First steps in a behavioral analysis of pattern discrimination in diptera

Visual fixation of objects is studied in Musca domestica using the closed-loop method. The fixation process is shown to be due to relative movements of patterns, i.e. vertically arranged black stripes, with regard to the fly’s compound eyes. The cause of the stripe transport in the closed-loop apparatus is the symmetric torque fluctuation and the asymmetric induced torque response to progressing and regressing motion. Only the lower parts of the compound eyes contribute to the fixation process. During the past years investigations have been undertaken in our laboratory with the aim to determine and to analyze spontaneous preferences of flying Diptera for elementary patterns in their optical environment, REICHARDT and WENKING (1969), REICHARDT (1970), REICHARDT (1971