Thesis defense Marius Zimmermann (Donders series 244)

23 November 2016

Promotor: prof. dr.  I. Toni, copromotors: dr. F. de Lange, dr. L. Verhagen

A cerebral mechanism for translating action goals into action plans

Visual information is processed along two cortical pathways in the human brain, a ventral visual stream for perception, and a dorsal visual stream for the generation of actions. It has been assumed that information processed in the two streams remains largely separated and is only combined at a late stage. However, in this thesis, I provide ideas and evidence of early contributions of the ventral visual stream to the generation of goal-directed object manipulating actions. Specifically, using functional and structural neuroimaging, as well as time resolved analyses of the effects of transcranial magnetic stimulation on overt action execution, I show that the extrastriate body area – a ventral stream area involved in the visual perception of human bodies – generates a representation of desired action goal states. This representation is subsequently used by dorsal stream areas during the specification and generation of motor commands. These findings provide a cortical mechanism for the translation of action goals into motor plans, and enhance our understanding of perception and action mechanisms in our brain.