. Thus, controlled attention was only necessary for detecting event-based prospective memory cues in the nonfocal task. These results have implications for theories of prospective memory, the processes necessary for cue detection, and the successful fulfillment of intentions.     

工作记忆广度：资源限制、记忆消退还是转换机制？

为了检验工作记忆广度有限性的3种假说,即资源限制假说、记忆消退假说和转换机制假说,实验要求被试首先完成一项转换效率任务,然后完成工作记忆广度任务。结果发现,加工负荷对工作记忆广度具有重要影响,保持时间不影响工作记忆广度,转换效率与工作记忆广度也没有显著相关。实验结果支持工作记忆广度受认知资源限制的观点     

视空工作记忆负载对真实场景搜索绩效的影响

采用视空工作记忆任务和真实场景搜索任务相结合的双任务范式, 结合眼动技术将搜索过程划分为起始阶段、扫描阶段和确认阶段, 探究视空工作记忆负载对真实场景搜索绩效的影响机制, 同时考查试次间搜索目标是否变化、目标模板的具体化程度以及搜索场景画面的视觉混乱度所起的调节作用。结果表明, 视空工作记忆负载会降低真实场景搜索的成绩, 在搜索过程中表现为视空负载条件下扫描阶段持续时间的延长、注视点数目的增加和空间负载条件下确认阶段持续时间的延长, 视空负载对搜索过程的影响与目标模板的具体化程度有关; 空间负载会降低真实场景搜索的效率, 且与搜索画面的视觉混乱度有关, 而客体负载则不会。由此可见, 视空工作记忆负载对真实场景搜索绩效的影响不同, 空间负载对搜索过程的影响比客体负载更长久, 二者均受到目标模板具体化程度的调节; 仅空间负载会降低真实场景的搜索效率, 且受到搜索场景画面视觉混乱度的调节。     

Prospective memory and aging: The effects of working memory and prospective memory task load

Abstract

A person's level of engagement in other actions may influence whether a prospective action is correctly performed. This study used a computerized prospective memory task in which participants remembered to perform an action when a specified background pattern appeared while they simultaneously performed a verbal working memory task. Amount of engagement in the working memory task was manipulated by increasing the number of words to be recalled. Prospective memory load was manipulated by varying the number of prospective targets. Older adults performed more poorly than younger adults on the prospective memory task under higher working memory load and also higher prospective load. Participants with lower working memory load performed better on the prospective task, regardless of age. There were no significant age differences in the absolute accuracy of performance postdictions (post experiment performance awareness). Age differences were also found with a second prospective memory task in which participants were told to write the day of the week (DOW) on the top of answer sheets for tasks performed later in the experiment. No significant correlations were observed between the two prospective memory tasks for either age group.     

Role of working memory load on selective attention to affectively valent information

Empirical evidence obtained with neutral stimuli has shown that selective attention relies on working memory functions as distractor processing occurs under conditions of high but not of low working memory load. We investigated whether these findings also hold for affectively valent distractors. In three experiments, participants completed the original Flanker task with famous people (Exps 1 and 2) and an affective Flanker task (Exp. 3) in which positive and negative words were presented superimposed onto happy, angry, and neutral faces under conditions of high or low working memory load. In line with past findings, results showed greater interference effects due to processing of distractors showing known people under high working memory load. In contrast interference effects due to processing of valent distractors occurred regardless of working memory load. The present findings are in contrast with those reported with neutral stimuli as they indicate that automatic evaluation of incoming affectively valent information occurs regardless of task priorities and of working memory load.     

Working memory involved in predicting future outcomes based on past experiences

Deficits in working memory have been shown to contribute to poor performance on the Iowa Gambling Task [IGT: Bechara, A., &; Martin, E.M. (2004). Impaired decision making related to working memory deficits in individuals with substance addictions. Neuropsychology, 18, 152–162]. Similarly, a secondary memory load task has been shown to impair task performance [Hinson, J., Jameson, T. &; Whitney, P. (2002). Somatic markers, working memory, and decision making. Cognitive, Affective, &; Behavioural Neuroscience, 2, 341–353]. In the present study, we investigate whether the latter findings were due to increased random responding [Franco-Watkins, A. M., Pashler, H., &; Rickard, T. C. (2006). Does working memory load lead to greater impulsivity? Commentary on Hinson, Jameson, and Whitney’s (2003). Journal of Experimental Psychology: Learning, Memory &; Cognition, 32, 443–447]. Participants were tested under Low Working Memory (LWM; n = 18) or High Working Memory (HWM; n = 17) conditions while performing the Reversed IGT in which punishment was immediate and reward delayed [Bechara, A., Dolan, S., &; Hindes, A. (2002). Decision making and addiction (part II): Myopia for the future or hypersensitivity to reward? Neuropsychologia, 40, 1690–1705]. In support of a role for working memory in emotional decision making, compared to the LWM condition, participants in the HWM condition made significantly greater number of disadvantageous selections than that predicted by chance. Performance by the HWM group could not be fully explained by random responding.     

Decision-making under risk conditions is susceptible to interference by a secondary executive task

Recent research suggests two ways of making decisions: an intuitive and an analytical one. The current study examines whether a secondary executive task interferes with advantageous decision-making in the Game of Dice Task (GDT), a decision-making task with explicit and stable rules that taps executive functioning. One group of participants performed the original GDT solely, two groups performed either the GDT and a 1-back or a 2-back working memory task as a secondary task simultaneously. Results show that the group which performed the GDT and the secondary task with high executive load (2-back) decided less advantageously than the group which did not perform a secondary executive task. These findings give further evidence for the view that decision-making under risky conditions taps into the rational-analytical system which acts in a serial and not parallel way as performance on the GDT is disturbed by a parallel task that also requires executive resources.     

Visual and verbal working memory loads interfere with scene-viewing

Working memory is thought to be divided into distinct visual and verbal subsystems. Studies of visual working memory frequently use verbal working memory tasks as control conditions and/or use articulatory suppression to ensure that visual load is not transferred to verbal working memory. Using these verbal tasks relies on the assumption that the verbal working memory load will not interfere with the same processes as visual working memory. In the present study, participants maintained a visual or verbal working memory load as they simultaneously viewed scenes while their eye movements were recorded. Because eye movements and visual working memory are closely linked, we anticipated the visual load would interfere with scene-viewing (and vice versa), while the verbal load would not. Surprisingly, both visual and verbal memory loads interfered with scene-viewing behavior, while eye movements during scene-viewing did not significantly interfere with performance on either memory task. These results suggest that a verbal working memory load can interfere with eye movements in a visual task.

     

An attempt to discriminate different types of executive functions in the Wisconsin Card Sorting Test

This study examined the roles of the phonological working memory and the central executive in the Wisconsin Card Sorting Test by altering the materials and the procedure of the task and using a dual-task design, in which cognitive abilities of normal participants were manipulated by performance of the secondary tasks selectively taxing the phonological loop or the central executive. The present study used three novel versions of the Wisconsin Card Sorting Test, namely the WCST-4 stimuli, the WCST-12-stimuli, and the WCST-12-stimuli-box, in all of which the participants were given the exact sorting criterion. So the tasks did not involve processes such as maintenance of inferences about the sorting criterion which would require phonological memory load. However, the tasks were assumed to require the executive process of response inhibition. In the WCST-4-stimuli condition no change was made to the WCST materials. In the other two conditions, relying on the assumption that the three-dimensional nature of the cards triggers inappropriate responses, unidimensional stimulus cards were used instead of the four normal three-dimensional WCST stimulus cards. The difference between these two conditions was that, in the WCST-12-stimuli-box condition, boxes were used to conceal the response cards previously sorted. The results supported Dunbar and Sussman's (1995) argument that some executive processes in the Wisconsin Card Sorting Test require the use of phonological store, and the present design was able to differentiate the type of executive functions that do not involve the use of a phonological loop from the ones that do. In addition, the results concerning manipulations of the visual aspects of the Wisconsin Card Sorting Test suggest that the three-dimensional nature of the WCST stimulus cards leads to an increase in the number of inappropriate responses produced with the executive secondary task interference.     

Simultaneous motor demands affect decision making under objective risk

Previous studies on factors influencing decision making focused on the effects of additional cognitive load, stress, psychological disorders, and the process of aging. The potential effects of simultaneously performing motor demands have been neglected, so far. However, previous motor / cognitive dual-task studies provide evidence for both negative as well as facilitating effects of simultaneously performing cognitive and motor tasks. The study at hand, aimed to investigate the effects of decision making under objective risk while performing additional motor demands. Seventy-two participants ranging from 18 to 30 years performed the Game of Dice Task either while sitting or while standing on one leg. Participants were asked to put similar effort on the decision task and the motor demand. The results revealed a significant main effect for “choice”, as well as a significant interaction of “choice”?×?“group”. Participants standing on one leg more frequently selected the most disadvantageous choice (one single number), whereas the “sitting group” most often selected the advantageous combination of four numbers. The findings are discussed under the aspects of executive functions, working memory, stress, somatic markers and the dual-process theory.