Abstract
The aim of this study was to investigate episodic memory in tasks using the five sensory modalities, i. e., visual, auditory, olfactory, gustatory and tactile, in dementia of the Alzheimer type (DAT).
Eleven DAT patients and five normal controls (NC) were tested on immediate recognition and recognition after five minutes for the five sensory modalities. The test consisted of five memory tasks and ten recognition tasks for each sensory modality. The rates of correct responses on immediate recognition and recognition after five minutes for each sensory modality were lower in the DATs than those of the NCs. Especially significant differences were observed in the rates of correct responses in visual, auditory and tactile modalities for both types of recognition. The NCs did not show differences in rate of correct responses for any sense between immediate recognition and recognition after five minutes. Meanwhile, the rate of correct responses for immediate recognition in the DATs decreased significantly in the visual, auditory and tactile modalities compared to those for recognition after five minutes, while those of the gustatory and olfactory modalities were almost identical for both immediate recognition and recognition after five minutes.
These results indicate that episodic memory of gustatory and olfactory modalities is relatively well preserved in DATs.
