title: (Un)awareness of unilateral spatial neglect: a quantitative evaluation of performance in visuo-spatial tasks.
abstract: Right-brain-damaged patients with unilateral spatial neglect are usually unaware (anosognosic) about their spatial deficits. However, in the scientific literature there is a lack of systematic and quantitative evaluation of this kind of unawareness, despite the negative impact of anosognosia on rehabilitation programs. This study investigated anosognosia for neglect-related impairments at different clinical tasks, by means of a quantitative assessment. Patients were tested in two different conditions (before and after execution of each task), in order to evaluate changes in the level of awareness of neglect-related behaviours triggered by task execution. Twenty-nine right-brain-damaged patients (17 with left spatial neglect) and 27 neurologically unimpaired controls entered the study. Anosognosia for spatial deficits is not pervasive, with different tasks evoking different degrees of awareness about neglect symptoms. Indeed, patients showed a largely preserved awareness about their performance in complex visuo-motor spatial and reading tasks; conversely, they were impaired in evaluating their spatial difficulties in line bisection and drawing from memory, showing over-estimation of their performance. The selectivity of the patients' unawareness of specific manifestations of spatial neglect is further supported by their preserved awareness of performance at a linguistic task, and by the absence of anosognosia for hemiplegia. This evidence indicates that discrete processes are involved in the aware monitoring of cognitive and motor performance, which can be selectively compromised by brain damage. Awareness of spatial difficulties is supported by a number of distinct components, and influenced by the specific skills required to perform a given task.
authors.affiliation: Department of Psychology, University of Milano-Bicocca, Milano, Italy; Neuropsychological Laboratory, S. Luca Hospital, IRCCS Istituto Auxologico Italiano, Milano, Italy; Laboratory of Cognitive Neuroscience, Brain Mind Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. Electronic address: roberta.ronchi@epfl.ch.
authors.forename: Roberta
authors.initials: R
authors.lastname: Ronchi
authors.affiliation: Department of Psychology, University of Milano-Bicocca, Milano, Italy; Neuropsychological Laboratory, S. Luca Hospital, IRCCS Istituto Auxologico Italiano, Milano, Italy; Milan Centre for Neuroscience, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo 1, Milano, Italy.
authors.forename: Nadia
authors.initials: N
authors.lastname: Bolognini
authors.affiliation: Department of Psychology, University of Milano-Bicocca, Milano, Italy; Milan Centre for Neuroscience, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo 1, Milano, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Gallucci
authors.affiliation: Unità di Psicologia Clinica, Ospedale Papa Giovanni XXIII, Bergamo, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Chiapella
authors.affiliation: Unità di Psicologia Clinica, Ospedale Papa Giovanni XXIII, Bergamo, Italy.
authors.forename: Lorella
authors.initials: L
authors.lastname: Algeri
authors.affiliation: Unità di Psicologia Clinica, Ospedale Papa Giovanni XXIII, Bergamo, Italy.
authors.forename: Maria Simonetta
authors.initials: MS
authors.lastname: Spada
authors.affiliation: Department of Psychology, University of Milano-Bicocca, Milano, Italy; Neuropsychological Laboratory, S. Luca Hospital, IRCCS Istituto Auxologico Italiano, Milano, Italy; Milan Centre for Neuroscience, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo 1, Milano, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vallar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000377:Agnosia / Q000209:etiology / Q000503:physiopathology*; D001364:Awareness / Q000502:physiology*; D001930:Brain Injuries / Q000150:complications / Q000503:physiopathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006429:Hemiplegia / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests
keywords: Evaluation of cognitive performance; Right-brain damage; Unawareness/anosognosia for left neglect and hemiplegia; Unilateral left spatial neglect