title: Global/local processing of hierarchical visual stimuli in a conflict-choice task by capuchin monkeys (Sapajus spp.).
abstract: In the last two decades, comparative research has addressed the issue of how the global and local levels of structure of visual stimuli are processed by different species, using Navon-type hierarchical figures, i.e. smaller local elements that form larger global configurations. Determining whether or not the variety of procedures adopted to test different species with hierarchical figures are equivalent is of crucial importance to ensure comparability of results. Among non-human species, global/local processing has been extensively studied in tufted capuchin monkeys using matching-to-sample tasks with hierarchical patterns. Local dominance has emerged consistently in these New World primates. In the present study, we assessed capuchins' processing of hierarchical stimuli with a method frequently adopted in studies of global/local processing in non-primate species: the conflict-choice task. Different from the matching-to-sample procedure, this task involved processing local and global information retained in long-term memory. Capuchins were trained to discriminate between consistent hierarchical stimuli (similar global and local shape) and then tested with inconsistent hierarchical stimuli (different global and local shapes). We found that capuchins preferred the hierarchical stimuli featuring the correct local elements rather than those with the correct global configuration. This finding confirms that capuchins' local dominance, typically observed using matching-to-sample procedures, is also expressed as a local preference in the conflict-choice task. Our study adds to the growing body of comparative studies on visual grouping functions by demonstrating that the methods most frequently used in the literature on global/local processing produce analogous results irrespective of extent of the involvement of memory processes.
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197, Rome, Italy. valentina.truppa@istc.cnr.it.
authors.forename: Valentina
authors.identifier: http://orcid.org/0000-0001-7623-7547
authors.initials: V
authors.lastname: Truppa
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.|Environmental and Evolutionary Biology PhD Program, Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Carducci
authors.affiliation: Institute of Cognitive Sciences and Technologies, National Research Council (CNR), Via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.|Department of Philosophy, Sapienza University of Rome, Via Carlo Fea 2, 00161, Rome, Italy.
authors.forename: Diego Antonio
authors.initials: DA
authors.lastname: De Simone
authors.affiliation: Department of General Psychology, University of Padua, Via Venezia 8, 35131, Padua, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Bisazza
authors.affiliation: Department of Neuroscience, Psychology and Behaviour, University of Leicester, University Road, Leicester, LE1 7RH, UK.
authors.forename: Carlo
authors.initials: C
authors.lastname: De Lillo
mesh_terms: D000818:Animals; D002428:Cebus; D002755:Choice Behavior; D006801:Humans; D057567:Memory, Long-Term
keywords: Global/local processing; Hierarchical stimuli; Long-term memory; New World monkeys; Visual perception