Developmental Disorders and Cognitive Architecture

For the last thirty years, cognitive scientists have attempted to describe the cognitive architecture of typically developing human beings, using, among other sources of evidence, the dissociations that result from developmental psychopathologies such as autism spectrum disorders, Williams syndrome, and Down syndrome. Thus, in his recent defense of the massive modularity hypothesis, Steven Pinker insists on the importance of such dissociations to identify the components of the typical cognitive architecture (2005, 4; my emphasis): This kind of faculty psychology has numerous advantages (...). It is supported by the existence of neurological and genetic disorders that target these faculties unevenly, such as a difficulty in recognizing faces (and facelike shapes) but not other objects, or a difficulty in reasoning about minds but not about objects or pictures. Similarly, Simon Baron-Cohen writes (1998, 335; my emphasis; see also Temple, 1997): I suggest that the study of mental retardation would profit from the application of the framework of cognitive neuropsychology (...). In cognitive neuropsychology, one key question running through the investigator’s mind is “Is this process or mechanism intact or impaired in this person?” When cognitive neuropsychology is done well, a patient’s cognitive system is examined with specific reference to a model of the normal cognitive system. And, not infrequently, evidence from the patient’s cognitive deficits leads to a revision of the model of the normal system. However, in recent years, the use of developmental psychopathologies to identify the components of the typical cognitive architecture has come under heavy fire. In a series of influential articles, neuropsychologist Annette Karmiloff-Smith has argued that findings about the pattern of impairments and preserved capacities in people with developmental psychopathologies say nothing about the cognitive architecture of