Temporal expectation triggers competition in working memory that leads to forgetting.

Area of Science:

• Cognitive Neuroscience
• Human Memory Systems

Background:

• Working memory (WM) is a limited capacity system for short-term information maintenance.
• Long-term memory (LTM) is a vast repository for enduring information storage.
• Competition within WM can negatively impact LTM representations.

Purpose of the Study:

• To investigate how dynamic competition for WM resources affects LTM retention.
• To examine the role of temporal expectations in modulating WM content and LTM forgetting.

Main Methods:

• Human participants (N=20) performed a WM task with manipulated temporal expectations and memory delays (1s or 4s).
• Electroencephalography (EEG) and multivariate pattern analysis (MVPA) tracked dynamic WM content fluctuations.
• WM temporal profiles were correlated with long-term recognition performance.

Main Results:

• Participants dynamically shifted WM item priority based on temporal expectations.
• Forgetting in LTM was linked to decreased neural evidence for de-prioritized WM items.
• Neural representations in WM fluctuated with expected task relevance.

Conclusions:

• WM representations are dynamic and influenced by temporal expectations.
• De-prioritization of information during WM maintenance is a key mechanism driving LTM forgetting.
• Understanding WM-LTM interactions is crucial for explaining memory dynamics.