Modes of information processing were examined for 91 subjects aged between 5 years 7 months and 6 years 3 months, using A.R. Luria's model of brain function as the theoretical basis of the study. A factor analysis of the results of six psychometric tests administered to all subjects indicated the presence of two distinct factors. These were hypothesised to represent the separate contributions of simultaneous and successive synthesis. Further separate factor analyses, of the six psychometric tests and tests of M-Space (derived from the work of R. Case) and tests of standard school assessment tasks (that were also administered to the subjects), were performed. The results indicated that although both modes of synthesis are available to children of this age, simultaneous synthesis is not a potent factor in school learning. A further exploratory study was carried out using the same 91 subjects. Subjects were given a series of verbal subtraction problems requiring understanding of mathematical relationships, and randomly assigned to two presentation groups. One group received pictorial information in addition to the verbal presentation. The other group received concrete materials. A multiple regression analysis was performed on the whole group using factor scores for simultaneous and successive syntheses (derived from the factor analysis of the six psychometric tests) as independent variables and criterion test scores for the verbal subtraction problems as the dependent variable. The analysis indicated that although neither aptitude for successive synthesis nor aptitude for simultaneous synthesis had predictive value for this kind of probelm solving, simultaneous synthesis was possibly the predominant mode of information processing. Further multiple regression analyses performed on each of the presentation groups indicated an interaction between successive synthesis and the modes of presentation of information. Due to the small numbers of subjects in each presentation group this result was inconclusive.