Meta-representation in primates: a proposal for a multimodal approach in the study of language recursiveness

According to the representational theory of mind, the ability to monitor and control one's own cognitive states (meta-cognition), and the ability to monitor the others’ mental states (theory of mind), are closely related to the conceptual ability to articulate representations in propositional form (meta-representation). Meta-representation, in order to be manifested, requires a language composed of hierarchically complex symbol systems which would allow the application of recursive rules to propositions. The lack of recursive language in primates still leads a huge number of researchers to argue that it is impossible for these animals to engage in both meta-cognitive or theory of mind activities. However, studies that state this impossibility are carried out with a unimodal approach and focus mainly on vocal and gestural signals, despite the fact that primates have a language that exploits different sensory channels and uses a wide range of signals (e.g. olfactory, tactile, gestural, facial and vocal). The aim of this research is proposing a study of language based on a multimodal approach and assisted by AI algorithms able to find correlations in the whole range of signals. This approach could show evidence of recursiveness not within a single language channel, but within the entire communicative overall of primates, allowing to assign them both metacognitive and theory of mind abilities, so far considered as a prerogative of human species.