Temporal information processing by young and senior adults and patients with senile dementia.

Temporal discrimination by healthy young and senior adults and patients with senile dementia was studied using the measure of transmitted information and two psychophysical methods (single-stimulus-ranking and pair-comparison). The patients with senile dementia showed very severe impairment on both methods and performed much less efficiently than the healthy adults of the same age; thus the former revealed a deficit in both memory and discrimination. The healthy seniors showed less alteration of temporal judgment with significant loss only with the single-stimulus method, which reflects memory deficit alone. Temporal cognition is very sensitive to changes in brain function.