Timing a Looming Object

We present a novel approach to extracting information relating to the absolute speed of a looming stimulus. The method makes use of two properties of looming detectors: They respond faster to a large approaching object with lower firing rate. The curves obtained by integrating the activity of the looming detectors in response to stimuli of various sizes looming at different speeds intersect within a small range. After proper thresholding, the integrated activity provides a temporal signal which reflects the absolute speeds of a looming object. This mechanism offers a flexible way for timing interaction with a looming object