title: Study of behavioural and neural bases of visuo-spatial working memory with an fMRI paradigm based on an n-back task.
abstract: The goal of this study was to propose a new functional magnetic resonance imaging (fMRI) paradigm using a language-free adaptation of a 2-back working memory task to avoid cultural and educational bias. We additionally provide an index of the validity of the proposed paradigm and test whether the experimental task discriminates the behavioural performances of healthy participants from those of individuals with working memory deficits. Ten healthy participants and nine patients presenting working memory (WM) deficits due to acquired brain injury (ABI) performed the developed task. To inspect whether the paradigm activates brain areas typically involved in visual working memory (VWM), brain activation of the healthy participants was assessed with fMRIs. To examine the task's capacity to discriminate behavioural data, performances of the healthy participants in the task were compared with those of ABI patients. Data were analysed with GLM-based random effects procedures and t-tests. We found an increase of the BOLD signal in the specialized areas of VWM. Concerning behavioural performances, healthy participants showed the predicted pattern of more hits, less omissions and a tendency for fewer false alarms, more self-corrected responses, and faster reaction times, when compared with subjects presenting WM impairments. The results suggest that this task activates brain areas involved in VWM and discriminates behavioural performances of clinical and non-clinical groups. It can thus be used as a research methodology for behavioural and neuroimaging studies of VWM in block-design paradigms.
authors.affiliation: Department of Biomedical Sciences, Institute of Biomedical Sciences Abel Salazar, University of Porto (ICBAS-UP), Portugal.|Psychosocial Rehabilitation Lab, School of Allied Health Technologies, Polytechnic Institute of Porto/Faculty of Psychology and Educational Sciences, University of Porto, Portugal.
authors.forename: Artemisa R
authors.initials: AR
authors.lastname: Dores
authors.affiliation: Laboratory of Neuropsychophysiology, Faculty of Psychology and Educational Sciences, University of Porto (FPCEUP), Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Barbosa
authors.affiliation: Department of Clinical Neurosciences and Mental Health, School of Medicine, University of Porto (FMUP), Portugal.
authors.forename: Irene P
authors.initials: IP
authors.lastname: Carvalho
authors.affiliation: Neuropsychological Rehabilitation Group, Gaia Vocational Rehabilitation Centre, Vila Nova de Gaia, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Almeida
authors.affiliation: Neuropsychological Rehabilitation Group, Gaia Vocational Rehabilitation Centre, Vila Nova de Gaia, Portugal.
authors.forename: Sandra
authors.initials: S
authors.lastname: Guerreiro
authors.affiliation: Order of Portuguese Psychologists, Oporto, Portugal.
authors.forename: Benedita M
authors.initials: BM
authors.lastname: da Rocha
authors.affiliation: Department of Biomedical Sciences, Institute of Biomedical Sciences Abel Salazar, University of Porto (ICBAS-UP), Portugal.
authors.forename: Liliana
authors.initials: L
authors.lastname: de Sousa
authors.affiliation: Centre for Interdisciplinary Research in Health - Universidade Catolica Portuguesa, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Castro-Caldas
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D004192:Discrimination, Psychological; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D065855:Spatial Processing / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: behavioural performance; functional Magnetic Resonance Imaging (fMRI); visuo-spatial n-back task; visuo-spatial working memory