Behavioural and EEG Frequency Spectral Outcomes of a tDCS-based Intervention in a Chronic Case of Spatial Neglect. A Single Case Study.

The spatial neglect is a neuropsychological syndrome related to the spatial attention due to an acquired brain injury. It is a common consequence of a unilateral stroke, most often after an extensive stroke in the right hemisphere, being present in up to 1 out of 2 cases. Some neuropsychological interventions have shown promising results to ameliorate the symptoms. The use of tDCS has being promoted as a promising tool to enhance the neuropsychological therapies. This study proposes an intervention protocol for neglect based on the use of tDCS as a boost for a virtual reality and visual search training paradigm. In addition, a computerised task is used to monitor the rehabilitation. The physiological correlates of the syndrome are studied with EEG time-frequency analysis. Behavioural results show positive effects of therapy on spatial neglect, as well as on other cognitive processes such as visuoconstructive praxis. Possible markers of the syndrome are detected in the EEG, with special attention to interhemispheric differences and alpha and delta waves. The computerised task developed may give rise to a line of work for further refinement and diagnostic use. The implications of this research are discussed.