Top-down attentional control for distractor locations: The benefit of precuing distractor locations on target localization and discrimination.

This study investigated the active inhibition of precued distractor locations. In this study, the distractor location was precued by an arrow. Experiment 1 indicated that a valid precue could facilitate target localization. Experiment 2 demonstrated that when conflict trials were included, the distractor precue benefit was eliminated. Experiment 3 further showed that active inhibition required time to operate. The distractor precue benefit was observed only when the stimulus onset asynchrony between the precue and the target and distractor display was long. Experiment 4 illustrated that the benefit was not contingent on precuing the distractor response. Experiment 5 indicated that the benefit of distractor precuing was not due to the activation of target locations, and Experiment 6 showed that this benefit was due to attentional inhibition. Finally, Experiment 7 demonstrated that active inhibition of spatial location required an attentional resource to operate. These results indicated how a top-down mechanism exerted control on distractor locations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distractor devaluation effect in the attentional blink: Direct evidence for distractor inhibition.

When two targets (T1 and T2) are embedded in rapid serial visual presentation (RSVP), T2 is often missed (attentional blink, AB) if T2 follows T1 by less than 500 ms. Some have proposed that inhibition of a distractor following T1 contributes to the AB, but no direct evidence supports this proposal. This study examined distractor inhibition by assessing a distractor devaluation effect where inhibited items were evaluated less positively than controls. Experiments 1 and 2 showed that a distractor presented just after T1 was evaluated less favorably when T2 was misidentified, independently of stimulus characteristics. Experiment 3 produced distractor devaluation in T2 incorrect trials when the evaluated distractor was the second item after T1. In contrast, a distractor presented before T1 was not devaluated (Experiment 4). Experiment 5 demonstrated that participants could not recognize presented distractors after an RSVP task, rejecting the possibility that memorized distractors were devalued. Results show a relationship between the devaluation of distractors following T1 and the AB, providing the first direct evidence of the distractor inhibition during the AB. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why do non-color words interfere with color naming?

In the non-color-word Stroop task, university students' response latencies were longer for low-frequency than for higher frequency target words. Visual identity primes facilitated color naming in groups reading the prime silently or processing it semantically (Experiment 1) but did not when participants generated a rhyme of the prime (Experiment 3). With auditory identity primes, generating an associate or a rhyme of the prime produced interference (Experiments 2 and 3). Color-naming latencies were longer for nonwords than for words (Experiment 4). There was a small long-term repetition benefit in color naming for low-frequency words that had been presented in the lexical decision task (Experiment 5). Facilitation of word recognition speeds color naming except when phonological activation of the base word increases response competition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective attention and the suppression of cognitive noise.

The distractor-suppression effect is the relative slowing of Stroop (1935) color naming when the current appropriate response is identical to the inappropriate response activated by the distractor word appearing in the immediately preceding trial. Two experiments investigated aspects of the time course of distractor suppression. Experiment 1 found the suppression effect when subjects were instructed to maintain strict accuracy but not when subjects were encouraged to sacrifice some accuracy for greater speed. Experiment 2 traced the recovery from suppression by varying the interval between successive trials (20, 520, 1020, or 2020 ms). The suppression effect was found to persist for at least a second; by 2 s the effect was completely dissipated. The results support the view of selective inhibition as an active, time-dependent control process that develops over time following the activation of distracting information and that it is released after response to the task-appropriate information has been made. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dilution, not load, affects distractor processing.

Lavie and Tsal (1994) proposed that spare attentional capacity is allocated involuntarily to the processing of irrelevant stimuli, thereby enabling interference. Under this view, when task demands increase, spare capacity should decrease and distractor interference should decrease. In support, Lavie and Cox (1997) found that increasing perceptual load by increasing search set size decreased interference from an irrelevant distractor. In three experiments, we manipulated the cue set size (number of cued locations) independently of the display set size (number of letters presented). Increasing the display set size reduced distractor interference regardless of whether the additional letters were relevant to the task. In contrast, increasing the cue set size increased distractor interference. Both findings are inconsistent with the load explanation, but are consistent with a proposed two-stage dilution account. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Semantic interference in a delayed naming task: Evidence for the response exclusion hypothesis.

In 2 experiments participants named pictures of common objects with superimposed distractor words. In one naming condition, the pictures and words were presented simultaneously on every trial, and participants produced the target response immediately. In the other naming condition, the presentation of the picture preceded the presentation of the distractor by 1,000 ms, and participants delayed production of their naming response until distractor word presentation. Within each naming condition, the distractor words were either semantic category coordinates of the target pictures or unrelated. Orthogonal to this manipulation of semantic relatedness, the frequency of the pictures' names was manipulated. The authors observed semantic interference effects in both the immediate and delayed naming conditions but a frequency effect only in the immediate naming condition. These data indicate that semantic interference can be observed when target picture naming latencies do not reflect the bottleneck at the level of lexical selection. In the context of other findings from the picture-word interference paradigm, the authors interpret these data as supporting the view that the semantic interference effect arises at a postlexical level of processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processing segmental and prosodic information in Cantonese word production.

Five experiments were conducted to investigate how subsyllabic, syllabic, and prosodic information is processed in Cantonese monosyllabic word production. A picture-word interference task was used in which a target picture and a distractor word were presented simultaneously or sequentially. In the first 3 experiments with visually presented distractors, null effects on naming latencies were found when the distractor and the picture name shared the onset, the rhyme, the tone, or both the onset and tone. However, significant facilitation effects were obtained when the target and the distractor shared the rhyme + tone (Experiment 2), the segmental syllable (Experiment 3), or the syllable + tone (Experiment 3). Similar results were found in Experiments 4 and 5 with spoken rather than visual distractors. Moreover, a significant facilitation effect was observed in the rhyme-related condition in Experiment 5, and this effect was not affected by the degree of phonological overlap between the target and the distractor. These results are interpreted in an interactive model, which allows feedback sending from the subsyllabic to the lexical level during the phonological encoding stage in Cantonese word production. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of a moving distractor object on time-to-contact judgments.

The effects of moving task-irrelevant objects on time-to-contact (TTC) judgments were examined in 5 experiments. Observers viewed a directly approaching target in the presence of a distractor object moving in parallel with the target. In Experiments 1 to 4, observers decided whether the target would have collided with them earlier or later than a standard (absolute identification task). A contrast effect was observed: If the distractor arrived later than the target, it caused a bias toward early responses, relative to the condition without a distractor. The early-arriving distractor had no significant effect. The pattern of results was unaltered when potentially confounding information from individual visual cues was removed. The availability of stereoscopic information reduced the effect. The contrast effect was also observed if target and distractor were abstract geometric objects rather than simulations of real-world vehicles, rendering less likely a simple safety strategy activated by a potentially threatening distractor. Experiment 5 showed that the effect of the late-arriving distractor generalized to a prediction-motion task. The results indicate that task-irrelevant information in the background has to be considered in revision of time-to-contact theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The distractor frequency effect in picture–word interference: Evidence for response exclusion.

In 3 experiments, subjects named pictures with low- or high-frequency superimposed distractor words. In a 1st experiment, we replicated the finding that low-frequency words induce more interference in picture naming than high-frequency words (i.e., distractor frequency effect; Miozzo & Caramazza, 2003). According to the response exclusion hypothesis, this effect has its origin at a postlexical stage and is related to a response buffer. The account predicts that the distractor frequency effect should only be present when a response to the word enters the response buffer. This was tested by masking the distractor (Experiment 2) and by presenting it at various time points before stimulus onset (Experiment 3). Results supported the hypothesis by showing that the effect was only present when distractors were visible, and if they were presented in close proximity to the target picture. These results have implications for the models of lexical access and for the tasks that can be used to study this process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distractor modality can turn semantic interference into semantic facilitation in the picture–word interference task: Implications for theories of lexical access in speech production.

A number of recent studies have questioned the idea that lexical selection during speech production is a competitive process. One type of evidence against selection by competition is the observation that in the picture–word interference task semantically related distractors may facilitate the naming of a picture, whereas the selection by competition account predicts them to interfere. In the experiments reported in this article, the authors systematically varied, for a given type of semantic relation—that is, basic-level distractors (e.g., fish) during subordinate-level naming (e.g., carp)—the modality in which distractor words were presented (auditory vs. visual) and the proportion of response-congruent trials (i.e., trials allowing for the correct naming response to be derived from both the distractor and the target). With auditory distractors, semantic interference was obtained irrespective of the proportion of response-congruent trials (low in Experiment 1, high in Experiment 2). With visual distractors, no semantic effect was obtained with a low proportion of response-congruent trials (Experiment 3), whereas a semantic facilitation effect was obtained with a high proportion of response-congruent trials (Experiment 4). The authors propose that two processes contribute to semantic effects observed in the picture–word interference paradigm, namely selection by competition (leading to interference) and response congruency (leading to facilitation). Whether facilitation due to response congruency overrules the interference effect because of competition depends on the relative strength of these two processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrusive cognitions: An investigation of the emotional Stroop task.

The role of intrusive cognitions was investigated using the emotional Stroop effect, in which irrelevant threat-related words interfered more with color naming than neutral words. In Experiment 1, the emotional Stroop effect decreased over blocks, indicating habituation. In Experiment 2, the interference persisted when different words were used in each block, suggesting that the habituation occurred at the level of the individual stimulus. However, there was some evidence for a decline in interference, suggesting some category-based habituation. In Experiment 3, the interference continued for emotional words relative to neutral words even when the neutral stimuli formed a category. In Experiment 4, neutral words were contrasted with positive and negative words; interference occurred only for the negative words. This result undermines alternative interpretations in terms of emotionality or self-relevance and highlights the critical role of threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identity negative priming in older adults and individuals with dementia of the Alzheimer type.

This study addressed the question of whether dementia of the Alzheimer type (DAT) produces a breakdown in aspects of the inhibitory component underlying selective attention. Two measures of identity negative priming and 2 measures of distractor interference were obtained. In Experiment 1, participants were presented with overlapping picture stimuli, and in Experiment 2, participants were presented with overlapping written word stimuli. The results of both experiments produced reliable and similar size negative priming in young and old adults, but there was no evidence of negative priming in the individuals with DAT. In contrast, the naming latencies of all 3 groups showed a reliable and similar size distractor interference effect. These results suggest that although the inhibitory component underlying selective attention is impaired in individuals with DAT, the ability to differentiate a target from a distractor may be preserved under certain task conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When more is less: A counterintuitive effect of distractor frequency in the picture-word interference paradigm.

Pictures were shown with superimposed word distractors of high and low frequency. Low-frequency distractors produced greater interference on picture naming than did high-frequency distractors. This distractor frequency effect was not affected by manipulations that facilitated or hindered distractor recognition. Interference was reduced for distractors that were read aloud several times prior to being shown in the picture-naming task. Together these findings suggest that the distractor frequency effect has its locus at some stage of lexical access for production. Other findings further constrain hypotheses about which level of speech production is involved in the effect. The distractor frequency effect has implications for models of lexical processing in speaking as well as for accounts of picture-word interference and the frequency effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Capacity demands of phoneme selection in word production: New evidence from dual-task experiments.

Three dual-task experiments investigated the capacity demands of phoneme selection in picture naming. On each trial, participants named a target picture (Task 1) and carried out a tone discrimination task (Task 2). To vary the time required for phoneme selection, the authors combined the targets with phonologically related or unrelated distractor pictures (Experiment 1) or words, which were clearly visible (Experiment 2) or masked (Experiment 3). When pictures or masked words were presented, the tone discrimination and picture naming latencies were shorter in the related condition than in the unrelated condition, which indicates that phoneme selection requires central processing capacity. However, when the distractor words were clearly visible, the facilitatory effect was confined to the picture naming latencies. This pattern arose because the visible related distractor words facilitated phoneme selection but slowed down speech monitoring processes that had to be completed before the response to the tone could be selected. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Precuing target location in a variable set size "nonsearch" task: Dissociating search-based and interference-based explanations for set size effects.

If a target's location is validly cued before a variable set size display, then an effect of set size on detection would indicate distractor interference rather than search. Observers performed a 1-, 3-, or 5-item detection task (indicate the presence or absence of a realistic target in the context of conceptually consistent distractors) under conditions of valid or neutral spatial precuing. Results from Experiment 1, and a replication blocking cue condition (Experiment 2), indicated set size effects in the cued target-present, but not target-absent, data. Experiment 3 determined that this interference was not due to a semantic relationship between target and distractors, and Experiment 4 used a preview paradigm to argue against distractor onsets as a source of interference. Experiment 5 eliminated this interference-based set size effect by having observers preposition their eyes over the cued location in the detection scene. Findings provide evidence for a set size effect in the absence of search and suggest that distractors may systematically diminish a visual preparatory priming advantage normally benefiting target-present detection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinetics of AMPA-type glutamate receptor channels in rat caudate-putamen neurones show a wide range of desensitization but distinct recovery characteristics

In 5 experiments the authors examine the role of object-based grouping on negative priming. The experiments used a letter-matching task with multiple letters presented in temporally separated prime and probe displays. On mismatch trials, distractor letters in primes were repeated as targets in probes, or distractor and target letters were completely different. Negative priming was shown by slowed responses when distractors were repeated as targets relative to when the stimuli differed. This occurred both when only letters were presented (Experiments 1 and 4) and when letters were surrounded by boxes (Experiment 5). Experiments 2, 3, and 4 showed that negative priming was affected by the grouping of target and distractor letters in prime displays. Negative priming was reduced when 1 of the distractor letters was placed in the target box and 1 was left outside the box; facilitatory priming was observed when both distractor letters appeared in the target box. The data were accounted for in terms of there being (a) object-based competition for visual selection, (b) inhibition of distractor objects that compete for selection with target objects, and (c) activation or inhibition of the identities of all component elements within target or distractor objects.     

The effect of perceptual load on attention-induced motion blindness: The efficiency of selective inhibition.

Recent visual marking studies have shown that the carry-over of distractor inhibition can impair the ability of singletons to capture attention if the singleton and distractors share features. The current study extends this finding to first-order motion targets and distractors, clearly separated in time by a visual cue (the letter X). Target motion discrimination was significantly impaired, a result attributed to the carry-over of distractor inhibition. Increasing the difficulty of cue detection increased the motion target impairment, as distractor inhibition is thought to increase under demanding (high load) conditions in order to maximize selection efficiency. The apparent conflict with studies reporting reduced distractor inhibition under high load conditions was resolved by distinguishing between the effects of "cognitive" and "perceptual" load. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Semantic interference, orthographic facilitation, and their interaction in naming tasks.

The relative merits of 3 views on the cause of the Stroop-like semantic interference effect in naming tasks were investigated in 2 experiments. In the 1st experiment, which consisted of a picture-word interference task, the authors found the usual Stroop-like semantic interference effect for distractor words that were not orthographically related to the picture's name. However, the semantic interference effect was significantly reduced when the distractor words were orthographically related to the picture's name. The results were replicated in the 2nd experiment by using a different paradigm in which, instead of pictures, definitions were used as target stimuli. The results are interpreted as favoring one of the views: a word-form retrieval account of the semantic interference effect in naming tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heightened conflict in cue-target translation increases backward inhibition in set switching.

Backward inhibition (BI) is a performance cost that occurs when an individual returns to a task after 1 (vs. more than 1) intervening trial, and it may reflect the inhibition of task-set components during switching. In 3 experiments, we support the theory that inhibition can target cue-based preparatory stages of a task. Participants performed a cued target-localization task that had been previously shown to produce BI. In Experiment 1, reassignment of arbitrary cue-target pairings midway through the experiment doubled the size of BI, though cue, target, and response sets remained unchanged. In Experiment 2, we controlled for effects of order of conditions or simple change of cue meaning. In Experiment 3, we demonstrated that the effect depends on re-pairing members of the same cue and target sets. The results are attributed to heightened conflict (and hence greater inhibition) during cue-target translation when a previously learned cue-target mapping is remapped. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object-based perceptual grouping affects negative priming.

In 5 experiments the authors examine the role of object-based grouping on negative priming. The experiments used a letter-matching task with multiple letters presented in temporally separated prime and probe displays. On mismatch trials, distractor letters in primes were repeated as targets in probes, or distractor and target letters were completely different. Negative priming was shown by slowed responses when distractors were repeated as targets relative to when the stimuli differed. This occurred both when only letters were presented (Experiments 1 and 4) and when letters were surrounded by boxes (Experiment 5). Experiments 2, 3, and 4 showed that negative priming was affected by the grouping of target and distractor letters in prime displays. Negative priming was reduced when 1 of the distractor letters was placed in the target box and 1 was left outside the box; facilitatory priming was observed when both distractor letters appeared in the target box. The data were accounted for in terms of there being (a) object-based competition for visual selection, (b) inhibition of distractor objects that compete for selection with target objects, and (c) activation or inhibition of the identities of all component elements within target or distractor objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)