The relative use of proximity, shape similarity, and orientation as visual perceptual grouping cues in tufted capuchin monkeys (Cebus apella) and humans (Homo sapiens).

Abstract

Recent experimental results suggest that human and nonhuman primates differ in how they process visual information to assemble component parts into global shapes. To assess whether some of the observed differences in perceptual grouping could be accounted for by the prevalence of different grouping factors in different species, we carried out 2 experiments designed to evaluate the relative use of proximity, similarity of shape, and orientation as grouping cues in humans (Homo sapiens) and capuchin monkeys (Cebus apella). Both species showed similarly high levels of accuracy using proximity as a cue. Moreover, for both species, grouping by orientation similarity produced a lower level of performance than grouping by proximity. Differences emerged with respect to the use of shape similarity as a cue. In humans, grouping by shape similarity also proved less effective than grouping by proximity but the same was not observed in capuchins. These results suggest that there may be subtle differences between humans and capuchin monkeys in the weighting assigned to different grouping cues that may affect the way in which they combine local features into global shapes.

Exploring whether nonhuman primates show a bias to overestimate dense quantities.

“…Relatedly, capuchin monkeys rely on density (i.e., the spatial proximity of items within an array) more so than other grouping cues such as orientation to guide perceptual matching (Spinozzi et al, 2009). These results suggest that density, like other non-numerical dimensions including area and volume, is a particularly salient cue for nonhuman primates whether one is in a foraging context judging the relative quantity of multiple food sets or discriminating complex visual stimuli in a perceptual discrimination task.…”

“…There is extensive evidence for a shared local advantage in perceptual processing mode across these two species. When perceiving complex arrays that are comprised of multiple smaller features, several species of monkey perceive the individual items (i.e., the local features) prior to and sometimes more accurately than the global configuration (cotton-top tamarins: Neiworth, Gleichman, Olinick, & Lamp, 2006; capuchin monkeys: De Lillo, Spinozzi, Truppa, & Naylor, 2005; Spinozzi, De Lillo, & Truppa, 2003; Spinozzi, De Lillo, Truppa, & Castorina, 2009; rhesus monkeys: Hopkins & Washburn, 2002; baboons: Deruelle & Fagot, 1998; Fagot & Deruelle, 1997). This local advantage stands in contrast to a robust global advantage documented in humans (e.g., Broadbent, 1977; Lamb & Robertson, 1990; Navon, 1977, 1981).…”

What’s in a face (made of foods)? Comparing children’s and monkey’s perception of faces in face-like images of food

“…When presented with multi-element arrays (e.g., a large letter F comprised of smaller letter Es), several monkey species perceive the individual items (i.e., the local features) prior to and sometimes more accurately than the global configuration, including rhesus macaques (Hopkins & Washburn, 2002), baboons (Deruelle & Fagot, 1998;Fagot & Deruelle, 1997), capuchin monkeys (De Lillo, Spinozzi, Truppa, & Naylor, 2005;Spinozzi, De Lillo, & Salvi, 2006;Spinozzi, De Lillo, & Truppa, 2003;Spinozzi, De Lillo, Truppa, & Castorina, 2009), and cotton-top tamarins (Neiworth, Gleichman, Olinick, & Lamp, 2006). This local processing bias is contrasted with a hallmark global advantage in typically-developing humans who process visual stimuli at the global level first (e.g., Broadbent, 1977;Kimchi, 1992;Lamb & Robertson, 1988;Navon, 1977Navon, , 1981.…”

Animal Camouflage: Disentangling Disruptive Coloration from Background Matching

“…2.2a). Such visual illusions of shape, caused by perceptual grouping, are found in a wide range of animals (mammals (Spinozzi et al, 2009, Vonderheydt et al, 1984, Fagot and Tomonaga, 2001, birds (Nieder andWagner, 1999, Zanforlin, 1981),…”

“…The influential contribution of perceptual grouping to vision is evident in many visual illusions (Halko et al, 2008). Similarly, animals from diverse taxa also respond to visual illusions involving perceptual grouping (mammals (Spinozzi et al, 2009, Vonderheydt et al, 1984, Fagot and Tomonaga, 2001, birds (Nieder andWagner, 1999, Zanforlin, 80 1981), fishes (Wyzisk andNeumeyer, 2007, Sovrano andBisazza, 2008) and insects (Horridge et al, 1992)). Within the context of the current study, a non-vertebrate animal, the cuttlefish (Sepia officinalis), provides a compelling example of the use of perceptual grouping to facilitate camouflage decisions (Zylinski et al, 2012).…”