Deficits In Divided Attention Research Articles

Effects of amateur choir experience on forced-attention dichotic listening in older adults

This study aimed to investigate the effects of amateur choir experience on “forced-attention” dichotic listening performance in older adults. Twenty older adults with choir experience and 20 without such experience were recruited, along with a group of 20 younger adults as the baseline. Participants were instructed to complete the dichotic listening task based on consonant-vowel (CV) syllables in four attentional conditions, that is, non-forced, forced-left, forced-right, and divided attention conditions. The results showed that choir experience may offset age-related deficits in temporal processing, inhibitory control, and divided attention in the non-forced, forced-left, and divided attention conditions, respectively. But in the forced-right condition where the orienting process was required, two groups of older adults performed similarly, comparable with the younger group. Our findings support the OPERA-e hypothesis and underscore the effects of amateur musical activities against declines in temporal processing, inhibitory control, and divided attention in aging populations.

A review of the effect of alcohol hangover on attention and memory

Alcohol hangover (AH) refers to adverse mental and physical symptoms after a heavy consumption of alcoholic drinks, which had a significant effect on socioeconomic development and drew a huge amount of interest among psychologists in recent years. Studies found that AH mainly affected peoples cognitive performances, especially memory and attention functioning, while the findings in this field were controversial. This paper aimed to review the articles and examine the effects of AH on attention and memory by focusing on their cognitive subdomains and different study designs to find explanations for their inconsistent results. The review article showed that among attention functioning, psychologists found consistent damaging effects of AH on selective attention and sustained attention behaviors whereas the effects of divided attention performance were inconsistent. Moreover, insufficient attentional resources were regarded as the mechanism of divided attention deficit during the AH state. Among studies of memory functioning, the encoding phase was believed to be a significant factor for impaired retrospective memory performance during the AH state compared with the retrieval phase, while the effect of the memory retrieval process was not clearly tested during AH. In addition, the AH state also negatively affected the prospective memory ability to implement behaviors at a specific future time or place. The distinct study methodologies (laboratory vs. naturalistic studies; within-subject vs. between-subject design; student vs. non-student sample) were suggested to be the contributors to these conflicting results.

Cognitive parameters can predict change of walking performance in advanced Parkinson's disease - Chances and limits of early rehabilitation.

Links between cognition and walking performance in patients with Parkinson's disease (PD), which both decline with disease progression, are well known. There is lack of knowledge regarding the predictive value of cognition for changes in walking performance after individualized therapy. The aim of this study is to identify relevant predictive cognitive and affective parameters, measurable in daily clinical routines, for change in quantitative walking performance after early geriatric rehabilitation. Forty-seven acutely hospitalized patients with advanced PD were assessed at baseline (T1) and at the end (T2) of a 2-week early rehabilitative geriatric complex treatment (ERGCT). Global cognitive performance (Montreal Cognitive Assessment, MoCA), EF and divided attention (Trail Making Test B minus A, delta TMT), depressive symptoms, and fear of falling were assessed at T1. Change in walking performance was determined by the difference in quantitative walking parameters extracted from a sensor-based movement analysis over 20 m straight walking in single (ST, fast and normal pace) and dual task (DT, with secondary cognitive, respectively, motor task) conditions between T1 and T2. Bayesian regression (using Bayes Factor BF10) and multiple linear regression models were used to determine the association of non-motor characteristics for change in walking performance. Under ST, there was moderate evidence (BF10 = 7.8, respectively, BF10 = 4.4) that lower performance in the ∆TMT at baseline is associated with lower reduction of step time asymmetry after treatment (R 2 adj = 0.26, p ≤ 0.008, respectively, R 2 adj = 0.18, p ≤ 0.009). Under DT walking-cognitive, there was strong evidence (BF10 = 29.9, respectively, BF10 = 27.9) that lower performance in the ∆TMT is associated with more reduced stride time and double limb support (R 2 adj = 0.62, p ≤ 0.002, respectively, R 2 adj = 0.51, p ≤ 0.009). There was moderate evidence (BF10 = 5.1) that a higher MoCA total score was associated with increased gait speed after treatment (R 2 adj = 0.30, p ≤ 0.02). Our results indicate that the effect of ERGT on change in walking performance is limited for patients with deficits in EF and divided attention. However, these patients also seem to walk more cautiously after treatment in walking situations with additional cognitive demand. Therefore, future development of individualized treatment algorithms is required, which address individual needs of these vulnerable patients.

Technological Solutions for Diagnosis, Management and Treatment of Alzheimer's Disease-Related Symptoms: A Structured Review of the Recent Scientific Literature.

In people with Alzheimer’s disease (PwAD), there is a need for specific tools for the timely diagnosis, management, and treatment of symptoms. New technological solutions, including digital devices, application programs (apps), sensors and virtual reality, represent promising possibilities for objective and reliable assessment, monitoring and intervention strategies in this field. Our structured review presents an up-to-date summary of the technological solutions for the (i) diagnosis, (ii) management and (iii) treatment of AD-related symptoms. To this end, we searched electronic databases (i.e., PubMed, Web of Science, and Cochrane Library) for studies published over the last 10 years. Two authors of the review extracted data of interest. A total of eight manuscripts were included. In the last decade, a series of technological solutions across AD stages have been proposed. These include: (i) innovative strategies for the early detection of deficits in finger dexterity, visuo-spatial abilities (including spatial navigation), divided attention and instrumental autonomy; (ii) tools to activate the patient’s responsiveness in terms of alertness and mood improvement; and (iii) useful interventions for retrieving memories, increasing body movements and improving spatial cognition. Methodological limitations, mainly pertaining to the paucity of randomized controlled trials and comprehensive assessments, were observed. Advances in technology currently provide the potential for designing innovative methods for evaluating, controlling and handling AD-related symptoms. The co-creation of technological solutions with all stakeholders represents the best way to design effective strategies for PwAD.

Effects of hemoencephalographic biofeedback with virtual reality on selected aspects of attention in children with ADHD

For children with attention deficit/hyperactivity disorder (ADHD), a reduction of inattention by biofeedback has been shown in several studies. As evidenced by previous reports, biofeedback (BFB) with virtual reality (VR) allows for controlling distractors, providing an environment that captures participants' attention. The purpose of this study was to evaluate the effects of hemoencephalographic (HEG) BFB with VR in treating deficits in vigilance (assessed using the short form of the Mackworth Clock Task), visual search (the Visual Search Task), and divided attention (Multitasking Test) among children with ADHD. Data subjected to analysis were collected from 87 participants aged 9–15 years. Children were assigned to one of three groups (standard 2D BFB in the lab, VR BFB with a limited visual scene, VR BFB with a complex visual scene) and were subjected to ten HEG BFB sessions. Children in the VR BFB groups exhibited a bigger regional cerebral blood oxygenation slope during BFB and better performance in cognitive tests following the experiment compared to children in the 2D BFB group. The data obtained suggest that HEG BFB with VR may have a more beneficial effect in treating attention deficits compared to standard 2D HEG BFB. We believe that the strong effects of HEG BFB with VR stem from the increased commitment and motivation in individuals, rather than from manipulation with regard to visual scene complexity.

Cross-sectional associations between cognition and mobility in Parkinson’s disease

ABSTRACT.Cross-sectional studies show an association of decline in mental flexibility and inhibitory control with reduced gait speed and falls, as well as divided attention deficit and difficulty in initiating gait.Objective:To investigate the relationships between cognitive function and gait performance in patients with Parkinson’s disease (PD) who participated in a hospital neurorehabilitation program.Methods:A total of 107 patients (79 males, 28 females; mean age 61.00±8.2 years; mean schooling 11.7±4.1 years) with idiopathic PD (mean disease duration 5.5±4.1 years) were recruited for this study. Among them, 78.50% were in stages I and II of the Hoehn & Yahr Scale. Cognitive functions were evaluated through the Digit Span test, Trail Making Test, and Addenbrooke’s Cognitive Examination III. Motor function was assessed with the 10-Meter Walk Test, the short version of the Balance Evaluation Systems Test (Mini-BESTest), and the Timed Up and Go Test.Results:Balance skills were significantly correlated with global cognition and specific domains, including divided attention, verbal fluency, and visuospatial function. Functional mobility showed a significant association with all cognitive tests, except for the number of errors on TMT-A. Gait speed presented a significant correlation with global cognition scores, memory, and attention, including divided attention.Conclusions:These findings might help early identification of cognitive deficits or motor dysfunctions in PD patients who may benefit from rehabilitation strategies, as well as facilitate fall risk assessments and strategies to prevent falls. Future prospective studies are needed to investigate the effects of cognitive training on motor performance, since the difficulty in motor rehabilitation may be more related to cognitive loss than to motor damage.

Age-related changes in gaze sampling strategies during obstacle navigation

BackgroundAppropriate coordination of gaze behavior and body motion is essential for navigating cluttered environments. This is often complicated by having to contend with a concurrent secondary task, like engaging in a conversation or looking for relevant landmarks. However, there is little evidence of how aging and multitasking affects how gaze is deployed during obstacle navigation to guide our movements. Research questionHow do gaze patterns differ between young and older adults when navigating around a series of obstacles under dual-task conditions? Methods17 young adults and 17 older adults navigated around vertically-oriented obstacles in isolation (i.e., single-task condition) and while engaging in a concurrent backward-counting or visual search task (i.e., dual-task conditions). In the visual search condition, participants had to identify the location of an object (i.e., a black shape on a tile) along the perimeter of the pathway, simulating a landmark. We quantified the spatial-temporal pattern of gaze to obstacles relative to body position, as well as the frequency and duration of gaze fixations to obstacles, route-planning features, and landmarks. ResultsWe found that older adults transferred gaze away from obstacles earlier and contacted obstacles more frequently than young adults. However, the proportion of fixation number and duration to obstacles did not differ between groups in any condition. In addition, older adults had to allocate gaze to landmarks to a greater extent in the visual search condition—at the expense of fixating route-planning areas—to maintain similar search performance in the dual-task condition compared to the single-task condition. SignificanceOlder adults use different gaze strategies and have greater difficulty under dual-tasking conditions than young adults when navigating around a series of obstacles. We suggest that deficits in visual working memory and/or divided attention may explain these results.

Association Between Fatigue and Cognitive Impairment at 6 Months in Patients With Ischemic Stroke Treated With Acute Revascularization Therapy.

Background: Fatigue is a frequent symptom after stroke. We aimed to determine the association between fatigue and cognitive performance in patients with ischemic stroke who received acute revascularization therapy (IV thrombolysis and/or mechanical thrombectomy).Methods: Seventy patients were prospectively included in the stroke unit of the University Hospital of Dijon, France. A follow-up was performed at 6 months with clinical examination, fatigue assessment by the Fatigue Severity Scale (FSS), and a comprehensive neuropsychological evaluation. Patients with fatigue (FSS score >4) were compared with patients without fatigue. Neuropsychological factors associated with fatigue at 6 months were analyzed using multivariable logistic regression models.Results: Fatigue was reported by 34.3% of patients. Patients with fatigue were older, had more frequent residual handicap, depressive symptoms, and impaired quality of life. They had more frequently low score (<26) on the MoCA scale (79.2 vs. 47.8%, OR = 4.15; 95% CI: 1.32–13, p = 0.015), memory impairment (60 vs. 30.6%, OR = 3.41; 95% CI: 1.09–10.7, p = 0.035), and executive dysfunction (65 vs. 30.8%, OR = 4.18; 95% CI: 1.33–13.1, p = 0.014). In multivariable logistic regression analysis, only memory impairment was independently associated with fatigue (OR = 5.70; 95% CI: 1.09–29.6, p = 0.039). Further analyses restricted to non-depressed patients (n = 58, 84.1%) showed in multivariable models that a score < 26 on MoCA scale (OR 5.12; 95% CI: 1.00–26.2, p = 0.05), and a memory impairment (OR = 6.17; 95% CI: 1.06–35.9, p = 0.043) were associated with fatigue. There was also a non-significant trend toward an association between divided attention deficit and fatigue (OR = 6.79; 95% CI: 0.80–57.6, p = 0.079).Conclusion: The association between fatigue and subtle cognitive impairment including memory or attention deficits could be of interest in elaborating future interventional studies to evaluate the impact of therapeutic strategies, including cognitive rehabilitation, on fatigue.

The Relationship between Types of Attention and Auditory Processing Skills: Reconsidering Auditory Processing Disorder Diagnosis.

Measures of attention have been found to correlate with specific auditory processing tests in samples of children suspected of Auditory Processing Disorder (APD), but these relationships have not been adequately investigated. Despite evidence linking auditory attention and deficits/symptoms of APD, measures of attention are not routinely used in APD diagnostic protocols. The aim of the study was to examine the relationship between auditory and visual attention tests and auditory processing tests in children with APD and to assess whether a proposed diagnostic protocol for APD, including measures of attention, could provide useful information for APD management. A pilot study including 27 children, aged 7–11 years, referred for APD assessment was conducted. The validated test of everyday attention for children, with visual and auditory attention tasks, the listening in spatialized noise sentences test, the children's communication checklist questionnaire and tests from a standard APD diagnostic test battery were administered. Pearson's partial correlation analysis examining the relationship between these tests and Cochrane's Q test analysis comparing proportions of diagnosis under each proposed battery were conducted. Divided auditory and divided auditory-visual attention strongly correlated with the dichotic digits test, r = 0.68, p < 0.05, and r = 0.76, p = 0.01, respectively, in a sample of 20 children with APD diagnosis. The standard APD battery identified a larger proportion of participants as having APD, than an attention battery identified as having Attention Deficits (ADs). The proposed APD battery excluding AD cases did not have a significantly different diagnosis proportion than the standard APD battery. Finally, the newly proposed diagnostic battery, identifying an inattentive subtype of APD, identified five children who would have otherwise been considered not having ADs. The findings show that a subgroup of children with APD demonstrates underlying sustained and divided attention deficits. Attention deficits in children with APD appear to be centred around the auditory modality but further examination of types of attention in both modalities is required. Revising diagnostic criteria to incorporate attention tests and the inattentive type of APD in the test battery, provides additional useful data to clinicians to ensure careful interpretation of APD assessments.

Effect of Age on Attentional Control in Dual-Tasking

Background/Study Context: The age-related differences in divided attention and attentional control have been associated with several negative outcomes later in life. However, numerous questions remain unanswered regarding the nature of these age differences and the role of attentional control abilities in dual-tasking. The aim of this study was to evaluate the sources for age differences in dual-tasking and more specifically: (1) whether they occur because of differences in attentional control skills, or (2) whether the age-related decrement in dual-tasking is due to a general resource reduction that would affect the ability to complete any demanding task.Methods: In two experiments, young and older adults were required to combine an auditory digit span task and a visuospatial tracking task, for which performance was individually adjusted on each task. In Experiment 1, attentional control skills were measured by instructing participants to deliberately vary attentional priority between the two tasks. In Experiment 2, resource availability was measured by varying the level of difficulty of the visuospatial tracking task in a parametric manner by increasing the speed of the target to be tracked.Results: Both experiments confirmed the presence of a larger dual-task cost in older adults than in young adults. In Experiment 1, older participants were unable to vary their performance according to task instructions compared with younger adults. Experiment 2 showed that the age-related difference in dual-task cost was not amplified by a variation in difficulty.Conclusion: A marked age-related difference was found in the ability to control attentional focus in response to task instructions. However, increasing resource demand in a parametric manner does not increase the age-related differences in dual-tasking, suggesting that the difficulties experienced by older adults cannot be entirely accounted for by an increased competition for resources. A reduction in attentional control skills is proposed to account for the divided attention deficit reported in aging.

Cognitive dysfunction in adult CHD with different structural complexity.

We carried out a cross-sectional study to assess cognitive function in a sample of adult CHD patients, within the Functioning in Adult Congenital Heart Disease study London. The association between cognitive functioning and disease complexity was examined. A total of 310 patients participated in this study. Patients were classified into four structural complexity groups - tetralogy of Fallot, transposition of the great arteries, single ventricle, and simple conditions. Each patient underwent neuropsychological assessment to evaluate cognitive function, including memory and executive function, and completed questionnaires to assess depression and anxiety. Among all, 41% of the sample showed impaired performance (>1.5 SD below the normative mean) on at least three tests of cognitive function compared with established normative data. This was higher than the 8% that was expected in a normal population. The sample exhibited significant deficits in divided attention, motor function, and executive functioning. There was a significant group difference in divided attention (F=5.01, p=0.002) and the mean total composite score (F=5.19, p=0.002) between different structural complexity groups, with the simple group displaying better cognitive function. The results indicate that many adult CHD patients display impaired cognitive function relative to a healthy population, which differs in relation to disease complexity. These findings may have implications for clinical decision making in this group of patients during childhood. Possible mechanisms underlying these deficits and how they may be reduced or prevented are discussed; however, further work is needed to draw conclusive judgements.

An event-related potential study of visual spatial attention span in children with Chinese learning disability

Objective To explore whether there is a visual spatial attention span deficit in children with Chinese language learning disability and the characteristics of brain electrophysiological dynamic change. Methods Adopting event-related potentials(ERP) technology and levels of visual spatial attention span with fixed location cuing pa-radigm were used to explore the characteristics of brain electrophysiological dynamic change. Results Based on the behavioral data, the repeated findings of analysis of variance on reaction time showed that both the main effect of the type of subjects[F(1, 35)=4.34, P<0.05, η2=0.11], and the main effect of attention span[F(1, 35)=138.75, P<0.001, η2=0.79] had statistical significance.The repeated analysis of variance on accuracy showed that the main effect of subjects type[F(1, 35)=4.99, P<0.05, η2=0.13], and the main effect of attention span[F(1, 35)=101.83, P<0.01, η2=0.74] were significantly different.Under large and small attention span conditions, the children with Chinese language learning disability showed a longer time of reaction and a lower accuracy rate than the children in the control group.With the electroencephalograph(EEG) data and under large and small attention span conditions, the Chinese learning disability children showed enhanced P1 amplitude and reduced N1 amplitude. Conclusions There is a visual spatial attention span deficit in children with Chinese learning disability which may be caused by a weak primary sensory processing ability and divided attention deficit. Key words: Chinese learning disability; Attention span; Event-related potential; Child

Attention dysfunction subtypes of developmental dyslexia.

BackgroundPrevious studies indicate that many different aspects of attention are impaired in children diagnosed with developmental dyslexia (DD). The objective of the present study was to identify cognitive profiles of DD on the basis of attentional test performance.Material/Methods78 children with DD (30 girls, 48 boys, mean age of 12 years ±8 months) and 32 age- and sex-matched non-dyslexic children (14 girls, 18 boys) were examined using a battery of standardized tests of reading, phonological and attentional processes (alertness, covert shift of attention, divided attention, inhibition, flexibility, vigilance, and visual search). Cluster analysis was used to identify subtypes of DD.ResultsDyslexic children showed deficits in alertness, covert shift of attention, divided attention, flexibility, and visual search. Three different subtypes of DD were identified, each characterized by poorer performance on the reading, phonological awareness, and visual search tasks. Additionally, children in cluster no. 1 displayed deficits in flexibility and divided attention. In contrast to non-dyslexic children, cluster no. 2 performed poorer in tasks involving alertness, covert shift of attention, divided attention, and vigilance. Cluster no. 3 showed impaired covert shift of attention.ConclusionsThese results indicate different patterns of attentional impairments in dyslexic children. Remediation programs should address the individual child’s deficit profile.

Sinais comportamentais dos Transtornos do Déficit de Atenção com Hiperatividade e do Processamento Auditivo: a impressão de profissionais brasileiros

OBJETIVO: Caracterizar os sinais comportamentais do Transtorno do Déficit de Atenção com Hiperatividade (TDAH) e do Transtorno do Processamento Auditivo (TPA), segundo a visão de profissionais que atuam no diagnóstico e intervenção relacionados a estes transtornos no Brasil. MÉTODOS: Participaram 42 profissionais (médicos, fonoaudiólogos, psicólogos e pedagogos). Todos responderam a um questionário contendo 58 sinais comportamentais de TDAH e TPA. Cada participante foi orientado a classificar os comportamentos de acordo com a frequência de ocorrência, elencando-os em categorias de 1 (nunca) a 5 (sempre). Os valores da média geral deste estudo foram comparados aos valores da média apresentados em estudo norte americano similar. RESULTADOS: Verificou-se que alguns sinais comportamentais foram mais citados do que outros em ambos os transtornos. No TDAH os sinais comportamentais mais evidentes foram: dificuldade em brincar silenciosamente, distraído, desorganizado, desatento, hiperativo, irrequieto, muda de um trabalho incompleto para o outro, pouco autocontrole, falta de persistência e apressado ou impulsivo. No TPA os sinais comportamentais mais evidentes foram: déficit na atenção auditiva dividida, déficit na atenção auditiva seletiva, dificuldade em seguir instruções orais, habilidade de associação auditiva ruim, dificuldade de ouvir em ambiente ruidoso, déficit na atenção auditiva sustentada, dificuldade em discriminar fala e taxa reduzida de processamento da informação auditiva. CONCLUSÃO: Foi possível concluir que os profissionais classificaram determinados sinais comportamentais como mais evidentes no TDAH e outros mais evidentes no TPA.

Attentional control in patients with temporal lobe epilepsy

Across different studies, patients with temporal lobe epilepsy (TLE) demonstrate impairments on numerous measures of attentional control that are classically associated with frontal lobe functioning. One aspect of attentional control that has not been examined in TLE is the ability to execute two modality-specific tasks concurrently. We sought to examine the status of dual-task coordination in TLE. We further examined the cohorts' performance on a range of traditional measures of attentional control. Eighteen TLE patients and 22 healthy controls participated in the study. Dual-task performance involved comparing the capacity to execute a tracking and a digit recall task simultaneously with the capacity to execute the tasks separately. We also administered measures of: set shifting (odd-man-out test), sustained attention (elevator counting), selective attention (elevator counting with distraction), and divided attention (trail making test). We found that the proportional decrement in dual-task performance relative to single-task performance did not vary between the groups (TLE=92.48%; controls=93.70%), nor was there a significant difference in sustained attention (p>.10). Patients with TLE did demonstrate marked deficits in selective attention (p<.0001), divided attention (p<.01), and set shifting (p<.01). These findings add to the knowledge about cognitive dysfunction in TLE, indicating that impairments in attentional control in TLE tend to be selective. The greatest deficits appear to be on tasks that invoke a high level of processing resources. In contrast, sustained attention is less compromised and the capacity to allocate cognitive resources appears to be normal in patients with TLE.

IC‐P‐052: Divided attention deficits in prodromal Alzheimer's disease at the stage of amnestic mild cognitive impairment

IC‐P‐052: Divided attention deficits in prodromal Alzheimer's disease at the stage of amnestic mild cognitive impairment

Cognitive Dysfunctions after Recovery from Major Depressive Episodes

Although recent studies have indicated that cognitive dysfunctions may persist after recovery from a major depressive episode (MDE), the claim remains controversial. To clarify this clinically important issue, we investigated the cognitive functions of people who had experienced one or more MDE, after controlling for several confounding variables: differences in (a) medications, (b) age ranges, and (c) disorder characteristics. Neuropsychological tests for memory, attention, and executive function were employed to compare 12 recovered depressed participants who had fully met the criteria for MDE to 30 participants who had partially met the criteria or had not met them at all. The recovered depressed participants were impaired on tasks of verbal learning and memory and selective or divided attention in contrast to others. After an alpha correction was applied, the deficits in divided attention remained significant. These cognitive shortfalls also distinguished people who had experienced an MDE from those who had partially experienced them or had not experienced them at all. We suggest that the experience of an MDE may have a persistent negative influence on cognitive functions, particularly on their higher levels, such as divided attention.

Attention Skills in Children With Neurofibromatosis Type 1

Children with neurofibromatosis type 1 are at increased risk for the development of attention problems relative to their unaffected peers. Previous studies have reported deficits in sustained auditory attention, but other aspects of attention, including sustained visual attention, divided attention, response inhibition, and selective attention, have not been consistently documented. In the present study, we specifically investigated attention skills in children with neurofibromatosis type 1 using measures of visual and sustained auditory attention, divided attention, selective attention, and response inhibition. Consistent with previous reports, we confirmed the presence of deficits in sustained visual and auditory attention in children with neurofibromatosis type 1 but also identified deficits in divided attention and response inhibition. Based on the high frequency and wide spectrum of attention system impairments in this at-risk population, we advocate screening children with neurofibromatosis type 1 for attention problems and providing appropriate interventions that address all aspects of their executive functioning.

Dual-task conditions modulate the efficiency of selective attention mechanisms in Alzheimer's disease

Given previous demonstrations of both selective and divided attention deficits in Alzheimer's disease (AD) patients, understanding how declines in the integrity of component processes of selective attention in these patients interact with impairments to executive processes mediating dual-task performance has both theoretical and practical relevance. To address this issue, healthy elderly and AD patients performed computerized tasks of spatial orienting, Simon response interference, and visual search both in isolation and while simultaneously engaged in a visuomotor tracking task (i.e., maintaining car position within a simulated driving environment). Results from the single-task conditions confirmed previous demonstrations of selective attention deficits in AD. Dual-task conditions produced in AD patients (but not healthy elderly) a change in the efficiency of the selective attention mechanisms themselves, as reflected in differential effects on cue or display conditions within each task. Rather than exacerbating the selective attention deficits observed under single-task conditions, however, dual-task conditions produced an apparent diminution of these deficits. We suggest this diminution is due to the combination of deficient top-down inhibitory processes along with a decrease in the attention-capturing properties of cue information under dual-task conditions in AD patients. These findings not only increase our understanding of the nature of the attentional deficits in AD patients, but also have implications for understanding the processes mediating attention in neurologically intact individuals.

Dual-task conditions modulate the efficiency of selective attention mechanisms in Alzheimer's disease

Given previous demonstrations of both selective and divided attention deficits in Alzheimer's disease (AD) patients, understanding how declines in the integrity of component processes of selective attention in these patients interact with impairments to executive processes mediating dual-task performance has both theoretical and practical relevance. To address this issue, healthy elderly and AD patients performed computerized tasks of spatial orienting, Simon response interference, and visual search both in isolation and while simultaneously engaged in a visuomotor tracking task (i.e., maintaining car position within a simulated driving environment). Results from the single-task conditions confirmed previous demonstrations of selective attention deficits in AD. Dual-task conditions produced in AD patients (but not healthy elderly) a change in the efficiency of the selective attention mechanisms themselves, as reflected in differential effects on cue or display conditions within each task. Rather than exacerbating the selective attention deficits observed under single-task conditions, however, dual-task conditions produced an apparent diminution of these deficits. We suggest this diminution is due to the combination of deficient top-down inhibitory processes along with a decrease in the attention-capturing properties of cue information under dual-task conditions in AD patients. These findings not only increase our understanding of the nature of the attentional deficits in AD patients, but also have implications for understanding the processes mediating attention in neurologically intact individuals.