Behavioral evidence for memory replay of video episodes in the macaque
- East China Normal University, China
- Korea Advanced Institute of Science and Technology, Republic of Korea
- University of York, United Kingdom
- Shenzhen University, China
Abstract
Humans recall the past by replaying fragments of events temporally. Here, we demonstrate a similar effect in macaques. We trained six rhesus monkeys with a temporal-order judgement (TOJ) task and collected 5000 TOJ trials. In each trial, they watched a naturalistic video of about 10 s comprising two across-context clips, and after a 2-s delay, performed TOJ between two frames from the video. The data is suggestive of a non-linear, time-compressed forward memory replay mechanism in the macaque. In contrast with humans, such compression of replay is however not sophisticated enough to allow them to skip over irrelevant information by compressing the encoded video globally. We also reveal that the monkeys detect event contextual boundaries and such detection facilitates recall by an increased rate of information accumulation. Demonstration of a time-compressed, forward replay-like pattern in the macaque provides insights into the evolution of episodic memory in our lineage.
Data availability
All data is available at Dryad (doi: 10.5061/dryad.3r2280gcc).
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Behavioral evidence for memory replay of video episodes in macaque monkeysDryad, doi: 10.5061/dryad.3r2280gcc.
Article and author information
Author details
Funding
National Key Fundamental Research Program of China Grant (2013CB329501)
- Yong-di Zhou
Ministry of Education of PRC Humanities and Social Sciences Research Grant (16YJC190006)
- Sze Chai Kwok
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: The experimental protocol was approved by the Institutional Animal Care and Use Committee (permission code: M020150902 & M020150902-2018) at East China Normal University. All experimental protocols and animal welfare adhered with the "NIH Guidelines for the Care and Use of Laboratory Animals".
Human subjects: The experimental protocol was approved by the the University Committee on Human Research Protection (permission code: HR 023-2017) at East China Normal University. . The participants provided informed consent.
Copyright
© 2020, Zuo et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Behavioral evidence for memory replay of video episodes in the macaque
eLife 9:e54519.
https://doi.org/10.7554/eLife.54519
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