Comparison of implicit and explicit learning abilities in human adults, children, apes and monkeys

Project Information

ImpExpPrimates

Grant agreement ID: 101030257

DOI

10.3030/101030257

Project closed

EC signature date 13 April 2021

Start date 1 February 2022

End date 31 January 2024

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 184 707,84

EU contribution

€ 184 707,84

Coordinated by

ECOLE NORMALE SUPERIEURE
France

Periodic Reporting for period 1 - ImpExpPrimates (Comparison of implicit and explicit learning abilities in human adults, children, apes and monkeys)

Reporting period: 2022-02-01 to 2024-01-31

Summary of the context and overall objectives of the project

This research project delves into the fascinating world of learning, exploring two distinct processes: implicit and explicit learning. Implicit learning is the incidental acquisition of a new skill through repeated exposure or practice, resulting in knowledge that cannot be consciously accessed or verbalized. On the other hand, explicit learning is a more intentional and effortful process that leads to conscious knowledge that can be verbally described. While most research in this area has focused on humans, this project takes a unique approach, aiming to assess the hypothesis of a similar dissociation between implicit and explicit learning processes in other, non-human primate species.
Understanding the relationship between learning and consciousness in humans and other species is a crucial step towards understanding consciousness, a fascinating property of the mind that we can all experience. Specifically, studying its evolutionary history offers a window into other species’ minds. This kind of research is not just a scientific pursuit; it has an ethical perspective: the more we understand animals’ mental lives, the better we can adjust our individual and collective behaviours towards them. In addition, this research allows us to better understand learning, with implications for pedagogy in schools (see last section for an example).
The objectives of the project were: (1) to develop entirely non-verbal versions of classical tests used to probe implicit/explicit learning; (2) to test the dissociation between implicit and explicit learning in four non-human primate species: capuchin monkeys (Sapajus sp.), Guinea baboons (Papio papio), orangutans (Pongo pygmaeus), and chimpanzees (Pan troglodytes); (3) to retrace the ontogeny of implicit and explicit learning during childhood; (4) to uncover new behavioural markers of implicit/explicit learning and (5) to set up touchscreen-based research in a zoo for testing non-human primates and children.
This project opened the avenue for studying the phylogeny and ontogeny of implicit and explicit learning, enhancing our understanding of the relationships between learning and consciousness in nonverbal or preverbal individuals.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The first study presents a fully non-verbal version of a standard test used to assess implicit/explicit sequence knowledge: the Process Dissociation Procedure. After a learning phase where participants are exposed to spatial regularities, their control over sequence reproduction -a hallmark of explicit learning- is probed by contrasting two conditions: an inclusion condition, where participants must reproduce the sequences they have learned, and an exclusion condition, where they must avoid reproducing these. Crucially, no verbal instructions were provided, and participants had to discover the rules through trial and error. Data collected from 32 human adults confirmed that successful reproduction and avoidance of reproduction were observed only in the subgroup of participants who were aware of the rules and the sequences (Malassis, Moscado, Sackur & Németh, 2024, PREPRINT).
In a second study, we conducted a large-scale, multi-site study that allowed us to use the nonverbal task we developed to test three nonhuman primate species: baboons, orang-utans, and chimpanzees (Malassis et al., in prep). In a third study, we developed another task requiring less training for testing capuchin monkeys (Moscado, Seed, Sackur & Malassis, in prep.). In a fourth study, we developed a technique to track primates’ hand movements while they are performing a task (Martin, Allritz, Sackur & Malassis, in prep.). Finally, my fellowship allowed me to set up a new data collection site. We have designed and installed a touchscreen apparatus in a zoo and are training the apes to use it (Malassis et al., in prep.).

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

By investigating what is the best learning technique (implicit or explicit), for learning what and for whom, this research can inform pedagogical practices. For example, the non-verbal tests of implicit/explicit learning we developed offer a new way to study learning in young children and to identify at which age children benefit more from explicit instructions, compared to repeated practice. Dissemination of this research is particularly well served by the experiments undergone in the zoo, where the visitors can watch the apes performing the experiments and engage in Q&A sessions with the researchers.

A chimpanzee performing the PDP task on a touchscreen