The study of genetic developmental disorders originally seemed to hold the promise for those of a nativist persuasion of demonstrating pure dissociations between different cognitive functions, as well as the existence of innately specified modules in the brain and the direct mapping of mutated genes to specific cognitive-level outcomes. However, more recent research within a neuroconstructivist perspective has challenged this promise, arguing that earlier researchers lost sight of one fundamental explanatory factor in both the typical and atypical case: the actual (...) process of ontogenetic development. The paper is divided into three parts on evolution, genetics, and ontogeny. Each section starts by examining nativist claims about innateness and modularity of function, and subsequently evaluates them within a neuroconstructivist approach to human development. (shrink)

Evidence from aphasia is considered that leads to a distinction between abstract and concrete thought processes and hence for a distinction between rules and similarity. It is argued that perceptual classification is inherently a rule-following procedure and these rules are unable to be followed when a patient has difficulty with name comprehension and retrieval.

The distinction between rules and similarity is central to our understanding of much of cognitive psychology. Two aspects of existing research have motivated the present work. First, in different cognitive psychology areas we typically see different conceptions of rules and similarity; for example, rules in language appear to be of a different kind compared to rules in categorization. Second, rules processes are typically modeled as separate from similarity ones; for example, in a learning experiment, rules and similarity influences would be (...) described on the basis of separate models. In the present article, I assume that the rules versus similarity distinction can be understood in the same way in learning, reasoning, categorization, and language, and that a unified model for rules and similarity is appropriate. A rules process is considered to be a similarity one where only a single or a small subset of an object's properties are involved. Hence, rules and overall similarity operations are extremes in a single continuum of similarity operations. It is argued that this viewpoint allows adequate coverage of theory and empirical findings in learning, reasoning, categorization, and language, and also a reassessment of the objectives in research on rules versus similarity. Key Words: categorization; cognitive explanation; language; learning; reasoning; rules; similarity. (shrink)