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, the monkeys 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 are 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 these monkeys to skip over irrelevant information by compressing the encoded video globally. We also reveal that the monkeys detect event contextual boundaries, and that such detection facilitates recall by increasing the 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.
Highlights
Accumulating evidence indicates that non-human primates possess the ability to remember temporal relationships among events (Templer and Hampton, 2013; Gower, 1992; Charles et al, 2004)
By applying representational similarity analyses (RSA), the Linear Approach to Threshold with Ergodic Rate (LATER) model and generalized linear models to the retrieval time (RT) data, we examined the presence of replay-like behavioral patterns in the monkeys
In light of recent reports on the neural correlates underlying how humans and rodents replay their past experiences (Liu et al, 2019; Michelmann et al, 2019; Panoz-Brown et al, 2018; Davidson et al, 2009), here, we demonstrate parallel behavioral findings in macaque monkeys looking at dynamic cinematic material
Summary
Accumulating evidence indicates that non-human primates possess the ability to remember temporal relationships among events (Templer and Hampton, 2013; Gower, 1992; Charles et al, 2004). It has been shown that episodes can be replayed sequentially on the basis of learned structures (Liu et al, 2019), sensory information (Michelmann et al, 2019), and pictorial content (Wimmer et al, 2019). These findings suggest the possibility that monkeys can rely on a similar mechanism in recalling events that are linked temporally during temporal order judgement
Sign-in/Register to view highlights & summary 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.
