​(Fig.6A)6A) and in the horizontal slots (Fig. ​(Fig.6B),6B), in each phase in each monkey. In the vertical slots in phase I, four monkeys exhibited a significant preference to use one hand over the other (left-hand preference in Mk-AN and Mk-TH; right-hand preference in Mk-DI and Mk-LO), whereas the other four monkeys did not show any significant hand preference (Mk-AT, Mk-CA, Mk-MA, Inhibitors,research,lifescience,medical and Mk-MI). In phase II, most of the scores for the vertical slots did not exhibit a

significant difference between both hands, except for Mk-LO and Mk-MA, with a significant preference for their right hand. In the horizontal slots (Fig. ​(Fig.6B),6B), in phase I, all monkeys but Mk-MA showed a significant hand preference. Four monkeys (Mk-AN, Mk-AT, Mk-MI, and Mk-TH) used preferably their left hand, whereas three monkeys (Mk-CA, Mk-DI, and Mk-LO) used more often their right hand. In phase

II, five out of eight monkeys showed a preference for one hand over the other, with a left-hand preference in Mk-AT Inhibitors,research,lifescience,medical and Mk-MI, whereas Mk-CA, Mk-LO, and Mk-MA exhibited a right-hand preference. Overall, there were clearly more significant hand preferences observed for the horizontal slots than for the vertical slots (Fig. ​(Fig.66). Figure 6 Hand preference statistical analysis for monkeys, applied to the modified Brinkman board task data, with free use of the two hands simultaneously, as find more illustrated Inhibitors,research,lifescience,medical in Figure ​Figure5,5, and represented by box and whiskers plots. Scores for vertical … The HI, derived from the three other tasks performed by the monkeys (the bimanual board task (Fig. ​(Fig.1B),1B), the tube task (Fig. ​(Fig.1C),1C), and the drawer task (Fig. ​(Fig.1D),1D), were plotted on the same bar graph (Fig. ​(Fig.7A,7A, rightmost part Inhibitors,research,lifescience,medical of the graph, separated from human subjects Inhibitors,research,lifescience,medical by

a vertical black line). In most cases, these three tasks were lateralized (large positive or negative HI). Mk-TH was the only monkey to exhibit a coherent hand preference for all three tasks, with a systematically positive HI, corresponding to a significant right-hand preference (P < 0.05; binomial test). In the other seven animals, there was an absence of systematic consistency across tasks. Three monkeys (Mk-AN, Mk-CA, and Mk-DI) exhibited a preference for the right hand in the bimanual board and the tube tasks (positive HI) and a preference Phosphoprotein phosphatase for the left hand in the drawer task (negative HI). These HI values were statistically significant (meaning lateralized; binomial test P < 0.05), except in Mk-CA for the tube task (Fig. ​(Fig.77A). Mk-LO and Mk-MI shared a comparable general pattern of HI distribution among the three tasks (Fig. ​(Fig.7A),7A), namely a clearly positive HI (>0.5) for the bimanual board and the drawer tasks, whereas the HI was strongly negative for the tube task (Fig. ​(Fig.7A).7A). In these two animals, all HI values were statistically significant (lateralized; P < 0.05).