Attentional capture of objects referred to by spoken language.

Participants saw a small number of objects in a visual display and performed a visual detection or visual-discrimination task in the context of task-irrelevant spoken distractors. In each experiment, a visual cue was presented 400 ms after the onset of a spoken word. In experiments 1 and 2, the cue was an isoluminant color change and participants generated an eye movement to the target object. In experiment 1, responses were slower when the spoken word referred to the distractor object than when it referred to the target object. In experiment 2, responses were slower when the spoken word referred to a distractor object than when it referred to an object not in the display. In experiment 3, the cue was a small shift in location of the target object and participants indicated the direction of the shift. Responses were slowest when the word referred to the distractor object, faster when the word did not have a referent, and fastest when the word referred to the target object. Taken together, the results demonstrate that referents of spoken words capture attention. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The time course of attentional and oculomotor capture reveals a common cause.

Eye movements are often misdirected toward a distractor when it appears abruptly, an effect known as oculomotor capture. Fundamental differences between eye movements and attention have led to questions about the relationship of oculomotor capture to the more general effect of sudden onsets on performance, known as attentional capture. This study explores that issue by examining the time course of eye movements and manual localization responses to targets in the presence of sudden-onset distractors. The results demonstrate that for both response types, the proportion of trials on which responses are erroneously directed to sudden onsets reflects the quality of information about the visual display at a given point in time. Oculomotor capture appears to be a specific instance of a more general attentional capture effect. Differences and similarities between the two types of capture can be explained by the critical idea that the quality of information about a visual display changes over time and that different response systems tend to access this information at different moments in time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delayed Attentional Engagement in the Attentional Blink.

Observers often miss the 2nd of 2 visual targets (first target [T1] and second target [T2]) when these targets are presented closely in time; the attentional blink (AB). The authors hypothesized that the AB occurs because the attentional response to T2 is delayed by T1 processing, causing T2 to lose a competition for attention to the item that follows it. The authors investigated this hypothesis by determining whether the AB is attenuated when T2 is precued. The results from 4 experiments showed that the duration and magnitude of the AB were substantially reduced when T2 was precued. The observed improvement in T2 report did not occur at the expense of T1 report, suggesting that processing of T1 was already completed or was at least protected when the cue was presented. The authors conclude that, during the AB, there is a delay between detection and the selection of target candidates for consolidation in short-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feature-based memory-driven attentional capture: Visual working memory content affects visual attention.

In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly with a visual search task when it was accompanied by an additional memory task. Singleton distractors interfered even more when they were identical or related to the object held in memory, but only when it was difficult to verbalize the memory content. Furthermore, this content-specific interaction occurred for features that were relevant to the memory task but not for irrelevant features of the same object or for once-remembered objects that could be forgotten. Finally, memory-related distractors attracted more eye movements but did not result in longer fixations. The results demonstrate memory-driven attentional capture on the basis of content-specific representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional spreading in object-based attention.

The authors investigated 2 effects of object-based attention: the spread of attention within an attended object and the prioritization of search across possible target locations within an attended object. Participants performed a flanker task in which the location of the task-relevant target was fixed and known to participants. A spreading attention account predicts that object-based attention will arise from the spread of attention through an attended object. A prioritization account predicts that there will be a small, if any, object-based effect because the location of the target is known in advance and objects are not required to prioritize the deployment of attentional search. The results suggested that object-based attention operates via the spread of attention within an object. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resolving Visual Interference During Covert Spatial Orienting: Online Attentional Control Through Static Records of Prior Visual Experience.

Models of attentional control usually describe online shifts in control settings that accommodate changing task demands. The current studies suggest that online control over distractor exclusion--a core component of visual selection--can be accomplished without online shifts in top-down settings. Measurements of target discrimination accuracy suggested that the degree of distractor exclusion was guided by retinotopic maps of the prior probability of distractor interference at the attended locations. These probability maps can be retrieved via object-based cues, and they interact with shifts of attention to elicit increased levels of distractor exclusion when it is most needed. Thus, static probability maps can provide an internal template that guides the resolution of visual interference as spatial attention traverses the visual field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capture with rapidly changing attentional control settings.

The classic theory of spatial attention hypothesized 2 modes, voluntary and involuntary. Folk, Remington, and Johnston (1992) reported that even involuntary attention capture by stimuli requires a match between stimulus properties and what the observer is looking for. This surprising conclusion has been confirmed by many subsequent studies. In these studies, however, the observer typically looks for the same property throughout an entire session. Real-world behavior, in contrast, often requires frequent shifts in attentional set. The present study examined whether such shifts weaken attentional settings, allowing task-irrelevant objects to capture attention. Surprisingly, fluctuating control settings did not increase vulnerability to capture by salient stimuli (color singletons and abrupt onsets). We conclude that the attention control system is remarkably flexible, able to rapidly and fully adopt new settings and abandon old settings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is position "special" in visual attention? Evidence that top-down processes guide visual selection.

The role of spatial position in selective visual processing has been the source of recent debate. The present study, using undergraduates, attempted to reconcile various findings by exploring the influence of top-down processes (task instructions) while explicitly controlling for eye movements. Exp 1 demonstrated there was no inherent selection bias for stimuli similar to those used by A. H. C. van der Heijden et al (1996), suggesting that the tendency to select according to colour found by van der Heijden et al was due to task demands. Exp 2 further established the role of top-down factors by replicating the results of van der Heijden et al with the current authors' stimuli. Exp 3 demonstrated that selection can be switched from colour to position by changing the demands of the task. These results suggest that selection may be accounted for by task demands (e.g., instructions) with no priority access for position information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Control of Fixation and Saccades in Humans With Chronic Lesions of Oculomotor Cortex.

To elucidate the dynamic interactions of cortical and subcortical oculomotor systems, the authors investigated reflexive and strategic control over fixation and saccades in patients with chronic unilateral lesions that involved either frontal or parietal cortex. They measured the effects of indicating the location of the forthcoming target and removing the fixation stimulus on the latencies of eye movements toward a peripheral visual target in 12 patients with frontal eye field (FEF) lesions, 9 patients with lesions restricted to parietal cortex, and 12 neurologically healthy controls. They found that chronic damage to FEF cortex disrupts cortico-collicular interactions, resulting in hypoactivity in the contralesional superior colliculus and a loss of strategic control over the intrinsic collicular circuits that regulate fixation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task Demands Control Acquisition and Storage of Visual Information.

Attention and working memory limitations set strict limits on visual representations, yet researchers have little appreciation of how these limits constrain the acquisition of information in ongoing visually guided behavior. Subjects performed a brick sorting task in a virtual environment. A change was made to 1 of the features of the brick being held on about 10% of trials. Rates of change detection for feature changes were generally low and depended on the pick-up and put-down relevance of the feature to the sorting task. Subjects' sorting decision suggests that changes may be missed because of a failure to update the changed feature. The authors also explore how hand and eye behavior are coordinated for strategic acquisition and storage of visual information throughout the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning by selection: Visual search and object perception in young infants.

The authors examined how visual selection mechanisms may relate to developing cognitive functions in infancy. Twenty-two 3-month-old infants were tested in 2 tasks on the same day: perceptual completion and visual search. In the perceptual completion task, infants were habituated to a partly occluded moving rod and subsequently presented with unoccluded broken and complete rod test stimuli. In the visual search task, infants viewed displays in which single targets of varying levels of salience were cast among homogeneous static vertical distractors. Infants whose posthabituation preference indicated unity perception in the completion task provided evidence of a functional visual selective attention mechanism in the search task. The authors discuss the implications of the efficiency of attentional mechanisms for information processing and learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for where, but not what, is used during visual search.

Although the role of memory in visual search is debatable, most researchers agree with a limited-capacity model of memory in visual search. The authors demonstrate the role of memory by replicating previous findings showing that visual search is biased away from old items (previously examined items) and toward new items (nonexamined items). Furthermore, the authors examined the type of memory representations used to bias search by changing an item's individuating feature or location during search. Changing the individuating feature of an item did not disrupt normal search biases. However, when the location of an item changed, normal search biases were disrupted. These results suggest that memory used in visual search is based on items' locations rather than their identity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of items in working memory on the deployment of attention and the eyes during visual search.

Paying attention to an object facilitates its storage in working memory. The authors investigate whether the opposite is also true: whether items in working memory influence the deployment of attention. Participants performed a search for a prespecified target while they held another item in working memory. In some trials this memory item was present in the search display as a distractor. Such a distractor has no effect on search time if the search target is in the display. In that case, the item in working memory is unlikely to be selected as a target for an eye movement, and if the eyes do land on it, fixation duration is short. In the absence of the target, however, there is a small but significant effect of the memory item on search time. The authors conclude that the target for visual search has a special status in working memory that allows it to guide attention. Guidance of attention by other items in working memory is much weaker and can be observed only if the search target is not present in the display. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent studies of eye movements in reading.

Grouping the studies under the general topic headings of techniques of measurement, analysis of the reading process, training to improve eye movements, typography and eye movements, and eye movements and fatigue the author reviews the relevant research literature which has appeared since January, 1945. In general there has been a dimunition of interest in this area. However, there has appeared a large amount of work on visual fixation, speed of eye movements, reaction time of the eye, oculomotor efficiency, and vision during eye movements. There is a need for more basic research. 72-item bibliography. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attending to Eye Movements and Retinal Eccentricity: Evidence for the Activity Distribution Model of Attention Reconsidered.

When testing between spotlight and activity distribution models of visual attention, D. LaBerge, R. L. Carlson, J. K. Williams, and B. G. Bunney (1997) used an experimental paradigm in which targets are embedded in 3 brief displays. This paradigm, however, may be confounded by retinal eccentricity effects and saccadic eye movements. When the retinal eccentricities of the targets are equated and eye position is monitored, the pattern of results reported by LaBerge et al., which supported the activity distribution model, is not found. This result underscores the importance of considering targets' eccentricity and people's inclination to make saccadic eye movements in certain types of visual cognition tasks. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Role of Stimulus-Driven and Goal-Driven Control in Saccadic Visual Selection.

Four experiments were conducted to investigate the role of stimulus-driven and goal-driven control in saccadic eye movements. Participants were required to make a speeded saccade toward a predefined target presented concurrently with multiple nontargets and possibly 1 distractor. Target and distractor were either equally salient (Experiments 1 and 2) or not (Experiments 3 and 4). The results uniformly demonstrated that fast eye movements were completely stimulus driven, whereas slower eye movements were goal driven. These results are in line with neither a bottom-up account nor a top-down notion of visual selection. Instead, they indicate that visual selection is the outcome of 2 independent processes, one stimulus driven and the other goal driven, operating in different time windows. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the control of attention.

An early interest in cognitive processes led me to study with Mike Posner from whom I acquired the intellectual tools to follow Hebb’s (1949) advice that “Everyone knows that attention and set exist so we had better get the skeleton out of the closet and see what can be done with it.” Using variants of the model task Posner developed for exploring the control of visual attention we have demonstrated that endogenous shifts of attention are not generated by unexecuted oculomotor activation, that endogenous and exogenous shifts of attention are fundamentally different on a variety of dimensions and that an aftermath of exogenous (but not endogenous) orienting, inhibition of return, facilitates search by encouraging orienting to novel items. A research strategy for understanding ambiguous forms of orienting (e.g., that controlled by conspecific gaze) is proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional asymmetry in schizophrenia: Disengagement and inhibition of return deficits.

This research examined 2 components of visual orienting in medicated schizophrenia patients: the validity effect and the inhibition of return (IOR). In the 1st experiment, patients showed the expected asymmetry in orienting attention, that is, larger validity effect in the right visual field than in the left. However, this asymmetry was due to a deficit in facilitatory processes rather than a disengagement deficit. In addition, patients showed a deficit in IOR. In the 2nd experiment, a 2nd central cue for summoning attention, explicitly, back to the center was used. In this experiment, normal IOR in schizophrenia patients was found. Because it was shown that schizophrenia patients do not have a disengagement deficit, IOR possibly could not be observed because of the increased facilitation in that location. It was proposed that the abnormality in visual attention in schizophrenia is due to a deficit in inhibitory processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parallel processing of objects in a naming task.

The authors investigated whether speakers who named several objects processed them sequentially or in parallel. Speakers named object triplets, arranged in a triangle, in the order left, right, and bottom object. The left object was easy or difficult to identify and name. During the saccade from the left to the right object, the right object shown at trial onset (the interloper) was replaced by a new object (the target), which the speakers named. Interloper and target were identical or unrelated objects, or they were conceptually unrelated objects with the same name (e.g., bat [animal] and [baseball] bat). The mean duration of the gazes to the target was shorter when interloper and target were identical or had the same name than when they were unrelated. The facilitatory effects of identical and homophonous interlopers were significantly larger when the left object was easy to process than when it was difficult to process. This interaction demonstrates that the speakers processed the left and right objects in parallel. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual Short-Term Memory During Smooth Pursuit Eye Movements.

Visual short-term memory (VSTM) was probed while observers performed smooth pursuit eye movements. Smooth pursuit keeps a moving object stabilized in the fovea. VSTM capacity for position was reduced during smooth pursuit compared with a condition with eye fixation. There was no difference between a condition in which the items were approximately stabilized on the retina because they moved with the pursuit target and a condition in which the items moved across the retina because they were stationary in space. The reduction of capacity for position was eliminated when miniature items were presented on the pursuit target. Similarly, VSTM capacity for color did not differ between smooth pursuit and fixation. The results suggest that visuospatial attention is tied to the target during smooth pursuit, which impairs VSTM for the position of peripheral objects. Sensory memory during smooth pursuit was only slightly impaired. (PsycINFO Database Record (c) 2010 APA, all rights reserved)