Fig. 4.
Heading direction error is reduced after learning. A: heading error angle (θE) is defined as the acute angle between the heading vector and food vector and ranges between 0 and 90°. B: averaged heading error angle in the active zone (background image) was decreased after learning. This indicates that animals learned to approach the food location more accurately. Box plot represents the median, interquartile range and extrema. *P < 0.05. C: the heading error angle distribution near (<5 cm) the first landmark (i.e., nearest to the corner compartment from which the fish enters) is used to compute the survivor function via its cumulative density function (CDF). The survivor function shows an overall reduction of heading angle error in the late phases of learning. Narrow shaded bands represent bootstrapped SE of the mean (95% confidence intervals). D: three example trajectories are shown where the animals corrected their heading directions after encountering the landmarks.