The role of working memory capacity and interference resolution mechanisms in task switching

Theories of task switching have emphasized a number of control mechanisms that may support the ability to flexibly switch between tasks. The present study examined the extent to which individual differences in working memory (WM) capacity and two measures of interference resolution, response–distractor inhibition and resistance to proactive interference (PI), account for variability in task switching, including global costs, local costs, and N-2 repetition costs. A total of 102 young and 60 older adults were tested on a battery of tasks. Composite scores were created for WM capacity, response–distractor inhibition, and resistance to PI; shifting was indexed by rate residual scores, which combine response time and accuracy and account for individual differences in processing speed. Composite scores served as predictors of task switching. WM was significantly related to global switch costs. While resistance to PI and WM explained some variance in local costs, these effects did not reach significance. In contrast, none of the control measures explained variance in N-2 repetition costs. Furthermore, age effects were only evident for N-2 repetition costs, with older adults demonstrating larger costs than young adults. Results are discussed within the context of theoretical models of task switching.     

Inner speech sustains predictable task switching: direct evidence in adults

It has been proposed that inner speech supports task selection in task-switching studies, especially when the need for endogenous control is increased. This has been established through the suppression of inner speech in cognitive-flexibility tasks that leads to poorer performance. The aim of this study is to quantify the role of inner speech in a flexibility task by using surface laryngeal electromyography, which, contrary to previous studies, enables participants to freely verbalise the tasks. We manipulated endogenous and exogenous flexibility in a mathematical switching task paradigm. Experiment 1 shows that inner speech acts as a support for switching and is recruited more often when the tasks are of an endogenous type. The main result of Experiment 2 that language is recruited more for the mixing cost than for the switch cost (regardless of the endogenous factor) extends past findings obtained through articulatory suppression.     

Crossing grammar and biology for gender categorisations: investigating the gender congruency effect in generic nouns for animates

In formal gender languages, all nouns have grammatical gender, regardless of whether their referents have a biological sex. The question of whether the grammatical gender affects how the denoted entities are conceptualised is subject to ongoing debate. Here, we investigate the extent to which a gender congruency effect emerges for three categories of nouns, with a particular focus on generic nouns (or epicenes). In two experiments and two replications with native speakers of German, we used an implicit measure to test possible associations of nouns with biological sex. These experiments revealed a stable gender congruency effect for congruent animates, and a weaker effect for generic animates and non-animates. In a fifth experiment, we combined the implicit measure with an explicit measure and contrasted items that have strong versus weak associations with biological sex. The results indicate that the congruency effect is driven by item-specific associations rather than by grammatical gender.     

Joint task switching

The present study investigates the representation of task-sets in a joint dual-task setting. To this end, a task-switching approach is used. Task switching is associated with a switch cost, which can be decomposed in several markers of task-set coordination. These markers can be used to investigate whether participants represent the co-actor's task-set in a joint dual-task setting. A joint task-switching procedure was used in which two participants performed a distinct task and the participants’ turn to respond could switch or repeat on a trial-by-trial basis. The results indicate that joint task switching also elicits a switch cost. However, this switch cost does not seem to be related to the representation of the co-actor's task-set. It is suggested that the switch cost observed in joint task switching is based on processes of task monitoring, which increase the saliency of task-irrelevant stimulus information.     

不同类型罪犯在爱荷华赌博任务中的决策功能缺陷

采用爱荷华赌博任务(Behcara等人1994年版本)测量了8类共222名在监男性罪犯以及32名普通男性的决策功能, 并运用前景效用学习模型分析了不同类型罪犯在情感决策中的心理功能缺陷。罪犯组选择牌1的比例与控制组没有显著差异, 选择牌2的比例显著高于控制组, 选择牌3和牌4的比例显著低于控制组。暴力犯和涉黑犯对收益和损失都不敏感, 对过去的预期效用折扣很快; 吸毒犯(已戒除)、涉毒犯、盗窃犯和抢劫犯对奖赏加工正常, 对惩罚不敏感; 经济犯选择一致性最低; 性罪犯选择一致性最高。结果表明不同类型罪犯在爱荷华赌博任务中都具有决策功能缺陷, 但他们的决策功能缺陷由不同的心理功能缺陷所致。     

得失框架效应的分离—— 来自收益与损失型跨期选择的研究

本研究通过创设收益和损失跨期选择情境, 采用不同表征方式(得框架、失框架)的跨期选择任务, 分别探讨了收益和损失情境下的跨期选择是否存在得失框架效应, 及其是否会受任务难度的影响。结果发现：(1)收益型跨期选择只在任务容易时存在得失框架效应, 与失框架相比, 被试在得框架下选择即时获益的概率更高; 任务困难时得失框架效应消失(实验a); (2)损失型跨期选择中不存在得失框架效应(实验b)。结果表明, 得失框架效应在损、益型跨期选择中出现了分离, 收益型跨期选择中的得失框架效应的内在认知机制很可能与风险决策中的框架效应类似并且是一种较为初级的认知加工过程。     

Extending Fitts' law to a three-dimensional pointing task

An attempt was made to extend Fitts' law to a three-dimensional movement (pointing) task to enhance its predictive performance in this domain. An experiment was conducted in which 10 subjects performed three-dimensional pointing movements under the manipulation of target size, distance to target and direction to target. As expected, the duration of these three-dimensional movements was rather variable and affected markedly by direction to target. As a result, the variance in the movement times produced was not satisfactorily explained by the conventional Fitts' model. The conventional model was extended by incorporating a directional parameter into the model. The extended model was shown to better fit the data than the conventional Fitts' model, both in terms of r(2) and the standard error of the residual between the measured movement time and the value predicted by model fit.     

The influence of intention on masked priming: a study with semantic classification of words

Unconscious perception is commonly described as a phenomenon that is not under intentional control and relies on automatic processes. We challenge this view by arguing that some automatic processes may indeed be under intentional control, which is implemented in task-sets that define how the task is to be performed. In consequence, those prime attributes that are relevant to the task will be most effective. To investigate this hypothesis, we used a paradigm which has been shown to yield reliable short-lived priming in tasks based on semantic classification of words. This type of study uses fast, well practised classification responses, whereby responses to targets are much less accurate if prime and target belong to a different category than if they belong to the same category. In three experiments, we investigated whether the intention to classify the same words with respect to different semantic categories had a differential effect on priming. The results suggest that this was indeed the case: Priming varied with the task in all experiments. However, although participants reported not seeing the primes, they were able to classify the primes better than chance using the classification task they had used before with the targets. When a lexical task was used for discrimination in experiment 4, masked primes could however not be discriminated. Also, priming was as pronounced when the primes were visible as when they were invisible. The pattern of results suggests that participants had intentional control on prime processing, even if they reported not seeing the primes.     

自闭症儿童对情景事件的情绪理解：基于内隐和外显的测量

该研究旨在采用生态效度更高的情绪情景事件以及内隐和外显两种测量方式考察自闭症儿童的情绪理解。选取自闭症和智商匹配的正常儿童各21名,以序列图片的方式呈现从动画片中截取的不同效价的情景事件,外显任务要求被试直接判断事件主角的情绪、内隐任务要求被试判断事件的一致性。结果发现：1.在外显任务中,自闭症儿童对正性和负性情绪的判断正确率均显著不如正常儿童,尤其是在负性情绪上存在明显的理解缺陷;2.在内隐任务中,正常儿童的正性负性情绪、自闭症儿童的正性情绪都表现出更弱的相对于中性情绪的理解效应;自闭症儿童的负性情绪理解则在两种任务中都接近于无。这些结果意味着自闭症儿童在外显和内隐任务中都存在负性情绪理解缺陷。     

Analyzing feature distinctiveness in the processing of living and non-living concepts in Alzheimer’s disease

The conceptual structure account (CSA) is a model specifying the role of the living and non-living domain dichotomy in the structure of semantic memory. According to this model, feature distinctiveness and the perceptual–functional inter-correlation of concepts are assumed to play a major role in impairing the ability to discriminate between living and non-living concepts in Alzheimer’s disease (AD). The hypothesis was tested in this study by using naming and sorting tasks traditionally considered as assessing distinctiveness, and a property verification task where distinctiveness and perceptual–functional inter-correlation were objectively controlled against norms especially created for this purpose. Alzheimer’s patients (n = 59) with minimal, mild or moderate dementia and normal elderly adults (n = 31) participated in the study. Overall, the findings did not support the CSA predictions. They revealed a distinctiveness effect on response accuracy with shared features dominating distinctive features regardless of domain. They also revealed more difficulties in the tasks involving effortful processes. The results stress the need to consider both cognitive demands of tasks and structural aspects of knowledge in the evaluation of semantic memory in AD.