During his engineering studies, he pursued an innovative dual curriculum in biology, earning additional degrees in biophysics, modeling, and neuroscience.

[2] A pivotal visit to Michel Imbert's laboratory at the Collège de France, where he witnessed neuronal recordings from the visual cortex, shaped his future career trajectory.

Frégnac completed two doctoral degrees under Michel Imbert's supervision: first in human biology (1978)[citation needed], then in neuroscience (1982) in the institute directed by Yves Laporte.

His early research focused on the development of visual cortical cells, publishing groundbreaking work on orientation selectivity and ocular dominance in kittens.

His 2017 Science publication critically examined the increasing industrialization of neuroscience and the challenges of big data approaches to understanding the brain.