Methodological Issues In Neuropsychological Assessment

The special issue about methodological considerations in neuropsychological assessment and rehabilitation grew out of a BIOMED 1 subprogramme funded by the European Community. It is intended to bridge the gap between the actual practice of studying the efficacy of neuropsychological remediation techniques on the one hand, and methodologies proposed by experts on the other, in order to help identifying neuropsychological treatments of proven efficacy. Therefore, in all contributions current or novel approaches and techniques for assessing brain-damaged patients and the evaluation of the efficacy of rehabilitation methods are applied to a particular substantial problem in neuropsychological assessment and/or rehabilitation of some aphasic disorders, acalculic number transcoding problems, various cognitive impairments in probable dementia, verbal short-term memory problems, spatial neglect, visual awareness and upper limb functioning in severe head trauma. In particular, problems with the use of normative data in (clinical) neuropsychology are pointed out. Strengths and weaknesses of different single-case treatment study designs are outlined and some (nonparametric) statistical procedures are proposed for their evaluation, including a procedure for the most probable sequence of spontaneous recovery. More general methodological issues are discussed, including the contribution of functional imaging to an understanding of functional recovery, the relevance of cognitive strategies of illiterates for the development of compensatory techniques for brain damaged literate subjects, and the evolution of handedness as a model case for studying the interplay of diverse factors influencing development of some cerebral function. Moreover, innovative, exemplary computerised assessment and training programs, including expert system tools, are presented that allow for a cognitive processing model based approach.