A simplified model of insect visual system is illustrated in Figure 3.11 .
Lamina consists of photodetectors and automatic gain control circuitry.
Medulla contains the small spatial field motion detectors, in addition to many other complicated functions. The primary wide-field motion computation is located in lobula complex. This output is then sampled and stored. Templates are formed by collating the outputs of two contiguous cells and at two consecutive sampling instants. The templates are then coded to represent low level motion information.