Feature bindings endure without attention: Evidence from an explicit recall task

Are integrated objects the unit of capacity of visual working memory, or is continued attention needed to maintain bindings between independently stored features? In a delayed recall task, participants reported the color and shape of a probed item from a memory array. During the delay, attention was manipulated with an exogenous cue. Recall was elevated at validly cued positions, indicating that the cue affected item memory. On invalid trials, participants most frequently recalled either both features (perfect object memory) or neither of the two features (no object memory); the frequency with which only one feature was recalled was significantly lower than predicted by feature independence as determined in a single-feature recall task. These data do not support the view that features are remembered independently when attention is withdrawn. Instead, integrated objects are stored in visual working memory without need for continued attention.     

Feature integration without visual attention: Evidence from the correlated flankers task

It is widely assumed that the separable features of visual objects, such as their colors and shapes, require attention to be integrated. However, the evidence in favor of this claim comes from experiments in which the colors and shapes of objects would have to be integrated and then also subjected to an arbitrary, instruction-based, stimulus-response (S-R) translation in order to have an observable effect. This raises the possibility that attention is not required for feature integration, per se, but is only required when color-shape conjunctions must undergo an arbitrary S-R translation. The present study conducted a more specific test and found strong evidence in favor of feature integration in the absence of attention. The implications of these results are discussed.     

Role of Gestalt grouping in selective attention: evidence from the Stroop task

Selective attention has been intensively studied using the Stroop task. Evidence suggests that Stroop interference in a color-naming task arises partly because of visual attention sharing between color and word: Removing the target color after 150 msec reduces interference (Neumann, 1986). Moreover, removing both the color and the word simultaneously reduces interference less than does removing the color only (La Heij, van der Heijden, & Plooij, 2001). These findings could also be attributed to Gestalt grouping principles, such as common fate. We report three experiments in which the role of Gestalt grouping was further investigated. Experiment I replicated the reduced interference, using words and color patches. In Experiment 2, the color patch was not removed but only repositioned (<2 degrees) after 100 msec, which also reduced interference. In Experiment 3, the distractor was repositioned while the target remained stationary, again reducing interference. These results indicate a role for Gestalt grouping in selective attention.     

Stress reduces attention to irrelevant information: Evidence from the Stroop task

Stroop interference can be reduced by stress, and this has been taken as evidence that stress decreases the attention paid to irrelevant information, a theory known as ‘Easterbrook’s hypothesis’. This contradicts more recent theories, which state that attentional control deteriorates in stress. Fifty-five participants undertook a Stroop task under high stress (loud white noise) and low stress conditions. Attention to the irrelevant word information was assessed by manipulating the proportion of congruent trials (e.g. the word RED in the colour red); it is known that Stroop interference increases when many such trials are presented. This effect was reduced when participants were stressed, which is evidence that stress does indeed reduce attention to irrelevant information. This pattern of results was not present in participants with low working memory spans, presumably because these participants had less attentional control. These findings highlight an important weakness in contemporary theories of cognition in stress.     

New objects do not capture attention without a top-down setting: Evidence from an inattentional blindness task

Past studies have suggested that a new object can involuntarily capture attention in a visual search task (Yantis & Jonides, 1984 Yantis, S. and Jonides, J. 1984. Abrupt visual onsets and selective attention: Evidence from visual search. Journal of Experimental Psychology: Human Perception and Performance, 10: 601–621. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). However, trials in these experiments usually begin with abrupt onsets that are considered to signal new objects; thus, there may be a bias toward paying attention to new objects. We examine whether new objects can still capture attention when this bias is excluded, using an inattentional blindness task. Our results showed that when the trials began with new objects, a new object captured attention. When new objects were totally irrelevant and all top-down settings for new objects were prevented, a new object did not capture attention. Our findings argue against the view that new objects capture attention in a purely stimulus-driven fashion.     

From reorienting of attention to biased competition: Evidence from hemifield effects

When a distractor was presented simultaneously with or directly following a target, it produced more interference when it was presented in the same visual hemifield as the target than when it was presented in the opposite visual field. This result is interpreted in terms of biased competition; there is more competition between stimuli when they are presented in the same visual field, rather than in opposite visual fields. However, when the distractor was presented 125 msec or more prior to the target, this pattern was reversed. In those cases, there was more distractor interference when target and distractor were presented in opposite visual fields. This can be explained by assuming that attention was captured by the distractor, and that there was an additional cost of reorienting to a location in the opposite visual field.     

Divided attention modulates semantic activation: Evidence from a nonletter-level prime task

Research has recently shown that semantic activation is modulated in proportion to the amount of attention required for letter-level processing of the prime (the attention modulation hypothesis; Smith, Bentin, & Spalek, 2001). In this study, we examined this hypothesis with an auditory divided-attention task. Participants were asked to decide whether the pitch of a probe tone presented with the prime word was higher or lower than the basic tone presented with the fixation cross. Their target task was lexical decision to the target word. Experiment 1 showed that semantic priming was modulated by the amount of attentional resources. Moreover, in Experiment 2, this modulation was also found in a situation that eliminated the possibility of participants' response strategies. Yet, Experiment 3 showed repetition priming to be unaffected. These results support an amended attention modulation hypothesis in which modulation is not limited to letter-level processing.     

Common region: a new principle of perceptual grouping.

A new principle of grouping is proposed that is based on elements being located within a common region of space. Demonstrations analogous to Wertheimer's original displays show that this factor strongly influences perceived grouping and is capable of overcoming the effects of other powerful grouping factors such as proximity and similarity. Grouping by common region is further shown to depend on perceived depth relations, indicating that it is influenced by processes that occur after at least some depth perception has been achieved. Further demonstrations suggest that it is dominated by the smallest background area and that it can follow a hierarchical embedding scheme. It is argued that common region cannot be reduced to the effects of proximity, closure, or any other previously known factor and therefore constitutes a genuinely new principle of grouping.     

Evidence of preliminary response preparation from a divided attention task

In a divided attention situation, preliminary response activations produced by stimuli on one channel were revealed through their effects on responses to stimuli on a secondary probe channel. Subjects performed concurrent but independent four-choice reaction-time tasks using the same four response fingers (middle and index fingers on both hands). In the main task, targets were large and small Ss and Ts, and medium-sized Ss and Ts sometimes appeared as distractors. Targets in the probe task were squares differing in location. A response to a probe square was faster if a distractor letter presented just before it had the same name as the target letter corresponding to that square (i.e., assigned to the same response key) than if the distractor letter had a different name--a result indicating that distractor letters cause partial response preparation. The timecourse of the effect demonstrated that preparation was based on preliminary information about distractor name that was available before distractor size had been determined. The results support models in which response preparation can sometimes begin before stimulus recognition has finished.     

Principles of cross-modal competition: Evidence from deficits of attention

How does the attentional system coordinate the processing of stimuli presented simultaneously to different sensory modalities? We investigated this question with individuals with neurological damage who suffered from deficits of attention. In these individuals, we examined how the processing of tactile stimuli is affected by the simultaneous presentation of visual or auditory stimuli. The investigation demonstrated that two stimuli from different modalities are in competition when attention is directed to the perceptual attributes of both, but not when attention is directed to the perceptual attributes of one and the semantic attributes of the other. These findings reveal a differentiated attentional system in which competition is modulated by the level of stimulus representation to which attention is directed.     

Links between neuroticism,emotional distress,and disengaging attention: Evidence from a single-target RSVP task

Anxiety and depression are often associated with attention control deficits, but few studies have explored whether neuroticism can account for these links. In the present study, undergraduate students (n=146) completed self-report measures of neuroticism, worry, anxious arousal, and anhedonic depression and also completed a visual attention task in which they were asked to identify a red target letter embedded within a rapid sequence of items. Neuroticism was associated with detection of the target when it was preceded by a distracter with which it shared a feature in common (a green letter). Specifically, these distracters produced longer attentional blinks in individuals with elevated levels of neuroticism. In contrast, target detection was not significantly associated with worry, anxious arousal, or anhedonic depression. We discuss the implications of this link between neuroticism and attention for cognitive models of emotional distress and disorders.     

Combined effects of perceptual grouping cues on object representation: Evidence from motion-induced blindness

We investigated the combined effects of perceptual grouping cues (proximity and contour closure/proximity and orientation similarity) on object representation, using motion-induced blindness, a phenomenon in which salient visual stimuli perceptually disappear when surrounded by moving patterns. We presented as visual targets two stimuli in which a solid square was embedded in an outlined square. Participants reported whether the targets disappeared independently or simultaneously. The results showed that a relatively high proximity cue (with a 0.2-deg separation between the targets) modulated the perceptions of the independent or simultaneous disappearances of targets, regardless of other grouping cues. The contour closure cue modulated these disappearances in the 0.4- to 0.8-deg separations. Finally, the orientation similarity cue began to modulate these disappearances in the 0.6- to 0.8-deg separations. We suggest that the separation between the visual stimuli modulates the combined effects of perceptual grouping cues on complete object representation.     

Speech perception engages a general timer: Evidence from a divided attention word identification task

Time is essential to speech. The duration of speech segments plays a critical role in the perceptual identification of these segments, and therefore in that of spoken words. Here, using a French word identification task, we show that vowels are perceived as shorter when attention is divided between two tasks, as compared to a single task control condition. This temporal underestimation pattern is consistent with attentional models of timing and hence demonstrates that vowel duration is explicitly estimated using a central general-purpose timer.     

The focus of attention in working memory: Evidence from a word updating task

Three experiments examined the cognitive costs of item switching within working memory with a novel word updating task, thereby extending previous research to the field of linguistic stimuli and linguistic-graphemic updating operations. In Experiments 1 and 2 costs for switching between working memory items were evident on the word level, and they increased with an increasing word set size (Experiment 2). In contrast, a surprisingly similar switch effect on the level of letters was not affected by word set size (Experiment 2). Experiment 3 showed that this effect is not simply based on the need for re-orienting visual spatial attention. To account for the overall picture of results, a recursive model of attentional foci is proposed. Moreover, individual working memory span appears to be associated with the accuracy of item switching, but not with its speed.     

Inescapable shock and attention to internal versus external cues in a water discrimination escape task

In these experiments we examined discrimination learning in a water escape task following exposure to escapable, yoked inescapable, or no electric shock. Inescapable shock did not have an effect on swim speeds in any of the experiments. Inescapable shock interfered with the acquisition of a position (left-right) discrimination when an irrelevant brightness cue (black and white stimuli) was present. However, inescapable shock did not affect the acquisition of the position discrimination when the irrelevant brightness cue was removed. Inescapably shocked subjects showed facilitated learning relative to escapably shocked and nonshocked subjects when the brightness cue was included as a relevant cue. These data may resolve discrepancies between studies that did, and did not, find inescapable shock to interfere with the acquisition of discriminations. Moreover, they point to attentional processes as one locus of the cognitive changes produced by inescapable shock and suggest that exposure to inescapable shock biases attention away from "internal" response-related cues toward "external" cues.     

The relationship between bilingualism and selective attention in young adults: Evidence from an ambiguous figures task

Previous research has shown that bilinguals outperform monolinguals on a variety of tasks that have been described as involving executive functioning, but the precise mechanism for those effects or a clear definition for “executive function” is unknown. This uncertainty has led to a number of studies for which no performance difference between monolingual and bilingual adults has been detected. One approach to clarifying these issues comes from research with children showing that bilinguals were more able than their monolingual peers to perceive both interpretations of an ambiguous figure, an ability that is more tied to a conception of selective attention than to specific components of executive function. The present study extends this notion to adults by assessing their ability to see the alternative image in an ambiguous figure. Bilinguals performed this task more efficiently than monolinguals by requiring fewer cues to identify the second image. This finding has implications for the role of selective attention in performance differences between monolinguals and bilinguals.     

Negative priming between pictures and words in a selective attention task: Evidence for semantic processing of ignored stimuli

This study examined the processing of ignored pictures and words when attention was directed to a different picture or word. Previous work by Tipper (1985) demonstrated that the priming effect of an ignored picture on a subsequent categorically related picture is inhibitory. This effect was termednegative priming. Tipper concluded that ignored pictures achieved abstract categorical levels of internal representation, and that these representations were inhibited during selection of a simultaneously presented picture. This conclusion, however, was premature. Observation of the figures used by Tipper suggests that objects within a category have greater structural similarity than do objects in different categories. The negative priming effect could therefore be at a structural level of representation. The present study examined priming across symbolic domains (pictures and words) where there was no structural relationship between objects. Negative priming was again observed and was equivalent to the negative priming observed within symbolic domain. These data suggest that ignored drawings and words do achieve abstract categorical levels of representation, and that the mechanisms underlying negative priming operate at, or beyond, this level.     

The role of numerical and non-numerical cues in nonsymbolic number processing: Evidence from the line bisection task

In line bisection tasks, adults and children bisect towards the numerically larger of two nonsymbolic numerosities [de Hevia, M. D., & Spelke, E. S. (2009 de Hevia, M. D., & Spelke, E. S. (2009). Spontaneous mapping of number and space in adults and young children. Cognition, 110, 198–207. doi:10.1016/j.cognition.2008.11.003[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Spontaneous mapping of number and space in adults and young children. Cognition, 110, 198–207. doi:10.1016/j.cognition.2008.11.003]. However, it is not clear whether this effect is driven by number itself or rather by visual cues such as subtended area [Gebuis, T., & Gevers, W. (2011 Gebuis, T., & Gevers, W. (2011). Numerosities and space: Indeed a cognitive illusion! A reply to de Hevia and Spelke (2009). Cognition, 121, 248–252. doi:10.1016/j.cognition.2010.09.008[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Numbers and space: Indeed a cognitive illusion! A reply to de Hevia and Spelke (2009 de Hevia, M. D., & Spelke, E. S. (2009). Spontaneous mapping of number and space in adults and young children. Cognition, 110, 198–207. doi:10.1016/j.cognition.2008.11.003[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). Cognition, 121, 248–252. doi:10.1016/j.cognition.2010.09.008]. Furthermore, this effect has only been demonstrated with flanking displays of two and nine items. Here, we report three studies that examined whether this “spatial bias” effect occurs across a range of absolute and ratio numerosity differences; in particular, we examined whether the bias would occur when both flankers were outside the subitizing range. Additionally, we manipulated the subtended area of the stimulus and the aggregate surface area to assess the influence of visual cues. We found that the spatial bias effect occurred for a range of flanking numerosities and for ratios of 3:5 and 5:6 when subtended area was not controlled (Experiment 1). However, when subtended area and aggregate surface area were held constant, the biasing effect was reversed such that participants bisected towards the flanker with fewer items (Experiment 2). Moreover, when flankers were identical, participants bisected towards the flanker with larger subtended area or larger aggregate surface area (Experiments 2 and 3). On the basis of these studies, we conclude that the spatial bias effect for nonsymbolic numerosities is primarily driven by visual cues.     

成人注意缺陷多动障碍在内外源冲突时的表现:眼动的证据

在注意定向与维持上,注意缺陷多动障碍(ADHD)个体更容易受到外部刺激的干扰而导致目标任务加工进程受阻,表现出了注意定向反应的缺陷,但导致任务失败的原因是由于对突然出现的外部无关刺激的过度兴奋还是对内源性目标刺激的持续维持能力减弱,尚不清楚。研究采用反向眼跳范式、记忆导向眼跳范式和视觉导向眼跳范式,来探索成人ADHD内外源注意定向反应的情况,以及当二者发生冲突时,成人ADHD失败的可能机制。结果发现,在反向眼跳任务上,成人注意缺陷多动障碍组错误率更高,并且差异性显著。但在记忆导向眼跳任务中,成人注意缺陷多动障碍组与正常组的差异不显著。在视觉导向眼跳任务中,成人注意缺陷多动障碍组的正确眼跳潜伏期比正常组要短,且二者之间的差异显著。这说明,在内外源刺激反应的冲突导致的情境中,成人注意缺陷多动障碍的反应明显落后于正常个体,这种缺陷并非由于其维持内源性注意产生定向反应落后所导致的,而是与其外源注意定向反应过强有关。     

Visuospatial attention: the role of target contrast and task difficulty when assessing the effects of cues

Cueing paradigms have become popular in assessing the processes of attention. In two experiments we manipulated (i) the contrast of the target, and (ii) the similarity between the targets discriminated. We used a cue that would isolate the exogenous component of attention. Both a reduction in target contrast and an increase in target similarity raised overall reaction times by a similar amount; however, the target contrast manipulation produced a much greater cueing effect compared with the target similarity manipulation. The results suggest that manipulation of target contrast changes the attention cueing effect at a stage of attracting attention to a location of the target (the 'move' stage), rather than at a later processing stage.