The scientist-practitioner model: how do advances in clinical and cognitive neuroscience affect neuropsychology in the courtroom?

One of the core tenets of the scientist-practitioner model, slightly modified to make it applicable to modern neuropsychology, is that assessment procedures should be developed, applied, and interpreted in a relevant scientific framework. However, over the last 30 years, the general structure of a neuropsychological assessment has changed little, if at all. It has continued to focus mainly on the assessment of cognitive constructs such as intelligence, memory, attention, and perception. During the same time period, cognitive neuroscience has focused on integrative systems, largely controlled by frontal mechanisms, that allow individuals to utilize cognitive functions in an adaptive way, especially in the context of novel situations or when social stimuli are ambiguous. Consequently, the gulf between cognitive neuroscience and the practice of clinical neuropsychology has grown uncomfortably large. This article attempts to review some of the developments in cognitive and affective neuroscience that are relevant to an evaluation of neuropsychological abilities, especially in a medicolegal context, to determine whether conventional neuropsychological methods can be considered fit for purpose.

Free will: reconciling German civil law with Libet's neurophysiological studies on the readiness potential.

The free will debate widely exceeds the neuroscientific and philosophical fields due to profound implications for legislation, case law and psychiatric expert opinion. Data from Benjamin Libet's experiments on the readiness potential have been used as an argument against personal responsibility and for changes in the law. Due to the explicit use of the term "free will" in German civil law, the psychiatrist as an expert witness is confronted with this debate. In this article we outline the role of this crucial term in German civil law and we describe the neurophysiologic challenge in the form of Libet's experiments, which is led on three levels: the correctness of the data, the impact on the question of whether free will exists and possible consequences for the law. We conclude that the problem of free will cannot be debated on the basis of the data provided by Libet's experiments and that doubts about the existence of a free will must not lead to changes in the law or in psychiatric expert testimony. Therefore, advice for the psychiatrist as an expert witness is offered on the basis of a psychopathological approach that takes into account cognitive and motivational preconditions and the structure of values and personality.