Luminance adaptation of preferred object size in identified dragonfly movement detectors

In a previous publication (R.M. Olberg, 1986), the anatomical identification and visual physiology of eight large interneurons descending in the dragonfly ventral nerve cord from the brain to the thoracic ganglia was described. These cells are strictly visual and respond only to movements of small patterns, such as dark squares on a white background, and are inhibited by large visual patterns such as gratings, or even small patterns slightly enlarged from the preferred size. To examine inhibitory circuit hypotheses for these visual interneurons, the authors measured the cells´ preferred small object size as a function of mean background luminance. Based on the results they propose a shunting inhibition model with antecedent multipliers