Figure 2
From: Female horses spontaneously identify a photograph of their keeper, last seen six months previously
Percentage of correct responses during training, probe and control trials. The last training session (32 trials) corresponded to the last time the animal was trained to touch the recurrent faces rather than a novel face (according to the individual performance, this session was not the same for all subjects). During the probe and control trials (8 trials each) rewards were given whichever face was touched. NS: Non-significant; **P < 0.01; ***P < 0.001, t-test, calculated according to the level of chance (50%), N = 11. 
: mean, : median.
