Previous studies suggest that monkeys process local elements of hierarchical visual patterns more quickly and more accurately than they process the global shape. These results could be indicative of differences between relatively high visual functions of @entity1 and non- @entity1 primates. It is, however, important to rule out that relatively low-level factors can explain these differences. We addressed this issue with two experiments carried out on capuchin monkeys ( @entity10450 ) using matching-to-sample tasks featuring hierarchical stimuli. The first experiment assessed whether manipulations of stimulus size can affect the local advantage so far observed in this New World monkey species. An overall local versus global advantage still emerges in capuchins, irrespectively of the amplitude of the visual angle subtended by the hierarchical shapes. Moreover, a local-to-global interference, indicative of a strong local advantage, was observed for the first time. In the second experiment, we manipulated size and numerosity of the local elements of hierarchical patterns, mimicking procedures that in @entity1 perception relegate the local elements to texture and enhance a global advantage. Our results show that in capuchin monkeys, a local advantage emerges clearly even when these procedures are used. These results are of interest since extensive neurophysiological research is carried out on non- @entity1 primate vision, often taking for granted a similarity of @entity227 in @entity1 and non- @entity1 primates. These behavioural results show that this assumption is not always warranted and that more research is needed to clarify the differences in the processes involved in basic @entity227 among primates.

Local advantage in the visual processing of hierarchical stimuli following manipulations of stimulus size and element numerosity in monkeys ( XXXX ).

@entity1 :: ('9606', 'Species') :: ['humans', 'human'] @entity10450 :: ('9515', 'Species') :: ['Cebus apella'] @entity227 :: ('MESH:D014786', 'Disease') :: ['visual skills']
@entity10450 :: (9515,Species) :: ['Cebus apella']
