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Ipsilesional deficit of selective attention in left homonymous hemianopia and left unilateral spatial neglect
- Source :
- Neuropsychologia, Neuropsychologia, Elsevier, 2019, 108, pp.305-314. ⟨10.1016/j.neuropsychologia.2018.03.013⟩, Neuropsychologia, Elsevier, 2019, 128, pp.305-314. ⟨10.1016/j.neuropsychologia.2018.03.013⟩
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- Aims Patients with homonymous hemianopia may present a subtle ipsilesional deficit, recently referred to as ‘sightblindness’ in addition to the contralesional visual field defect. We recently demonstrated that this deficit could be worse in right brain-damaged patients with left hemianopia than in left brain-damaged patients with right hemianopia, confirming right hemisphere dominance for visuo-spatial and attentional capacities. In the present study we investigate whether this ipsilesional deficit could be attentional in nature and to what extent it is comparable in right brain-damaged (RBD) patients with left hemianopia and in RBD patients with left neglect. The study was also conducted in RBD patients with neither left hemianopia nor left neglect signs in order to test if a right hemisphere lesion per se could be responsible for subtle ipsilesional attentional deficit. To reach this aim, we tested selective attentional capacities in both visual fields of 10 right brain-damaged patients with left neglect (LN), 8 right brain-damaged patients with left homonymous hemianopia (LHH), 8 right brain-damaged patients with no signs of left neglect or left hemianopia (RBD controls), and 17 healthy age-matched participants (Normal controls). Method A lateralized letter-detection task was used to test if right-brain damaged patients with LN or LH may present a deficit of selective attention in their right, ipsilesional visual field, in comparison to Normal and RBD controls. Participants were asked to detect a target letter in either a single large stimulus (low attentional load) or a small stimulus surrounded by flankers (high attentional load). Stimuli were displayed either in the left or in the right visual field. Accuracy and reaction times were recorded. Results Results on accuracy showed that both LN and LH patients exhibited lower correct responses than Normal controls in their ipsilesional right visual field, suggesting an attentional deficit in their ipsilesional, supposed healthy visual field. More specifically, LH patients exhibited a specific deficit for processing single large stimuli, but not for processing flanked stimuli, relative to normal controls. LN patients exhibited lower correct responses for processing all types of stimulus than normal controls, but also than right brain damaged controls, in both visual fields suggesting a non-lateralized deficit not only due to the right hemisphere lesion. Furthermore, this deficit is more pronounced for flanked small stimuli, requiring higher attentional load. Conclusions The present results bring further evidence that patients with left homonymous hemianopia or left unilateral neglect both present a weaker but significant ipsilesional deficit in addition to their well-known massive contralesional deficit. The presence of a specific attentional deficit in the right ipsilesional visual field of left hemianopic and left neglect patients is discussed regarding the hypothesis of hemispheric specialization for selective spatial attention and may have clinical implications for both conditions.
- Subjects :
- Male
medicine.medical_specialty
Cognitive Neuroscience
media_common.quotation_subject
selective attention
Experimental and Cognitive Psychology
Unilateral spatial neglect
Audiology
Stimulus (physiology)
Functional Laterality
050105 experimental psychology
Lateralization of brain function
Neglect
Perceptual Disorders
Lesion
[SCCO]Cognitive science
03 medical and health sciences
Behavioral Neuroscience
0302 clinical medicine
Reaction Time
medicine
Humans
Attention
0501 psychology and cognitive sciences
Selective attention
ComputingMilieux_MISCELLANEOUS
Aged
media_common
hemispheric specialization
[SCCO.NEUR]Cognitive science/Neuroscience
05 social sciences
PhD
Middle Aged
eye diseases
Visual field
Reading
Unilateral neglect
sighblindness
[SCCO.PSYC]Cognitive science/Psychology
Hemianopsia
Visual Field Tests
Homonymous hemianopia
Visual Fields
medicine.symptom
Psychology
Psychomotor Performance
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 00283932 and 18733514
- Volume :
- 128
- Database :
- OpenAIRE
- Journal :
- Neuropsychologia
- Accession number :
- edsair.doi.dedup.....f3e4f4c81b6ec37150259160c07dc0fa