Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ATTENTION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 811 records · Page 45Linked to original sources
PubMed2000

Attention mechanisms in visual search -- an fMRI study.

The human visual system is usually confronted with many different objects at a time, with only some of them reaching consciousness. Reaction-time studies have revealed two different strategies by which objects are selected for further processing: an automatic, efficient search process, and a conscious, so-called inefficient search [Treisman, A. (1991). Search, similarity, and integration of features between and within dimensions. Journal of Experimental Psychology: Human Perception and Performance, 17, 652--676; Treisman, A., & Gelade, G. (1980). A feature integration theory of attention. Cognitive Psychology, 12, 97--136; Wolfe, J. M. (1996). Visual search. In H. Pashler (Ed.), Attention. London: University College London Press]. Two different theories have been proposed to account for these search processes. Parallel theories presume that both types of search are treated by a single mechanism that is modulated by attentional and computational demands. Serial theories, in contrast, propose that parallel processing may underlie efficient search, but inefficient searching requires an additional serial mechanism, an attentional "spotlight" (Treisman, A., 1991) that successively shifts attention to different locations in the visual field. Using functional magnetic resonance imaging (fMRI), we show that the cerebral networks involved in efficient and inefficient search overlap almost completely. Only the superior frontal region, known to be involved in working memory [Courtney, S. M., Petit, L., Maisog, J. M., Ungerleider, L. G., & Haxby, J. V. (1998). An area specialized for spatial working memory in human frontal cortex. Science, 279, 1347--1351], and distinct from the frontal eye fields, that control spatial shifts of attention, was specifically involved in inefficient search. Activity modulations correlated with subjects' behavior best in the extrastriate cortical areas, where the amount of activity depended on the number of distracting elements in the display. Such a correlation was not observed in the parietal and frontal regions, usually assumed as being involved in spatial attention processing. These results can be interpreted in two ways: the most likely is that visual search does not require serial processing, otherwise we must assume the existence of a serial searchlight that operates in the extrastriate cortex but differs from the visuospatial shifts of attention involving the parietal and frontal regions.

Adult↗
PubMed2001

Emotion and attention interaction studied through event-related potentials.

Several studies on hemodynamic brain activity indicate that emotional visual stimuli elicit greater activation than neutral stimuli in attention-related areas such as the anterior cingulate cortex (ACC) and the visual association cortex (VAC). In order to explore the temporo-spatial characteristics of the interaction between attention and emotion, two processes characterized by involving short and rapid phases, event-related potentials (ERPs) were measured in 29 subjects using a 60-electrode array and the LORETA source localization software. A cue/target paradigm was employed in order to investigate both expectancy-related and input processing-related attention. Four categories of stimuli were presented to subjects: positive arousing, negative arousing, relaxing, and neutral. Three attention-related components were finally analyzed: N280pre (from pretarget ERPs), P200post and P340post (both from posttarget ERPs). N280pre had a prefrontal focus (ACC and/or medial prefrontal cortex) and presented significantly lower amplitudes in response to cues announcing negative targets. This result suggests a greater capacity of nonaversive stimuli to generate expectancy-related attention. P200post and P340post were both elicited in the VAC, and showed their highest amplitudes in response to negative- and to positive-arousing stimuli, respectively. The origin of P200post appears to be located dorsally with respect to the clear ventral-stream origin of P340post. The conjunction of temporal and spatial characteristics of P200post and P340post leads to the deduction that input processing-related attention associated with emotional visual stimulation involves an initial, rapid, and brief "early" attentional response oriented to rapid motor action, being more prominent towards negative stimulation. This is followed by a slower but longer "late" attentional response oriented to deeper processing, elicited to a greater extent by appetitive stimulation.

Adult↗
PubMed2002

Serial attention mechanisms in visual search: a direct behavioral demonstration.

In visual search, inefficient performance of human observers is typically characterized by a steady increase in reaction time with the number of array elements-the so-called set-size effect. In general, set-size effects are taken to indicate that processing of the array elements depends on limited-capacity resources, that is, it involves attention. Contrasting theories have been proposed to account for this attentional involvement, however. While some theories have attributed set-size effects to the intervention of serial attention mechanisms, others have explained set-size effects in terms of parallel, competitive architectures. Conclusive evidence in favor of one or the other notion is still lacking. Especially in view of the wide use of visual search paradigms to explore the functional neuroanatomy of attentional mechanisms in the primate brain, it becomes essential that the nature of the attentional involvement in these paradigms be clearly defined at the behavioral level. Here we report a series of experiments showing that highly inefficient search indeed recruits serial attention deployment to the individual array elements. In addition, we describe a number of behavioral signatures of serial attention in visual search that can be used in future investigations to attest a similar involvement of serial attention in other search paradigms. We claim that only after having recognized these signatures can one be confident that truly serial mechanisms are engaged in a given visual search task, thus making it amenable for exploring the functional neuroanatomy underlying its performance.

Adult↗
PubMed2002

Changes in the spatial distribution of visual attention after early deafness.

There is much anecdotal suggestion of improved visual skills in congenitally deaf individuals. However, this claim has only been met by mixed results from careful investigations of visual skills in deaf individuals. Psychophysical assessments of visual functions have failed, for the most part, to validate the view of enhanced visual skills after deafness. Only a few studies have shown an advantage for deaf individuals in visual tasks. Interestingly, all of these studies share the requirement that participants process visual information in their peripheral visual field under demanding conditions of attention. This work has led us to propose that congenital auditory deprivation alters the gradient of visual attention from central to peripheral field by enhancing peripheral processing. This hypothesis was tested by adapting a search task from Lavie and colleagues in which the interference from distracting information on the search task provides a measure of attentional resources. These authors have established that during an easy central search for a target, any surplus attention remaining will involuntarily process a peripheral distractor that the subject has been instructed to ignore. Attentional resources can be measured by adjusting the difficulty of the search task to the point at which no surplus resources are available for the distractor. Through modification of this paradigm, central and peripheral attentional resources were compared in deaf and hearing individuals. Deaf individuals possessed greater attentional resources in the periphery but less in the center when compared to hearing individuals. Furthermore, based on results from native hearing signers, it was shown that sign language alone could not be responsible for these changes. We conclude that auditory deprivation from birth leads to compensatory changes within the visual system that enhance attentional processing of the peripheral visual field.

Adult↗
PubMed2006

Attention-memory interactions in scene perception.

The perception of natural scenes relies on the integration of pre-existing knowledge with the immediate results of attentional processing, and what can be remembered from a scene depends in turn on how that scene is perceived and understood. However, there are conflicting results in the literature as to whether people are more likely to remember those objects that are consistent with the scene or those that are not. Moreover, whether any discrepancy between the likelihood of remembering schema-consistent or schema-inconsistent objects should be attributed to the schematic effects on attention or on memory remains unclear. To address this issue, the current study attempted to directly manipulate attention allocation by requiring participants to look at (i) schema-consistent objects, (ii) schema-inconsistent objects, or (iii) to share attention equally across both. Regardless of the differential allocation of attention or object fixation, schema-consistent objects were better recalled whereas recognition was independent of schema-consistency, but depended on task instruction. These results suggest that attention is important both for remembering low-level object properties, and information whose retrieval is not supported by the currently active schema. Specific knowledge of the scenes being viewed can result in the recall of non-fixated objects, but without such knowledge attention is required to encode sufficient detail for subsequent recognition. Our results demonstrate therefore that attention is not critical for the retrieval of objects that are consistent with a scene's schematic content.

Attention↗
PubMed2006

Modulation of visual stimulus discrimination by sustained focal attention: an MEG study.

PURPOSE: Visual attention, normally focused on the center of the visual field, can be shifted to a location in the periphery. This process facilitates the recognition of objects in the attended region. The present experiment was designed to investigate the time course of sustained attention that is known to augment stimulus perception in normal subjects. METHODS: Cortical activity of the human brain related to shifts of the attentional focus was examined with magnetoencephalography. Subjects had to identify a stimulus presented on a screen at one of two locations in the periphery of their visual fields. Sustained attention was either deployed toward the target by a preceding cue or not. RESULTS: Results confirmed a reaction time advantage on recognizing objects in the part of the visual field where attention had been deployed. A stronger magnetic brain response was detected for noncued targets at a latency of 260 to 380 ms after target onset. Source localization revealed a neuronal generator of the attention-related component in the parietal cortex. CONCLUSIONS: Sustained attention facilitates target detection. The component that is localized in the parieto-occipital cortex in the noncued condition is thought to reflect a transient shift of attention toward the target location.

Adult↗
PubMed1993

The Wender Utah Rating Scale: an aid in the retrospective diagnosis of childhood attention deficit hyperactivity disorder.

OBJECTIVE: In an attempt to surmount the problem of retrospectively establishing the childhood diagnosis of attention deficit hyperactivity disorder, the authors constructed the 61-item Wender Utah Rating Scale (WURS) for adults to use to describe their own childhood behavior. In this paper they present their initial data collection and evaluation of the instrument's validity. METHOD: The scale was administered to 81 adult outpatients with attention deficit hyperactivity disorder, 100 "normal" adults, and 70 psychiatric adult outpatients with unipolar depression. The authors analyzed data from the 25 items of the scale that showed the greatest difference between the patients with attention deficit hyperactivity disorder and the normal comparison subjects and the relationship between the WURS and the patients' parents' judgment of childhood activity as measured by the Parents' Rating Scale. RESULTS: The patients with attention deficit hyperactivity disorder had significantly higher mean scores on all 25 items than did the two comparison groups. The difference between the mean total scores of the patients with attention deficit hyperactivity disorder and the normal subjects was also highly significant. A cutoff score of 46 or higher correctly identified 86% of the patients with attention deficit hyperactivity disorder, 99% of the normal subjects, and 81% of the depressed subjects. Correlations obtained between WURS scores and Parents' Rating Scale scores were moderate but impressive. The ability of WURS scores to predict response to methylphenidate replicated the authors' finding regarding the ability of Parents' Rating Scale scores to predict response to pemoline. CONCLUSIONS: The WURS is sensitive in identifying childhood attention deficit hyperactivity disorder and may be useful in recognizing attention deficit hyperactivity disorder in patients with ambiguous adult psychopathology.

Adult↗
PubMed1993

Anxiety and depressive disorders in attention deficit disorder with hyperactivity: new findings.

OBJECTIVE: The authors examined the discriminant validity of the diagnosis of attention deficit disorder with hyperactivity. METHOD: They used standardized rating scales of life stresses and child and family functioning to assess psychosocial and family risk factors in 47 children who had the diagnosis of attention deficit disorder with hyperactivity, a matched group of 47 children in the community, and a matched group of 47 children seen in a psychiatric clinic. RESULTS: Children who had the diagnosis of attention deficit disorder and children in the psychiatric clinic reported significantly more depression and anxiety than did the children in the community; furthermore, children diagnosed as having attention deficit disorder with hyperactivity had more externalizing symptoms than did children in the psychiatric clinic. Children diagnosed as having attention deficit disorder with hyperactivity plus a comorbid anxiety or depressive disorder had higher levels of coexisting life stresses and parental symptoms than did children who had the single diagnosis of attention deficit disorder with hyperactivity. CONCLUSIONS: These results underscore the need for future studies to carefully assess children diagnosed as having attention deficit disorder with hyperactivity for concurrent psychiatric disorders as well as family and psychosocial stressors that may contribute to childhood symptoms. Such information is essential because different subtypes of attention deficit disorder with comorbid disorders may arise from different etiologic pathways, may require varying treatment options, and may foreshadow different eventual outcomes.

Anxiety Disorders↗
PubMed2000

Attention, automaticity, and affective disorder.

This article reviews possible mechanisms for attentional bias in affective disorders and anxiety. Attentional bias is sometimes conceptualized as automatic in nature. However, there are methodological difficulties with studies purporting to demonstrate automaticity, and empirical and simulation evidence suggest that bias may be predominantly strategic. Bias in the voluntary control of attention may be driven by coping strategies, which in turn depend on appraisal of external demands, metacognitions of mental function, access of self-relevant knowledge in long-term memory, and self-focus of attention. The Self-Regulatory Executive Function (S-REF) model of emotion and attention specifies how these processes interact to influence attentional control. Clinical disorder is associated with loss of dynamic adaptability and a syndrome of perseverative rumination and worry that directs attention toward monitoring for threat and away from restructuring of maladaptive self-knowledge. Implications of the S-REF model for therapeutic interventions directed toward attentional control are discussed.

Adaptation, Psychological↗
PubMed1992

Severe problem behaviors related to social interaction. 1: Attention seeking and social avoidance.

Studies concerning the functional analysis of severe problem behaviors have suggested that it is important to identify the different categories of stimuli that control problem behavior because each has unique treatment implications. The present study explored the differential effects of adult attention on the severe problem behaviors of two groups of children with developmental disabilities. A third group of nonproblem children was examined for comparison purposes. Children participated in three experimental conditions in which the level of adult attention was manipulated: noncontingent high attention, noncontingent low attention, and contingent attention. Results validated the existence of two groups of children who differed as to their social orientation: (a) One group of children commonly initiated social interactions and was most likely to exhibit problem behaviors under conditions of low adult attention, and (b) the other group of children rarely initiated social interactions and exhibited frequent problem behaviors under conditions of high adult attention. Implications of these data for escape and attention theories of child problem behavior are discussed, as are the applied implications for reinforcer assessment and teaching strategies.

Attention↗
PubMed1993

Situation specificity in attention-seeking problem behavior. A case study.

Previous research on attention-seeking problem behavior has focused on individuals who misbehaved under general conditions of low adult attention. In general, no detailed analyses were conducted to determine whether different situations involving low levels of adult attention (such as familiar vs. unfamiliar adults, setting events, or the presence or absence of peers) exacerbated or attenuated problem behavior. The current case study demonstrates that, for one adolescent, all situations involving low levels of adult attention were not equally discriminative for problem behavior. Two functional analyses concerning different situations involving low levels of adult attention were conducted. The first analysis consisted of systematically manipulating antecedent and consequence conditions related to adult attention and task demands. This analysis indicated that low levels of adult attention evoked problem behavior. The second analysis involved two different conditions presenting low levels of adult attention. In one, the adult spoke to another child; in the second, the adult spoke to another adult. This second analysis revealed that, when the adult spoke to another adult, problem behavior resulted. However, when the adult spoke to another child, problem behavior did not occur. On the basis of these functional analyses, a positive intervention was designed to reduce problem behavior. Theoretical implications related to functional analysis are discussed, and applied issues concerning functionally based treatment selection are explored.

Adolescent↗
PubMed1991

The neuroanatomy and neurophysiology of attention.

Attention is a distributed process. The activity of neurons in many brain structures can be modulated by the attentional state of the animal. Attention directed toward a particular external stimulus is often reflected in an enhancement of the sensory response to that stimulus. Enhancement is spatially selective for neurons in many areas and explicitly eye-movement related in most. Attention directed toward the internal representation of a stimulus may be associated with a prolongation of neural activity. These modulations of neuronal responsiveness underscore the dynamic nature of neural processing. Competition between left- and right-brain structures in the control of attention is common. While attention is perceived as a unitary process, it is subserved by many brain structures. Given the wide distribution of attentional processes, it is not surprising that children diagnosed as having attentional deficits show considerable diversity in symptoms and etiology.

Animals↗
PubMed2002

Assessing the molecular genetics of attention networks.

BACKGROUND: Current efforts to study the genetic underpinnings of higher brain functions have been lacking appropriate phenotypes to describe cognition. One of the problems is that many cognitive concepts for which there is a single word (e.g. attention) have been shown to be related to several anatomical networks. Recently, we have developed an Attention Network Test (ANT) that provides a separate measure for each of three anatomically defined attention networks. RESULTS: In this study we have measured the efficiency of neural networks related to aspects of attention using the ANT in a population of 200 adult subjects. We then examined genetic polymorphisms in four candidate genes (DRD4, DAT, COMT and MAOA) that have been shown to contribute to the risk of developing various psychiatric disorders where attention is disrupted. We find modest associations of several polymorphisms with the efficiency of executive attention but not with overall performance measures such as reaction time. CONCLUSIONS: These results suggest that genetic variation may underlie inter-subject variation in the efficiency of executive attention. This study also shows that genetic influences on executive attention may be specific to certain anatomical networks rather than affecting performance in a global or non-specific manner. Lastly, this study further validates the ANT as an endophenotypic assay suitable for assessing how genes influence certain anatomical networks that may be disrupted in various psychiatric disorders.

Adolescent↗
PubMed2006

Does attentional cueing affect dichotic listening performance in children?

This study addresses the effects of verbal versus nonverbal (tone) shifts of attention on dichotic listening (DL) performance with children. Theoretically, a tonal cue may be more effective in increasing attention than a verbal cue following instruction. The inconsistency of studies reporting substantial effects of attention on ear asymmetries in children with or without learning disabilities (LDs) may be due to a developmental difference in their ability to use verbal or tone cues to select stimuli for recall. Participants included 30 right-handed children (15 control, 15 with LDs) with a mean age of 10.8 years. Each participant received 60 trials of a monaural tone cue task, 60 trials of a binaural verbal cue task, and 60 trials of a monaural verbal cue task, to direct attention to either the left or right ear before the presentation of consonant-vowel syllable pairs in a DL task. A factorial design analysis of variance yielded a significant right-ear advantage for both groups. More important, the Group x Task interaction was found to be significant, indicating that group performance on ear scores was dependent on type of cueing condition. Whereas all 3 cue conditions were effective in orienting attention for control participants, larger shifts were apparent under both binaural and monaural verbal instructional cue conditions. In contrast, participants with LD showed larger shifts of attention under the tonal cue condition. These results show that control participants have greater ability to focus attention with the use of a verbal cue, whereas participants with LD show greater ability to orient attention with the use of a tone cue in reducing error rates in DL performance.

Acoustic Stimulation↗
PubMed2006

Attentional demands and daily functioning among community-dwelling elders.

Everyday life is full of numerous demands for attention that can affect the ability to function. For elders, examples of these attentional demands include negotiating public transportation and driving, sensory losses, and physical discomforts and worries that make it harder to concentrate and complete tasks. The purpose of this study was to examine the relation between attentional demands and the ability to manage daily activities requiring concentration for 54 community-dwelling elders (34 women, 20 men). As theorized, attentional demands correlated (r = -.58) significantly with daily functioning: Elders with more attentional demands perceived themselves as having greater difficulty managing tasks requiring concentration. Attentional demands accounted for a significant proportion of variance in functioning (12%), even after partialling out the effects of depressive symptoms and health. Findings support the theorized relation between attentional demands and daily functioning, as well as nursing interventions aimed at decreasing attentional demands to promote effective functioning for elders.

Activities of Daily Living↗
PubMed2002

Fluctuations in attention: PD dementia vs DLB with parkinsonism.

BACKGROUND: Marked impairments in and fluctuation of attention are characteristic of dementia with Lewy bodies (DLB). The comparative impairment of these cognitive domains in PD and PD dementia (PD dementia) has not been studied, and is important to the conceptual understanding of parkinsonian dementias. METHOD: Detailed evaluations of attention and fluctuating attention (Cognitive Drug Research computerized battery) were undertaken in 278 subjects (50 DLB, 48 PD dementia, 50 PD, 80 AD, 50 elderly controls) from the Newcastle dementia register and the Stavanger PD register (controls, PD, and PD dementia patients were recruited from both centers). DLB, AD, PD, and PD dementia were diagnosed using operationalized criteria. RESULTS: Impairments in reaction time, vigilance, and fluctuating attention were comparable in patients with DLB and PD dementia, but were less substantially impaired in patients with DLB without parkinsonism. Patients with PD had significantly greater impairment of cognitive reaction time than elderly controls, and comparable impairments of cognitive reaction time to patients with AD. Patients with PD, however, did not exhibit fluctuation of attention. CONCLUSION: The profile of attentional impairments and fluctuating attention is similar in PD dementia and DLB with parkinsonism. The current findings do not support the current arbitrary distinctions between these patient groups. Importantly, patients with PD do not experience fluctuating attention.

Aged↗
PubMedDate not supplied

Attentional processing in hyperthyroid children before and after treatment.

To determine whether specific components of attentional processing may be differentially disrupted during thyrotoxicosis, nine children with hyperthyroidism were assessed for intelligence and attention before and after one year of therapy. The attention test allowed for measurement of sustain, disengage, and shift subcomponents of attentional processing. Comparison with pediatric controls revealed lower nonverbal intelligence during thyrotoxicosis, which improved to normal following euthyroidism. On the attention task, an effect was observed during thyrotoxicosis only on the shift and disengage functions of attentional processing but not sustain. Attention results were unrelated to self-reported anxiety at time of testing. Results are discussed in terms of thyroid hormone activation of the prefrontal cortex, which is thought to be the cerebral substrate underlying the shift and disengage functions of attentional processing.

Anxiety↗
PubMed2005

An event-related functional magnetic resonance imaging study of voluntary and stimulus-driven orienting of attention.

Attention can be voluntarily directed to a location or automatically summoned to a location by a salient stimulus. We compared the effects of voluntary and stimulus-driven shifts of spatial attention on the blood oxygenation level-dependent signal in humans, using a method that separated preparatory activity related to the initial shift of attention from the subsequent activity caused by target presentation. Voluntary shifts produced greater preparatory activity than stimulus-driven shifts in the frontal eye field (FEF) and intraparietal sulcus, core regions of the dorsal frontoparietal attention network, demonstrating their special role in the voluntary control of attention. Stimulus-driven attentional shifts to salient color singletons recruited occipitotemporal regions, sensitive to color information and part of the dorsal network, including the FEF, suggesting a partly overlapping circuit for endogenous and exogenous orienting. The right temporoparietal junction (TPJ), a core region of the ventral frontoparietal attention network, was strongly modulated by stimulus-driven attentional shifts to behaviorally relevant stimuli, such as targets at unattended locations. However, the TPJ did not respond to salient, task-irrelevant color singletons, indicating that behavioral relevance is critical for TPJ modulation during stimulus-driven orienting. Finally, both ventral and dorsal regions were modulated during reorienting but significantly only by reorienting after voluntary shifts, suggesting the importance of a mismatch between expectation and sensory input.

Adult↗