Finding faces among faces: human faces are located more quickly and accurately than other primate and mammal faces

Abstract

We tested the specificity of human face search efficiency by examining whether there is a broad window of detection for various face-like stimuli—human and animal faces—or whether own-species faces receive greater attentional allocation. We assessed the strength of the own-species face detection bias by testing whether human faces are located more efficiently than other animal faces, when presented among various other species’ faces, in heterogeneous 16-, 36-, and 64-item arrays. Across all array sizes, we found that, controlling for distractor type, human faces were located faster and more accurately than primate and mammal faces, and that, controlling for target type, searches were faster when distractors were human faces compared to animal faces, revealing more efficient processing of human faces regardless of their role as targets or distractors (Experiment 1). Critically, these effects remained when searches were for specific species’ faces (human, chimpanzee, otter), ruling out a category-level explanation (Experiment 2). Together, these results suggest that human faces may be processed more efficiently than animal faces, both when task-relevant (targets), and when task-irrelevant (distractors), even when in direct competition with other faces. These results suggest that there is not a broad window of detection for all face-like patterns, but that human adults process own-species’ faces more efficiently than other species’ faces. Such own-species search efficiencies may arise through experience with own-species faces throughout development, or may be privileged early in development, due to the evolutionary importance of conspecifics’ faces.

Face detection in 2‐ to 6‐month‐old infants is influenced by gaze direction and species

“…Another study found differences in infants' sensitivity to gaze in human and nonhuman stimuli: 12‐month‐olds looked longer to, and were better at gaze following, when observing videos of humans compared to apes (Kano & Call, ). We also found our infants looked longer to human than animal faces (Prediction 3b), consistent with studies in adults, reporting privileged detection of conspecifics (Simpson, Buchin, et al, ; Simpson, Husband, Yee, Fullerton, & Jakobsen, ; Stein, Sterzer, & Peelen, ). Our findings of an early own‐species bias suggest that infants have already specialized for processing conspecific faces by 2 to 6 months of age.…”

“…This facilitated processing of human faces is known as an own-species bias (Scott & Fava, 2013). Already by 6 months, infants, like adults, are more likely to detect, more quickly detect, and look longer at human than animal faces in in complex arrays (Gluckman & Johnson, 2013;Jakobsen et al, 2016;Simpson, Buchin, Werner, Worrell, & Jakobsen, 2014a), suggesting an own-species bias for face detection may emerge early in development. In fact, newborns may even display an early bias for human compared to animal faces (Heron-Delaney, Wirth, & Pascalis, 2011).…”

Efficient human face detection in infancy

“…Given the social and ecological importance of faces for infants, and their early exposure to conspecifics, biases to detect conspecific faces may be evident in the first year of life (Simpson et al, ). In adults, conspecific faces are detected more efficiently than heterospecific faces (Simpson et al, ; 2014c). The present study explored whether this OSB in face detection is present in 6‐ and 11‐month‐old infants.…”

“…In adults, animal faces engage similar visual processing as human faces (Diamond & Carey, 1986) and elicit similar neural activation (Blonder et al, 2004); therefore, comparisons of human and animal face processing can disentangle developmental patterns in face processing generally from human face processing specifically (Whyte, Behrmann, Minshew, Garcia, & Scherf, 2015). While adults exhibit an OSB in face detection (Simpson, Buchin, Werner, Worrell, & Jakobsen, 2014a), it is unclear when this bias emerges.…”

Rapid Attentional Selection of Non-native Stimuli despite Perceptual Narrowing

“…Perceptual narrowing impacts one’s ability to discriminate non-native exemplars (i.e., one face from another face) from infancy through adulthood (e.g., Mondloch, Maurer, & Ahola, 2006; Pascalis et al, 2002), and therefore, it also affects target selection in visual search tasks (Simpson, Buchin, Werner, Worrell, & Jakobsen, 2014). Results from visual search tasks can provide evidence for the mechanism underlying the reduced sensitivity with non-native stimuli.…”