Enhancement from targets and suppression from cues in fast task-irrelevant perceptual learning

Task-irrelevant perceptual learning (TIPL) refers to the phenomenon where the stimulus features of a subject's task are learned when they are consistently presented at times when behaviorally relevant events occur. In this article, we addressed two points concerning TIPL. First, we address the question, are all behaviorally relevant events equal in their impact on encoding processes? Second, we address the hypothesis that TIPL involves mechanisms of the alerting attentional system. Two experiments of fast-TIPL were conducted in which the attentional state of participants was manipulated by using an alerting cue (visual or auditory) that informed participants of the arrival of an upcoming target. Images were presented with task-related stimuli (cues, targets and distractors) and subjects were tested on their memory of those images. Results indicate that memory for target-paired images was enhanced and cue-paired images were suppressed relative to that of distractor-paired images. The alerting cue increased the ability to recall target-paired images presented after this cue, although this result depended on the proportion of cued trials in a session. These results demonstrate a complex interplay between task-elements and the encoding of stimuli paired with them where both enhancement and suppression of task-paired stimuli can be found depending whether those stimuli are paired with task-targets or cues.     

类别意义连结在无意视盲中的作用

本研究考察在无注意定势的参与下,类别信息的意义连结对于无意视盲的作用。被试在实验任务之前观察、学习某一类别的若干刺激,以激活其类别概念和表征。结果表明,启动相关类别概念的被试在非注意情况下觉察到非预期的、显著刺激的可能性更大。这说明,意义连结可以广泛地作用于类别刺激,即使没有注意定势的影响,也能自动地注意到相关的刺激,从而促进其意识的加工。     

Implicit learning of new verbal associations

Implicit learning of a series of new verbal associations was studied in four experiments. The first two experiments demonstrated that learning of a repeating sequence of verbal stimuli may occur without awareness, but only when the stimulus-response mapping requires an attention-demanding activity: Subjects who were unaware of the sequence learned when instructed to categorize the stimuli, but not when instructed simply to read them. However, in both situations, unaware subjects performed no better than untrained control subjects in expressing their knowledge of the sequence explicitly. In Experiments 3 and 4, subjects showed implicit learning when the task involved either motor responses to verbal stimuli or verbal responses to spatially arranged stimuli. These findings are discussed in terms of the conditions under which implicit learning can be obtained. First, they demonstrate implicit learning of a set of new associations in the verbal domain. Second, the data suggest that attention is important in implicit learning. Finally, the degree of interitem organization that is familiar preexperimentally seems to partially determine the amount of implicit learning.     

Investigating the Role of Instructional Focus in Incidental Pattern Learning

The authors used a novel dual-component training procedure that combined a serial reaction time task and an artificial grammar learning task to investigate the role of instructional focus in incidental pattern learning. In Experiment 1, participants either memorized letter strings as a primary task and reacted to the stimuli locations as a secondary task or vice versa. In Experiment 2, participants were given the same dual-component stimuli but performed only one of the two training tasks. Instructional focus affected the amount of learning and the likelihood of acquiring explicit knowledge of the underlying pattern. However, the effect of instructional focus varied for the different types of stimuli. These results are discussed in terms of the role of focused attention in incidental learning.     

Eye movements as a gatekeeper for memorization: evidence for the persistence of attentional sets in visual memory search

Attention is known to serve multiple goals, including the selection of information for further perceptual analysis (selection for perception) and for goal-directed behavior (selection for action). Here, we study the role of overt attention (i.e., eye movements) as a gatekeeper for memorization processes (selection for memorization). Subjects memorized complex multidimensional stimulus displays and subsequently indicated whether a specific (probe) item was present. In Experiment 1 we utilized an incidental learning setting where in the beginning only a subset of display stimuli was relevant, whereas in a transfer block all stimuli were possible probe items. In Experiment 2, we used an explicit learning setting within a between-group design. Response times and gaze patterns indicated that subjects learned to ignore irrelevant stimuli while forming memory representations. The findings suggest that complex feature binding processes in peripheral vision may serve to guide overt selective attention, which eventually contributes to filtering out irrelevant information even in highly complex environments. Gaze patterns suggested that attentional control settings persisted even when they were no longer required.     

注意和工作记忆对交错呈现优势的影响

以家族相似性图案为材料,让被试在单任务或双任务条件下以集中呈现或交错呈现的方式进行观察（实验1）或反馈（实验2）学习,记录眼动,探究注意对交错呈现优势的影响,以及工作记忆在其中的作用。发现当进行观察学习时,注意影响交错呈现优势,结果支持区别对比理论和注意衰减理论;当进行反馈学习时,注意的影响还有待进一步探究。同时,工作记忆影响交错呈现优势,但工作记忆并非完全通过影响注意从而影响交错呈现优势。     

Attentional load and implicit sequence learning

A widely employed conceptualization of implicit learning hypothesizes that it makes minimal demands on attentional resources. This conjecture was investigated by comparing learning under single-task and dual-task conditions in the sequential reaction time (SRT) task. Participants learned probabilistic sequences, with dual-task participants additionally having to perform a counting task using stimuli that were targets in the SRT display. Both groups were then tested for sequence knowledge under single-task (Experiments 1 and 2) or dual-task (Experiment 3) conditions. Participants also completed a free generation task (Experiments 2 and 3) under inclusion or exclusion conditions to determine if sequence knowledge was conscious or unconscious in terms of its access to intentional control. The experiments revealed that the secondary task impaired sequence learning and that sequence knowledge was consciously accessible. These findings disconfirm both the notion that implicit learning is able to proceed normally under conditions of divided attention, and that the acquired knowledge is inaccessible to consciousness. A unitary framework for conceptualizing implicit and explicit learning is proposed.     

When people’s judgments of learning (JOLs) are extremely accurate at predicting subsequent recall: the “Displaced-JOL effect”

Judgments of learning (JOL) made after a delay more accurately predict subsequent recall than JOLs made immediately after learning. One explanation is that delayed JOLs involve retrieving information about the target item from secondary memory, whereas immediate JOLs involve retrieval from primary memory. One view of working memory claims that information in primary memory is displaced to secondary memory when attention is shifted to a secondary task. Thus, immediate JOLs might be as accurate as delayed JOLs if an intervening task displaces the target item from primary memory, requiring retrieval from secondary memory, prior to making the JOL. In four experiments, participants saw related word-pairs and made JOLs predicting later recall of the item. In Experiment 1, delayed JOLs were more accurate than JOLs made shortly after learning, regardless of whether a secondary task intervened between learning and JOL. In Experiments 2–4, the secondary task demands increased and JOLs made shortly after learning with an intervening task were just as accurate as delayed JOLs, and both were more accurate than immediate JOLs with no intervening task (Experiment 4). These results are consistent with a retrieval-based account of JOLs, and demonstrate that the “delayed-JOL effect” can be obtained without a long delay.     

中小学生内隐序列学习的机制

内隐序列学习是内隐学习的一种重要形式。该文探讨了中小学生内隐序列学习的心理机制及次级任务影响内隐序列学习的实质。结果表明,中小学生对不同结构序列的内隐学习是由一个单一的学习机制完成的,学习的过程即是形成序列内相邻元素间联合的过程;另外,注意能量并不是内隐序列学习的重要影响因素,次级任务影响内隐序列学习并不是因为其分散了注意能量,而是破坏了对序列元素的组织。     

Types of semantic category and stimulus modality in procedural learning: implications for models of semantic memory

The present work attempts to determine whether procedural learning of a semantic categorisation task is influenced by the type of semantic category of the stimuli (biological and non-biological elements). It is also an attempt to determine the effect of the stimulus presentation modality on the categorisation task. A semantic categorisation task (4 series of 40 stimuli) was administered to 256 participants (128 classifying pictures, and 128 classifying words). Biological categories were responded to faster than non-biological ones although there were no significant differences between the interaction of the category type and the stimulus presentation modality. Reaction times progressively decreased with practice. However, the initial differences disappeared when subjects were trained. The way that current models account for these investigation findings is discussed. In addition, it is suggested that there is an attentional bias in favor of biological elements, which disappears when presumably less relevant elements become more relevant as a function of the task characteristics.     

The self: Your own worst enemy? A test of the self-invoking trigger hypothesis

The self-invoking trigger hypothesis was proposed by Wulf and Lewthwaite [Wulf, G., & Lewthwaite, R. (2010). Effortless motor learning? An external focus of attention enhances movement effectiveness and efficiency. In B. Bruya (Ed.), Effortless attention: A new perspective in attention and action (pp. 75–101). Cambridge, MA: MIT Press] as a mechanism underlying the robust effect of attentional focus on motor learning and performance. One component of this hypothesis, relevant beyond the attentional focus effect, suggests that causing individuals to access their self-schema will negatively impact their learning and performance of a motor skill. The purpose of the present two studies was to provide an initial test of the performance and learning aspects of the self-invoking trigger hypothesis by asking participants in one group to think about themselves between trial blocks—presumably activating their self-schema—to compare their performance and learning to that of a control group. In Experiment 1, participants performed 2 blocks of 10 trials on a throwing task. In one condition, participants were asked between blocks to think about their past throwing experience. While a control group maintained their performance across blocks, the self group's performance was degraded on the second block. In Experiment 2, participants were asked to practice a wiffleball hitting task on two separate days. Participants returned on a third day to perform retention and transfer tests without the self-activating manipulation. Results indicated that the self group learned the hitting task less effectively than the control group. The findings reported here provide initial support for the self-invoking trigger hypothesis.     

Optional-shift behaviour in rats: a novel procedure for assessing attentional processes in discrimination learning

A novel, optional-shift procedure was used to assess changes in the attention paid to stimuli that occur over the course of discrimination learning. In Phase 1, rats were trained on a conditional instrumental discrimination using audiovisual stimulus compounds; one stimulus dimension (auditory or visual) was relevant to the solution of the discrimination, the other was irrelevant. In Phase 2, all animals received three sessions of training with novel audiovisual compounds where both dimensions were equally diagnostic. Results from probe test trials indicated that, during Phase 2, animals learnt most about cues belonging to the stimulus dimension that was relevant during Phase 1. These results suggest that over the course of discrimination learning there was an increase in the amount of attention paid to relevant stimuli and/or a decrease in the attention paid to irrelevant stimuli.     

Implicit visual learning: How the task set modulates learning by determining the stimulus–response binding

Implicit learning is one of the most fundamental learning mechanisms that enables humans to adapt to regularities inherent in the environment. Despite its high flexibility, it depends on constraints, such as selective attention. Here, we focused on the stimulus-to-response binding which defines the dimensions of the stimuli and the responses participants attend to. In a serial reaction time task with a visual sequence, we investigated whether this stimulus–response binding influences the amount of sequence learning. The results of Experiments 1 and 2 showed that visual sequence learning is reduced when participants do not attend to the relevant response dimension. Furthermore, the findings of Experiment 3 suggest that attention to the relevant response dimension increased the development of explicit knowledge without affecting implicit knowledge. This latter finding is difficult to reconcile with the assumption that explicit learning results from the gradual strengthening of sequence representations.     

Teaching students with ASD: Does teacher enthusiasm make a difference?

There is a general belief that students perform better in an environment in which teachers exude enthusiasm. In elementary, secondary, and college settings, the display of teacher enthusiasm is associated with positive attitudes toward teachers, recall of information, and improved classroom behavior. Although the assumption that students perform better when teachers are enthusiastic is frequently extended to individuals diagnosed with autism spectrum disorder (ASD), there is currently no published research on the topic. Research on social avoidance suggests that individuals with ASD may have no reaction or even respond negatively to teacher enthusiasm and thus perform better in conditions of low teacher attention. The current study was conducted to examine the effects of teacher enthusiasm on task performance for 12 students diagnosed with ASD. For each participant, performance on a matching task was measured during a high attention condition and during a low attention condition. Inspection of performance data indicated that out of 12 participants, only one demonstrated better performance under high teacher attention and one demonstrated better performance under low teacher attention. Interestingly, when experimenters who served as teachers in the study were asked to judge student performance, they stated that all students performed better with high teacher attention. Based on the findings of the current study, educators and parents of children with ASD are cautioned against attributing differences or changes in student performance to type and intensity of social attention provided during task instruction in the absence of conducting a functional analysis. Implications from the current study serve as a reminder to avoid oversimplifying the complex learning challenges of children with autism and reiterate the importance of obtaining continuous objective performance data. Copyright © 2008 John Wiley & Sons, Ltd.     

Optional-shift behaviour in rats: A novel procedure for assessing attentional processes in discrimination learning

A novel, optional-shift procedure was used to assess changes in the attention paid to stimuli that occur over the course of discrimination learning. In Phase 1, rats were trained on a conditional instrumental discrimination using audiovisual stimulus compounds; one stimulus dimension (auditory or visual) was relevant to the solution of the discrimination, the other was irrelevant. In Phase 2, all animals received three sessions of training with novel audiovisual compounds where both dimensions were equally diagnostic. Results from probe test trials indicated that, during Phase 2, animals learnt most about cues belonging to the stimulus dimension that was relevant during Phase 1. These results suggest that over the course of discrimination learning there was an increase in the amount of attention paid to relevant stimuli and/or a decrease in the attention paid to irrelevant stimuli.     

Beyond fear: rapid spatial orienting toward positive emotional stimuli

There is much empirical evidence for modulation of attention by negative -- particularly fear-relevant -- emotional stimuli. This modulation is often explained in terms of a fear module. Appraisal theories of emotion posit a more general mechanism, predicting attention capture by stimuli that are relevant for the needs and goals of the organism, regardless of valence. To examine the brain-activation patterns underlying attentional modulation, we recorded event-related potentials from 20 subjects performing a dot-probe task in which the cues were fear-inducing and nurturance-inducing stimuli (i.e., anger faces and baby faces). Highly similar validity modulation was found for the P1 time-locked to target onset, indicating early attentional capture by both positive and negative emotional stimuli. Topographic segmentation analysis and source localization indicate that the same amplification process is involved whether attention orienting is triggered by negative, fear-relevant stimuli or positive, nurturance-relevant stimuli. These results confirm that biological relevance, and not exclusively fear, produces an automatic spatial orienting toward the location of a stimulus.     

Attention,instruction, and response representation

A two-dimensional Simon-type task was devised to investigate the impact of task requirements and explicit instructions on spatial action coding. Subjects performed actions that were defined on two spatial dimensions: horizontal (left-right) or vertical (top-bottom). The relevant stimulus feature was nonspatial but the stimuli varied on the horizontal and the vertical dimension, so that horizontal and vertical S-R compatibility effects could be measured separately. Implicit task requirements were manipulated by having the subjects perform an unrelated task before the Simon task—a task in which only one of the two spatial dimensions was relevant. Instructions were varied by describing the responses in the unrelated priming task and/or in the Simon task in spatial terms or by referring to nonspatial features of the response keys. Priming a particular dimension increased the Simon effect on that dimension, whereas instructions had no differential effect. These findings suggest that, first, drawing attention to a particular dimension leads to a stronger contribution to event representation of those features defined on that dimension (intentional weighting) and, second, that instructions do not affect action coding if the manipulation does not change the task goal.     

Are hyperactive children deficient in attentional capacity?

A dual task was used to study attentional capcity in three groups: in 6- to 12- year- old boys with attention deficit disorder plus hyperactivity (ADDH) or with ADDH and conduct disorder, and in normal children. Subjects performed a primary-choice reaction-time task first without and then with a secondary task that also required a response. Our prediction that the reaction time of ADDH subjects to the secondary task would increase more with increasing temporal overlap of the primary and secondary stimuli, if they were deficient in capacity, was not supported. However, the performance of ADDH subjects on the primary task deteriorated more than that of control subjects with the introduction of the secondary task, indicating a greater concurrence cost or a different allocation policy. Moreover, ADDH subjects had longer reaction times to the secondary task, indicating greater refractory effects or difficulty shifting capacity from primary- to secondary-task processes.The authors would like to acknowledge the support of the Ontario Mental Health Foundation and the assistance of Diane Chajczyk. This paper was prepared with the assistance of Medical Publications, The Hospital for Sick Children, Toronto, Ontario.     

Selective attention in the speeded classification and comparison of multidimensional stimuli

Selective attention was studied when subjects were required to make either speeded classifications of single stimuli or comparisons of pairs of multidimensional stimuli. Experiment 1 established that subjects were able to attend selectively to form when the irrelevant dimension of size or shading varied in a speeded-classification (card-sorting) task. Experiment 2 confirmed this finding in a discrete-trials task. However, subjects werenot able to filter out irrelevant dimensional disparity in a comparably designed simultaneous-comparison (i.e., “same”-“different”) task. Mean “same” reaction time increased monotonically with increases in disparity between the two stimuli on the irrelevant dimension. Experiment 3 also revealed a monotonie increase in “same” RT as a function of irrelevant disparity in a successive-comparison task. These results were discussed in terms of a normalization model proposed by Dixon and Just (1978) in which it is assumed that a subject equates the two stimuli on the irrelevant dimension before deciding that they are the same along the relevant dimension. It was concluded that: (1) although subjects can efficiently filter out irrelevant disparity in a speeded-classification task, interference due to irrelevant disparity is obtained in the comparison tasks, (2) a common process such as normalization does not necessarily underlie performance in the speeded-classification and comparison tasks, (3) the ability to attend selectively to a stimulus dimension may be task determined as well as stimulus determined, and (4) contrary to the Dixon and Just proposal, normalization of irrelevant disparity occurs in a comparison task, even when the relevant dimension is represented as a separate encoding feature.