Active inhibition of a distractor word: The distractor precue benefit in the Stroop color-naming task.

The current study investigated attentional control through active inhibition of the identity of the distractor. Adapting a Stroop paradigm, the distractor word was presented in advance and made to disappear, followed by the presentation of a Stroop stimulus. Participants were instructed to inhibit the distractor in order to reduce its interference. Experiments 1 and 2 demonstrated that the distractor precue facilitated Stroop color naming by reducing Stroop interference. Experiment 3 demonstrated beneficial effects of the distractor precue when congruent trials were introduced. Experiment 4 showed that the distractor precue benefit was observed when the cue and target were in different forms. Experiment 5 indicated that if the item used as the cue became the target, naming it took longer in order to overcome the inhibitory effect. Experiment 6 demonstrated that the benefit of the distractor precue was not observed when the cue was uninformative. Finally, Experiment 7 demonstrated that active inhibition required working-memory resources to operate. This study suggests that the best explanation for the distractor precue benefit is the active inhibition account. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Constraints on the selection of auditory information.

Four experiments were conducted to determine whether or not (a) selection of auditory information may be guided separately by location and frequency channels and (b) auditory attention is allocated to spatial locations and frequency regions or to auditory objects (i.e., streams). In Experiment 1, listeners were to categorize tones by location or frequency. In Experiments 2A and 2B, target identification was examined as a function of its similarity to a precue. In Experiment 3, the time required to detect a target embedded within a sequence of distractor tones was examined. In all experiments, performance depended on both location and frequency information even if 1 of these features was completely irrelevant with respect to the task. Results indicate that selection of auditory information is accomplished by an attentional template normally defined by both location and frequency parameters. (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)     

The adaptive character of the attentional system: Statistical sensitivity in a target localization task.

A localization task required participants to indicate which of 4 locations contained a briefly displayed target. Most displays also contained a distractor that was not equally probable in these locations, affecting performance dramatically. Responses were faster when a display had no distractor and almost as fast when the distractor was in its frequent location. Conversely, responses were slower when targets appeared in frequent-distractor locations, even though targets were equally likely in each location. Negative-priming effects were reliably smaller when targets followed distractors in the frequent-distractor location compared to the rare-distractor location, challenging the episodic-retrieval account. Experiment 2 added a 5th location that rarely displayed distractors and never targets, yet responses slowed most when distractors appeared there. The results confirmed that the attentional system is sensitive to first- and higher-order statistical patterns and can make short- and long-term adjustments in preferences based on prior history of inspecting unsuccessful locations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The time to detect targets at inhibited and noninhibited locations: Preliminary evidence for attentional momentum.

Inhibition of return refers to the finding that response latencies are longer for targets appearing at previously attended (cued) locations than at novel (uncued) locations. The present research was designed to examine the pattern of detection latencies that occurred for targets appearing at various uncued locations. The first 2 experiments showed that responses were fastest when the target occurred at a location directly opposite the cue. Experiment 3 showed that latencies were related to the angle between the target and the direction in which attention was being oriented. Experiments 4 and 5 showed that manipulating the direction of attentional orientation affected inhibition of return. Overall, the results suggest that inhibition of return may be due to the difference between orienting attention to locations along the path of attention versus orienting attention to those off the path of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The attentional white bear phenomenon: The mandatory allocation of attention to expected distractor locations.

The authors devised a prestimulus-probe method to assess the allocation of attention as a function of participants' top-down expectancies concerning distractor and target locations. Participants performed the flanker task, and distractor locations remained fixed. On some trials, instead of the flanker display, either 2 simultaneous dots or a horizontal line appeared. The dot in the expected distractor location was perceived to occur before the dot in the expected empty location, and the line appeared to extend from the expected distractor location to the expected empty location, suggesting that attention is allocated to expected distractor locations prior to stimulus onset. The authors propose that a process-all mechanism guides attention to expected locations of all stimuli regardless of task demands and that this constitutes a major cause for failures of selective attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult Age Differences in the Implicit and Explicit Components of Top-Down Attentional Guidance During Visual Search.

Two experiments investigated adult age differences in the explicit (knowledge-based) and implicit (repetition priming) components of top-down attentional guidance during discrimination of a target singleton. Experiment 1 demonstrated an additional contribution of explicit top-down attention, relative to the implicit effect of repetition priming, which was similar in magnitude for younger and older adults. Experiment 2 examined repetition priming of target activation and distractor inhibition independently. The additional contribution of explicit top-down attention, relative to the repetition priming of distractor inhibition, was greater for older adults than for younger adults. The results suggest that some forms of top-down attentional control are preserved as a function of adult age and may operate in a compensatory manner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some experimental evidence for and against a parametric conception of movement programming.

In Experiment 1, subjects were supplied with prior information about 1, 2 or all dimensions (the active hand, direction, and extent) of a pointing movement. RTs showed that dimensional effects were found in highly compatible stimulus-response conditions, dimensions specification times were underadditive, and the difference in RT between dimension values when that dimension remained to be specified, disappeared when the dimension was precued. In Experiment 2, subjects were required to name target color after a set of colored targets was presented as a precue, and dimensional effects disappeared. In Experiment 3, a target was presented as a prime, followed by presentation of either the same or a different target. As compared to Experiment 1, dimensional effects were amplified. In conclusion, when two or more movement dimensions have to be specified simultaneously, dimension values are independently selected, then integrated in a compound programming operation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Negative priming for spatial locations: Identity mismatching, not distractor inhibition.

Negative priming (NP) is commonly thought to occur because distractor inhibition is necessary for target selection (the distractor inhibition hypothesis). Contrary to this account, the selection of a target in the preceding trial is shown to be neither necessary (Exp 1) nor sufficient (Exps 2 and 3) for NP in a target localization task modeled after S. P. Tipper et al (see record 1991-00251-001). Exps 4 and 5 provide further evidence against the distractor inhibition hypothesis and support an alternative mismatching account: NP in the spatial selection task apparently results from a change in the symbol bound to a given location (D. Kahneman et al; see record 1992-37866-001), rather than a change in the status of that location from distractor to target (Tipper et al). (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)     

Attentional flexibility and aging: You don't need to be 20 years of age to split the beam.

Whether young and old adults were able to selectively attend to noncontiguous locations in the visual field and ignore physically interspersed distractor stimuli was examined. Participants decided whether 2 letters matched or mismatched. Target letter locations were precued by square boxes on an imaginary circle centered on fixation. Distractors were located between the 2 targets. Young and old were unable to ignore the distractors when the targets and distractors were presented as onset stimuli; however, both young and old were able to ignore the distractors when the target and distractors were presented as non-onset stimuli. The time course of attentional allocation was equivalent for young and old. Results are discussed in terms of models of visual selective attention and the flexibility of attentional control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of return along the path of attention.

Investigated inhibition of return (IOR) at 4 target locations (a near and a far location in each visual hemifield). Exp 1 was conducted to determine if IOR extends over a cued visual hemifield. 12 Ss indicated when they visually detected a cross after being instructed to keep their eyes fixed on a specific point. The target locations were aligned horizontally and IOR was observed at the near locations when cues were presented at the far locations but not at the far locations when cues were presented at the near locations. In Exp 2, the target locations were not horizontally aligned and IOR was not observed for near locations when the far locations were cued. Otherwise, the same procedure and apparatus as in Exp 1 were used by 12 different Ss. The authors conclude that IOR may be an attentional phenomenon and that attention may operate in an analog fashion such that locations in the path of the attentional movement may be attended to. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Span of apprehension in schizophrenic patients as a function of distractor masking and laterality.

Compared 20 schizophrenic patients, 10 depressed control patients, and 20 normal control Ss in a forced-choice, target-detection method for assessing the span of apprehension. The detection task required the S to report which of 2 target letters was presented among 7 other (distractor) letters. Performance accuracy was examined as a function of target location and whether the distractor letters were masked after their presentation. The backward masking of the distractors improved target-detection accuracy of both control groups but reduced accuracy of the schizophrenic group. In addition, schizophrenics performed particularly poorly on targets located in the left half or lower half of the display. Results suggest that response to the masking of distractors may be a new index of attentional shortcoming in schizophrenia. Various theoretical explanations for the target location findings are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When does visual attention select all features of a distractor?

What happens after visual attention is allocated to an object? Although many theories of attention assume that all of its features are selected and processed, there has been little direct evidence that an irrelevant feature dimension of an attended nontarget is processed. In 5 experiments presented here, the authors used a singleton paradigm to investigate the effect of attention on nontarget objects. Participants made a speeded feature discrimination of a target for which the response was either compatible or incompatible with an irrelevant feature dimension of a distractor. The results show that the irrelevant distractor features were processed to the point that they interfered with the response to the target. The response compatibility effect was observed even when the location of the target or the distractor was invariant, although it was much weaker when both locations were invariant. These results demonstrate that in many circumstances, an attended distractor is completely selected and fully processed, and the complete processing of distractors depends on a number of factors, many of which are related to the strength of attention to the distractor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention effects of moving and stationary single-element and multiple-element precues: limits of automaticity

A multiple-element precue (MEP), in which one unique element defines the actual precue, results in efficient precuing for identification of a target. The time course for identification in this case is similar to that for a central precue, even though it is presented peripherally (Chastain, 1996; Chastain & Cheal, in press). Five experiments were conducted to gain further information on the function of MEPs and to question what advantage prior knowledge of the precue may give. In Experiments 1 and 2, it was shown that for "pop-out" features, accuracy of identification of a target was higher if the precue type was known in advance. In contrast, as shown in Experiments 3, 4, and 5, when the precue was defined by apparent motion, there was no difference in accuracy due to advanced knowledge of the precue. Further, accuracy was considerably better for motion precues than for stationary precues.     

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)     

Attentional capture by irrelevant emotional distractor faces.

We establish attentional capture by emotional distractor faces presented as a “singleton” in a search task in which the emotion is entirely irrelevant. Participants searched for a male (or female) target face among female (or male) faces and indicated whether the target face was tilted to the left or right. The presence (vs. absence) of an irrelevant emotional singleton expression (fearful, angry, or happy) in one of the distractor faces slowed search reaction times compared to the singleton absent or singleton target conditions. Facilitation for emotional singleton targets was found for the happy expression but not for the fearful or angry expressions. These effects were found irrespective of face gender and the failure of a singleton neutral face to capture attention among emotional faces rules out a visual odd-one-out account for the emotional capture. The present study thus establishes irrelevant, emotional, attentional capture. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of inhibition of return on voluntary and visually guided saccades.

Four experiments examined the effects of exogenously and endogenously activated inhibition of return (IOR) on endogenously generated and visually guided saccades. In Exps 1–3, 37 Ss responded to a peripheral target by making either a prosaccade (toward the target) or an antisaccade (toward the field opposite the target). Results of Exps 1 and 3 suggest that when IOR is activated by a peripheral precue, it functions as a location tagging mechanism that inhibits detection of signals at the tagged location; thus, IOR cannot simply be a motor alternation bias. Exp 2 showed that IOR could be generated by the execution of an endogenous saccade. Unlike Exp 1, however, IOR was manifest only in the prosaccade task. Exp 4, in which 24 Ss made endogenous saccades in response to a central arrow target, provided some evidence that IOR can influence the latency of endogenously generated saccades to the precued location. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task-irrelevant angry faces capture attention in visual search while modulated by resources.

We investigated the attentional capture effect of emotional faces under sufficient or restricted attentional conditions. In a modified visual search paradigm, three kinds of schematic faces (angry, happy, and neutral) served as stimuli. Participants were instructed to search for a target face indicated by a dot and to respond to the dot's position. In this design, the emotional content of the face is task-irrelevant and does not need to be attended. The results of Experiment 1 demonstrate that having an angry face as the target face elicited a faster response than did the neutral target face, and when the angry face is used as a distractor, the response to the target was delayed compared to the response with no such distractor. Experiment 2 included inverted faces to decrease emotional content; results showed that inversion of the faces reduced the effect of angry faces on the search performance. When attention was cued to a specific area in Experiment 3, the effect of angry faces outside of the cued area became weaker. In conclusion, the results indicate that a task-irrelevant angry face can capture attention beyond top-down control, but this effect is modulated by the availability of attentional resources. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Selective attentional delays and attentional capture among simultaneous visual onset elements

Visual discrimination and detection responses to a single stimulus presented simultaneously with noise stimuli are slower and less accurate than are responses to a single stimulus presented alone. This occurs even though the location of the relevant stimulus (target) is known or visually indicated with stimuli onset. Results showed that noise elements delay focal attending and processing of a target. Furthermore, precuing the target location reduces, and can eliminate, target processing delays. Processing delays were not due to response competition or to random attentional capture by noise. It is suggested that simultaneous stimuli are perceived initially as a single object, and delays in processing a single stimulus are due to difficulties in perceptually segregating this stimulus from noise. Precuing is assumed to facilitate this segregation process.