Superior modulation of activation levels of stimulus representations does not underlie superior discrimination in autism

The performance of children with and without autism was compared in object-based positive and negative priming tasks within a visual search procedure. Object-based positive and negative priming effects were found in both groups of children. This result provides the first evidence for the activation of object-based representations during visual search task performance and further supports the notion that both excitatory and inhibitory guidance mechanisms are involved in target location in visual search. The children with autism were overall better than the typically developing children at visual search, thus replicating demonstrations of superior discrimination in autism. Furthermore, there was no difference between the magnitude of the positive nor the negative priming effects of the groups. This finding suggests that excitatory and inhibitory control operate comparably in autism and normal development. These results are discussed in the light of the superior ability of individuals with autism to discriminate between items. More specifically, it is argued that superior discrimination in autism does not result from enhanced top-down excitatory and inhibitory control.     

Processing of distractors inside and outside the attentional focus in a priming procedure

A priming procedure was used to study the processing of distractors located either inside (between the location of two targets) or outside (peripherally to the locations of the targets) the focus of attention. The stimuli were five-letter arrays, and participants had to decide whether two marked target letters were the same or different. In Experiments 1 and 2, positive priming was obtained both when targets and in-distractors in primes repeated as targets in probes; negative priming was found when out-distractor primes repeated as targets in probes. In Experiment 3, we also manipulated the match in letter case from primes to probes. In-distractors produced reliable positive priming, irrespective of whether the letters matched in case. In contrast out-distractors produced negative priming but only when the letters had the same case in primes and probes. These results are attributed to a spatial attention process operating (in this case) on low-level visual features, and an object-based selection process that enables more abstract information to be processed for selected stimuli.     

Affective Priming Effects in the Left and Right Cerebral Hemispheres in Patients With Alzheimer's Disease

Alzheimer’s disease (AD) patients and control subjects were tested in an affective priming paradigm associated with an affective discrimination task. Two pictures, one affectively positive or affectively negative and the other neutral, were presented simultaneously in the right and in the left visual fields; the participants had to decide which of the two pictures was the most affectively positive or negative. The target pictures were preceded by a prime picture that was either affectively positive, affectively negative, or neutral. The principal result was the observation, in AD patients as well as in control subjects, of negative affective priming effects for targets presented in the right hemisphere, and of positive affective priming effects for targets presented in the left hemisphere. The presence of affective priming effects suggests that AD patients have no particular deficit in the automatic activation of emotional information; the fact that priming effects were also observed for targets presented in the left hemisphere showed that AD patients probably have no left hemisphere deficit in the automatic activation of emotional information. However, in AD patients, affective priming effects were significant with negative targets but not with positive targets, which could suggest that AD patients processed positive targets in a more semantic way than negative targets.     

客体表征质量在语义客体注意效应中的作用

已有研究表明,除自下而上因素外,自上而下因素也能够对客体知觉起到调节作用,从而影响注意的分配。本研究以不同词频（高频和低频）的汉语双字词为实验材料,采用双矩形线索范式变式考察不同语义客体表征质量对基于语义客体注意效应的影响。结果发现,在高语义客体表征质量的条件下出现了基于语义客体的注意效应,而在低语义客体表征质量的条件下并未出现基于语义客体的注意效应。该结果表明,语义客体表征质量的高低是影响基于语义客体注意效应的重要因素。     

Facilitating and inhibiting effects of priming and selection criteria in a sequence of dichotic listening trials

Competing models of attention make different predictions of how priming from recent stimulus processing could interact with intended selection. The present experiment examined the interaction between exogenous attention and endogenous priming across trial sequences. A sound cue directed attention to left, right or both sides before a dichotic syllable pair was presented. Participants were asked to report one syllable from each trial. Results showed that responses were slower on trials where one of the presented syllables had also been presented on the previous trial. Within these trials, the repeated syllable was selected less frequently, and the responses doing so were slower. Examined according to response choice on the preceding trial, syllables that had been ignored on the preceding trial tended to be ignored on the current trial (negative priming), while syllables that had been selected on the preceding trial tended to be selected on the current trial (positive priming). Responses that followed these selection biases were faster than responses that did not. Response selection was also influenced by the attention direction cue for the current trial, but not by the cue presented on the preceding trial. The results support an attentional model where traces from the preceding processing are retained, and current selection is biased to minimize cognitive conflict between recent and current processing. Negative priming appears to be due to after-effects of preceding processing, independently of the intentions behind that processing. The study accounts for positive and negative priming of dichotic listening sequences within an established, computationally viable biased competition framework.     

选择性注意加工机制上学困生和学优生的比较研究

本实验使用正、负启动技术 ,在严格控制各种条件下比较学困生和学优生在选择性注意加工机制———目标激活和分心物抑制方面的差异 ,进而探讨学困生在选择性注意加工机制上所存在的问题。结果显示 ,学困生和学优生的正启动量差异不显著 (p >0 .0 5 ) ,但学困生的负启动量显著小于学优生 (p <0 .0 0 1。这一结果说明 ,学困生在对目标反应期间易受分心物干扰 ,其抑制分心物干扰的能力较弱。同时启示我们应注重训练学困生抑制分心物干扰的能力     

The effect of memory load on negative priming: An individual differences investigation

The effect of a verbal (Experiment 1) and a nonverbal (Experiment 2) memory load on negative priming was investigated by employing a concurrent memory task with a letter naming task. Across both experiments, negative priming was reliable only under conditions of zero memory load, suggesting that the processes that contribute to negative priming are resource demanding and dependent on a domain-free resource pool. Individual differences in negative priming were observed, such that high working memory capacity subjects showed reliable negative priming whereas low working memory capacity subjects did not. The results suggest that the negative priming effect results from allocation of controlled attention and that individual differences in working memory capacity correspond to the ability to efficiently handle irrelevant information.     

选择性注意中的客体与空间因素

注意选择理论可以分为空间选择和客体选择两大模型,文章首先介绍了这两类模型的观点,概述了客体选择和空间因素的关系与区别,也介绍了包括距离操纵和线索启动在内的客体选择和空间选择分离技术及其理论逻辑。     

The immediate effects of positive and negative feedback signals

Reaction time priming techniques were used in 4 experiments to assess the effects of feedback signals on arousal, response, and attentional processes. The letter A, C, or F served as a priming signal presented 100 ms before a target letter. Emotional value was manipulated by using A, C, and F to reflect good, average, and poor performance on the previous trial. The positive (A), neutral (C), and negative (F) primes did not differ in their effects on arousal. At the response level, positive and neutral primes exerted similar effects, and negative primes led to response inhibition. Regarding attention, positive and negative primes attracted greater attention than neutral primes, with the effect stronger for positive than for negative primes. These effects disappeared when the emotional value of the stimuli was removed, and the effects were not a consequence of expectancies or performance factors extending across trials.     

Surface segmentation cues influence negative priming for novel and familiar shapes

In a series of experiments, a negative priming paradigm was used to determine how the visual system represents novel shapes under conditions of inattention. Observers in a shape-matching task viewed overlapping shapes with or without surface segmentation cues. Positive priming occurred with opaque and transparent surface-like shapes, whereas negative priming was found with outlined and transparent shapes that lacked surface segmentation cues. This effect generalized to familiar shapes. These results support the importance of segmentation cues in negative priming and suggest that, under otherwise identical conditions, surface segmentation processes can determine whether positive or negative priming occurs in an implicit memory task. Thus, selective attention for overlapping shapes may be best understood in relation to surface segmentation processes.     

Pre-cuing Target Location Reduces Interference but Not Negative Priming from Visual Distractors

Research on visual selective attention has shown that processing of distractors can produce (1) interference with response to a concurrent target, and (2) negative priming of response to a subsequent target. These results support late-selection accounts of attention. However, recent findings demonstrate that when conditions are optimal for attentional focusing, the interference effects are almost entirely eliminated. This result has been interpreted as supporting early-selection accounts. The present study investigates the impact of focusing attention on negative priming in addition to interference effects. In a letter-identification task, reliable interference and negative priming effects were observed from distractors. However, when the location of the target in the prime display was pre-cued, interference effects were significantly reduced, but negative priming effects did not decrease. This pattern of results provides further evidence that the absence of interference is insufficient to determine whether distractors have been semantically processed (Driver & Tipper, 1989).     

对选择注意中负启动效应的研究

以数字命名作业为任务对选择注意中的负启动效应作了探讨,发现在强调反应正确性时,有负启动效应产生;若强调反应速度,则表现出正启动效应。干扰项的活动状态是启动效应性质的决定因素。研究结果还验证了扩散抑制及其扇形效应的构想,并支持注意后期选择理论。     

To the influence of general slowing and medication on identity‐ and location‐based priming effects in patients with Parkinson's disease

Previous studies on inhibitory mechanisms assessed by negative priming (NP) paradigms in patients suffering from Parkinson's disease (PD) have yielded highly ambiguous results. The present study examined two possible reasons for this heterogeneity: general slowing and anti‐Parkinsonian medication. Their effects on identity and location NP and positive priming (PP) were investigated. Twenty medicated PD patients and 20 PD patients after drug withdrawal were compared to 20 sex‐ and age‐matched healthy controls. The influence of PD patients' general slowing on priming effects was statistically controlled. Location NP was found not to be affected by PD, whereas identity NP was reduced in medicated PD patients compared to non‐medicated PD patients and healthy controls. At first, identity and location PP appeared to be enhanced in both PD groups. After controlling for general slowing, however, differences between PD patients and healthy controls disappeared. These findings endorse the notion that uncontrolled effects of both, PD‐related general slowing and anti‐Parkinsonian medication may have contributed to previously conflicting results on priming effects in PD patients.     

Selective attention versus selection for action: negative priming is not the result of distractors being unattended

Using a novel referent size-selection task, MacDonald, Joordens, and Seergobin (1999; MacDonald & Joordens, 2000) found that negative priming persisted even when participants were encouraged to attend to distractors before selectively responding to targets. This finding suggested that negative priming is not caused by processes that operate on stimuli that are to be ignored in the traditional selective attention sense. Mackintosh, Mathews, and Holden's (2002) attempt to replicate the MacDonald et al. study resulted in the discovery of possible artifacts in the referent size-selection task, thereby making the implications with respect to the role of attention less clear. In the present study, we describe a different method for directing attention to distractors in a negative priming context, one that does not suffer from the same potential artifacts as the referent size-selection task. Our results are consistent with those found by MacDonald et al., in that negative priming persisted even when participants were explicitly encouraged to attend to distractors. Implications are discussed in the context of the related concepts of selective attention (e.g., Broadbent, 1965) versus selection for action (e.g., Allport, 1987).     

基于空间与基于物体的视觉选择的交互作用

已有的大量实验证据表明,基于空间和基于物体的注意成分都存在于视觉系统中,两者并不是相互排斥的。然而,过去对基于空间和基于物体的视觉选择的研究是分别在非常不同的实验范式下进行的,从而导致对两种注意成分之间的内在关系的理论争论。本文介绍近十年来在单任务范式下对基于空间和基于物体的注意的内在关系的研究,并指出未来的研究应该重点从神经生理水平上揭示两种注意成分之间的交互作用关系。     

不同注意对视觉工作记忆外部特征绑定的影响

采用变化觉察范式,在工作记忆保持阶段插入客体特征辨别或视觉搜索次任务,探讨基于客体的注意和基于空间的注意对视觉工作记忆外部特征绑定表征的影响。结果发现,与单特征相比,两类次任务均对外部特征绑定的记忆成绩损耗更大。这表明视觉工作记忆中外部特征绑定的表征比单特征消耗更多基于客体的注意和更多基于空间的注意。     

Attention level and negative priming in hierarchical patterns1

Abstract: This study explored object processing associated with attention level dependent on task, using a paradigm of negative priming. Participants were required to identify target characters that appeared at either the global or local level in hierarchically structured patterns. Two experiments were conducted to examine how the global and local characters were processed in the attended and unattended levels. In the results of Experiment 1, where stimuli were presented for 10 ms, negative priming was observed in a local‐directed task, but not in a global‐directed one. These results suggested that the inhibition of local characters in the unattended level did not occur during global attention. The results of Experiment 2 revealed that negative priming was observed in both global‐ and local‐directed tasks in the 500 ms presentation, showing that inhibition in the unattended level occurred. As a result, the exposure duration influences inhibition in the unattended, especially the local level. At short exposure duration, the local characters are not inhibited when one directs attention to the global characters, whereas these are inhibited at long exposure duration.     

启动刺激含有多个靶子条件下的负启动效应

采用数字命名任务,在通常的负启动范式基础上增加启动刺激靶子数目．进行了两个实验。实验一发现,当启动刺激靶子个数为1个和2个时。出现负启动效应;当启动刺激靶子个数为3个和4个时。则不出现负启动效应。这提示靶子所获注意资源数量的作用。实验二发现．当启动刺激有2个和3个靶子时．如果未被选择来反应的靶子成为探测刺激的靶子,其反应时与控制组无显著差异。即不出现负启动。这表明在启动刺激中未被选择来反应的靶子与干扰项所受到的加工是有差别的。     

Object-based selection under focused attention: a failure to replicate

In a recent study, Lavie and Driver (1996) reported that object-based effects found with distributed attention disappear when attention is focused on a narrow area of the display. This finding stands in contrast with previous reports of object-based effects under conditions of focused attention (e.g., Atchley & Kramer, 1998; Egly, Driver, & Rafal, 1994). The present study was an attempt to replicate Lavie and Driver's finding, using similar task and stimuli. While Lavie and Driver's object-based effect in the distributed attention condition was replicated, its absence in the focused attention condition was not. In the two experiments reported in this paper, object-based effects were found under conditions of both distributed and focused attention, with no difference in the magnitude of the object-based effects in the two conditions. It is concluded that, in contrast with Lavie and Driver's claim, the initial spatial setting of attention does not influence object-based constraints on the distribution of attention.     

Single‐prime negative priming in the shape‐matching task: Implications for the role of perceptual segmentation processes

Using the shape‐matching task developed by DeSchepper and Triesman (1996), Loula, Kourtzi, and Shiffrar (2000) demonstrated that negative priming only occurred in that task when minimal segmentation cues were available in the prime display. Loula et al. (2000) interpreted their results as revealing that negative priming in the shape‐matching task is directly caused by difficulty in segmenting the prime target from the prime distractor. We offer an alternative interpretation of their results, suggesting that a failure to observe negative priming when segmentation cues are present was incidental to the perceptual segmentation process. Instead, we provide evidence suggesting that an easier perceptual segmentation task contributes positive priming influences that makes a negative priming effect more difficult to observe. Once these positive priming influences are removed, we observed negative priming both when the perceptual segmentation task is trivial and when perceptual segmentation is not a component of the prime task at all.