Abstract
Episodic memories are contextual experiences ordered in time. This is underpinned by associative binding between events within the same contexts. The role of prediction errors in declarative memory is well established but has not been investigated in the time dimension of complex episodic memories. Here we combine these two properties of episodic memory, extend them into the temporal domain and demonstrate that prediction errors in different naturalistic contexts lead to changes in the temporal ordering of event structures in them. The wrongly predicted older sequences were weakened despite their reactivation. Interestingly the newly encoded sequences with prediction errors, seen once, showed accuracy as high as control sequences which were viewed repeatedly without change. Drift–diffusion modelling revealed a lower decision threshold for the newer sequences than older sequences, reflected by their faster recall. Moreover, participants’ adjustments to their decision threshold significantly correlated with their relative speed of sequence memory recall. These results suggest a temporally distinct and adaptive role for prediction errors in learning and reorganizing episodic temporal sequences.
Highlights
In the present study, we test the hypothesis that the contextual prediction errors would fundamentally alter the memorized sequence of events
We hypothesized that the association strength of the inaccurately predicted Old sequences would be weaker compared to the New sequences because of the prediction error
There was a significant difference in percentage accuracy between recalling the Old (Mean = 47.69, SE = 3.04) and New sequence (Mean = 58.76, SE = 3.05) in Substitution condition (t(23) = 3.416, p = 0.002, 95% CI [4.36, 17.77], Bayes factor (BF) = 16.60, d = 0.74) (Fig. 2a)
Summary
We test the hypothesis that the contextual prediction errors would fundamentally alter the memorized sequence of events. From the perspective of predictive c oding[27,28] new surprising information that violates expectations drives stronger learning These newly formed sequences would be strengthened over older encoded sequential information to minimize future errors. Our key finding is that contextual prediction errors strengthen the newer memory sequences in time while weakening the order of previously encoded sequences, thereby reorganizing encoded temporal memories. This enhanced performance, reflected by faster reaction times, on subsequent modelling showed that it results from a lower decision threshold while remembering, signifying a more automatic response for the newer sequences. Our findings reveal how prediction errors play a crucial role in determining how episodic memories are organized in time
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
