1
|
Aziz JR, Good SR, Horne SC, Eskes GA. A scoping review and critique of the Input-Output subtyping dimension of spatial neglect. Cortex 2024; 176:11-36. [PMID: 38729033 DOI: 10.1016/j.cortex.2024.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 02/28/2024] [Accepted: 04/22/2024] [Indexed: 05/12/2024]
Abstract
Spatial neglect is a common and debilitating disorder after stroke whereby individuals have difficulty reporting, orienting, and/or responding to the contralesional side of space. Given the heterogeneity of neglect symptom presentation, various neglect subtypes have been proposed to better characterize the disorder. This review focuses on the distinction between Input neglect (i.e., difficulty perceiving and/or attending to contralesional stimuli) and Output neglect (i.e., difficulty planning and/or executing movements toward contralesional stimuli). Conceptualizations of Input and Output neglect have varied considerably. We provide a novel summary of the terminology, measurement approaches, and neural correlates of these subtypes. A protocol detailing our systematic scoping review strategy is registered on the Open Science Framework (https://osf.io/bvtxf/). For feasibility and greater comparability across studies, we limited our inclusion criteria to tasks focused on visual stimuli and upper-limb movements. A total of 110 articles were included in the review. Subtyping tasks were categorized based on whether they mainly manipulated aspects of the input (i.e., congruence of visual input with motor output, presence of visual input) or the output (i.e., modality, goal, or direction of output) to produce an Input-Output subtype dissociation. We used our review results to identify four main critiques of this literature: 1) lack of consistency/clarity in conceptual models; 2) methodological issues of dissociating Input and Output subtypes; 3) a need for updated neural theories; and 4) barriers to clinical application. We discuss the lessons learned from this subtyping dimension that can be applied to future research on neglect subtype assessment and treatment.
Collapse
Affiliation(s)
- Jasmine R Aziz
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Canada.
| | - Samantha R Good
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Canada
| | - Samantha C Horne
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Canada; Faculty of Medicine, Dalhousie University, Halifax, Canada
| | - Gail A Eskes
- Department of Psychology & Neuroscience, Dalhousie University, Halifax, Canada; Department of Psychiatry, Dalhousie University, Halifax, Canada
| |
Collapse
|
2
|
Brodtmann A, Loetscher T. What's Left in Neglect Research? Neurology 2022; 98:53-54. [PMID: 34996876 DOI: 10.1212/wnl.0000000000013051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Amy Brodtmann
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Tobias Loetscher
- Cognitive Ageing & Impairment Neurosciences Laboratory, UniSA Justice & Society, University of South Australia, Adelaide, Australia
| |
Collapse
|
3
|
Williams LJ, Kernot J, Hillier SL, Loetscher T. Spatial Neglect Subtypes, Definitions and Assessment Tools: A Scoping Review. Front Neurol 2021; 12:742365. [PMID: 34899565 PMCID: PMC8653914 DOI: 10.3389/fneur.2021.742365] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/14/2021] [Indexed: 12/03/2022] Open
Abstract
Objective: The objective of this scoping review was to capture the reported definitions for the subtypes of neglect post stroke and map the range of assessment tools employed for each neglect subtype. Methods: EMBASE, Emcare, Medline, and psychINFO were searched from database inception. Searching included all allied terms and mesh headings for stroke, spatial neglect, measurement, screening tools, psychometric properties. Two reviewers independently screened studies for inclusion. Primary studies with documented protocols of a spatial neglect tool for adults post stroke, with some aspect of validity or reliability were included. Two reviewers independently reviewed the documented protocols of each tool to determine the underlying subtypes and disagreements were resolved through discussion. Results: There were 371 articles included with 292 tools used for the screening or diagnosis of neglect. The majority of studies (67%) included a tool that did not specify the neglect subtype being assessed, therefore an analysis of the underlying subtypes for each tool is presented. Conclusions: There is no consistency with the terms used to refer to the syndrome of spatial neglect with over 200 different terms used within the included studies to refer to the syndrome as a whole or one of its subtypes. It is essential to unify the terminology and definition for each neglect subtype. There are hundreds of neglect tools available, however many are not able to differentiate presenting subtypes. It is important for clinicians and researchers to critically evaluate the neglect tools being used for the screening and diagnosis of neglect.
Collapse
Affiliation(s)
- Lindy J Williams
- Cognitive Aging and Impairment Neurosciences Lab, University of South Australia, Adelaide, SA, Australia.,Innovation IMPlementation and Clinical Translation (IIMPACT) in Health, University of South Australia, Adelaide, SA, Australia.,Allied Health and Human Performance, University of South Australia, Adelaide, SA, Australia
| | - Jocelyn Kernot
- Allied Health and Human Performance, University of South Australia, Adelaide, SA, Australia
| | - Susan L Hillier
- Innovation IMPlementation and Clinical Translation (IIMPACT) in Health, University of South Australia, Adelaide, SA, Australia.,Allied Health and Human Performance, University of South Australia, Adelaide, SA, Australia
| | - Tobias Loetscher
- Cognitive Aging and Impairment Neurosciences Lab, University of South Australia, Adelaide, SA, Australia.,Justice and Society, University of South Australia, Adelaide, SA, Australia
| |
Collapse
|
4
|
Vestito L, Trombini M, Mori L, Dellepiane S, Trompetto C, Morando M, Bandini F. Improved visuospatial neglect after tDCS and computer-assisted cognitive training in Posterior Cortical Atrophy: a single-case study. Neurocase 2021; 27:57-63. [PMID: 33332244 DOI: 10.1080/13554794.2020.1862242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Visuospatial neglect (VN) frequently occurs in Posterior Cortical Atrophy (PCA) and requires specific rehabilitation. In this single-case study, we investigated the efficacy of a computer-assisted cognitive training (CCT) alone or coupled with multiple sessions of anodal transcranial direct-current stimulation (A-tDCS) over the right posterior parietal cortex in improving left VN symptoms in a patient with PCA. The digital ReMoVES platform was used for both VN assessment and training. We found a significant improvement after CCT combined with A-tDCS within the limits of a single-case, our results suggest, for the first time, the usefulness of this combined approach in a neurodegenerative disorder.
Collapse
Affiliation(s)
| | - Marco Trombini
- Department of Naval, Electric, Electronic and Telecommunications Engineering (DITEN), University of Genoa, Genoa, Italy
| | - Laura Mori
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy.,Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Silvana Dellepiane
- Department of Naval, Electric, Electronic and Telecommunications Engineering (DITEN), University of Genoa, Genoa, Italy
| | - Carlo Trompetto
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy.,Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Matteo Morando
- Department of Naval, Electric, Electronic and Telecommunications Engineering (DITEN), University of Genoa, Genoa, Italy
| | - Fabio Bandini
- Department of Neurology, San Paolo Hospital, Savona, Italy
| |
Collapse
|
5
|
Spreij LA, Ten Brink AF, Visser-Meily JM, Nijboer TC. Increasing cognitive demand in assessments of visuo-spatial neglect: Testing the concepts of static and dynamic tests. J Clin Exp Neuropsychol 2020; 42:675-689. [DOI: 10.1080/13803395.2020.1798881] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Lauriane A. Spreij
- Center of Excellence for Rehabilitation Medicine, UMC Utrecht Brain Center, University Medical Center Utrecht, and De Hoogstraat Rehabilitation, Utrecht, Netherlands
| | - Antonia F. Ten Brink
- Center of Excellence for Rehabilitation Medicine, UMC Utrecht Brain Center, University Medical Center Utrecht, and De Hoogstraat Rehabilitation, Utrecht, Netherlands
- De Hoogstraat Rehabilitation, Utrecht, Netherlands
- Department of Psychology, University of Bath, Bath, UK
| | - Johanna M.A. Visser-Meily
- Center of Excellence for Rehabilitation Medicine, UMC Utrecht Brain Center, University Medical Center Utrecht, and De Hoogstraat Rehabilitation, Utrecht, Netherlands
- Department of Rehabilitation, Physical Therapy Science & Sports, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht, Netherlands
| | - Tanja C.W. Nijboer
- Center of Excellence for Rehabilitation Medicine, UMC Utrecht Brain Center, University Medical Center Utrecht, and De Hoogstraat Rehabilitation, Utrecht, Netherlands
- Department of Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, Netherlands
| |
Collapse
|
6
|
Zebhauser PT, Vernet M, Unterburger E, Brem AK. Visuospatial Neglect - a Theory-Informed Overview of Current and Emerging Strategies and a Systematic Review on the Therapeutic Use of Non-invasive Brain Stimulation. Neuropsychol Rev 2019; 29:397-420. [PMID: 31748841 PMCID: PMC6892765 DOI: 10.1007/s11065-019-09417-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 09/27/2019] [Indexed: 01/12/2023]
Abstract
Visuospatial neglect constitutes a supramodal cognitive deficit characterized by reduction or loss of spatial awareness for the contralesional space. It occurs in over 40% of right- and 20% of left-brain-lesioned stroke patients with lesions located mostly in parietal, frontal and subcortical brain areas. Visuospatial neglect is a multifaceted syndrome - symptoms can be divided into sensory, motor and representational neglect - and therefore requires an individually adapted diagnostic and therapeutic approach. Several models try to explain the origins of visuospatial neglect, of which the "interhemispheric rivalry model" is strongly supported by animal and human research. This model proposes that allocation of spatial attention is balanced by transcallosal inhibition and both hemispheres compete to direct attention to the contralateral hemi-space. Accordingly, a brain lesion causes an interhemispheric imbalance, which may be re-installed by activation of lesioned, or deactivation of unlesioned (over-activated) brain areas through noninvasive brain stimulation. Research in larger patient samples is needed to confirm whether noninvasive brain stimulation can improve long-term outcomes and whether these also affect activities of daily living and discharge destination.
Collapse
Affiliation(s)
- Paul Theo Zebhauser
- Department of Neuropsychology, Max-Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804, Munich, Germany.,Department of Psychiatry and Psychotherapy, Klinikum Rechts der Isar der Technischen Universität, Munich, Germany
| | - Marine Vernet
- Section on Neurocircuitry, Laboratory of Brain and Cognition, NIMH/NIH, Bethesda, MD, USA
| | - Evelyn Unterburger
- Division of Neuropsychology, Universitätsklinik Zürich USZ, Frauenklinikstrasse 26, Zurich, Switzerland
| | - Anna-Katharine Brem
- Department of Neuropsychology, Max-Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804, Munich, Germany. .,Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
7
|
Bosma MS, Nijboer TCW, Caljouw MAA, Achterberg WP. Impact of visuospatial neglect post-stroke on daily activities, participation and informal caregiver burden: A systematic review. Ann Phys Rehabil Med 2019; 63:344-358. [PMID: 31200080 DOI: 10.1016/j.rehab.2019.05.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/25/2019] [Accepted: 05/08/2019] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Visuospatial neglect (VSN) is a common cognitive disorder after stroke. The primary aim of this systematic review was to provide an overview of the impact of VSN in 3 aspects: (1) activities of daily living (ADL), (2) participation, and (3) caregiver burden. The second aim was to investigate the differences in studies focusing on populations with mean age<65 versus≥65 years. METHODS PubMed, EMBASE, Web of Science, Cochrane Library, Emcare, PsychINFO, Academic Search Premier and CENTRAL were searched systematically. Quality was assessed with the Mixed Methods Appraisal Tool. RESULTS Of the 115 included studies, 104 provided outcomes on ADL, 15 on participation (4 studies with mean age≥65), and 2 on caregiver burden (1 study with mean age≥65). Quality assessment yielded scores ranging from 0 to 100%. VSN had a negative impact on ADL (i.e., independence during ADL and performance in self-care, household tasks, reading, writing, walking, wheelchair navigation) and participation (i.e., driving, community mobility, orientation, work). The impact of VSN on fulfilling social roles was unclear. VSN had a negative effect on caregiver burden. We found no clear age-related differences. CONCLUSIONS AND IMPLICATIONS VSN has a negative impact not only on patients' independence but particularly on the performance of ADL. Despite the far fewer studies of VSN as compared with ADL, VSN also seems to hamper participation and increase caregiver burden, but further research is needed. Because of the large impact, VSN should be systematically and carefully assessed during rehabilitation. A considerable number of different instruments were used to diagnose VSN. Diagnosing VSN at more than one level [function (i.e., pen-and-paper test), activities, and participation] is strongly recommended. Consensus is needed on how to assess VSN and its negative impact for research and rehabilitation practice. SYSTEMATIC REVIEW REGISTRATION NO PROSPERPO Registration No. CRD42018087483.
Collapse
Affiliation(s)
- Martine S Bosma
- Department of public health and primary care, Leiden university medical center, Post zone V0-P, P.O. Box 9600, 2300 RC, Leiden, The Netherlands; Zorggroep Florence, Laan van Vredenoord 1, 2289 DA, Rijswijk, The Netherlands.
| | - Tanja C W Nijboer
- Center of excellence for rehabilitation medicine, UMC Utrecht brain center, university medical center Utrecht, and De Hoogstraat rehabilitation, Utrecht, The Netherlands; Utrecht university, department of experimental psychology, Heidelberglaan 1, 3584 CS, Utrecht, The Netherlands
| | - Monique A A Caljouw
- Department of public health and primary care, Leiden university medical center, Post zone V0-P, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| | - Wilco P Achterberg
- Department of public health and primary care, Leiden university medical center, Post zone V0-P, P.O. Box 9600, 2300 RC, Leiden, The Netherlands
| |
Collapse
|
8
|
Klinke ME, Hjaltason H, Tryggvadóttir GB, Jónsdóttir H. Hemispatial neglect following right hemisphere stroke: clinical course and sensitivity of diagnostic tasks. Top Stroke Rehabil 2017; 25:120-130. [DOI: 10.1080/10749357.2017.1394632] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Marianne E. Klinke
- Faculty of Nursing, School of Health Sciences, University of Iceland, Reykjavik, Iceland
- Neurological Department, Landspitali, The National University Hospital of Iceland, Reykjavik, Iceland
| | - Haukur Hjaltason
- Neurological Department, Landspitali, The National University Hospital of Iceland, Reykjavik, Iceland
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | | | - Helga Jónsdóttir
- Faculty of Nursing, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| |
Collapse
|
9
|
Abstract
PURPOSE Patching for double vision is a common palliative treatment for head-trauma patients with acquired strabismus when prisms are not feasible. METHODS We review literature on spatial neglect and discuss possible effects of monocular occlusion on spatial attention. RESULTS Patching the left eye has been shown to worsen spatial judgments in some brain-injured patients with left neglect by inhibiting the right superior colliculus further impairing contralateral leftward orienting (the Sprague Effect). CONCLUSIONS Because more peripheral parts of the visual field increasingly project to the contralateral superior colliculus with the temporal crescent being entirely contralateral, avoiding patching of the temporal crescent was advised, and in most cases can be achieved by taping off the spectacle lens and avoiding an elastic eye patch.
Collapse
|
10
|
He XF, Lan Y, Zhang Q, Liu DX, Wang Q, Liang FY, Zeng JS, Xu GQ, Pei Z. Deferoxamine inhibits microglial activation, attenuates blood-brain barrier disruption, rescues dendritic damage, and improves spatial memory in a mouse model of microhemorrhages. J Neurochem 2016; 138:436-47. [PMID: 27167158 DOI: 10.1111/jnc.13657] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/01/2016] [Accepted: 05/06/2016] [Indexed: 11/30/2022]
Abstract
Cerebral microbleeds are strongly linked to cognitive dysfunction in the elderly. Iron accumulation plays an important role in the pathogenesis of intracranial hemorrhage. Deferoxamine (DFX), a metal chelator, removes iron overload and protects against brain damage in intracranial hemorrhage. In this study, the protective effects of DFX against microhemorrhage were examined in mice. C57BL6 and Thy-1 green fluorescent protein transgenic mice were subjected to perforating artery microhemorrhages on the right posterior parietal cortex using two-photon laser irradiation. DFX (100 mg/kg) was administered 6 h after microhemorrhage induction, followed by every 12 h for three consecutive days. The water maze task was conducted 7 days after induction of microhemorrhages, followed by measurement of blood-brain barrier permeability, iron deposition, microglial activation, and dendritic damage. Laser-induced multiple microbleeds in the right parietal cortex clearly led to spatial memory disruption, iron deposits, microglial activation, and dendritic damage, which were significantly attenuated by DFX, supporting the targeting of iron overload as a therapeutic option and the significant potential of DFX in microhemorrhage treatment. Irons accumulation after intracranial hemorrhage induced a serious secondary damage to the brain. We proposed that irons accumulation after parietal microhemorrhages impaired spatial cognition. After parietal multiple microhemorrhages, increased irons and ferritin contents induced blood-brain barrier disruption, microglial activation, and further induced dendrites loss, eventually impaired the water maze, deferoxamine treatment protected from these damages.
Collapse
Affiliation(s)
- Xiao-Fei He
- Guangdong Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yue Lan
- Department of Rehabilitation Medicine, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, China
| | - Qun Zhang
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Dong-Xu Liu
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qinmei Wang
- Key Laboratory on Assisted Circulation, Department of Cardiovascular Medicine, Ministry of Health, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Feng-Ying Liang
- Guangdong Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jin-Sheng Zeng
- Guangdong Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Guang-Qing Xu
- Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhong Pei
- Guangdong Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
11
|
Abstract
The syndrome of visuospatial neglect is a common consequence of unilateral brain injury. It is most often associated with stroke and is more severe and persistent following right hemisphere damage, with reported frequencies in the acute stage of up to 80%. Neglect is primarily a disorder of attention whereby patients characteristically fail to orientate, to report or to respond to stimuli located on the contralesional side. Neglect is usually caused by large strokes in the middle cerebral artery territory and is heterogeneous, such that most patients do not manifest every feature of the syndrome. A number of treatments may improve neglect, but there is no widely accepted universal approach to therapy. Although most patients recover spontaneously, the evidence suggests that they continue to have significant cognitive impairments, particularly relating to attention.
Collapse
Affiliation(s)
- Korina Li
- Centre for Restorative Neuroscience, Division of Brain Sciences, Imperial College London, London, UK Department of Neurology, University Hospital Coventry, Coventry, West Midlands, UK
| | - Paresh A Malhotra
- Centre for Restorative Neuroscience, Division of Brain Sciences, Imperial College London, London, UK
| |
Collapse
|
12
|
Hach S, Schütz-Bosbach S. In (or outside of) your neck of the woods: laterality in spatial body representation. Front Psychol 2014; 5:123. [PMID: 24600421 PMCID: PMC3928589 DOI: 10.3389/fpsyg.2014.00123] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 01/29/2014] [Indexed: 11/28/2022] Open
Abstract
Beside language, space is to date the most widely recognized lateralized systems. For example, it has been shown that even mental representations of space and the spatial representation of abstract concepts display lateralized characteristics. For the most part, this body of literature describes space as distal or something outside of the observer or actor. What has been strangely absent in the literature on the whole and specifically in the spatial literature until recently is the most proximal space imaginable – the body. In this review, we will summarize three strands of literature showing laterality in body representations. First, evidence of hemispheric asymmetries in body space in health and, second in body space in disease will be examined. Third, studies pointing to differential contributions of the right and left hemisphere to illusory body (space) will be summarized. Together these studies show hemispheric asymmetries to be evident in body representations at the level of simple somatosensory and proprioceptive representations. We propose a novel working hypothesis, whereby neural systems dedicated to processing action-oriented information about one’s own body space may ontogenetically serve as a template for the perception of the external world.
Collapse
Affiliation(s)
- Sylvia Hach
- School of Psychology, The University of Auckland Auckland, New Zealand
| | | |
Collapse
|
13
|
Immediate effects of exposure to positive and negative emotional stimuli on visual search characteristics in patients with unilateral neglect. Neuropsychologia 2013; 51:2729-39. [PMID: 24080263 DOI: 10.1016/j.neuropsychologia.2013.09.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 08/19/2013] [Accepted: 09/23/2013] [Indexed: 11/21/2022]
Abstract
The performance of patients with unilateral neglect (UN) in tasks demanding visual attention is characterized by contralesional disadvantage which is markedly unstable in magnitude. Such instability of the attentional system is seen very clearly in clinical practice and thus far has no satisfying explanation. Here we examined the immediate effect of exposure to non-lateralized emotional stimuli on UN patients' attentional bias and performance variability. We tested eight right-hemisphere damaged stroke patients with left-sided neglect and eight age-matched healthy subjects in a visual conjunction-search task, each trial performed immediately after viewing a centrally-presented picture, which was emotionally negative, positive or neutral. Both performance bias and variability in performing the search task was analyzed as a function of the valence of the picture, and a method for analyzing reaction time (RT) variance in a small sample is introduced. Overall, UN subjects, but not controls, were slower and more variable in their RT for left- compared to right-sided targets. In the UN group, detecting left-sided targets was significantly slower in trials that followed presentation of negative pictures as compared to positive pictures, regardless of the fact that both picture types were judged as equally arousing by the patients. Moreover, UN patients exhibited larger performance variance on the left then on the right, and negative emotional stimuli were associated with larger variance asymmetry than positive emotional stimuli. Examining the coefficient of variation pointed to a possible dissociation between the effects of emotional stimuli on the lateralized RT mean (reflecting attentional bias) and on the lateralized RT variance (reflecting system instability). We conclude that emotional stimuli affect the spatial imbalance of both performance speed and stability in UN patients.
Collapse
|
14
|
Goedert KM, Boston RC, Barrett AM. Advancing the science of spatial neglect rehabilitation: an improved statistical approach with mixed linear modeling. Front Hum Neurosci 2013; 7:211. [PMID: 23730283 PMCID: PMC3657689 DOI: 10.3389/fnhum.2013.00211] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/02/2013] [Indexed: 11/13/2022] Open
Abstract
Valid research on neglect rehabilitation demands a statistical approach commensurate with the characteristics of neglect rehabilitation data: neglect arises from impairment in distinct brain networks leading to large between-subject variability in baseline symptoms and recovery trajectories. Studies enrolling medically ill, disabled patients, may suffer from missing, unbalanced data, and small sample sizes. Finally, assessment of rehabilitation requires a description of continuous recovery trajectories. Unfortunately, the statistical method currently employed in most studies of neglect treatment [repeated measures analysis of variance (ANOVA), rANOVA] does not well-address these issues. Here we review an alternative, mixed linear modeling (MLM), that is more appropriate for assessing change over time. MLM better accounts for between-subject heterogeneity in baseline neglect severity and in recovery trajectory. MLM does not require complete or balanced data, nor does it make strict assumptions regarding the data structure. Furthermore, because MLM better models between-subject heterogeneity it often results in increased power to observe treatment effects with smaller samples. After reviewing current practices in the field, and the assumptions of rANOVA, we provide an introduction to MLM. We review its assumptions, uses, advantages, and disadvantages. Using real and simulated data, we illustrate how MLM may improve the ability to detect effects of treatment over ANOVA, particularly with the small samples typical of neglect research. Furthermore, our simulation analyses result in recommendations for the design of future rehabilitation studies. Because between-subject heterogeneity is one important reason why studies of neglect treatments often yield conflicting results, employing statistical procedures that model this heterogeneity more accurately will increase the efficiency of our efforts to find treatments to improve the lives of individuals with neglect.
Collapse
Affiliation(s)
- Kelly M Goedert
- Department of Psychology, Seton Hall University South Orange, NJ, USA
| | | | | |
Collapse
|
15
|
Di Monaco M, Schintu S, Dotta M, Barba S, Tappero R, Gindri P. Severity of Unilateral Spatial Neglect Is an Independent Predictor of Functional Outcome After Acute Inpatient Rehabilitation in Individuals With Right Hemispheric Stroke. Arch Phys Med Rehabil 2011; 92:1250-6. [DOI: 10.1016/j.apmr.2011.03.018] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 03/14/2011] [Accepted: 03/20/2011] [Indexed: 11/26/2022]
|
16
|
Abstract
Unilateral spatial neglect is a common neurological syndrome following predominantly right hemisphere injuries and is characterized by both spatial and non-spatial deficits. Core spatial deficits involve mechanisms for saliency coding, spatial attention, and short-term memory and occur in conjunction with nonspatial deficits that involve reorienting, target detection, and arousal/vigilance. We argue that neglect is better explained by the dysfunction of distributed cortical networks for the control of attention than by structural damage of specific brain regions. Ventral lesions in right parietal, temporal, and frontal cortex that cause neglect directly impair nonspatial functions partly mediated by a ventral frontoparietal attention network. Structural damage in ventral cortex also induces physiological abnormalities of task-evoked activity and functional connectivity in a dorsal frontoparietal network that controls spatial attention. The anatomy and right hemisphere dominance of neglect follow from the anatomy and laterality of the ventral regions that interact with the dorsal attention network.
Collapse
Affiliation(s)
- Maurizio Corbetta
- Departments of Neurology, Radiology, and Anatomy and Neurobiology, Washington University School of Medicine, 314-362-4530, 4525 Scott Avenue, St. Louis, MO 63110
| | - Gordon L. Shulman
- Department of Neurology, Washington University School of Medicine, 314-362-8880, 4525 Scott Avenue. St. Louis, MO 63110
| |
Collapse
|
17
|
Hamilton RH, Stark M, Coslett HB. Increased effect of target eccentricity on covert shifts of visual attention in patients with neglect. Cortex 2009; 46:68-76. [PMID: 19345939 DOI: 10.1016/j.cortex.2009.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 02/10/2009] [Accepted: 02/12/2009] [Indexed: 10/21/2022]
Abstract
Debate continues regarding the mechanisms underlying covert shifts of visual attention. We examined the relationship between target eccentricity and the speed of covert shifts of attention in normal subjects and patients with brain lesions using a cued-response task in which cues and targets were presented at 2 degrees or 8 degrees lateral to the fixation point. Normal subjects were slower on invalid trials in the 8 degrees as compared to 2 degrees condition. Patients with right-hemisphere stroke with neglect were slower in their responses to left-sided invalid targets compared to valid targets, and demonstrated a significant increase in the effect of target validity as a function of target eccentricity. Additional data from one neglect patient (JM) demonstrated an exaggerated validity x eccentricity x side interaction for contralesional targets on a cued reaction time task with a central (arrow) cue. We frame these results in the context of a continuous 'moving spotlight' model of attention, and also consider the potential role of spatial saliency maps. By either account, we argue that neglect is characterized by an eccentricity-dependent deficit in the allocation of attention.
Collapse
Affiliation(s)
- Roy H Hamilton
- Department of Neurology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
| | | | | |
Collapse
|