Intelligence after early brain injury II: IQ scores of subjects classified on the basis of medical history variables

Abstract

The problem of multivariate classification in early brain-damaged individuals was addressed by generating a typology based on various dimensions of brain damage, and by describing the consequences for intelligence of membership in the typology. More than 100 medical-history variables were expressed as a small set of factors that represented common patterns of medical variables; subjects were clustered on the basis of all these factors considered simultaneously, rather than on any single variable or set of variables; and the IQ scores of the subject clusters were compared. The results provide both a descriptive account of intelligence in most of the frequently occurring forms of early brain insult and allow a set of inferences to be drawn about the neural basis of intelligence in the young damaged brain.