the world upside down: the ventral stream leads dorsal processing

Our brains plan our actions using a dedicated dorsal parieto-frontal circuit. This circuit is thought to be fast, nearly automatic, and independent from perceptual processing in a ventral visual stream. Yet in a new paper in eNeuro Marius Zimmermann shows how representations in the ventral stream can lead the way in action planning. This is the world upside down. He used transcranial magnetic stimulation and time-resolved analyses to get a precisely index the causal role the ventral stream plays in action planning. He focussed on the extrastriate body area (EBA), showing how it specifies the intended goal-state of an action in terms of body posture. This perceptual representation is subsequently used by dorsal parietal regions to initiate the computation of an action planning.