Fig. 1.

The apparatus used in the behavioural experiments. Black speaker/spout modules indicate those used for stimulus presentation (0°; including LED) and response/reward locations for no-signal (‘no’; −90°) and signal (‘yes’; 90°) trials. Grey modules were not used in this task. A continuous broadband noise and the target stimulus were played from the loudspeaker positioned at 0°. The ferret triggered a new trial by approaching the centre platform and licking the centre spout. When the target tone was presented (‘signal-trial’), the ferret could receive water reward at the 90° spout; if no tone was presented (‘no-signal trial’) then a reward was obtainable at −90°. The LED (indicated by the bulb) at 0° was illuminated on every trial.