Fig. 1. The salamander Plethodon jordani responding to a contrast-reduced cricket presented as a single stimulus. The animal turns its head towards the stimulus and then follows it with its entire body.
Fig. 2. The orienting response of a salamander. (A) The head of the animal is in a centred position in front of the screen. (B) A pair of stimuli (a leftward-moving rectangle and a rightward-moving large-sized cricket) appear in the centre of the screen. (C) After a delay of 1.7 s, the salamander turns its head towards the large-sized cricket.
Fig. 3. Frequencies of orienting responses to the different stimuli in all individuals. (A) Mean number of orienting responses for both directions of movement. (B) Mean number of responses for leftward and rightward stimulus movement. Values are means ± S.D., N=8. For abbreviations, see Table 3A.
Fig. 4. Preference scale for the different stimuli in all individuals. The thick horizontal line represents the probability of responses to the ‘standard cricket’ (ST) as a baseline for the probability of responses to the other stimuli. Vertical bars indicate the confidence interval for each stimulus; grey rectangles indicate stimulus clusters containing stimuli with similar efficacy. For abbreviations, see Table 3A.
