Responses of high-frequency movement detector neurons in dragonfly larvae to motion of complex patterns

Neurons of the class described respond by a discharge with a frequency of 150–200/sec to the appearance and motion of single dark objects in a new part of the large receptive field. Movement of a complex pattern induces a weak initial response. Repeated movements of a complex pattern evoke habituation and do not affect the firing rate but they suppress the response to movement of a single object at distances of up to 15–30° away from the zone of habituation. The features of optic stimuli evoking maximal responses in high-frequency movement detector neurons correspond in many cases to the features of objects evoking fright and flight in the larvae.