Female and male pigs’ performance in a spatial holeboard and judgment bias task  Sanne Roelofs, Rebecca E. Nordquist, Franz Josef van der Staay  Applied Animal Behaviour Science  Volume 191, Pages 5-16 (June 2017) DOI: 10.1016/j.applanim.2017.01.016 Copyright © 2017 The Author(s) Terms and Conditions

Fig. 1 Overview of the holeboard arena. The four reward configurations (A, B, C and D) are highlighted (illustration: Yorrit van der Staay). Applied Animal Behaviour Science 2017 191, 5-16DOI: (10.1016/j.applanim.2017.01.016) Copyright © 2017 The Author(s) Terms and Conditions

Fig. 2 Constructional details of the food bowls used in the holeboard and judgment bias task. Each food bowl is equipped with a false bottom covering 4 candies to mask odour cues. A red ball covers the food bowl to hide visual cues (illustration: Yorrit van der Staay). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.) Applied Animal Behaviour Science 2017 191, 5-16DOI: (10.1016/j.applanim.2017.01.016) Copyright © 2017 The Author(s) Terms and Conditions

Fig. 3 Overview of the judgment bias task arena, with start box (S) and goal boxes (G) containing food bowls (illustration: Yorrit van der Staay). Applied Animal Behaviour Science 2017 191, 5-16DOI: (10.1016/j.applanim.2017.01.016) Copyright © 2017 The Author(s) Terms and Conditions

Fig. 4 Performance of female and male pigs in the spatial holeboard task. A Working memory (WM) and reference memory (RM) performance. B Trial duration (TD) and latency to first reward (LFR). C Number of locations visited (LOC) and number of rewards found (REW). Applied Animal Behaviour Science 2017 191, 5-16DOI: (10.1016/j.applanim.2017.01.016) Copyright © 2017 The Author(s) Terms and Conditions

Fig. 5 Judgment bias testing. A Optimistic choice percentage for female and male pigs. B Optimistic choice percentage of all pigs combined for first and last test sessions. C Latency to respond for female and male pigs. Applied Animal Behaviour Science 2017 191, 5-16DOI: (10.1016/j.applanim.2017.01.016) Copyright © 2017 The Author(s) Terms and Conditions