Dement Neurocogn Disord.  2023 Oct;22(4):148-157. 10.12779/dnd.2023.22.4.148.

Time Perception and Memory in Mild Cognitive Impairment and Alzheimer’s Disease: A Preliminary Study

• Woo SH
• Hahm J
• Kyong JS
• Kim HR
• Kim KK

• KMID: 2548247
• DOI: http://doi.org/10.12779/dnd.2023.22.4.148

Abstract

Background and Purpose
Episodic memory is a system that receives and stores information about temporally dated episodes and their interrelations. Our study aimed to investigate the relevance of episodic memory to time perception, with a specific focus on simultaneity/ order judgment.
Methods
Experiment 1 employed the simultaneity judgment task to discern differences in time perception between patients with mild cognitive impairment or dementia, and agematched normals. A mathematical analysis capable of estimating subjects’ time processing was utilized to identify the sensory and decisional components of temporal order and simultaneity judgment. Experiment 2 examined how differences in temporal perception relate to performance in temporal order memory, in which time delays play a critical role.
Results
The temporal decision windows for both temporal order and simultaneity judgments exhibited marginal differences between patients with episodic memory impairment, and their healthy counterparts (p = 0.15, t(22) = 1.34). These temporal decision windows may be linked to the temporal separation of events in episodic memory (Pearson’s ρ = −0.53, p = 0.05).
Conclusions
Based on our findings, the frequency of visual events accumulated and encoded in the working memory system in the patients’ and normal group appears to be approximately (5.7 and 11.2) Hz, respectively. According to the internal clock model, a lower frequency of event pulses tends to result in underestimation of event duration, which phenomenon might be linked to the observed time distortions in patients with dementia.

Keyword

Dementia; Time Perception; Memory; Episodic; Alzheimer Disease; Models; Statistical; Memory Disorders