Uncertainty is maintained and used in working memory.

Area of Science:

• Cognitive Psychology
• Neuroscience
• Computational Modeling

Background:

• Working memory models typically represent information as point estimates.
• The role of memory uncertainty in decision-making remains unclear.

Purpose of the Study:

• To investigate whether humans maintain and utilize uncertainty in working memory.
• To compare optimal Bayesian observer models with and without uncertainty representation.

Main Methods:

• Two-condition orientation change detection task.
• Comparison of models assuming optimal vs. no use of uncertainty.
• Testing model variants to ensure robustness of conclusions.

Main Results:

• A model incorporating uncertainty ('Use Uncertainty') provided a better fit for all participants across both conditions.
• Participants used uncertainty optimally when available and maintained it during a working memory delay.
• Conclusions were robust across different assumptions about encoding, inference, and decision rules.

Conclusions:

• Humans possess item-specific uncertainty reflecting memory precision.
• This uncertainty is maintained over working memory delays.
• Implicit use of uncertainty aligns with optimal observer behavior, necessitating updates to computational working memory models.