Integrating Bottom-up and Top-down Processing in Active Dendrites

| The classical view of information processing in the cortex is that of a bottom-up process in a feed-forward hierarchy. However there is psychophysical, anatomical and physiological evidence that top-down eeects play a crucial role in the processing of input stimuli. Hardly anything is known about the neural mechanisms underlying these effects. Here we investigate a physiologically inspired model of two reciprocally connected cortical areas. Each area receives bottom-up as well as top-down information which are integrated in active dendrites. I) This integration results in a burst signal that is extremely robust in the context of noise in bottom-up signals. II) Priming like eeects can be demonstrated by investigating the innuence of additional top-down information about the actual stimulus. III) The model takes into account recent physiological ndings: It has been shown that the interareal coupling in low frequency ranges is characteristically enhanced due to top-down mechanisms. Corresponding eeects can be demonstrated with the model presented here.