From faces to hands: Changing visual input in the first two years

Abstract

Human development takes place in a social context. Two pervasive sources of social information are faces and hands. Here, we provide the first report of the visual frequency of faces and hands in the everyday scenes available to infants. These scenes were collected by having infants wear head cameras during unconstrained everyday activities. Our corpus of 143 hours of infant-perspective scenes, collected from 34 infants aged 1 month to 2 years, was sampled for analysis at 1/5 Hz. The major finding from this corpus is that the faces and hands of social partners are not equally available throughout the first two years of life. Instead, there is an earlier period of dense face input and a later period of dense hand input. At all ages, hands in these scenes were primarily in contact with objects and the spatio-temporal co-occurrence of hands and faces was greater than expected by chance. The orderliness of the shift from faces to hands suggests a principled transition in the contents of visual experiences and is discussed in terms of the role of developmental gates on the timing and statistics of visual experiences.

Real-world visual statistics and infants' first-learned object names

“…Egocentric vision is an emerging field that studies vision from the individual perceiver's point of view; a viewpoint dependent on momentary location and bodily orientation [38][39][40][41]. Research with infants, toddlers and adults (e.g.…”

Why are faces denser in the visual experiences of younger than older infants?

“…The head-camera data generated by these infants is part of a growing corpus of infant-perspective scenes collected to understand the natural statistics of early visual experience and how it changes with age. Thus, twenty-two of the infants in the present analysis (all younger than 13 months of age) contributed head-camera data to the earlier study (Jayaraman et al, 2015) that first reported an age-related decline in the faces in view within the first year; 34 of the infants contributed head camera images to the study (Fausey et al, in press) that analyzed hands in infant-perspective scenes. Two infants in the present study were new to the corpus.…”

“…Because humans are social animals and because human faces provide important social information, it seems reasonable to assume that faces are visually prevalent throughout life (e.g., Calder & Young, 2005; Cohen & Cashon, 2001; Haxby et al, 2000; Kadosh & Johnson, 2007; Kanwisher & Yovel, 2006; McKone et al, 2007; Nelson, 2003; Tarr & Gauthier, 2000; Zhao & Bentin, 2008). However, recent research using head cameras suggests potentially significant changes in the faces in infant views (Fausey et al, in press; Jayaraman et al, 2015; Sugden et al, 2014). The two experiments reported here were designed to answer the question of whether this age-related decline in faces was about a change in the frequency of people positioned in front of the infant or more specifically about the frequency of faces in front of the infant.…”

“…However, in aggregate they indicate a clear developmental pattern. Findings from studies using head-cameras at-home (Fausey, Jayaraman, & Smith, in press; Jayaraman, Fausey, & Smith, 2015; Sugden, Mohamed-Ali, & Moulson, 2014) as well as in-laboratory settings (Frank et al, 2013; Pereira, Smith, & Yu, 2014; Yu & Smith, 2012) show that faces are much more frequent in the captured images for infants younger than 4 months of age than they are for toddlers. For all infants, the faces in the images appear to be most typically frontal (or near frontal) views within 4 feet of the infant (Jayaraman et al, 2015).…”

Synchronized practice helps bearded capuchin monkeys learn to extend attention while learning a tradition

“…Young children extend the duration of sustained attention to an object while an older person shows attention to that object, suggesting how social interactions can support the development of sustained attention in the particular context of handling objects (27). The visual salience to humans of others' hand movements is evident by the second year of life, when toddlers shift their visual attention toward another person handling an object from predominantly toward the face to predominantly toward the hands (28).…”