This special issue of Cognition, Brain, Behavior is concerned with the developmental neuropsychological approach viewed through multiple lens. The field is, by its very essence, interdisciplinary; it exists at the interplay of multiple influences from traditional neuropsychology, cognitive psychology, developmental psychology and cognitive neuroscience.
The fundamental aims of developmental neuropsychology have changed across time; while initially it was claimed that - as in the case of adult cognitive neuropsychology - the ultimate aim was to construct theoretical models of cognitive domains, against which all childhood cases of disorders of those domains could be explained (Temple, 1997), it is nowadays clear that the purpose is hardly reachable, and maybe even unrealistic. The multilevel analysis of the development of atypical groups does not support the perspective of a normal brain with whole circuits intact or impaired, as in the adult neuropsychological model; there is a different dynamic of brain development at multiple levels (genetic, metabolic, functional), throughout embryogenesis and postnatal development (Karmiloff-Smith, 2007).
Contemporary non-invasive neuroimaging methods have provided developmental scientists with the opportunity to track "on-line" neural underpinnings of task-solving processes (see Casey et al., 2006, for a review); however, the tasks that can be examined through these lenses are simplified, and to a great extent, non-ecological. In addition, the investigation of atypical brain phenotypes is extremely limited due to difficulties in interpreting the neuroimaging results for tasks that the children have difficulties in resolving (Filipek, 1999; Humphreys & Price, 2001). Only by combining the results of neuroimaging investigations with the results from studies in developmental cognitive neuropsychology will we be able to map the behavioral level onto contrasting and complementary patterns of brain morphology and generate new hypotheses about the brain systems responsible for those atypical patterns of behavior (Bates & Appelbaum, 1994).
Before analyzing the contributions of the papers in this special issue to this generous aim, we have to mention that there are distinct types of designs involved in neuropsychological assessment according to the format and the logic of the tests being used (Fennell, 2000). First of all, the researcher could rely on a fixed battery approach, administering the same set of standardized tests to each child, regardless of the diagnostic question. The developmental neuropsychological batteries are empirically derived, sometimes from adult versions of the tests with items altered, deleted or eliminated, to make them more age appropriate for children. The emphasis is in this case on the quantitative differentiation of patient groups from normal children, without respect to many qualitative aspects of this difference. A second approach would be the flexible battery approach, which utilizes a core battery of standardized tests that are administered, along with additional tests that are selected to address specific referral questions. Finally, the patient-centered approach allows the examiner to select tests to be employed based on both the referral question and the child's performance on a given task, which provides an individualized portrait of the child's cognitive-behavioral status. At this point, we would add to Fennell's (2000) classification a profile-centered approach, which is either exploratory or confirmatory in nature, and which employs refined experimental tasks evaluating critical abilities consider to be impaired or spared in children with a certain diagnosis (Petra & Benga, 2004). The resulting evaluation leads to the identification of cognitive-behavioral phenotypes, namely "the heightened probability of a behavior or cognitive feature to characterize a particular syndrome" (Dykens, 2000), with important implications both for the intervention plan in the case of children with that diagnosis and for theoretical models regarding patterns of brain-behavior relationships noticed in these profiles. …