On Friday, October 25, 2019, Meng successfully defended her doctoral thesis on the “Neural circuits of appetitive extinction in the pigeon brain”. Extinction learning is a key learning procedure that proceeds with predictable sequences of behavioral changes in all studied vertebrates and invertebrates. But do these similarities of behavior also point to equivalencies of neural mechanisms? This is the core question of Meng’s thesis. She approaches it by behavioral pharmacology and fMRI. In her behavioral studies she probes the contribution of a visual associative structures and can show that it contributes to the processing of the context in learning extinction. This is highly interesting since context memory is in mammals the contribution of the hippocampus. Previous studies could not convincingly show that the pigeon’s hippocampus has a truly visible contribution to memorize the extinction context. Then Meng moves on to study the medial striatum and demonstrates that its contribution is mostly in the realm of the acquisition of extinction, possibly due to insufficient prediction error coding. Finally, she moves on to study for the first time extinction learning in a scanner and yields a huge amount of novel insights on the extinction network. Among these novel information is the finding that the first extinction session is characterized by a broad activation of a large number of forebrain areas. With every further extinction session, however, these activations get smaller and smaller and astonishingly encompass primary visual areas. Based on all these new data, Meng sketches the outline as well as the details of the avian extinction network. She shows that its main outline is similar but not identical to that of mammals. The committee consisting of Onur Güntürkün, Nikolai Axmacher, Martina Manns, and Maik Stüttgen was deeply impressed and awarded this great series of studies with a magna cum laude.

Congratulations Meng! You are fantastic.