Motion adaptation enhances object-induced neural activity in three-dimensional virtual environment.

Many response characteristics of neurons sensitive to visual motion depend on stimulus history and change during prolonged stimulation. Although the changes are usually regarded as adaptive, their functional significance is still not fully understood. With experimenter-defined stimuli, previous research on motion adaptation has mainly focused on enhancing the detection of changes in the stimulus domain, on preventing output saturation and on energy efficient coding. Here we will analyze in the blowfly visual system the functional significance of motion adaptation under the complex stimulus conditions encountered in the three-dimensional world. Identified motion sensitive neurons are confronted with seminatural optic flow as is seen by semi-free-flying animals as well as targeted modifications of it. Motion adaptation is shown to enhance object-induced neural responses in a three-dimensional environment although the overall neuronal response amplitude decreases during prolonged motion stimulation.