Attention: Reaction Time and Accuracy Reveal Different Mechanisms.

The authors propose that there are 2 different mechanisms whereby spatial cues capture attention. The voluntary mechanism is the strategic allocation of perceptual resources to the location most likely to contain the target. The involuntary mechanism is a reflexive orienting response that occurs even when the spatial cue does not indicate the probable target location. Voluntary attention enhances the perceptual representation of the stimulus in the cued location relative to other locations. Hence, voluntary attention affects performance in experiments designed around both accuracy and reaction time. Involuntary attention affects a decision as to which location should be responded to. Because involuntary attention does not change the perceptual representation, it affects performance in reaction time experiments but not accuracy experiments. The authors obtained this pattern of results in 4 different versions of the spatial cuing paradigm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

d-amphetamine-induced enhancement of inhibitory mechanisms involved in visual search.

The authors examined the effects of d-amphetamine on the ability to perform a cued target-detection task that measured inhibition of return (IOR). IOR is a reflexive inhibitory mechanism that delays attention from returning to a previously attended location and has been shown to increase the efficiency of a visual search. Adults (N=14) with a history of cocaine use performed the task under 4 doses of d-amphetamine (0, 10, 20, and 30 mg). The results showed active d-amphetamine doses increased the duration of IOR. By increasing the delay in returning attention to a previously attended location, d-amphetamine might reduce time spent searching previously attended locations, increasing the efficiency of visual searches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of probe-trial selection on the location negative priming effect.

Using the location variant of the typical negative priming procedure, participants were cued (100% reliable) before (Experiment 1) or after (Experiment 2) the prime trial as to whether a distractor would or would not accompany the target on the probe trial. The crucial results were that on cued trials, the predictable absence of the probe-trial distractor, but not its cued presence, produced the removal of the negative priming effect (disengagement), and that this disengagement of the priming process, motivated by the predictable absence of a probe-trial distractor, could take place on-line. These findings demonstrated the "selection-state" dependency (probe trial) of the location negative priming process, supporting inhibition-based and episodic retrieval models in their contention that the ultimate function of this process is to enhance the efficiency of future distractor processing, and hence selection. The disengagement results revealed an adaptive feature of a process that can be detrimental or irrelevant to upcoming processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcohol-Induced Impairment of Inhibitory Mechanisms Involved in Visual Search.

The present study examined the effects of alcohol on the ability to perform a cued target detection task that measured inhibition of return (IOR). IOR is a reflexive inhibitory mechanism that delays attention from returning to a previously attended location and has been shown to increase the efficiency of a visual search. Ten social drinkers performed the task under 3 alcohol doses: 0.0 g/kg (placebo), 0.45 g/kg, and 0.65 g/kg. The results showed both active alcohol doses reduced the IOR effect by shortening its duration of influence. The reduced duration of IOR under alcohol suggests that repeated searches in previously explored locations might be more likely under the drug, thereby reducing search efficiency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the uniqueness of attentional capture by uninformative gaze cues: Facilitation interacts with the Simon effect and is rarely followed by IOR.

Orienting to an uninformative peripheral cue is characterized by a brief facilitation followed by a long-lasting inhibition once attention is removed from the cued location. Although central gaze cues cause reflexive orienting, the inhibitory effect that is relatively ubiquitous following exogenous orienting to uninformative peripheral cues has been relatively rare. We hypothesized that IOR might be seen following gaze-induced orienting if attention were effectively returned to centre by a return gaze or return flash. The timecourse of gaze-directed orienting was measured by varying the interval between the gaze cue and a peripheral target requiring an orientation discrimination (permitting measurement of the Simon effect). Significant facilitation was observed at all but the longest SOA tested, 2,880 ms, by which time the facilitation had disappeared with no evidence of IOR. Gaze-induced cuing (which was unaffected by return cue condition) interacted with the Simon effect, decreasing it at the gazed-at location, a pattern that is not seen with more typical endogenous and exogenous cuing. (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)     

Target location probability effects in visual search: An effect of sequential dependencies.

Target location probability was manipulated in a visual search task. When the target was twice as likely to appear on 1 side of the display as the other, manual button-press response times were faster (Experiment 1A) and first saccades were more frequently directed (Experiment 1B) to the more probable locations. When the target appeared with equal probability at each location in this search task, performance benefited from repetition of target location in the preceding trials (Experiment 2). When the trial sequence was constrained so that target location did not repeat within a series of 4 trials, there was no longer an advantage for more probable locations (Experiment 3). The authors conclude that the search benefits for more probable locations resulted from short-term target location repetitions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced facilitation of spatial attention in schizophrenia.

Objective: While attentional functions are usually found to be impaired in schizophrenia, a review of the literature on the orienting of spatial attention in schizophrenia suggested that voluntary attentional orienting in response to a valid cue might be paradoxically enhanced. We tested this hypothesis with orienting tasks involving the cued detection of a laterally presented target stimulus. Method: Subjects were chronic schizophrenia patients (SZ) and matched healthy control subjects (HC). In Experiment 1 (15 SZ, 16 HC), cues were endogenous (arrows) and could be valid (100% predictive) or neutral with respect to the subsequent target position. In Experiment 2 (16 SZ, 16 HC), subjects performed a standard orienting task with unpredictive exogenous cues (brightening of the target boxes). Results: In Experiment 1, SZ showed a larger attentional facilitation effect on reaction time than HC. In Experiment 2, no clear sign of enhanced attentional facilitation was found in SZ. Conclusions: The voluntary, facilitatory shifting of spatial attention may be relatively enhanced in individuals with schizophrenia in comparison to healthy individuals. This effect bears resemblance to other relative enhancements of information processing in schizophrenia such as saccade speed and semantic priming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional scene content drives the saccade generation system reflexively.

The authors assessed whether parafoveal perception of emotional content influences saccade programming. In Experiment 1, paired emotional and neutral scenes were presented to parafoveal vision. Participants performed voluntary saccades toward either of the scenes according to an imperative signal (color cue). Saccadic reaction times were faster when the cue pointed toward the emotional picture rather than toward the neutral picture. Experiment 2 replicated these findings with a reflexive saccade task, in which abrupt luminosity changes were used as exogenous saccade cues. In Experiment 3, participants performed vertical reflexive saccades that were orthogonal to the emotional–neutral picture locations. Saccade endpoints and trajectories deviated away from the visual field in which the emotional scenes were presented. Experiment 4 showed that computationally modeled visual saliency does not vary as a function of scene content and that inversion abolishes the rapid orienting toward the emotional scenes. Visual confounds cannot thus explain the results. The authors conclude that early saccade target selection and execution processes are automatically influenced by emotional picture content. This reveals processing of meaningful scene content prior to overt attention to the stimulus. (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)     

Visuospatial attention is guided by both the symbolic value and the spatial proximity of selected arrows.

There is considerable evidence that overlearned symbols, especially arrows, can orient attention to peripheral locations. In 2003, Pratt and Hommel showed that when 1 arrow is selected from a set of arrows, based on an attentional control setting for a specific target color, the selected arrow determines the orientation of attention. Recently, Leblanc and Jolicoeur (2010) reexamined this finding, and concluded that spatial proximity of the arrow to the target, not the symbolic value of the arrow, determines the orienting of attention. Here, we manipulated both the symbolic value of the cue (direction arrows or directionless circles) and the proximity of the cue to the peripheral target location (near or far), and found that although proximity does play a role in the orienting of attention (larger cuing effects were found with far cues than near cues), the symbolic content of the cue also plays an important role (larger cuing effects were found with arrows than circles). Thus, both the symbolic value and the spatial proximity of cues affect the orienting of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How do selected arrows guide visuospatial attention? Dissociating symbolic value and spatial proximity.

Previous research on the control of visuospatial attention showed that overlearned symbols like arrows have the potential to induce involuntary shifts of attention. Following work on the role of attentional control settings and of the content of working memory in the involuntary deployment of visuospatial attention, Pratt and Hommel (2003) found that this unintentional orienting by an arrow depended on its top-down selection, contingent on the attentional control settings, that is to say, the target selection cue. However, in this study, each arrow was closer to the location it indicated than to any other location, raising the issue of attention being drawn to the arrow location, facilitating processing at adjacent locations, rather than pushed to the symbolically cued location. In the present study, we dissociated symbolic cueing and spatial proximity cueing by the selected arrow. The results support the proximity cueing hypothesis. (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)     

A controlled-attention view of working-memory capacity.

In 2 experiments the authors examined whether individual differences in working-memory (WM) capacity are related to attentional control. Experiment 1 tested high- and low-WM-span (high-span and low-span) participants in a prosaccade task, in which a visual cue appeared in the same location as a subsequent to-be-identified target letter, and in an antisaccade task, in which a target appeared opposite the cued location. Span groups identified targets equally well in the prosaccade task, reflecting equivalence in automatic orienting. However, low-span participants were slower and less accurate than high-span participants in the antisaccade task, reflecting differences in attentional control. Experiment 2 measured eye movements across a long antisaccade session. Low-span participants made slower and more erroneous saccades than did high-span participants. In both experiments, low-span participants performed poorly when task switching from antisaccade to prosaccade blocks. The findings support a controlled-attention view of WM capacity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional momentum does not underlie the inhibition of return effect.

J. Pratt, T. M. Spalek, and F. Bradshaw (1999) recently proposed that attentional momentum is the mechanism underlying the inhibition of return (IOR) effect. They suggested that momentum associated with an attentional movement away from a peripherally cued location and toward an uncued opposite location is essential and fundamental to the finding of an IOR effect. Although it is clear from the present study and from a reanalysis of data from Pratt et al. that response time can be facilitated at an uncued opposite location, this putative effect of attentional momentum is neither robust nor reliable. First, it occurs for only a minority of participants. Second, it occurs in only a subset of the cued display positions. And finally, it is uncorrelated with the occurrence of IOR. Together the data indicate that the attentional momentum hypothesis is an overgeneralization and that it does not underlie the robust and reliable IOR effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new component of visual orienting: Implicit effects of peripheral information and subthreshold cues on covert attention.

Four experiments examined effects of peripheral cue stimuli on covert spatial attention. In Experiment 1 target stimuli were preceded by a pair of bilaterally presented cue letters. The relative location of the cues predicted target location (left or right), but participants were not informed of this. After a brief practice period, visual orienting was influenced by the letter cues. This implicit peripheral cuing effect was unrelated to participants' awareness of the cue-target relationship. Experiments 2 and 3 showed that visual orienting may occur independently of both perceptual awareness of the peripheral cue event itself and contingency awareness concerning the cue–target relation. Experiment 4 demonstrated that implicit peripheral cuing is qualitatively distinct from voluntary orienting. These findings are discussed in relation to work on spatial attention, implicit learning, and perception without awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic versus volitional orienting and the production of the inhibition-of-return effect.

A single, to-be-ignored peripheral flash (i.e., cue) reflexively attracts an orienting response (oculomotor/attention/head turn) that ultimately causes reaction time delays to target stimuli that later arise at this cued location, in relation to when the target appears at a new position (i.e., the inhibition-of-return [IOR] effect). The basic question posed here dealt with whether an IOR effect is also produced following volitional orienting. Results from paired cue-trial stimulations, one a distractor and one a target (nonsalient/salient) event, positioned more or less symmetrically on either side of fixation, supported the net vector model of IOR (R. Klein, J. Christie, & E. P. Morris, 2005). Automatic orienting did not yield an IOR effect at the stimulated positions. When the need to later report cue-trial target location was added, an IOR effect appeared at distractor-occupied, but not at target-occupied, locations. Seemingly, an IOR effect can follow volitional orienting. In this instance, the IOR process seems capable of undergoing modulation; however, such modulation was not evident following automatic orienting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial relevance determines facilitatory and inhibitory effects of auditory covert spatial orienting.

Eight experiments examined the conditions necessary for covert orienting and inhibition of return (IOR) to occur in audition. Spatially uninformative auditory cues facilitated responses to auditory targets at short stimulus onset asynchronies (SOAs) and inhibited them at longer SOAs when the decision to respond was based on the location of the target (Experiments 1, 3, and 4). The same cues did not influence performance when the decision to respond was based on nonspatial criteria (Experiments 2, 5, and 7) unless the cues predicted the location of the target (Experiment 6). In the absence of cues, the location of a previous target influenced performance when the decision to respond was based on spatial, but not nonspatial, criteria (Experiment 8). These findings demonstrate that covert orienting and IOR occur in audition only when spatial relevance is established, presumably inducing use of location-sensitive neurons in generating responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Covert orienting of visuospatial attention in children with developmental coordination disorder

It is still unclear whether impairments in visuospatial processing in children with developmental coordination disorder (DCD) are a consequence of their motor deficits or are independent of them. In two experiments, 20 children with DCD and 20 matched controls were tested on the covert orienting of a visuospatial attention task (COVAT). Experiment 1 used a COVAT with peripheral cues and an 80% probability that targets would appear at the cued location. While the results suggested a deficit in the disengage operation of orienting covert attention for the DCD group, they were difficult to reconcile with models of covert orienting and the results of past research. Experiment 2 tested subjects on two new versions of the COVAT: the first used peripheral cues and no probability information (exogenous mode), and the second used central cues and an 80% probability that targets would appear at the cued location (endogenous mode). The DCD group displayed attentional orienting deficits only for the endogenous mode. These results suggest that impairments in the endogenous control of visuospatial attention are independent of motor deficits in DCD.     

Reflexive and voluntary orienting of visual attention: Time course of activation and resistance to interruption.

To study the mechanisms underlying covert orienting of attention in visual space, subjects were given advance cues indicating the probable locations of targets that they had to discriminate and localize. Direct peripheral cues (brightening of one of four boxes in peripheral vision) and symbolic central cues (an arrow at the fixation point indicating a probable peripheral box) were compared. Peripheral and central cues are believed to activate different reflexive and voluntary modes of orienting (J. Jonides, 1981; M. I. Posner; see record 1981-09397-001). Experiment 1 showed that the time courses of facilitation and inhibition from peripheral and central cues were characteristic and different. Experiment 2 showed that voluntary orienting in response to symbolic central cues is interrupted by reflexive orienting to random peripheral flashes. Experiment 3 showed that irrelevant peripheral flashes also compete with relevant peripheral cues. The amount of interference varied systematically with the interval between the onset of the relevant cue and of the distracting flash (cue-flash onset asynchrony) and with the cuing condition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)