Developmental change and invariance in semantic processing

Abstract

Two experiments were conducted to explore the characteristics of semantic processing in 8-, 10-, and 19-year-olds. In the first study subjects read through lists of words and responded to either a member or nonmember of a prespecified category. Semantic processing speed was found to increase with age even when motor response latencies were partialed out. The second study was designed to establish whether this increase in semantic processing speed was due to developmental changes in semantic organization and accessibility, to changes in the organization and execution of decision processes, or more simply to faster, nonsemantic encoding of words. Subjects read through lists of words and made decisions based on category membership and/or physical size attributes of the individual concepts. For 8-year-olds size and category decisions were made at approximately the same speed, whereas category information was processed more rapidly than size information for the older groups. A parallel, self-terminating model best accounted for the data at all age levels. These results are interpreted in terms of developmental changes in the organization and accessibility of semantic information, as well as invariance in certain characteristics of information processing.