Results on individual latencies (s) to the first visit of a bowl, main statistical effects and probabilities.

Results are presented either by mean ± S.E.M. or median and interquartile (Q25–Q75). Friedman statistics are presented for test A: the “previous signals exposure test”; Fisher’s statistics for test B: the pointing and voice test 1, for test C: the dynamic pointing and voice test, for test D: the pointing and voice test 2, and for the comparison between test B, C and D; Wilcoxon and Mann and Whitney statistics for test E: the voice direction test. Values with different bold letters are significantly different on a same row and between two rows for groups of piglets.