Thesis defense Nadine Dijkstra (Donders series 414)

30 September 2020

Promotor: prof. dr. M. van Gerven, co-promotor: dr. S. Bosch

Envisioning imagination: neural overlap between visual imagery and perception

Our eyes give us access to the outside world. However, exactly how we perceive the world is determined by our brain. During perception, lightwaves that fall unto our eyes are translated into a coherent experience by our brain. We can also ‘see’ things with our eyes closed: using mental imagery. During her PhD, Nadine Dijkstra investigated how similar the brain processes underlying mental imagery are to the brain processes underlying perception. She had volunteers perceive and imagine different objects while measuring their brain activity using for example MRI-machines. Her research showed that during perception and imagery, similar brain areas were activated and that the more vivid the imagery, the larger this overlap. However, the way in which these brain areas became active was different: during perception activation travelled from the back of the brain to the front, but during imagery this was exactly the opposite. This suggests that imagery is a kind of reversed perception.