Effects of identical context on visual pattern recognition by pigeons

Abstract

The effects of identical context on pattern recognition by pigeons for outline drawings of faces were investigated by training pigeons to identify (Experiment 1) and categorize (Experiment 2) these stimuli according to the orientation of the mouth-an upright U shape representing a smiling mouth or an inverted U shape representing a sad mouth. These target stimuli were presented alone (Pair 1), with three dots in a triangular orientation to represent a nose and eyes (Pair 2), and with the face pattern surrounded by an oval (Pair 3). In Experiment 1, the pigeons trained with Pair 1 were most accurate, those trained with Pair 2 were less so, and those trained with Pair 3 failed to acquire the discrimination within eighty 100-trial sessions. The same ordering was found in Experiment 2 for pigeons trained on the three pairs simultaneously. The authors suggest that a contrasting finding in humans, the face superiority effect, might be due to a gain in discriminability resulting from recognition of the pattern as a face. An exemplar model of information processing that excludes linguistic coding accounts for the present results.

Experimental Divergences in the Visual Cognition of Birds and Mammals

“…Testing stimuli that produce a face superiority effect in humans, Donis, Chase, and Heinemann (2005) found that their pigeons' capacity to discriminate the feature of a U (the ”smile”) versus its flipped counterpart ∩ (the “frown”) was impaired when a triplet of dots arranged as “eyes” and a “nose” was placed above it. The pigeons were further impaired when these features were enclosed within a larger ellipse, a condition in which humans see a clear and readily discriminable face.…”

Supplemental Material for Perception of Emergent Configurations in Humans (Homo sapiens) and Chimpanzees (Pan troglodytes)

“…Among nonhuman vertebrates, the facilitative effects of redundant contexts have only been examined in pigeons (Donis & Heinemann, 1993;Donis, Chase, & Heinemann, 2005;Kelly & Cook, 2003). Although contextual information facilitated pattern recognition in humans, the same contextual information dismpted pattern recognition in pigeons in these studies.…”

“…Donis and colleagues (Donis & Heinemann, 1993;Donis et al, 2005) speculated that facilitation of discrimination occurs because emergent configurations are easily named (e.g., arrows and triangles in the configurai stimuli in Figure I). Donis and colleagues (Donis & Heinemann, 1993;Donis et al, 2005) speculated that facilitation of discrimination occurs because emergent configurations are easily named (e.g., arrows and triangles in the configurai stimuli in Figure I).…”

Processing of conflicting and redundant stimulus information by pigeons

“…NIM has been applied successfully to more complex categorization tasks (Donis, Chase, & Heinemann, 2005;Donis & Heinemann, 1993;Van Hamme et al, 1992) than those used here. Details of how NIM works for simple dot matrix patterns such as those used by Donis and Heinemann are available in Chase and Heinemann (2001) along with a computer program that can be used for simple simulations.…”