Directional Hyperattention in Tactile Neglect within Grasping Space

Abstract

This study was motivated by the fact that unilateral neglect, an impediment to progress in patient rehabilitation, is often reported to occur in a wider area of space than that usually assessed in clinical settings. Neglect within "grasping space" (Halligan & Marshall, 1991; Kolb & Whishaw, 1990) was assessed via two search tasks: one in which search was guided by visual information and the other in which search was guided by tactile information. The performance of 10 left brain-damaged patients (LBD) and 20 right brain-damaged patients, 10 of whom showed left visual neglect (RBD+) while 10 did not (RBD-), was compared with that of age-matched controls. The visual search task confirmed the clinical diagnoses of unilateral visual neglect. On the tactile test, both RBD groups showed reduced search within the left hemispace, although this was a particularly strong feature of the performance of the RBD+ patients. Furthermore, this reduced leftwards exploration in RBD+ patients was associated with an increased frequency of repetitions made within the right hemispace, as had also been noted in some of these patients on conventional visual star cancellation. Results are discussed in relation to hyperattentional theories of directional spatial neglect.

Robot-assisted line bisection in patients with Complex Regional Pain Syndrome

“…Altogether, our findings suggest that cognitive difficulties in CRPS are likely to reflect more than specific somatospatial perceptual difficulties, and are thus probably more heterogeneous than originally described, such as in HSN after a stroke. For instance, authors highlighted that HSN can specifically affect body and somatosensory stimuli perception, while preserving the ability to perceive and react to external visual stimuli [63–68]. Somatospatial deficits are therefore not specific of CRPS.…”

Visuo-Haptic Interactions in Unilateral Spatial Neglect: The Cross Modal Judd Illusion

“…As established by motor exploratory tasks, USN may occur in both the visual and the tactile modality (De Renzi et al, 1970; Beschin et al, 1996; Haeske-Dewick et al, 1996). Evidence has however been provided to the effect that USN may be less severe and even absent in the tactile modality, in the absence of visual input.…”

Repetitive exploration towards locations that no longer carry a target in patients with neglect

“…In contrast, patients revisited items more often in the full-erase condition, even though no targets or other stimuli were present after touching them for the first time. This finding in the full-erase condition resembles certain aspects of the daily behaviour of neglect patients such as repetitive grasping in empty space (Haeske-Dewick et al, 1996), or deviation of head and eye movements even when no ipsilesional stimuli are present (Fruhmann-Berger & Karnath, 2005;Haeske-Dewick et al, 1996). Mark et al (1988) also reported that patients visited ipsilesional locations repeatedly in the erasure task, but attributed this to the fact that patients may have wanted to wipe off the powdery tissue, which came of the sponge.…”

“…Some neglect studies also report an enhanced performance on attentional tasks in ipsilesional hemispace (Natale, Posteraro, Prior, & Marzi, 2005; Smania et al , 1998). Behaviorally, patients show this ‘exaggerated attention’ for the ipsilesional field in a deviation of eye and head movements (Behrmann, Watt, Black, & Barton, 1997; Fruhmann‐Berger & Karnath, 2005), repetitive fixations (Mannan et al , 2005), and grasping (Haeske‐Dewick, Canavan, & Homberg, 1996) on this side. In addition, they exhibit remarkings and exaggerations in drawings on the ipsilesional side (Na et al , 1999; Nys, van Zandvoort, van der Worp, Kappelle, & de Haan, 2006; Rusconi, Maravita, Bottini, & Vallar, 2002), and the failure to prevent attention from revisiting ipsilesional stimuli (inhibition of return; Bartolomeo, Sieroff, Decaix, & Chokron, 2001).…”