Fig. 2.
Conditioning and generalization stimuli for counterbalancing groups A and B. Half of the participants were assigned to counterbalancing group A and half to B. For both counterbalancing groups A and B , GS 3 consisted of the ring closest in size to CS+, with GS 2 and GS 1 further decreasing in similarity to CS+. Ring diameters in centimetres (and visual angles) from smallest to largest were: 6.63 (0.93°), 8.02 (1.12°), 9.38 (1.31°), 10.98 (1.54°) and 12.46 (1.75°). vCS− = v-shaped conditioned safety cue; oCS− = ring-shaped conditioned safety cue; GS 1 , GS 2 and GS 3 = three classes of generalization stimuli; CS+ = conditioned danger cue.