Top-down influences on perceptual grouping.

Observers are faster to find and discriminate a target pair of adjacent, same-shaped objects that are within the same perceptual group (within group) versus within adjacent perceptual groups. Manipulating the probability of a within-group pair modulated this grouping effect such that it increased as the percentage of within-group trials (25%, 50%, or 75%) increased. This probability effect was stronger for extrinsic grouping factors (common region and connectedness) than for intrinsic factors (proximity and color similarity). Further experiments, however, suggested that this extrinsic-intrinsic difference was due to differences in overall speed with which the target pair was found. The results are interpreted as indicating that grouping is sensitive to top-down influences as long as there is sufficient time for feedback to operate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitating a benign attentional bias reduces negative thought intrusions.

The causal role of biased attention in worry was investigated in an experiment in which high worriers were assigned either to a condition requiring attention to nonthreatening words and text while ignoring worry-related material or to a mixed-attention control condition. The former procedure led to fewer negative thought intrusions in a worry test (as rated by both participants and an assessor) than did the control condition. These findings suggest that attentional bias plays a causal role in worry and that its modification can reduce excessive worry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Threat-related attentional bias in anxious and nonanxious individuals: A meta-analytic study.

This meta-analysis of 172 studies (N = 2,263 anxious,N = 1,768 nonanxious) examined the boundary conditions of threat-related attentional biases in anxiety. Overall, the results show that the bias is reliably demonstrated with different experimental paradigms and under a variety of experimental conditions, but that it is only an effect size of d = 0.45. Although processes requiring conscious perception of threat contribute to the bias, a significant bias is also observed with stimuli outside awareness. The bias is of comparable magnitude across different types of anxious populations (individuals with different clinical disorders, high-anxious nonclinical individuals, anxious children and adults) and is not observed in nonanxious individuals. Empirical and clinical implications as well as future directions for research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What's in a name? Attachment-related attentional bias.

Participants completed a dot probe task that presented pairs of first names: the participant's own name and a neutral name (Experiments 1-4), the name of their attachment figure and a neutral name (Experiments 1-4), or the name of a known person and a neutral name (Experiments 2-4). A significant attentional bias effect was found for the attachment name in attachment-related contexts, whether they were threatening or positive. The results of Experiments 2 and 4 showed that the attentional bias effects for the attachment name were not driven by familiarity effects and could not be interpreted in terms of salience. Attachment anxiety was associated with hypervigilance toward the attachment name in threatening and positive attachment contexts. Attachment avoidance was unrelated to any attentional bias effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Malleability of attentional bias for positive emotional information and anxiety vulnerability.

Recent research supports a causal link between attentional bias for negative emotional information and anxiety vulnerability. However, little is known about the role of positive emotional processing in modulating anxiety reactivity to stress. In the current study, we used an attentional training paradigm designed to experimentally manipulate the processing of positive emotional cues. Participants were randomly assigned to complete a computerized probe detection task designed to induce selective processing of positive stimuli or to a sham condition. Following training, participants were exposed to a laboratory stressor (i.e., videotaped speech), and state anxiety and positive affect in response to the stressor were assessed. Results revealed that individual variability in the capacity to develop an attentional bias for positive information following training predicted subsequent emotional responses to the stressor. Moreover, individual differences in social anxiety, but not depression, moderated the effects of the attentional manipulation, such that, higher levels of social anxiety were associated with diminished attentional allocation toward positive cues. The current findings point to the potential value of considering the role of positive emotional processing in anxiety vulnerability. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The roles of feature-specific task set and bottom-up salience in attentional capture: An ERP study.

We investigated the roles of top-down task set and bottom-up stimulus salience for feature-specific attentional capture. Spatially nonpredictive cues preceded search arrays that included a color-defined target. For target-color singleton cues, behavioral spatial cueing effects were accompanied by cue-induced N2pc components, indicative of attentional capture. These effects were only minimally attenuated for nonsingleton target-color cues, underlining the dominance of top-down task set over salience in attentional capture. Nontarget-color singleton cues triggered no N2pc, but instead an anterior N2 component indicative of top-down inhibition. In Experiment 2, inverted behavioral cueing effects of these cues were accompanied by a delayed N2pc to targets at cued locations, suggesting that perceptually salient but task-irrelevant visual events trigger location-specific inhibition mechanisms that can delay subsequent target selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lack of flexibility in visual grouping in patients with schizophrenia.

The study attempted to distinguish automatic grouping processes from top-down processes in a visual perceptual task in 30 patients with schizophrenia and 30 matched controls. Participants decided whether 7 figures were all different or whether 2 adjacent figures were identical. The distance between figures was manipulated to produce 3 separated pairs of figures, the targets belonging to either the same pair (within-group trials) or different pairs (between-groups trials). As controls, patients benefited from proximity for grouping. Top-down processes were explored by manipulating the proportion of within-group and between-groups trials in 3 experimental blocks. In patients, response times (RTs) decreased for within-group trials when within-group trials were more frequent, indicating that performance was correctly adapted to the type of block. Unlike controls, however, this RT decrease was not accompanied by a cost for between-groups trials. Ocular movement recordings revealed that controls were able to focus on between-groups regions selectively when between-groups trials were more frequent, whereas patients were unable to do so. The authors suggest that top-down processes allowing the construction of a selective representation of between-groups regions are impaired in patients with schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alcohol-related attentional bias in problem drinkers with the flicker change blindness paradigm.

The authors used a flicker paradigm for inducing change blindness as a more direct method of measuring attentional bias in problem drinkers in treatment than the previously used, modified Stroop, Posner, and dual-task paradigms. First, in an artificially constructed visual scene comprising digitized photographs of real alcohol-related and neutral objects, problem drinkers detected a change made to an alcohol-related object more quickly than to a neutral object. Age- and gender-matched social drinkers showed no such difference. Second, problem drinkers given the alcohol-related change to detect showed a negative correlation between the speed with which the change was detected and the problem severity as measured by the number of times previously treated. Coupled with other data from heavy and light social drinkers, the data support a graded continuity of attentional bias underpinning the length of the consumption continuum. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cue summation enables perceptual grouping.

In order to study how basic features interact in shape perception, subjects detected target figure presence and identified target figure shape in a combined 2-alternative forced-choice task. Target figures were embedded in Gabor random fields and were defined by feature contrast in spatial frequency, orientation, or both. Two figure classes were used: block figures, which could not be identified at low feature-contrast levels, and lozenge figures, which could be identified to a moderate degree. Results showed a substantial double-cue benefit for both figure classes in detection. In identification, however, a double-cue benefit was practically absent for blocks, whereas, for lozenges, cue summation proved to be much stronger than in detection. The finding that the way basic features interact is modulated by figure class and psychophysical task indicates involvement of 2 distinct perceptual mechanisms in shape perception. The 1st one highlights salient features and enables local grouping on an early feature-specific processing level. The 2nd one is higher level, serves form completion and grouping of salient contours into global shapes, and enables figure perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bottom-up guidance in visual search for conjunctions.

Understanding the relative role of top-down and bottom-up guidance is crucial for models of visual search. Previous studies have addressed the role of top-down and bottom-up processes in search for a conjunction of features but with inconsistent results. Here, the author used an attentional capture method to address the role of top-down and bottom-up processes in conjunction search. The role of bottom-up processing was assayed by inclusion of an irrelevant-size singleton in a search for a conjunction of color and orientation. One object was uniquely larger on each trial, with chance probability of coinciding with the target; thus, the irrelevant feature of size was not predictive of the target's location. Participants searched more efficiently for the target when it was also the size singleton, and they searched less efficiently for the target when a nontarget was the size singleton. Although a conjunction target cannot be detected on the basis of bottom-up processing alone, participants used search strategies that relied significantly on bottom-up guidance in finding the target, resulting in interference from the irrelevant-size singleton. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Top-down controlled, delayed selection in the attentional blink.

In a previous study, it was shown that the attentional blink (AB)--the failure to recall the 2nd of 2 visual targets (T1 and T2) presented within 500 ms in rapid serial visual presentation--is reduced when T2 is preceded by a distractor that shares a feature with T2 (e.g., color; Nieuwenstein, Chun, van der Lubbe & Hooge, 2005). Here, this cuing effect is shown to be contingent on attentional set. For example, a red distractor letter preceding a green digit T2 is an effective cue when the task is to look for red and green digits, but the same red cue is relatively ineffective when the task is to look for only green digits or when the color of T2 is not specified. It is also shown that cuing is not interrupted by a distractor intervening between the cue and T2. These findings provide evidence for a contingent, delayed selection account of the AB. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of smoking opportunity on attentional bias in smokers.

The emotional Stroop task was used to examine the influence of opportunity to smoke on attentionall bias to smoking-related stimuli. At the outset of the study, 92 nicotine-deprived smokers were told that they (a) would, (b) would not, or (c) might be able to smoke during the experiment. Next, participants completed an emotional Stroop task, in which they were presented with smoking-related or -unrelated words in an unblocked format. Smokers demonstrated interference to the smoking words, relative to matched neutral words, F(1, 87)?=?18.0, p?F(2, 87)?=?4.35, p?     

The influence of temporal selection on spatial selection and distractor interference: An attentional blink study.

Both spatial and temporal selection require focused attention. The authors examine how temporal attention affects spatial selection. In a dual-task rapid serial visual presentation paradigm, temporal selection of a target (T1) impairs processing of a second target (T2) that follows T1 within 500 ms. This process is the attentional blink (AB). To test the effects of withdrawing temporal attention, the authors measured concurrent distractor interference on T2 when the distractors were presented during and outside of the AB. Perceptual interference was manipulated by the similarity in color between T2 and concurrent distractors, and response interference was manipulated by the flanker congruency task. Results showed that perceptual interference was larger during the AB. Response interference also increased during the AB, but only when perceptual interference was high. The authors conclude that temporal selection and spatial selection rely on a common attentional process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term abstract learning of attentional set.

How does past experience influence visual search strategy (i.e., attentional set)? Recent reports have shown that, when given the option to use 1 of 2 attentional sets, observers persist with the set previously required in a training phase. Here, 2 related questions are addressed. First, does the training effect result only from perseveration with the currently active set or from long-term learning? Experiment 1 supported the latter alternative: When training and test were separated by up to 1 week, to prevent perseveration across the 2 sessions, the training effect was still obtained. Second, is the learning feature-specific (tuned to a precise set of colors) or more abstract? Experiments 2 and 3 supported the latter: When stimulus colors were switched between training and test to remove the possibility of feature-specific learning, the training effect again was obtained. These experiments indicate that attentional set is largely guided by long-term abstract learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The reduction of anxiety vulnerability through the modification of attentional bias: A real-world study using a home-based cognitive bias modification procedure.

Recent laboratory work suggests that biased attentional responding to negative information causally impacts anxiety reactivity to a contrived laboratory stressor. However, it remains unknown whether such attentional bias contributes to real-world anxiety vulnerability. In the present study, the authors addressed this issue by experimentally inducing biased attentional response to emotionally negative stimuli, using a home-based attentional training program and then examining the influence of this attentional manipulation on trait anxiety scores and on state anxiety responses to a subsequent stressful life event. The attentional bias modification procedure was effective in inducing attentional avoidance of negative information. Furthermore, this attentional manipulation served to reduce trait anxiety scores and to attenuate state anxiety responses to the subsequent naturalistic stressor. These findings support the hypotheses that biased attentional responding to emotionally negative information contributes causally to real-world anxiety vulnerability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparative study of drug-related attentional bias: Evidence from Iran.

The Addiction-Stroop test has been widely used to investigate the attentional correlates of alcohol and drug abuse; however, the majority of the studies have been conducted with European and American participants. The present study tested whether Iranian drug abusers show higher attentional bias for drug-related stimuli. Participants included drug abusers (N = 53; 100% male), with a clinical history of opium and heroin abuse, who were in a Methadone Maintenance Therapy program. Only nonabusers (N = 71; 71, 54% male) with a history of having never abused of drugs or alcohol participated in the study as controls. All participants completed a computerized Persian version of classic and addiction Stroop tests. The results of a multivariate analysis of covariance (MANCOVA) showed that drug abusers had a higher attentional bias for drug-related stimuli than nonabusers, after the effects of age and education had been controlled. The results of repeating the MANCOVA (a) limited to men only, and (b) to men and women in the nonabuser sample showed that the observed difference in the drug-related attentional bias of drug-abusers and nonabusers was not an artifact of gender imbalance. Our findings support the idea that drug-related attentional bias is culture-free. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning-induced attentional bias for face stimuli measured with the emotional Stroop task.

People with anxiety disorder display attentional bias toward threat-related objects. Using classical fear conditioning, the authors investigated the possible source of such bias in normal participants. Following differential fear conditioning in which an angry face of either male or female (conditioned stimulus: CS+) was paired with mild electric fingershock (unconditioned stimulus: US) but the angry face of the other gender and all other facial expressions unpaired (CS-), an emotional Stroop task was administered. In the Stroop task, participants were required to identify the color of the facial stimuli (red, green, blue, or yellow). Response latency was significantly longer for the CS+ angry face than the other unpaired facial stimuli (CS-). Furthermore, this acquired attentional bias was positively correlated with the level of trait-anxiety measured before the conditioning and the degree of self-reported aversiveness of the US. Our results demonstrated that attentional bias could be induced in normal individuals through a simple associative learning procedure, and the acquisition is modulated by the level of trait anxiety and the level of perceived fear of the aversive US. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Substance use and the paradox of good and bad attentional bias.

Habitual substance use is associated with attentional bias for stimuli related to the use. The current study tested whether individuals’ substance use can be predicted from their attentional bias for concern-related and substance-related stimuli. Participants (N = 71; 54% male) were selected among university students and the community. The study was conducted in Iran, in which alcohol consumption is illegal. Participants completed a substance use questionnaire and classic, substance-, and concern-related Stroop tests. The results show that after controlling for demographic variables and classic Stroop interference, increases in substance-related but decreases in concern-related reaction times predicted the amount of substances that had been consumed by the participants. Individuals’ attentional bias for both substance-related and substance-unrelated goals may be important in predicting substance use behavior. The implication of the findings for treatment prognosis has been discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial grouping resolves ambiguity to drive temporal recalibration.

Cross-modal temporal recalibration describes a shift in the point of subjective simultaneity (PSS) between 2 events following repeated exposure to asynchronous cross-modal inputs—the adaptors. Previous research suggested that audiovisual recalibration is insensitive to the spatial relationship between the adaptors. Here we show that audiovisual recalibration can be driven by cross-modal spatial grouping. Twelve participants adapted to alternating trains of lights and tones. Spatial position was manipulated, with alternating sequences of a light then a tone, or a tone then a light, presented on either side of fixation (e.g., left tone—left light—right tone—right light, etc.). As the events were evenly spaced in time, in the absence of spatial-based grouping it would be unclear if tones were leading or lagging lights. However, any grouping of spatially colocalized cross-modal events would result in an unambiguous sense of temporal order. We found that adapting to these stimuli caused the PSS between subsequent lights and tones to shift toward the temporal relationship implied by spatial-based grouping. These data therefore show that temporal recalibration is facilitated by spatial grouping. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Automatic guidance of visual attention from verbal working memory.

Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize, Experiment 2; or merely to attend, Experiment 3) and subsequently were required to search for a target among different distractors, each embedded within a colored shape. In half of the trials, an object in the search array matched the prime, but this object never contained the target. Despite this, search was impaired relative to a neutral baseline in which the prime and search displays did not match. An interesting finding is that verbal primes were effective in generating the effects, and verbalization of visual primes elicited similar effects to those elicited when primes were held in WM. However, the effects were absent when primes were only attended. The data suggest that there is automatic encoding into WM when items are verbalized and that verbal as well as visual WM can guide visual attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)