J. Peter Denny

TRAIL-MAKING TEST PERFORMANCE IN RELATION TO CERTAIN EXPERIMENTER, TEST AND SUBJECT VARIABLES.

The Trail Making Test, previously reported highly effective in differentiating brain-damaged from non-brain-damaged Ss, was administered to 21 brain-damaged Ss and 63 non-brain-damaged Ss. Since the latter Ss performed at a level indistinguishable from that of the brain-damaged Ss, several studies were designed in an attempt to “explain” the poor performance of the non-brain-damaged Ss. The possible effects of behavioral agitation, anxiety, examiner differences, facility with letters of the alphabet, order of administration, and ego-involvement were investigated. Only anxiety was found to be significantly related to performance. However, in other analyses age, education, vocabulary, and degree of psychiatric disturbance were significantly related to performance. Until these variables are considered in the scoring system, it seems unlikely that the TMT will be effective as a general screening test for brain-damage.

INTERACTION OF ABILITY LEVEL AND INTERPOLATED ACTIVITY (OPPORTUNITY FOR INCUBATION) IN HUMAN PROBLEM SOLVING

Performance on a functional fixedness problem was investigated under conditions of continuous work on the problem vs interpolation of unrelated activity, and in Ss of low vs high problem-solving ability. The performance of low-ability Ss was most proficient under the interpolated-activity condition, whereas for high-ability Ss performance was best under continuous work. It was suggested that different types of problem-solving processes occurred in low- and high-ability Ss, and that interpolated activity influenced these processes in opposite ways.

Integrative Cognitive Style in Middle Eastern and Western Groups Multidimensional Classification and Major and Minor Property Sorting

Integrative cognitive style among Middle Eastern immigrants to Canada and native-born Euro-Canadians was assessed by looking at their performance on a multidimensional classification task and an object sorting task. Results showed high levels of integrative thinking in Middle Eastern immigrants compared with Euro-Canadians. The contrasting differentiative cognitive style was avoided by the Middle Eastern group, whereas a higher level of differentiation was observed in the Euro-Canadian groups. These results are congruent with previous studies showing higher levels of integrative style in Middle Eastern groups than in Euro-Canadian groups. A secondary finding revealed higher levels of integrative thinking among Middle Easterners with comparatively low levels of Western education. In sum, findings show preferences for integrative thinking in Middle Eastern groups, and through new measures of cognitive style, qualitative aspects of integrative thinking, which have traditionally been viewed indirectly as the opposite of differentiative thinking, are revealed.

Context in the Assessment of Mathematical Concepts from Hunting Societies

For some years now I have been studying the nature of mathematical concepts in certain societies which were traditionally hunters and are now adopting portions of industrial technology (Denny, 1981). The general aim of this research is to discover major variables in the structure of thinking that are influenced by the type of subsistence system, whether hunting, some kind of agriculture, or industry. One of the most pervasive variables to emerge is the integration of contextual information with focal information, for thinking processes in hunting societies (and also agricultural ones), but not in industrial society. In the first part of this paper I will describe how even the simplest of mathematical concepts is encoded in the language of a hunting society so that some context is represented together with the main concept, e.g., it is not possible to say ‘two’ but at a minimum ‘two-elements’ or ‘two-sets.’

Memory-Load and Concreteness in the Order of Dominance Effect for Verbal Concepts.

Previous research has shown that concrete concepts are more readily attained than abstract concepts. This order of dominance phenomenon has been well established for figural concepts and has been suggested for verbal concepts. In the present study the effect was confirmed for verbal materials, even when the instances and concepts were equivalent with respect to instance frequency, meaningfulness, and conjoint frequency. In addition, the dominance effect was especially marked under high memory-load conditions, and for subjects who had difficulty in remembering previously presented instances. These findings were interpreted to support a new theory of the order of dominance effect for verbal materials: Concrete concepts are in part more readily attained because, under the high memory-load for previous instances which was obtained in earlier experiments, concrete word instances are more readily available from memory.

Concept identification strategies used for positive and negative instances

Previous investigators have speculated about strategies of reasoning which might account for poorer proficiency in concept identification from negative than from positive instances. In this study novel dependent variables were used to provide a broad data base from which Ss’ strategies could be inferred. These measures were Ss’ responses indicating their conclusions about the concept as they developed during the course of the task, and Ss’ reports, using stimulated recall after the task, of their reasoning used to infer these conclusions from the information given in the task. Three types of strategies were discovered: formal strategies consisting of correct deductive reasoning, concrete strategies consisting of unintegrated inferences from particular pieces of information, and nonprocessing strategies in which no inferences were drawn. Ss receiving a negative instance task used correct formal strategies less frequently and incorrect concrete strategies more frequently than Ss receiving a positive instance task. They did so because of a strong tendency to infer that an attribute absent from an instance was not in the concept.

Interpretation of information that an instance is positive or negative in concept identification

Previous authors have speculated about the reasoning Ss have used to identify concepts more proficiently from positive than from negative instances. In the present study, a part of this reasoning, Ss’ interpretation of information that an instance is positive or negative, was observed by means of novel measures. These were Ss’ conclusions about the concept at each stage of the task, and Ss’ stimulated recall of the reasoning they used to draw each conclusion. Ss’ made equally frequent but different misinterpretations of positive and negative instances. These misinterpretations appeared to be part of a particular reasoning strategy which yielded correct conclusions when applied to positive instances and incorrect conclusions when applied to negative instances.