Facilitation of return in voluntary orienting to visual attributes1

Abstract: The present study examined the effects of voluntary and automatic orienting after a relatively long interval in an attentional cueing paradigm. Facilitation of return was observed after the voluntary orienting to a designated color (Experiment 1) and motion direction (Experiment 2), whereas inhibition of return was observed after the automatic orienting to an abrupt stimulus onset (Experiment 1). These results suggest that the voluntary orienting to a visual attribute modulates subsequent processes differently from the automatic orienting to an abrupt onset. In the voluntary orienting to visual attributes, it would be advantageous to return attention to the previously attended location, which is a potential source of information.     

Retrospective perceptual distortion of position representation does not lead to delayed localization

Previous studies have reported retrospective influences of visual events that occur after target events. In the attentional attraction effect, a position cue presented after a target stimulus distorts the target’s position towards that of the cue. The present study explored the temporal relationship between stimulus presentation and reaction time (RT) in this effect in two experiments. Participants performed a speeded localization task on two vertical lines, the positions of which were to be distorted by an additional attentional cue. No significant difference in RTs was found between the conditions with simultaneous and delayed cues. RTRT was modulated by the perceived (rather than physical) alignment of the lines. In Experiment 2, we manipulated the strength of attentional capture by modulating the color relevance of the cue to the target. Trials with cues producing stronger attentional capture (with cues of a different color from the targets) were found to induce apparently stronger distortion effects. This result favors the notion that the observed repulsion and attraction effects are driven by attentional mechanisms. Overall, the results imply that the attentional shift induced by the cue might occur rapidly and complete before the establishment of conscious location representation of the cue and the target without affecting overall response time.     

Slow Motor Responses to Visual Stimuli of Low Salience in Autism

ABSTRACT

The authors studied 2 tasks that placed differing demands on detecting relevant visual information and generating appropriate gaze shifts in adults and children with and without autism. In Experiment 1, participants fixated a cross and needed to make large gaze shifts, but researchers provided explicit instructions about shifting. Children with autism were indistinguishable from comparison groups in this top-down task. In Experiment 2 (bottom-up), a fixation cross remained or was removed prior to the presentation of a peripheral target of low visual salience. In this gap–effect experiment, children with autism showed lengthened reaction times overall but no specific deficit in overlap trials. The results show evidence of a general deficit in manual responses to visual stimuli of low salience and no evidence of a deficit in top-down attention shifting. Older children with autism appeared able to generate appropriate motor responses, but stimulus-driven visual attention seemed impaired.     

内隐序列学习与注意负荷关系的实验研究

采用2(注意负荷:高、低)单因素被试内实验设计,以18名在校大学生为被试,运用行为实验及事件相关电位技术,对内隐序列学习是否需要注意负荷的参与进行实验研究。结果发现:(1)在高、低注意负荷条件下都出现了内隐序列学习效应;(2)高注意负荷序列探测刺激诱发的P1、N1波幅显著大于低注意负荷序列探测刺激诱发的,表明高注意负荷条件下需要更多的注意;(3)高、低注意负荷序列内隐序列学习量差异不显著,表明内隐序列学习不受注意负荷影响。     

内隐序列学习不受注意负荷的影响:来自眼动的证据

利用眼动记录方法,采用内隐序列学习的观察范式,通过操纵注意负荷高和低,考察内隐序列学习是否需要注意参与。结果发现:(1)在高、低注意负荷条件下都出现了内隐序列学习效应;(2)高注意负荷条件下眼跳反应时长于低注意负荷条件下的;(3)高、低注意负荷序列内隐序列学习量差异不显著,表明内隐序列学习不受注意负荷影响。     

Intraindividual reaction time variability predicts prospective memory failures in older adults

This study investigated the relationship between intraindividual variability (IIV) in reaction time and prospective memory errors in older adults using data from the Zurich Longitudinal Study of Cognitive Aging (n = 336 individuals aged 66–81 years). The results indicated that increased IIV measured from independent tasks was associated with a greater proportion of prospective memory errors. These significant findings were not influenced by age and did not vary according to prospective memory cue type. Variability is thought to reflect fluctuations in attentional and executive control and these attentional processes may also impact on prospective memory through failure to detect the target cue. The findings suggest, therefore, that measures of variability may have some potential in the identification of older persons who are more vulnerable to everyday errors such as prospective memory failures.     

Learning to Minimize Energy Costs and Maximize Mechanical Work in a Bimanual Coordination Task

The authors addressed the hypothesis that economy in motor coordination is a learning phenomenon realized by both reduced energy cost for a given workload and more external work at the same prepractice metabolic and attentional energy expenditure. "Self-optimization" of movement parameters has been proposed to reflect learned motor adaptations that minimize energy costs. Twelve men aged 22.3 ± 3.9 years practiced a 90° relative phase, upper limb, independent ergometer cycling task at 60 rpm, followed by a transfer test of unpracticed (45 and 75 rpm) and selfpaced cadences. Performance in all conditions was initially unstable, inaccurate, and relatively high in both metabolic and attentional energy costs. With practice, coordinative stability increased, more work was performed for the same metabolic and attentional costs, and the same work was done at a reduced energy cost. Selfpaced cycling was initially below the metabolically optimal, but following practice at 60 rpm was closer to optimal cadence. Given the many behavioral options of the motor system in meeting a variety of everyday movement task goals, optimal metabolic and attentional energy criteria may provide a solution to the problem of selecting the most adaptive coordination and control parameters.     

The Role of Precues in the Preparation of Motor Responses in Humans

The authors investigated how precues about the location of an upcoming target are used by the sensorimotor system to reduce manual reaction time. In 4 experiments, participants (N = 12 in each experiment) pressed a response key as fast as possible when a precued or a nonprecued visual target appeared. Precues remained effective when a visual mask was interposed between the display of the precue and the target (Experiment 1), which suggests that precues act downstream from visual sensory memory. The precue effect was abolished when precues were presented along with a task requiring attention and a verbal response (Experiment 2) but not when presented with a task that required verbal output but had no attention demands (Experiment 3). Those findings indicate that precues must be processed attentively to become effective. When the attention-demanding task was interposed between precue and target display, the precue effect was still abolished (Experiment 4), which suggests that individuals' attention must remain in the precued area until target appearance.     

Preattentive control of serial auditory processing in dichotic listening

Dichotic listening performance was examined in an auditory selective attention task where subjects responded to occasional consonant-vowel (CV) or shaped broadband noise-burst (NB) targets in rapid serial auditory presentation (RASP). Trial types were randomized and included monaural CVs and NBs as well as dichotic CV-CV and CV-NB pairings. CVs were spoken by two different voices (male and female), and the two NB stimuli differed in their filter slopes at higher frequencies. The target was designated by stimulus category (/ba/, /da/, /ga/, or NB) and voice (e.g., "female /ba/"). Performance was compared for targets in the left and right ears on monaural and dichotic trials using accuracy and reaction time (RT) measures. Right ear advantages (REAs) were present for CV targets with either CV or NB distractors, but not for monaural CVs. The REA found for monaural NB targets was eliminated by CV distractors, yielding a left ear advantage (LEA) for the distractor effect of CVs on NB targets. The pattern of results suggests initial preprocessing of speech stimuli through phonetic feature analysis, followed by serial attentional processing of the objects in the auditory field. REAs are attributed to a rightward asymmetry in the preattentive control of auditory attention similar to that found in visual search.     

Manipulating attentional load in sequence learning through random number generation

Implicit learning is often assumed to be an effortless process. However, some artificial grammar learning and sequence learning studies using dual tasks seem to suggest that attention is essential for implicit learning to occur. This discrepancy probably results from the specific type of secondary task that is used. Different secondary tasks may engage attentional resources differently and therefore may bias performance on the primary task in different ways. Here, we used a random number generation (RNG) task, which may allow for a closer monitoring of a participant's engagement in a secondary task than the popular secondary task in sequence learning studies: tone counting (TC). In the first two experiments, we investigated the interference associated with performing RNG concurrently with a serial reaction time (SRT) task. In a third experiment, we compared the effects of RNG and TC. In all three experiments, we directly evaluated participants' knowledge of the sequence with a subsequent sequence generation task. Sequence learning was consistently observed in all experiments, but was impaired under dual-task conditions. Most importantly, our data suggest that RNG is more demanding and impairs learning to a greater extent than TC. Nevertheless, we failed to observe effects of the secondary task in subsequent sequence generation. Our studies indicate that RNG is a promising task to explore the involvement of attention in the SRT task.     

Attentional Resources Measured by Reaction Times Highlight Differences Within Pleasant and Unpleasant,High Arousing Stimuli

Simple reaction times (RTs) to acoustic tones were recorded during picture viewing in order to investigate attentional resource allocation to threat stimuli compared with pleasant (sport/adventure) and neutral (household objects) contents. Stimuli were selected as equally arousing according to standardized subjective ratings. In the late stage of picture processing threat pictures showed shorter RTs compared with neutral and pleasant ones. In a second study, a choice-RT task was employed, and a wider range of both pleasant and unpleasant contents was shown. Results indicated slower RTs when blood/injury and erotic couples were presented, compared with other threat, and with other positive (sport/adventure) scenes. Specifically, erotic couples require a greater amount of attentional resources compared with sport/adventure; the same is true for blood/injury stimuli as compared with threat. Remarkable differences were thus shown in attentional deployment to specific stimulus contents within the same valence category. These differences should be taken into account when using such stimuli to investigate emotional processing.     

Implicit sequence learning in a search task

This study investigated the effects of selection demands on implicit sequence learning. Participants in a search condition looked for a target among seven distractors and responded on the target identity. The responses followed a deterministic sequence, and sequence learning was compared to that found in two control conditions in which the targets were presented alone, either at a central location or over a series of unpredictable locations. Sequence learning was obtained in all conditions, and it was equivalent for the two variable location conditions, regardless of the perceptual demands. Larger effects of learning were observed in the central location, both on the indirect measures and on the measures taken from a cued-generation task. The expression of learning decreased selectively in this condition when the sequence validity was reduced over a test block. These results are consistent with the claims that implicit and explicit learning are mixed in this central condition and that implicit learning is not affected by selection difficulty.     

工作记忆的存储时间及目标时距对时间知觉的影响

本研究操作记忆信息与计时开始之间的时间间隔（ISI）和目标时距,探讨工作记忆影响时间判断的灵活性。被试首先记忆一个客体,然后在每个trial的最后判断测试刺激是否与记忆项相同;在延迟阶段,被试完成时间判断任务,即判断相继出现的两个刺激的时距哪个更长（或更短）。时间任务中的一个刺激与记忆内容完全相同,相应的另一个刺激与记忆内容在形状和颜色上都不同。重复条件下,被试忽略第一个刺激,仅完成时间判断任务。结果发现,时间间隔（ISI）短时,记忆匹配条件下的准确率更高,匹配刺激延长了知觉的时间;但随着时间间隔的增加,工作记忆匹配对时间判断的影响降低甚至消失。并且,长或短ISI,记忆任务或重复条件下,目标时距长时,记忆匹配反而缩短了知觉的时间。研究说明工作记忆对时间判断的影响是灵活的,受到注意或工作记忆等高级认知系统的调控。