Exploratory behavior in patients suffering from senile dementia: a comparison with children

Thirty-seven patients with the diagnosis of senile dementia and 70 children aged 6 months to 4 years were observed in three tasks that stimulated exploratory behavior. The subjects were rated according to the frequencies of certain forms of behavior in 52 variables. It was assumed that certain behavior would be more frequent among children in specific age periods and for that reason a factor analysis of the children's behavior would generate factors characterizing clusters of behavior typical for certain periods. The factor analyses of the children's behavior yielded three factors, which were interpreted as an oral factor, a factor characterizing interest in three-dimensional relationships, and a factor regarding goal-directed manipulation. Indices of the three factors demonstrated that the oral factor had a very high frequency in the infants 6-11 months old; after that age it decreased steeply and disappeared at about 2 years of age. Activities involving three-dimensional relationships and goal-directed manipulation were scarcely displayed in the youngest infants but appeared at about 12 months. Both modes of exploratory behavior tended to disappear before the age of 4. Analyses were carried out to see if the behavior of the patients yielded similar factors, and to see if the distributions of the factor indices for the group of patients, when broken down according to the degree of mental deterioration, had forms similar to the distributions for the children in the different age groups. Similar factors were obtained for the patients, but the structures were less clear and less meaningful than those obtained for the children. The forms of the distributions of factor indices over the degree of mental deterioration were similar to the distributions over the age groups for the children. Motor activity was reduced among more deteriorated patients. When explaining the childlike strategies in the exploratory behavior of the demented patients, it was hypothesized that, due to deficient memory, the patients had to manipulate the objects to find their qualities. This exploratory behavior was more or less advanced and flexible depending on the degree of mental deterioration. However, possible negative effects of high anxiety and high social inhibition were also touched upon.