In the last ten years significant progress has been made to understand the first steps in visual processing. One is the integration of information from different modalities.
Second problem is the fact that vision is very expensive in terms of computational cycle.
However, the majority of work done in this field is made using digital machines to approach the problem. We believe that this approach may be good solution to the computational bottleneck. In the simplest SEEDs, the photocurrent generated by absorbed photons in a reversed bias diode influences the voltage across the diode by passing through an appropriate electronic circuit. The voltage across the diode influences the absorption of light by the diode and therefore the photocurrent, hence establishing a feedback. The behavior of such SEEDs depends on the electronic circuit configuration and the sign of the feedback.