abstract Max Hopf

Max Hopf (Leibniz Institute for Neurobiology, Magdeburg, Germany)

Dynamics of global feature-based attentional selection in vision.

Attention to elementary nonspatial features is known to operate in a spatially global way. That is, attended features become biased for selection outside the spatial focus of attention. In this talk I will review observations from electromagnetic brain recordings in human observers relevant for understanding the cortical mechanisms behind global feature-based selection. We will learn that global feature-based attention refers to a sequence of separable modulatory effects in visual cortex. Importantly, these modulations arise in reversed hierarchical order in ventral extrastriate cortex, with an initial component in higher-tier areas reflecting the matching of the input against task relevant feature descriptions, and a later component in lower-tier areas reflecting the segmentation of target properties from the distribution of attended features inside the spatial focus of attention.