Behavioral and Eye-Tracking Evidence for Disrupted Event Segmentation during Continuous Memory Encoding Due to Short Video Watching

The widespread use of short-video platforms (e.g., TikTok), with over one billion monthly active users worldwide in 2023, necessitates an examination of their effects on cognitive functions. We hypothesized that because of the frequent, user-driven shifts in content during short-video watching, it mainly impairs event segmentation, a critical cognitive process in continuous perception and memory formation. To investigate this, we integrated memory encoding-retrieval tasks, eye-tracking technology, self-report questionnaires, and advanced machine learning analyses of eye movements. Our experiments (Study1 N=113, Study2 N=60), which varied the types of videos (random vs. personalized) and memory stimuli (continuous movies vs. static images), demonstrated that watching randomly selected short videos, particularly when integrated into daily viewing patterns, detrimentally affects memory encoding, especially in the initial and middle phases of continuous memory encoding. However, this impairment was not evident in trial-based image encoding tasks, suggesting a selective disruption in continuous memory processes. Intersubject correlation (ISC) analysis of eye movements revealed decreased synchronization at event boundaries during movie watching after exposure to random short videos. Furthermore, Hidden Markov Model (HMM) analyses indicated that participants were more likely to experience fragmented event segmentation during continuous memory encoding following exposure to random short videos. These findings underscore the potentially harmful impact of short-video watching on event segmentation and memory formation, emphasizing the role of recommendation algorithms in modulating human cognition.