The strong convergence in cortical visual pathways results in neuronal receptive fields of increasing size. Therefore, neurons in extra-striate visual cortex receive under natural viewing conditions simultaneous, competing input from multiple stimuli within their extended receptive fields. Selective visual attention is well known to resolve this conflict in favour of generating responses to the attended stimulus while ignoring non-attended stimuli. However, the question, which neuronal mechanisms are responsible for such selective processing of the attended stimulus, is under debate.
In this talk, it will be discussed, at which site attention intervenes to effect selective stimulus processing and evidence will be presented for a dynamic gating mechanism based on strong and highly selective modulations of effective connectivities. Furthermore, I will show experimental evidence for a causal role of neuronal -band synchronization in attention-dependent selective information routing. From these findings a picture emerges, in which attention flexibly configures effective neuronal networks for selective processing of behaviourally relevant stimuli