Temporal cue–target overlap is not essential for backward inhibition in task switching

Lag 2 repetition costs are a performance cost observed when participants return to a task after just one intervening trial of a different task, compared to returning after a longer interval (AB A vs. CB A sequences, where A, B, C are tasks). This effect is known as backward inhibition (BI) and is thought to reflect the need to overcome inhibition applied specifically to Task “A” during disengagement at trial n – 1. Druey and Hübner (2007) Druey, M. and Hübner, R. 2007. The role of temporal cue–target overlap in backward inhibition under task switching. Psychonomic Bulletin & Review, 14: 749–754. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar] have suggested that employment of such a specific inhibitory mechanism relies upon the cue and the target of the task overlapping temporally. We provide evidence across three experiments (including a direct replication attempt) that this is not the case, and that the presence of task-specific BI relies to some extent on the need to translate the cue–target relationship into working memory. Additionally, we provide evidence that faster responses in no overlap conditions are driven by low-level perceptual differences between target displays across overlap conditions. We conclude that BI is an effective sequential control mechanism, employed equally in cases of temporally overlapping and temporally separated cues and targets.     

Selective impairment of masked priming in dual-task performance

This study investigated the impact of divided attention on masked priming. In a dual-task setting, two tasks had to be carried out in close temporal succession: a tone discrimination task and a masked priming task. The order of the tasks was varied between experiments, and attention was always allocated to the first task—that is, the first task was prioritized. The priming task was the second (nonprioritized) task in Experiment 1 and the first (prioritized) task in Experiment 2. In both experiments, “novel” prime stimuli associated with semantic processing were essentially ineffective. However, there was intact priming by another type of prime stimuli associated with response priming. Experiment 3 showed that all these prime stimuli can reveal significant priming effects during a task-switching paradigm in which both tasks were performed consecutively. We conclude that dual-task specific interference processes (e.g., the simultaneous coordination of multiple stimulus–response rules) selectively impair priming that is assumed to rely on semantic processing.     

Between-task competition for intentions and actions

People can switch quickly and flexibly from one task to another, but suffer the effects of between-task competition when they do so: After switching, they tend to be distracted by irrelevant stimulus information and hampered by incorrect actions associated with recently performed tasks. This competition results in performance costs of switching, as well as a bias against switching when there is choice over which task to perform, particularly when switching from a difficult task to an easier one. Two experiments investigated the locus of these between-task competition effects in voluntary task switching. Participants switched between an easy location classification and a harder shape classification, making two responses on each trial: the first to register their task choice, the second to perform the chosen task on a subsequently presented stimulus. The results indicated that participants chose to perform the difficult shape task more often than the easier location task, evidence that between-task competition affects intentions that are expressed independently of task-specific actions. The bias was stronger in participants with faster choice speed, suggesting that these influences are relatively automatic. Moreover, even though participants had unlimited time to choose and prepare a task before stimulus presentation, their subsequent performance was nonetheless sensitive to persisting effects of between-task competition. Altogether these results indicate the pervasive influence of between-task competition, which affects both the expression of global task intentions and the production of task-specific actions.     

Control processes in voluntary and explicitly cued task switching

Explicitly cued task switching slows performance relative to performing the same task on consecutive trials. This effect appears to be due partly to more efficient encoding of the task cue when the same cue is used on consecutive trials and partly to an additional task-switching process. These components were examined by comparing explicitly cued and voluntary task switching groups, with external cues presented to both groups. Cue-switch effects varied in predictable ways to dissociate explicitly cued and voluntary task switching, whereas task-switch effects had similar characteristics for both instructional groups. The data were well fitted by a mathematical model of task switching that included a cue-encoding mechanism (whereby cue repetition improves performance) and an additional process that was invoked on task-switch trials. Analyses of response-time distributions suggest that this additional process involves task-set reconfiguration that may or may not be engaged before the target stimulus is presented.     

Attention and action: The role of response mappings in auditory attention switching

Switching auditory attention incurs a performance decrement (i.e. auditory attention-switch costs). Using an auditory attention-switching paradigm, we aimed to generalise these across different response mappings. In all three experiments, two number words, spoken by a female and male speaker, were presented dichotically via headphones. A visual cue indicated the gender of the to-be-attended speaker in each trial. The task was a magnitude judgement of the relevant number word (i.e. smaller vs. larger than 5). We additionally varied the interval between cue onset and auditory stimulus onset (cue-stimulus interval) to explore cue-based preparatory effects. In Experiment 1, attention switching was more costly with direct-verbal responses (e.g. ‘smaller’) than in the shadowing task (e.g. ‘three’). In Experiment 2, performance was largely similar for direct-verbal responses and abstract-verbal responses (e.g. ‘left’). In Experiment 3, performance was generally worse with abstract-verbal responses than with abstract-manual responses (e.g. left key press) and auditory attention-switch costs were similar for both response mappings. Overall, auditory switch costs occurred more or less invariably across response mappings in categorical (magnitude) judgements suggesting a minor role of the response mapping in auditory attention switching. Furthermore, verbal identity-based judgements (i.e. shadowing) generally seem to benefit from ideomotor compatibility.     

Investigating the face inversion effect in a deaf population using the Dimensions Tasks

Early experience can change the way people process faces. Early deafness provides deaf children with the opportunity to learn sign language, which is likely to alter their face processing strategy. The goal of the current study was to investigate whether early deafness, combined with the sign language experience, was able to change the face processing strategy using the Dimensions Task. In the Face Dimensions Task, configural and featural information were parametrically and independently manipulated in the eye and mouth region of the face. The manipulations for configural information involved changing the distance between the eyes or the distance between the mouth and the nose. The manipulations for featural information involved changing the size of the eyes or the size of the mouth. Similar manipulations were applied in the House Dimensions Task, with top and bottom windows treated as eyes and mouth. In the Face Dimensions Task, both the signing deaf and hearing participants showed a larger inversion effect in the mouth condition than the eye condition. However, as compared to hearing participants, deaf participants showed smaller inversion effect in the mouth condition, because their performance in the inverted mouth condition was not compromised by inversion to the same extent as the hearing participants. In the House Dimensions Task, this effect was not present, suggesting that it was face specific. This effect could be explained by the redistributed attentional resources from the centre to peripheral visual fields of deaf participants.     

小学儿童规则发现的类比迁移研究

本研究以小学儿童为被试,证实了在策略提示条件下解决规则发现(合取规则和析取规则)的类比问题时,任务难度和表面相似性是影响策略的迁移的重要因素,并且发现小学儿童的思维能力存在着较大的个体差异.他们在问题解决时主要使用单维检验策略,多数小学儿童缺乏较强的元认知监控.     

中学生快速阅读训练的实验研究

本实验以初中学生为被试,围绕着快速阅读训练的作用及其条件问题,进行了两个实验。实验结果如下:(1)对初中学生进行一段时间的快速阅读训练,可以显著提高阅读成绩;(2)难度较大的文章,不适于采用快速阅读;(3)问题-文章的阅读方式在阅读速度、有效读速方面优于文章-问题的阅读方式。