Dissociation between top-down attentional control and the time course of visual attention as measured by attentional dwell time in patients with mild cognitive impairment

Objective: The aim of this study was to determine which characteristics could better distinguish dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) at the mild cognitive impairment (MCI) stage, with particular emphasis on visual space and object perception abilities. Methods: Fifty-three patients with mild cognitive deficits that were eventually diagnosed with probable DLB (MCI-DLB: n = 25) and AD (MCI-AD: n = 28) at a 3-year follow-up were retrospectively studied. At the first visit, the patients underwent cognitive assessment including the Qualitative Scoring Mini Mental State Examination Pentagon Test and the Visual Object and Space Perception Battery. The Neuropsychiatric Inventory Questionnaire, Unified Parkinson's Disease Rating Scale (UPDRS) and questionnaires for cognitive fluctuations and sleep disorders were also administered. Results: The best clinical predictor of DLB was the presence of soft extrapyramidal signs (mean UPDRS score: 4.04 ± 5.9) detected in 72% of patients, followed by REM sleep behavior disorder (60%) and fluctuations (60%). Wrong performances in the pentagon's number of angles were obtained in 44% of DLB and 3.7% of AD patients and correlated with speed of visual attention. Executive functions, visual attention and visuospatial abilities were worse in DLB, while verbal episodic memory impairment was greater in AD. Deficits in the visual-perceptual domain were present in both MCI-DLB and AD. Conclusions: Poor performance in the pentagon's number of angles is specific of DLB and correlates with speed of visual attention. The dorsal visual stream seems specifically more impaired in MCI-DLB with respect to the ventral visual stream, the latter being involved in both DLB and AD. These cognitive features, associated with subtle extrapyramidal signs, should alert clinicians to a diagnostic hypothesis of DLB.

Download Full-text

Young skilled deaf readers have an enhanced perceptual span in reading

Quarterly Journal of Experimental Psychology ◽

10.1080/17470218.2017.1324498 ◽

2018 ◽

Vol 71 (1) ◽

pp. 291-301 ◽

Cited By ~ 4

Author(s):

Nathalie N Bélanger ◽

Michelle Lee ◽

Elizabeth R Schotter

Keyword(s):

Visual Attention ◽

Attentional Control ◽

Time Course ◽

Visual Stimuli ◽

Reading Level ◽

Deaf Children ◽

Moving Window ◽

Perceptual Span ◽

Deaf Readers ◽

Deaf Adults

Recently, Bélanger, Slattery, Mayberry and Rayner showed, using the moving-window paradigm, that profoundly deaf adults have a wider perceptual span during reading relative to hearing adults matched on reading level. This difference might be related to the fact that deaf adults allocate more visual attention to simple stimuli in the parafovea. Importantly, this reorganization of visual attention in deaf individuals is already manifesting in deaf children. This leads to questions about the time course of the emergence of an enhanced perceptual span (which is under attentional control) in young deaf readers. The present research addressed this question by comparing the perceptual spans of young deaf readers (age 7-15) and young hearing readers (age 7-15). Young deaf readers, like deaf adults, were found to have a wider perceptual span relative to their hearing peers matched on reading level, suggesting that strong and early reorganization of visual attention in deaf individuals goes beyond the processing of simple visual stimuli and emerges into more cognitively complex tasks, such as reading.

Download Full-text