Altered temporal features of visual processing in subjective cognitive decline

Subjective cognitive decline (SCD) is possibly the earliest known stage of Alzheimer's disease. Individuals with SCD report perceiving a decline in their cognitive functioning and express concern about it. However, when assessed with standard neuropsychological tests, they perform within normal limits.

The present study focuses on the temporal features of visual processing in SCD using the random temporal sampling technique. This method reveals the perceptual oscillations which occur during a visual task by presenting stimuli with randomly varying signal-to-noise ratio through time. Fourteen individuals with SCD and 15 others without (i.e., controls), aged between 60 and 85 years old, took part in the study.

Participants with SCD performed within normal limits on neuropsychological tasks, as did the control group. In the experimental task, participants had to recognize briefly presented five-letter French words. The results take the form of classification images, which depict how visual processing efficiency fluctuates over time and across different frequency bands of signal-to-noise ratio oscillations. The classification images reveal significant differences between groups on the temporal patterns of visual processing. A machine learning classifier was used to categorize the data of individual participants according to group membership. The classifier achieved 79.3% classification accuracy using 18.0% of the available features.

Even though SCD individuals show no detectable cognitive impairment in neuropsychological testing, random temporal sampling can reveal anomalies in their perceptual function. (PsycInfo Database Record (c) 2026 APA, all rights reserved).