Human ostension enhances attentiveness but not performance in domestic pigs.

Humans convey their communicative intentions ostensively, e.g., calling others' name and establishing eye-contact. Also when interacting with animals, humans use ostension. In some companion-animal species, ostension increases attentiveness and/or alters how animals process human-provided information. However, it is unclear whether domesticated species selected for purposes other than companionship, like pigs, would also be sensitive. We investigated whether pigs are sensitive to human ostension and whether experience with humans modulates pigs' sensitivity. Fifty-four pigs with varying experience with humans completed ostensive and non-ostensive versions of (1) an object-choice task with directional cues, (2) an A-not-B-task, and (3) a detour task with human demonstrations. We expected pigs to respond to human ostension with increased attentiveness and possibly altered performance. Further, if sensitivity to ostension increases with experience with humans, more intensively socialized pigs should be more attentive and more likely to change in performance than less socialized ones. Results suggest that pigs were more attentive to ostensive than non-ostensive detour demonstrations. Otherwise ostension did not affect attentiveness or performance. This suggests that pigs might be less inclined than species selected for companionship to process human-provided information differently. Attentiveness, however, seems to be enhanced by ostension also in animals selected for production purposes. Moreover, we found that living conditions and experience, e.g., training, influenced pigs' attentiveness and performance, independently of ostension. These findings highlight the influence of training experience and enrichment on pigs' cognitive performance.