Abstract
In some situations, satisfactory neuropsychological assessment of a patient is not possible using conventional methods of investigation such as standardized tests, clinical interview, or neurological methods of examination. This is the case when interfering variables or complex cases in which there is a mixture of impaired function preclude the use of some standardized tests. Under certain conditions, the use of experimentation (i.e., experimental designs) can be of interest and can complement classical neuropsychological assessment. Even if it entails a number of constraints, experimentation may lead to a better understanding of the abilities of a patient and make it possible to set up a more effective program of rehabilitation.