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

Abstract

Humans detect faces efficiently from a young age. Face detection is critical for infants to identify and learn from relevant social stimuli in their environments. Faces with eye contact are an especially salient stimulus, and attention to the eyes in infancy is linked to the emergence of later sociality. Despite the importance of both of these early social skills—attending to faces and attending to the eyes—surprisingly little is known about how they interact. We used eye tracking to explore whether eye contact influences infants' face detection. Longitudinally, we examined 2‐, 4‐, and 6‐month‐olds' (N = 65) visual scanning of complex image arrays with human and animal faces varying in eye contact and head orientation. Across all ages, infants displayed superior detection of faces with eye contact; however, this effect varied as a function of species and head orientation. Infants were more attentive to human than animal faces and were more sensitive to eye and head orientation for human faces compared to animal faces. Unexpectedly, human faces with both averted heads and eyes received the most attention. This pattern may reflect the early emergence of gaze following—the ability to look where another individual looks—which begins to develop around this age. Infants may be especially interested in averted gaze faces, providing early scaffolding for joint attention. This study represents the first investigation to document infants' attention patterns to faces systematically varying in their attentional states. Together, these findings suggest that infants develop early, specialized functional conspecific face detection.

Differential sensitivity to species‐ and race‐based information in the development of attention orienting and attention holding face biases in infancy

“…These results converge with previous research to highlight a divergence in species-and race-based attention orienting biases in infancy. While studies have found that infants were faster and more likely to orient to human faces by 2 months of age (Jakobsen et al, 2016;Simpson, Maylott, Leonard, et al, 2019;Simpson, Maylott, Mitsven, et al, 2019), Prunty et al (2020) found no differences in frequency or speed of orienting to own-and other-race faces. By using a within-subjects design the current study integrates F I G U R E 5 Infants' proportion of total looks to the face, salient distractor, and remaining general distractors during monkey, other-race, and own-race faces.…”

“…These results converge with previous research to highlight a divergence in species‐ and race‐based attention orienting biases in infancy. While studies have found that infants were faster and more likely to orient to human faces by 2 months of age (Jakobsen et al., 2016; Simpson, Maylott, Leonard, et al, 2019; Simpson, Maylott, Mitsven, et al, 2019), Prunty et al. (2020) found no differences in frequency or speed of orienting to own‐ and other‐race faces.…”

“…Species‐based orienting biases may also be mediated by specific face features common to both own‐ and other‐race faces, such as human eyes. Infants preferentially looked at non‐human primate faces that were edited to include human eyes (Dupierrix et al., 2014) and showed increased sensitivity to human versus non‐human primate eye gaze cues (Kano & Call, 2014; Simpson, Maylott, Mitsven, et al, 2019). Thus species‐based orienting biases may reflect a more specific attention bias to own‐species eyes that supports early learning from any human, regardless of race.…”

“…Although less work has examined the development of species‐ and race‐based biases in attention orienting, the available research suggests that species‐based attention orienting biases are robust early in infancy. By 2 months of age, infants showed faster and more frequent orienting to human faces compared to non‐human faces appearing in multi‐object search arrays (Jakobsen, Umstead, & Simpson, 2016; Simpson, Maylott, Leonard, Maylott, Leonard, Lazo, & Jakobsen, 2019; Simpson, Maylott, Mitsven, Maylott, Mitsven, Zeng, & Jakobsen, 2019). In contrast, the only prior study examining the development of race‐based orienting biases in infancy found no differences in 6‐, 9‐, and 12‐month‐old infants’ speed or frequency of orienting to own‐ and other‐race faces in naturalistic scenes (Prunty, Jackson, Keemink, & Kelly, 2020).…”

Superior Detection of Faces in Male Infants at 2 Months

“…At 2 months, infants also display improvements in facial identity recognition (Johnson, 1990), facial expression discrimination (Nelson, 1987), and face‐voice cross‐modal matching (Patterson & Werker, 2003). Additionally, 2‐month olds exhibit some adult‐like face preferences (e.g., relying more on structural than contrast information; Kleiner & Banks, 1987), and display experience‐driven face specialization (e.g., preferences for own‐species’ faces; Heron‐Delaney, Wirth, & Pascalis, 2011; Simpson, Maylott, Mitsven, Zeng, & Jakobsen, 2020), as well as brain activation in core face perception regions, including the fusiform face area (Tzourio‐Mazoyer et al, 2002). The wide‐ranging physical, cognitive, and psychosocial advances at 2 months underscore the importance of studying this period of development.…”