|
Figure 5 Progression of learning in a single zebrafish during operant conditioning. (a): Fish does not show any overt response to the presentation of a sound stimulus. (b). Fish shows awareness and attempts to trigger the sensor on the correct (red) side, but is unsuccessful. (c). Fish successfully triggers the sensor twice to receive a food reward. Dotted lines indicate the swimming path obtained from individual frames in the recorded video of the fish. A shortening of the distance between successive dots along the swim path indicates slowing down of the fish after hearing the sound. Blue circles indicate time point of sound onset superimposed on the fish’s swimming path. Arrows next to the trajectory indicate the heading of the fish. Green arrows indicate trajectory early in time and red arrows indicate trajectory later in time. Sensor activation/beam-disruption was indicated by a small LED flash on the sensor board that is reflected back in water (red rectangles in the image).