The Evolution of Executive Functions

Executive functions are cognitive processes which control behaviour, e.g. working memory. They are governed by different brain regions in mammals (prefrontal cortex) and birds (nidopallium caudolaterale, NCL). At a neuronal level, these processes function in the same way.

Recent studies found that 1) the NCL differs considerably in size between bird lineages, with the corvids (the most cognitively complex birds) having the biggest; and 2) crocodilians, the closest living relatives of birds, have a small version of the NCL.In this three-year project, we will run a task battery testing different executive functions in crocodilians and representatives of the main bird lineages.

We will compare their performance with the size of their NCL.

Executive functions for which the performance scales with the size of the NCL, might have contributed to the enlargement of this structure.

Executive functions without this relationship, might either only require a rudimentary version of the NCL or are not solely governed by it.The experiments are all non-invasive behavioural observations with captive animals conducted by a PI, an assistant, and two senior experts in animal cognition and evolutionary analysis.This project will elucidate how executive functions evolve and which ones lead to an enlargement of the associated brain region.

This will also advance our understanding of the evolution of the large human prefrontal cortex, a defining characteristic of our own species.