Perceptual grouping and visual selective attention

The present study demonstrates that incongruent distractor letters at a constant distance from a target letter produce more response competition and negative priming when they share a target’s color than when they have a different color. Moreover, perceptual grouping by means of color, attenuated the effects of spatial proximity. For example, when all items were presented in the same color, near distractors produced more response competition and negative priming than far distractors (Experiment 3A). However, when near distractors were presented in a different color and far distractors were presented in the same color as the target, the response competition × distractor proximity interaction was eliminated and the proximity × negative priming interaction was reversed (Experiment 3B). A final experiment demonstrated that distractors appearing on the same object as a selected target produced comparable amounts of response competition and negative priming whether they were near or far from the target. This suggests that the inhibitory mechanisms of visual attention can be directed to perceptual groups/objects in the environment and not only to unsegmented regions of visual space.     

Negative priming and perceptual fluency: More than what meets the eye

In two priming experiments, we manipulated the perceptual quality of the target or the distractor on the prime trial; the stimuli were repeated or novel. Negative priming was found to be contingent on stimulus repetition, because it was obtained with repeated items but not with novel items. Prime trial perceptual degradation modulated negative priming for repeated items but had no effect on priming in ignored repetition conditions using novel stimuli. These patterns were obtained even when the effect of perceptual degradation was (1) greater than the effect of stimulus repetition and (2) greater for novel words than for repeated words. Although stimulus repetition increases perceptual fluency, the activation of perceptual representations by itself is not sufficient to produce negative priming. Instead, we suggest that negative priming is a manifestation of an activation-sensitive inhibitory mechanism that functions to reduce response competition.     

Negative priming and perceptual fluency: more than what meets the eye

In two priming experiments, we manipulated the perceptual quality of the target or the distractor on the prime trial; the stimuli were repeated or novel. Negative priming was found to be contingent on stimulus repetition, because it was obtained with repeated items but not with novel items. Prime trial perceptual degradation modulated negative priming for repeated items but had no effect on priming in ignored repetition conditions using novel stimuli. These patterns were obtained even when the effect of perceptual degradation was (1) greater than the effect of stimulus repetition and (2) greater for novel words than for repeated words. Although stimulus repetition increases perceptual fluency, the activation of perceptual representations by itself is not sufficient to produce negative priming. Instead, we suggest that negative priming is a manifestation of an activation-sensitive inhibitory mechanism that functions to reduce response competition.     

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).     

Probe distractors can influence negative priming by perceptual grouping

Negative priming occurs when a response is slower to a target that was a previously ignored stimulus. According to a computational model of inhibition, negative priming results from relative activation between a target and a distractor in probe trials. Thus, the degree of competition in the probe trial should influence negative priming. The results from three experiments supported this hypothesis. Probe distractors grouped with a target by a rectangle produced a larger negative priming effect than did distractors isolated from the target. Moreover, neither prime-probe similarity nor perceptual interference could explain the grouping effect. The results suggest that perceptual mechanisms can influence negative priming via a race in the probe trial.     

Posthypnotic amnesia for recently learned material: Interactions with “episodic” and “semantic” memory

In two experiments, posthypnotic amnesia was suggested for a word list memorized during hypnosis. After an initial test of amnesia the subjects gave word associations (Experiment 1) or category instances (Experiment 2) to stimuli intended to elicit the critical (word list) items covered by the amnesia. The extent of initial amnesia observed was strongly associated with measured hypnotic susceptibility. Even among the most hypnotizable subjects, however, the dense amnesia did not prevent the critical items from being elicited by the semantic memory tasks, nor did it modulate the priming which these associations received by virtue of the prior learning experience. Moreover, production of the critical items did not, in general, remind the amnesic subjects of those items which they had previously learned, but could not now remember. Full memory was restored after the amnesia suggestion was canceled by a prearranged cue. Posthypnotic amnesia appears to represent a temporary dissociation of episodic features from memory traces, so that the subject has difficulty in reconstructing the context in which the target events occurred.     

Negative stimulus-response compatibility observed with a briefly displayed image of a hand

Manual responses can be primed by viewing an image of a hand. The left-right identity of the viewed hand reflexively facilitates responses of the hand that corresponds to the identity. Previous research also suggests that when the response activation is triggered by an arrow, which is backward-masked and presented briefly, the activation manifests itself in the negative priming effect. The present study showed that response activation, which is produced by an identity of a briefly presented image of a hand, can be similarly associated with a negative priming effect. However, in contrast to the previously reported negative priming effects, the hand stimuli produced negative priming even when the hand was not backward-masked and did not contain task-relevant information. The study supports the view that the automatic inhibition of motor activation triggered by briefly viewed objects is a general and basic functional principle in exogenous motor control processes.     

Negative stimulus–response compatibility observed with a briefly displayed image of a hand

Manual responses can be primed by viewing an image of a hand. The left–right identity of the viewed hand reflexively facilitates responses of the hand that corresponds to the identity. Previous research also suggests that when the response activation is triggered by an arrow, which is backward-masked and presented briefly, the activation manifests itself in the negative priming effect. The present study showed that response activation, which is produced by an identity of a briefly presented image of a hand, can be similarly associated with a negative priming effect. However, in contrast to the previously reported negative priming effects, the hand stimuli produced negative priming even when the hand was not backward-masked and did not contain task-relevant information. The study supports the view that the automatic inhibition of motor activation triggered by briefly viewed objects is a general and basic functional principle in exogenous motor control processes.     

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.     

The role of extralist associations in false

The finding that new items are judged as remembered in the remember-know paradigm presents a challenge to traditional process and systems accounts of memory. In three experiments, we demonstrated that false remember responses can be caused by misattributing recollection to a context other than the study list. In Experiments 1 and 2, false remember responses to distractors that were unrelated to studied words increased if they were encountered in a “preexposure” phase a few minutes or even a few days prior to the studied list. A third experiment demonstrated that remember responses to preexposed distractors increased when they were encoded in a manner similar to studied items, despite the more similar items being of weaker overall memory strength. We propose a source misattribution account of false remembering to explain these data, suggesting that all remember judgments reflect conscious recollection of contextual details, but false remember judgments are partly the result of recollection of details from an extralist context (i.e., from a source other than the study list).     

Bigger than a breadbox? Attention to distractors may not enhance negative priming

In several recent studies, P. A. MacDonald and colleagues (e.g., P. A. MacDonald & S. Joordens, 2000) reported unusually large negative priming effects and claimed that attention to distractors, counter to expectations, served to enhance the magnitude of the effect. In 3 experiments using their novel comparative judgment task, negative priming was assessed using both a control condition based on that of P. A. MacDonald, S. Joordens, and K. N. Seergobin (1999) and one in which control probe items exactly matched those on ignored repetition trials. In MacDonald et al.'s unmatched control condition, participants were faster than on ignored repetition trials, but this difference was reduced or absent when control items were matched. This result led to the conclusion that the apparently large negative priming effect reported by MacDonald and colleagues may be an artifact arising because judgments for a subset of their control trials were relatively easier than for ignored repetition trials.     

The effects of study-task relevance on perceptual repetition priming

Repetition priming is easily elicited in many traditional paradigms, and the possibility that perceptual priming may be other than an automatic consequence of perception has received little consideration. This issue is explored in two experiments. In Experiment 1, participants named the target from a four-item category search study task more quickly than the nontarget study items at a later naming test. Experiment 2 extended this finding to conditions in which stimuli were individually presented at study. In three different study tasks, stimuli relevant to study-task completion elicited priming on a later test, but stimuli presented outside the context of a task did not. In both experiments, recognition was above chance for nonrelevant stimuli, suggesting that participants explicitly remembered stimuli that did not elicit priming. Results suggest that priming is sensitive to study-task demands and may reflect a more adaptive and flexible mechanism for modification of perceptual processing than previously appreciated.     

归类任务中负启动效应与分心物特性抑制的实验研究

以汉语单字词为材料,采用负启动技术,在归类任务中考察了作为负启动效应根源的扩散抑制是否遵循资源有限机制以及在要求操作反应的情况下是否也能获得来自分心物特性抑制的负启动效应。结果表明：１．被试对曾在启动显示中作为分心物的探测目标的反应时随着启动显示中分心物数目的增加而缩短。因此,扩散抑制遵循资源有限机制;２．在操作反应要求下能获得非常显著的来自分心物特性抑制的负启动效应。     

Conceptual activation of distractors during selection is not sufficient to produce negative priming

Negative priming (NP) occurs when responses are slower because the targets were distractors on the preceding trial. Word-naming NP occurs only with words that have been presented repeatedly as targets; novel words do not show NP. The activation-inhibition explanation is that representations of repeated-word distractors are activated already and must be inhibited; the inhibition carries over to the next trial. If this explanation is correct, novel-word NP should occur if the word is semantically primed (thus activating its representation) before it occurs as a distractor. In two experiments, there was NP for words from a repeated set, and the magnitude of NP increased when the same word could occur as a target on consecutive trials. There was positive, rather than negative, priming for novel-word targets that had been semantically primed as distractors. Either the activation from semantic priming was not sufficiently strong to require inhibition, or the activation-inhibition hypothesis does not refer to activation of conceptual representations.     

rTMS stimulation on left DLPFC increases the correct recognition of memories for emotional target and distractor words

According to a recent hypothesis, the prefrontal cortex has been proposed as the site of emotional memory integration, because it is sensitive to the recognition of emotional contents. In the present research, we explored the role of the dorsolateral prefrontal cortex (DLPFC) in memory recognition processes for positive versus negative emotional stimuli when old (target) and new (distractor, either semantically related or unrelated to the target) stimuli were presented. The role of the DLPFC was analysed using an rTMS (repeated transcranial magnetic stimulation) paradigm that induced increased cortical activation of the left DLPFC. The subjects were required to perform a task that consisted of two experimental phases (i.e., an encoding and a recognition phase) in which the targets and the distractors were presented and recognition performance was measured. rTMS stimulation was provided over the left DLPFC during the recognition phase. We found that the rTMS stimulation affected the memory recognition of positive emotional material. Moreover, related and unrelated distractors were discarded better when they were positively valenced, and a more significant effect (i.e., increased performance) was produced in response to related distractors. This result suggests that the activation of the left DLPFC favours the memory recognition of positive emotional information, and that such activation is able to induce a more appropriate selective process to distinguish target from distractor stimuli in the presence of more complex processes (related distractors). The valence model of emotional cue processing may explain this increased performance by demonstrating the distinct role of the left hemisphere in the retrieval of positive emotional information.     

Repetition and laterality effects on recognition memory for words and pictures*

Recognition memory for a list of words was tested by presenting a series of items with Ss instructed to make positive responses to targets (list items) and negative responses to distractors (nonlist items). The test items were either words or pictures, and they were presented tachistoscopically either to the left or right visual field. The results showed mean response latencies to be generally faster for stimuli presented to the right visual field. Response times were faster for target and distractor stimuli on their second test presentations than on initial tests, but this effect was much larger for targets. Repetitions were shown to decrease the amount of time necessary to execute the stimulus encoding and initial retrieval stages of recognition. This was also true, although to a lesser extent, if different stimulus forms (words or pictures) were used on the two tests. Subsequent recognition stages, including memory search and decision processes. were apparently independent of test stimulus form.     

Semantic priming in the prime task effect: Evidence of automatic semantic processing of distractors

The automaticity of the semantic processing of words has been questioned because of the reduction of semantic priming when the prime word is processed nonsemantically--for example, in letter search (the prime task effect). In two experiments, prime distractor words produced semantic priming in a subsequent lexical decision task, but with the direction of priming (positive or negative) depending on the prime task. Lexico-semantic tasks produced negative semantic priming, whereas letter search produced positive semantic priming. These results are discussed in terms of task-based inhibition. We argue that, given the results from the distractors, the absence of semantic priming does not indicate an absence of semantic activation but reflects the action of control processes on prepotent responses when less practiced responses are needed.     

Semantic and repetition priming effects for Deese/Roediger—McDermott (DRM) critical items and associates produced by DRM and unrelated study lists

Two lexical decision experiments investigated priming for a critical item (CI, sleep) and its related yoked associate (YA, blanket) when one had been studied in a related Deese/Roediger-McDermott (DRM) list (Experiments 1 & 2) or a list of totally unrelated words (Experiment 2) and the other had been nonstudied. Semantic priming from the related DRM list occurred for nonstudied CIs (but not YAs) regardless of whether the CI received within-test priming from its studied related YA during the lexical decision task, though the effect in the absence of within-test priming averaged across experiments was only significant by a one-tailed test. Also averaged across experiments, repetition priming occurred for both studied CIs and YAs when they had been studied in related DRM lists whether or not there was also within-test priming from a nonstudied related yoked pairmate, though individual effects within the two experiments were sometimes not significant. Repetition priming boosted semantic priming from related DRM lists less for CIs than for YAs, similar to the finding that memory discriminability is poorer for CIs than for YAs in episodic recognition. This smaller repetition priming boost for CIs than for YAs occurred to the same degree when the CIs or YAs were studied in an unrelated list. When nonstudied CIs and YAs were totally unrelated to all previously studied items and separated by 3-7 items in the lexical decision task, aYA produced a small 16 msec priming effect for its CI, averaged across both experiments. The implications of these results for the activation account of the DRM false-memory effect and for single-prime versus multiple-prime long-term semantic priming effects are discussed. The online addendum may be downloaded from www.psychonomic.org/archive.     

Intertrial priming due to distractor repetition is eliminated in homogeneous contexts

Targets are found more easily in a visual search task when their feature is repeatedly presented, an effect known as intertrial priming. Recent findings suggest that priming of distractors can also improve search performance by facilitated suppression of repeated distractor features. The efficacy of intertrial priming for targets can be potentiated by the expectancy of a specific target feature; systematic repetition shows larger intertrial priming than random repetition. For distractors, the underlying mechanism is less clear. We used the systematic lateralization approach to disentangle target- and distractor-related processing with subcomponents of the N2pc. We found no modulation of the N_T component, which reflects prioritization of target processing. The N_D component, which reflects attentional capture by irrelevant stimuli, however, showed intertrial priming: N_D monotonically decreased with repetition of a distractor color, but only if a specific distractor feature was expected, and if the context induced a search that was vulnerable to attentional capture. These observations suggest that distractor priming only improves visual search if volitional control is relatively high. The results also suggest that intertrial priming for distractors is due to decreased attentional capture by repeatedly presented distractors, whereas target processing remains unaffected.     

Retrieval independence between parts and wholes in successive recognition tasks

Participants studied AB word pairs and completed three recognition tests. In one recognition test each A word was presented with two distractors that did not appear on the study list. In another recognition test each B word was presented with two distractors that did not appear on the study list. In a third recognition test an AB target was presented with two distractors composed of words not on the study list. Six different groups of participants each performed the recognition tests in a different order, so that all possible orders were tested. Recognition of the A, B, and AB targets for a given study pair were independent of each other when single-word recognition preceded double-word recognition. There was almost complete independence in the reverse order. Even when recognition judgements were restricted to those for which the participants were most confident, there was independence of recognition among the three tests. A pair recognition test served as an additional study trial for the individual words; however, the reverse was not the case. All of these results were predicted by a single three-parameter mathematical model derived from the hypothesis that single-word and double-word targets had independent representations in memory.