Feature linking via stimulus-evoked oscillations: experimental results from cat visual cortex and functional implications from a network model

Until recently, no known physiological mechanism could explain the transient linking of local visual features into global coherent percepts. The authors have found such principles at a ´computational stage´ of preattentive processing in the cat´s primary visual cortex. The results show that stimulus-evoked oscillations of local processing units, representing local visual features, are transiently locked into a common resonance state by an appropriate global stimulus. The experimental results suggest further that the activities of those neural groups that represent features that are to be linked in the current visual situation become synchronized. Synchronization was found among assemblies in a single cortex column (where similar local features are processed) and, more important, among remote assemblies of the same cortex area and even among assemblies in different areas when the assemblies share some common local visual features. These cortical linking features are considered to be the neural representations of the corresponding perceptual linking features.<>