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Smaczny S, Bauder D, Sperber C, Karnath HO, de Haan B. Reducing alertness does not affect line bisection bias in neurotypical participants. Exp Brain Res 2024; 242:195-204. [PMID: 37994915 PMCID: PMC10786967 DOI: 10.1007/s00221-023-06738-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/31/2023] [Indexed: 11/24/2023]
Abstract
Alertness, or one's general readiness to respond to stimulation, has previously been shown to affect spatial attention. However, most of this previous research focused on speeded, laboratory-based reaction tasks, as opposed to the classical line bisection task typically used to diagnose deficits of spatial attention in clinical settings. McIntosh et al. (Cogn Brain Res 25:833-850, 2005) provide a form of line bisection task which they argue can more sensitively assess spatial attention. Ninety-eight participants were presented with this line bisection task, once with and once without spatial cues, and both before and after a 50-min vigilance task that aimed to decrease alertness. A single participant was excluded due to potentially inconsistent behaviour in the task, leaving 97 participants for the full analyses. While participants were, on a group level, less alert after the 50-min vigilance task, they showed none of the hypothesised effects of reduced alertness on spatial attention in the line bisection task, regardless of with or without spatial cues. Yet, they did show the proposed effect of decreased alertness leading to a lower level of general attention. This suggests that alertness has no effect on spatial attention, as measured by a line bisection task, in neurotypical participants. We thus conclude that, in neurotypical participants, the effect of alertness on spatial attention can be examined more sensitively with tasks requiring a speeded response compared to unspeeded tasks.
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Affiliation(s)
- Stefan Smaczny
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Dominik Bauder
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Christoph Sperber
- Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Hans-Otto Karnath
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Department of Psychology, University of South Carolina, Columbia, USA
| | - Bianca de Haan
- Division of Psychology, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK.
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2
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McIntosh RD, Ishiai S. Endpoints and viewpoints on spatial neglect. J Neuropsychol 2022; 16:299-305. [PMID: 35507737 PMCID: PMC9321190 DOI: 10.1111/jnp.12278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 11/30/2022]
Abstract
In this issue of the Journal of Neuropsychology, Abe and Ishiai (2022) report an experiment designed to probe the subjective experience of line bisection in neglect. A re-analysis of their data can also offer insights into how best to characterise neglect performance for this and other tasks. We show that sensitive measures of neglect can be obtained by quantifying the difference in the influence (or 'weighting') that each endpoint has on the response. The right endpoint is dramatically more influential than the left in people with neglect performing line bisection and endpoint reproduction tasks. This supports the view that neglect may limit the ability to simultaneously represent two locations, so that the response is determined primarily with respect to the right endpoint. We also discuss Abe and Ishiai's conclusion that bisection responses in neglect are accompanied by the subjective experience of a complete line extending equally to either side of the chosen midpoint.
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Affiliation(s)
- Robert D McIntosh
- Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK
| | - Sumio Ishiai
- Department of Rehabilitation Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
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Abe M, Ishiai S. Mental representation of a line when patients with left unilateral spatial neglect bisect it: A study with an endpoint reproduction task. J Neuropsychol 2021; 16:283-298. [PMID: 34159740 DOI: 10.1111/jnp.12258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 06/02/2021] [Indexed: 11/30/2022]
Abstract
Patients with left unilateral spatial neglect (USN) typically place the subjective midpoint to the right of the objective centre. Based on the previous findings (e.g., Ishiai et al. 1989, Brain, 112, 1485), we hypothesized that the patients with left USN may see the representational image of a line that extends equally towards either side of the subjective midpoint depending not upon the information about the leftward extent. The present study tested whether patients with left USN would place the subjective midpoint at the centre of their mental representation of the line. The participants were 10 patients with left USN and 10 neurologically healthy controls. We devised a new 'endpoint reproduction task' using a computer display with a touch panel to seek the representational image when patients with left USN bisect lines and asked the participants to reproduce the location of the right or left endpoint after bisecting lines. The results showed that the representational image of the bisected line depends primarily on the location of the objective right endpoint, not on the location of the objective left endpoint in space. The analyses of the estimated right and left representational extents confirmed our hypotheses that patients with left USN would bisect a line seeing the representational line image that centred across their subjective midpoint. We believe that the findings of the present study with the use of the endpoint reproduction task will contribute to a better understanding of the visuospatial process underlying line bisection of patients with left USN.
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Affiliation(s)
- Masako Abe
- Department of Speech and Hearing Sciences, International University of Health and Welfare, Tochigi, Japan
| | - Sumio Ishiai
- Department of Rehabilitation Medicine, Sapporo Medical University School of Medicine, Hokkaido, Japan
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Arduino LS, Veronelli L, Cai L, Xue S, Corbo M, Zhang Y. Pseudoneglect in sentence bisection: a comparison between Italian and Chinese. JOURNAL OF COGNITIVE PSYCHOLOGY 2016. [DOI: 10.1080/20445911.2016.1170689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Balconi M, Amenta S, Sozzi M, Cannatà AP, Pisani L. Eye movement and online bisection task in unilateral patients with neglect: A new look to the ‘gradient effect’. Brain Inj 2013; 27:310-7. [DOI: 10.3109/02699052.2012.750739] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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6
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Sosa Y, Clarke AM, McCourt ME. Hemifield asymmetry in the potency of exogenous auditory and visual cues. Vision Res 2011; 51:1207-15. [PMID: 21447353 DOI: 10.1016/j.visres.2011.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Revised: 02/13/2011] [Accepted: 03/21/2011] [Indexed: 11/26/2022]
Abstract
Neurologically normal subjects misperceive the midpoints of lines (PSE) as reliably leftward of veridical center, a phenomenon known as pseudoneglect. This leftward bias reflects the dominance of the right cerebral hemisphere in deploying spatial attention. Transient visual cues, delivered to either the left or right endpoints of lines, modulate PSE such that leftward biases are increased by leftward cues, and are decreased by rightward cues, relative to a no-cue control condition. We ask whether lateralized auditory cues can similarly influence PSE in a tachistoscopic visual line bisection task, and describe how visual and auditory cues, in spatially synergistic or antagonistic combinations, jointly influence PSE. Our results demonstrate that whereas auditory and visual cues both modulate PSE, visual cues are overall more potent than auditory cues. Visual and auditory cues are weighted such that visual cues are significantly more potent than auditory cues when visual cues are delivered to left hemispace. Visual and auditory cues are equipotent when visual cues are delivered to right hemispace. These results are consistent with the existence of independent lateralized networks governing the deployment of visuospatial and audiospatial attention. An analysis of the weighting of unisensory visual and auditory cues which optimally predicts PSE in multisensory cue conditions shows that cues combine additively. There was no evidence for a superadditive multisensory cue combination.
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Affiliation(s)
- Yamaya Sosa
- Center for Visual and Cognitive Neuroscience, Department of Psychology, North Dakota State University, Fargo, ND 58108-6050, USA
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7
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Singh VVW, Stojanoski B, Le A, Niemeier M. Spatial frequency-specific effects on the attentional bias: Evidence for two attentional systems. Cortex 2010; 47:547-56. [PMID: 20447620 DOI: 10.1016/j.cortex.2010.03.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Revised: 03/04/2010] [Accepted: 03/17/2010] [Indexed: 11/16/2022]
Abstract
Using a gratingscales task as a sensitive measure of the attentional bias, we have recently observed a new form of frequency-specific cross-over; people showed left-biased preferences when comparing the high spatial frequency (HiSF) components of the task and rightward biases when comparing low spatial frequencies (LoSFs). Here we investigated which mechanisms underlie the cross-over. (1) We found that leftward and rightward biases were positively correlated, suggesting that the same set of mechanisms are involved in both versions of the task. (2) When we cued attention to the left or right side we found transient effects on gratingscales biases that were symmetrical for the LoSF condition but asymmetrical for the HiSF condition. This indicates that the HiSF condition itself biased stimulus-driven attention more to the left side than the LoSF condition. (3) When we lowered the contrast of the HiSF or the LoSF stimulus components, specifically the latter case made HiSF and LoSF conditions more different. This suggests that HiSF and LoSF conditions differ because HiSF components are more salient and more likely stir stimulus-driven attention. Our data are consistent with the idea that the attentional bias results from right-dominant control mechanisms of stimulus-driven attention potentially interacting with voluntary control mechanisms.
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Affiliation(s)
- Vaughan V W Singh
- Department of Psychology, University of Toronto Scarborough, Toronto, Ontario, Canada
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8
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The perceptual consequences of the attentional bias: evidence for distractor removal. Exp Brain Res 2008; 189:411-20. [DOI: 10.1007/s00221-008-1438-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2008] [Accepted: 05/18/2008] [Indexed: 10/22/2022]
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9
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Niemeier M, Stojanoski B, Singh VW, Chu E. Paradoxical cross-over due to attention to high or low spatial frequencies. Brain Cogn 2008; 67:115-25. [DOI: 10.1016/j.bandc.2007.12.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Revised: 12/13/2007] [Accepted: 12/14/2007] [Indexed: 12/01/2022]
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Baheux K, Yoshizawa M, Yoshida Y. Simulating hemispatial neglect with virtual reality. J Neuroeng Rehabil 2007; 4:27. [PMID: 17640377 PMCID: PMC1965467 DOI: 10.1186/1743-0003-4-27] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 07/19/2007] [Indexed: 12/05/2022] Open
Abstract
Background Hemispatial neglect is a cognitive disorder defined as a lack of attention for stimuli contra-lateral to the brain lesion. The assessment is traditionally done with basic pencil and paper tests and the rehabilitation programs are generally not well adapted. We propose a virtual reality system featuring an eye-tracking device for a better characterization of the neglect that will lead to new rehabilitation techniques. Methods This paper presents a comparison of eye-gaze patterns of healthy subjects, patients and healthy simulated patients on a virtual line bisection test. The task was also executed with a reduced visual field condition hoping that fewer stimuli would limit the neglect. Results We found that patients and healthy simulated patients had similar eye-gaze patterns. However, while the reduced visual field condition had no effect on the healthy simulated patients, it actually had a negative impact on the patients. We discuss the reasons for these differences and how they relate to the limitations of the neglect simulation. Conclusion We argue that with some improvements the technique could be used to determine the potential of new rehabilitation techniques and also help the rehabilitation staff or the patient's relatives to better understand the neglect condition.
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Affiliation(s)
- Kenji Baheux
- Graduate School of Engineering, Tohoku University, Sendai, Japan
| | | | - Yasuko Yoshida
- Graduate School of Engineering, Tohoku University, Sendai, Japan
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11
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Abstract
In this issue of Cortex, Ishiai et al. (2006) report the eye movements of patients with left neglect during the bisection of lines of different lengths. This is the latest in a series of papers from Ishiai's group, which form an important corpus of data on the oculomotor behaviour of neglect patients during line bisection and related tasks. In this article, I argue that these data should critically constrain theoretical models of bisection errors in neglect, but that these constraints have been applied rarely in practice. First, I briefly introduce bisection behaviour in neglect and describe some of the models proposed to account for its character. I then consider the implications for these models of Ishiai and colleagues' observations. Finally, I outline a novel view of the bisection task that is more compatible with their observations.
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Affiliation(s)
- Robert D McIntosh
- Human Cognitive Neuroscience Research Group, Psychology Department, University of Edinburgh, Edinburgh, UK.
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Ishiai S, Koyama Y, Seki K, Hayashi K, Izumi Y. Approaches to Subjective Midpoint of Horizontal Lines in Unilateral Spatial Neglect. Cortex 2006; 42:685-91. [PMID: 16909627 DOI: 10.1016/s0010-9452(08)70405-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Patients with unilateral spatial neglect usually bisect longer lines with greater rightward errors, while they sometimes err leftward for very short lines (e.g., 25 mm). We analysed movements of eye fixation from the time before line presentation to elucidate whether patients with neglect approach the subjective midpoint differently for lines of various lengths. Four patients with left neglect bisected 200 mm, 100 mm, and 25 mm lines that appeared across the centre of a liquid crystal display (LCD) monitor. The fixation immediately before line presentation was located on average near the centre of the lines. Three of the patients approached the subjective midpoint point directly from the left side in more than 70% of the 200 mm and 100 mm trials. The subjective midpoint frequently deviated leftward on the "attended" segment between the leftmost point of fixation and the right endpoint, while it was displaced rightward on the total extent. The three patients initially explored the 25 mm lines searching for the left endpoint. They thereafter bisected the same lines with leftward errors approaching the subjective midpoint from the left side. The remaining patient searched beyond the right endpoint and in turn approached the subjective midpoint from the right side in about half of the trials and independently of line length. In the 200 mm and 100 mm trials, the subjective midpoint divided the attended right segment nearer to the right endpoint. On the attended right extent of a line, patients with neglect may place the subjective midpoint toward the side from which they approached that point. In the bisection of very short lines, approaches from the left endpoint may cause leftward errors of the subjective midpoint. For longer lines, however, approaches from the left side may result in rightward error of bisection for the total length, as the leftward extent from the fixation immediately before line presentation is hardly explored.
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Affiliation(s)
- Sumio Ishiai
- Department of Rehabilitation, Sapporo Medical University, School of Medicine, Sapporo, Japan.
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13
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Doricchi F, Guariglia P, Figliozzi F, Silvetti M, Bruno G, Gasparini M. Causes of cross-over in unilateral neglect: between-group comparisons, within-patient dissociations and eye movements. Brain 2005; 128:1386-406. [PMID: 15758037 DOI: 10.1093/brain/awh461] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Patients with left unilateral neglect bisect long horizontal lines to the right of the true centre. However, when given short lines, many of the same patients mark the midpoint to the left of the true centre, towards the otherwise neglected space. This paradoxical phenomenon has been termed 'cross-over' and is difficult to explain based on current accounts of the neglect syndrome. To explore the causes of cross-over, in a first study we evaluated bisection of 20, 100 and 200 mm horizontal lines in groups of unilateral brain-damaged patients with neglect and hemianopia, with neglect and no hemianopia, with hemianopia and no neglect and without neglect or hemianopia. Cross-over of 20 mm lines was found only in neglect patients with hemianopia. To ascertain further the influence of visual field defects on cross-over, in a second study we compared the performance of two right-brain-damaged patients with contralesional neglect and inferior quadrantanopia with that of a patient with inferior quadrantanopia and no neglect. Patients bisected lines oriented so as to cross or uncross the blind quadrant of the visual field. When short 20 mm lines crossed the blind quadrant, neglect patients showed cross-over; when the same lines crossed the seeing quadrants cross-over was absent. These findings were confirmed by the examination of a neglect patient with sparing of the central 5 degrees of the contralesional left visual hemifield in the right eye and no sparing in the left eye. In monocular viewing, cross-over was present when 20 mm lines were bisected with the left eye and absent when bisected with the right eye. Recording of eye movements showed that at the moment of bisection left eye fixations shifted towards the contralesional line endpoint whereas right eye fixations remained anchored to the centre of the line. With long lines, both eyes deviated ipsilesionally. These results show that in neglect patients ipsilesional deviation in the bisection of long lines turns into apparently paradoxical contralesional bisection of short ones only when these cross a retinotopically blind sector of the neglected space. Cross-over seems to depend on the small spatial effects produced by reflexive contralesional gaze shifts allowing eccentric fixations with the seeing hemifield. During the bisection of long lines, these effects are cancelled out by the strong attentional deviation induced by the marked extension of the ipsilesional line segment. This explanation establishes coherence between cross-over and current accounts of the neglect syndrome.
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Affiliation(s)
- F Doricchi
- Fondazione Santa Lucia IRCCS, Università degli Studi di Roma La Sapienza, Rome, Italy.
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Keller I, Schindler I, Kerkhoff G, von Rosen F, Golz D. Visuospatial neglect in near and far space: dissociation between line bisection and letter cancellation. Neuropsychologia 2005; 43:724-31. [PMID: 15721185 DOI: 10.1016/j.neuropsychologia.2004.08.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Accepted: 08/18/2004] [Indexed: 11/29/2022]
Abstract
The differential performance on a line bisection and a cancellation task in near and far space was studied. A group of 10 patients with severe left-sided visuospatial neglect and a group of 10 right-brain damaged patients without neglect were examined. The stimuli were presented at a distance of 60 cm (near space) and 160 cm (far space), respectively, and corrected for visual angle. In the line bisection task, patients were asked to point to the estimated line centre with a pencil (near space) or a stick (far space). In the cancellation task, patients pointed to all target stimuli they could detect using either a pencil (near space) or a stick (far space). Most patients with left hemineglect showed a more prominent neglect in far space as compared to near space for the line bisection task, whereas no difference of performance between near and far space was found in the control patients. In contrast, no group showed a distance effect in the cancellation task. The observation that only line bisection is influenced by the distance of the stimulus suggests that line bisection and cancellation are processed differentially. It is proposed that line bisection requires an allocentric reference system focusing attention on objects, whereas cancellation tasks are based on an egocentric reference system responsible for visuospatial attention. Our results indicate that distance changes perception within the allocentric but not within the egocentric system.
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Affiliation(s)
- I Keller
- Neurological Clinic Bad Aibling, Kolbermoorer Strasse 72, 83043 Bad Aibling, Germany.
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15
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Grossi D, Di Cesare G, Trojano L. Left on the Right or Viceversa: A Case of “Alternating” Constructional Allochiria. Cortex 2004; 40:511-8. [PMID: 15259330 DOI: 10.1016/s0010-9452(08)70143-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe a patient with an ischemic right frontal lesion and mild left neglect who showed a systematic tendency to transpose drawings on one side of the page, which varied depending on the starting point (left or right) of his graphic productions. When not specifically cued, the patient started to draw in the ipsilesional (right) side and tended to show allochiria on the right, but occasionally, or under specific instructions, the patient started drawing from the left side and then showed a complete reversion of his spatial transpositions. To clarify the basic mechanisms underlying such a peculiar constructional phenomenon, we performed a series of experimental investigations, including extended copying tasks, a clock-marking test (to mark the position of single hours on a clock-face), and a line bisection task with progressive left-toright or right-to-left stimulus presentation. Findings suggested that "alternating" allochiria in copying and drawing from memory tasks is an epiphenomenon of a basic inability to move attention and action away from the starting point of graphic productions. The present case study, contrasted with observations on other brain-damaged patients, demonstrates that allochiria may have different neuro-cognitive bases and offers new insights for theoretical interpretations of unilateral spatial neglect.
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Affiliation(s)
- Dario Grossi
- Department of Psychology, Second University of Naples, Italy
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16
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Ishiai S, Koyama Y, Seki K. Significance of paradoxical leftward error of line bisection in left unilateral spatial neglect. Brain Cogn 2001; 45:238-48. [PMID: 11237369 DOI: 10.1006/brcg.2000.1242] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We intended to determine if leftward error of line bisection means "right" or "left" neglect in a patient with left unilateral spatial neglect. The patient placed the subjective midpoint to the left of the true center when bisecting lines without cueing. By contrast, when cued to the left endpoint, he showed typical rightward errors that became greater as longer lines were presented. Cueing to the right endpoint increased leftward errors compared with the bisections without cueing. The results suggest that paradoxical leftward error of line bisection is a form of "left" unilateral spatial neglect in that the shortness of the left extent is ignored.
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Affiliation(s)
- S Ishiai
- Department of Rehabilitation, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan.
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17
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Ishiai S, Koyama Y, Seki K, Izawa M. Line versus representational bisections in unilateral spatial neglect. J Neurol Neurosurg Psychiatry 2000; 69:745-50. [PMID: 11080226 PMCID: PMC1737171 DOI: 10.1136/jnnp.69.6.745] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To clarify the mechanisms of left unilateral spatial neglect found in the bisection of lines after cueing to the left end point and to determine whether neglect occurs for the mental representation of a line. METHODS A new representational bisection task was developed to eliminate the influence of the right segment of the physical line that would attract attention. Eight patients with typical left unilateral spatial neglect underwent line and representational bisection tasks on a computer display with a touch panel. In the line bisection with cueing, they bisected a line after touching the left end point. In the representational bisection, the patients were presented with a line until they touched the left end point. On the blank display, they pointed to the subjective midpoint of the erased line. The performances of the two bisection tasks were compared when the length and position of stimulus lines were varied. RESULTS The rightward errors in the representational bisection were greater than or equivalent to those in the line bisection with cueing. The effect of line length in which the errors became greater for the longer lines was equally found in the line bisection with cueing and the representational bisection. This was confirmed in the condition where the right end point was placed at a fixed position and the line length was varied. CONCLUSIONS After cueing to the left end point, rightward bisection errors of patients with neglect are not caused by overattention to the right segment of the physical line. Left neglect occurs mainly for the mental representation formed at the time of cueing or seeing the whole extent of a line.
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Affiliation(s)
- S Ishiai
- Department of Rehabilitation, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu City, Tokyo 183-8526, Japan.
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18
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Rustenbach SJ, Pawlik K, Wein C. Effektivität experimenteller und rehabilitativer Interventionen bei visuellem Neglect - Eine Metaanalyse. ZEITSCHRIFT FUR NEUROPSYCHOLOGIE 2000. [DOI: 10.1024//1016-264x.11.1.23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Zusammenfassung: Präsentiert wird eine Metaanalyse zur Wirksamkeit neuropsychologischer Interventionen bei visuellem Hemineglect. Es wurden die publizierten Outcome-Ergebnisse Experimental- und Rehabilitationsstudien zur Modifikation und Modulation des Neglectsyndroms quantitativ integriert. 133 identifizierte Studien wurden in sechs Klassen eingeteilt. Studien-, Interventions- und Patientenmerkmale dienten zur Bestimmung moderierender Einflüsse, über Sensitivitätsanalysen wurde die Robustheit der Ergebnisse abgeschätzt. Die mittlere Gesamteffektivität der Interventionen liegt um 0.8 Standardeinheiten Symptomverbesserung gegenüber dem Prä-Niveau bei Patienten mit chronischem Neglect. Spontanremissionseffekte sind aufgrund der durchschnittlichen Erkrankungsdauer als gering zu veranschlagen und konnten empirisch nicht nachgewiesen werden. Explorationstrainings, personale Intervention und Hinweisreiz-Verfahren stellen sich als überdurchschnittlich effektiv und signifikant effektiver als bloße Reduktion der Umweltanforderungen heraus.
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Affiliation(s)
| | - Kurt Pawlik
- Psychologisches Institut I, Universität Hamburg
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Ishiai S, Koyama Y, Seki K, Nakayama T. What is line bisection in unilateral spatial neglect? Analysis of perceptual and motor aspects in line bisection tasks. Brain Cogn 1998; 36:239-52. [PMID: 9647677 DOI: 10.1006/brcg.1998.0980] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Three patients with unilateral spatial neglect could detect the difference of length between the right and left segments when a line had a transection mark. To examine the effect of response mode, the manual line bisection task and a new "line bisection task by fixation" were given to the patients. In tasks that used lines with no landmark, they showed apparent rightward errors. The results suggest that line bisection is not a task that examines the ability of patients with neglect to compare the right and left extents of a line. Where to fixate as the subjective midpoint may determine the rightward errors of bisection, whether manual response is used or not.
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Affiliation(s)
- S Ishiai
- Department of Rehabilitation, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan
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Koyama Y, Ishiai S, Seki K, Nakayama T. Distinct processes in line bisection according to severity of left unilateral spatial neglect. Brain Cogn 1997; 35:271-81. [PMID: 9356166 DOI: 10.1006/brcg.1997.0943] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We investigated the line bisection performances in 24 patients with left unilateral spatial neglect. They bisected lines of two lengths in three positions relative to the sagittal midplane of the body. The results showed that in the mild or moderate neglect patients, length and spatial locations of the lines affected the placement of the subjective midpoint. In the severe neglect patients, however, length had little effect on their performances, and location of the right endpoint in the egocentric space mainly determined the subjective midpoint. The line bisection process of the severe neglect patients was not only quantitatively but also qualitatively different from that of the mild or moderate cases.
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Affiliation(s)
- Y Koyama
- Department of Rehabilitation, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan
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Abstract
Patients with right hemisphere injury frequently neglect to cancel targets primarily in the left part of the page nearest the body. Since this region is diagonally opposite the area from where such patients usually begin cancelling, near left ('diagonal') neglect may be consequent to stimulus order effects ('fatigue'). We evaluated the persistence of near left neglect in nine stroke patients when they had to cancel either the near or the far half of the page before proceeding to the other half. Our results showed that near left neglect on the page was largely unaffected by cancellation order. Furthermore, a near left gradient of omissions was established within both radial (near and far) halves of the page, as well as for the entire page. Our findings suggest that diagonal cancellation neglect is unrelated to fatigue and reflects a consistent, two-dimensional disorder of spatial attention. Such neglect may be related to the extent of the visible stimulus array, as well as to the array's location in egocentric space.
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Affiliation(s)
- V W Mark
- Department of Neuroscience, University of North Dakota School of Medicine, Fargo, USA.
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Ishiai S, Seki K, Koyama Y, Gono S. Ineffective leftward search in line bisection and mechanisms of left unilateral spatial neglect. J Neurol 1996; 243:381-7. [PMID: 8741077 DOI: 10.1007/bf00868996] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We examined the eye-fixation pattern of a patient with severe left unilateral spatial neglect who showed leftward searches of various extent in more than half of line bisection trials. Because of complete left homonymous hemianopia, he perceived only the segment of the line between its right endpoint and the point of the leftmost fixation. In the trials with leftward searches, he frequently placed the subjective midpoint on the right part of the perceived segment. In the trials without leftward searches, he placed it near the left extreme point of the perceived segment. For all these bisections, the subjective midpoint was constantly placed far to the right of the true midpoint of the line irrespective of the length perceived. We consider that in severe left unilateral spatial neglect, rightward attentional bias is the predominant factor that determines where to place the subjective midpoint. Transient attentional shift to the left may produce leftward searches, but it does not induce effective processing of line bisection.
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Affiliation(s)
- S Ishiai
- Department of Rehabilitation, Tokyo Metropolitan Institute for Neuroscience, Japan
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Seki K, Ishiai S. Diverse patterns of performance in copying and severity of unilateral spatial neglect. J Neurol 1996; 243:1-8. [PMID: 8869379 DOI: 10.1007/bf00878523] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We analysed the performances of 69 patients with left unilateral spatial neglect in copying a multi-object figure, as well as their performance of the line cancellation and line bisection tests. Three patterns of copying were mainly observed. The first pattern was almost satisfactory performance in copying the central figure with occasional omission of the elements located more laterally to the left. The second pattern was omission of the left half of the whole figure, which was the pattern expected of patients with typical left unilateral spatial neglect. The third pattern was left unilateral spatial neglect when copying the central figure, with favourable copying of left lateral objects; this may be regarded as "object-centered" neglect. Performance of the line cancellation test, which requires exploratory ability, was significantly better for the patients with the third pattern than for those with the second pattern. A significant difference was also observed between the two groups of patients in performance of the line bisection test, in which exploratory ability plays a more minor role. No significant difference was found in performance of the line cancellation and line bisection tests between the patients with the third and first patterns, in spite of remarkable differences in their copying performances. No distinctive characteristics were found for any group of patients as regards lesion, age, duration after onset, education, and WAIS scores. Therefore we concluded that in most of our patients with neglect, these diverse patterns of copying deficits resulted from different levels of neglect severity but not from different types of unilateral spatial neglect.
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Affiliation(s)
- K Seki
- Department of Rehabilitation, Tokyo Metropolitan Institute for Neuroscience, Japan
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