Fig. 4.

Coupling improves detection of the center of rotation. (A) An artificial image rotating clockwise around its center. A snapshot of the visual flow-field as determined from a two-dimensional motion detector array is superimposed. The rotational structure is clearly visible. (B) Same as A, but using a natural image (taken from the natural image database, Hans van Hateren, http://hlab.phys.rug.nl/imlib/index.html). The flow-field structure is much less homogenous. (C and D) Visual response in the VS network model when the vertical vector components of the flow-field are fed into the respective VS dendrite synapses for both the artificial and the natural image. Black squares indicate unprocessed signals in the dendrites; red circles indicate axonal outputs. (E and F) VS cell with minimum absolute potential during the rotation of both images around 360°. Black line, potentials at the dendrites; red line, potentials at the axon.