Fig. 4. Frequency distribution of response angles from post-hoc analysis of fish-to-source angles before and after orienting responses. Frequency distributions are grouped according to how responses were judged during the real-time execution of the experiment — i.e. as hits (A) or misses (B) for signal trials, and false alarms (C) or correct rejections (D) for blank trials. Each solid line represents the distribution of response angles (pooled from 4 individuals) for one of four flow conditions (0, 2, 4 and 8 cm s^-1). In E, the mean distributions of all flow conditions are plotted for responses judged as hits, misses, correct rejections and false alarms. Bin width=10°.