WaterMaze uses a state-of-the-art image-processing software and video-capture card. Images can be acquired at up to 30 frames per second. The program identifies the animal whether it is lighter or darker than the background. A unique algorithm screens out changing shadows and changing lighting conditions that might occur during the trial. On-line interpolation identifies and smoothes occasional loss of signal that can occur if an animal swims briefly underwater or under hanging cue objects. The path taken can be displayed in real time as the trial proceeds. No special lighting is needed for WaterMaze to track animals. A few standard incandescent or halogen lamps placed strategically around the pool are sufficient. A special set-up window can be used to measure the evenness of lighting across the pool surface, which helps to eliminate deep shadows.
The image below is a screen shot of the tracking window. The yellow cursor shows the computer’s determination of current position. The yellow dots show the path.
At the end of each trial, the experimenter can type in notes concerning the trial just completed. The trial can be stopped manually or automatically when the animal reaches the platform. The trial is then saved, again either manually or automatically after a set interval. The program then indicates which animal should be run next, to which platform location and from which starting position.
Remote switches can be used to start, stop and save trials. Multiple switches for each function can be placed around the pool if desired. With the program in auto-sequence mode and auto-save mode, multiple trials can be performed without touching the computer’s mouse or keyboard.