Ipsilesional deficit of selective attention in left homonymous hemianopia and left unilateral spatial neglect

Abstract

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.

Ipsilesional Impairments of Visual Awareness After Right-Hemispheric Stroke

“…According to this hypothesis, patients’ ipsilesional slowing would be strictly related to the severity of left neglect and would not – or at least not directly – reflect unspecific impairments (Bartolomeo and Chokron, 1999; Bartolomeo et al, 1999). As reported by Chokron et al (2018), it is also possible to conceive the rightward attentional bias in left neglect patients as a paradoxical effect depending on task difficulty, which would thus manifest itself as ranging between facilitation for simple tasks and deficient performance in more complex ones (see also Bartolomeo and Chokron, 2000). According to this view, the seemingly hyperefficient ipsilesional space processing would be the consequence of a defective, and not enhanced, attention.…”

“…A second possibility, thoroughly reviewed and tested by Chokron et al (2018), is that ipsilesional processing should be more appropriately considered as impaired. At odds with the idea of ipsilesional facilitation, Chokron et al (2018) reported that left neglect patients often have difficulties when responding to right-sided stimuli.…”

“…A second possibility, thoroughly reviewed and tested by Chokron et al (2018), is that ipsilesional processing should be more appropriately considered as impaired. At odds with the idea of ipsilesional facilitation, Chokron et al (2018) reported that left neglect patients often have difficulties when responding to right-sided stimuli. According to this hypothesis, patients’ ipsilesional slowing would be strictly related to the severity of left neglect and would not – or at least not directly – reflect unspecific impairments (Bartolomeo and Chokron, 1999; Bartolomeo et al, 1999).…”

Dissociation between objective and subjective perceptual experiences in a population of hemianopic patients: A new form of blindsight?

“…suggesting that objective and subjective scales (binary or otherwise) could include non-visual questions to elucidate patients' perceptual experiences in the contralesional visual field. Another critical point to address in the future will be to ascertain any possible differences between left and right HH patients, as our group has previously demonstrated the effect of lesion lateralization on capacities in the contralesional as well as ipsilesional visual field in HH patients (Cavézian et al, 2015;Chokron, S., Peyrin, C. & Perez, 2018;.…”

Mapping visuospatial attention: the greyscales task in combination with repetitive navigated transcranial magnetic stimulation

“…There are several publications on the occurrence of ipsilesional neglect after right-hemispheric damage [ 62 , 63 , 68 , 69 ]. Chokron et al [ 70 ] even reported right visual neglect in patients with left hemianopia plus neglect. Especially the role of frontal and subcortical areas is discussed, albeit, so far, there is no generally accepted explanation that could be integrated into the model of Corbetta and Shulmann [ 61 , 64 ].…”