Diverse Face Images (DFI): Validated for racial representation and eye gaze.

Face processing is a central component of human communication and social engagement. The present investigation introduces a set of racially and ethnically inclusive faces created for researchers interested in perceptual and socio-cognitive processes linked to human faces. The Diverse Face Images (DFI) stimulus set includes high-quality still images of female faces that are racially and ethnically representative, include multiple images of direct and indirect gaze for each model and control for low-level perceptual variance between images. The DFI stimuli will support researchers interested in studying face processing throughout the lifespan as well as other questions that require a diversity of faces or gazes. This report includes a detailed description of stimuli development and norming data for each model. Adults completed a questionnaire rating each image in the DFI stimuli set on three major qualities relevant to face processing: (1) strength of race/ethnicity group associations, (2) strength of eye gaze orientation, and (3) strength of emotion expression. These validation data highlight the presence of rater variability within and between individual model images as well as within and between race and ethnicity groups.

Infants' individuation of human faces across race and identity.

Young infants' face perception capabilities quickly tune to the features of their primary caregiver. The current study examines whether infants distinguish faces in a more conceptual manner using a manual-search, violation of expectation task that has previously been used to test kind-based individuation. We tested how well infants between 11 and 27 months of age individuated faces that varied by superordinate category (human vs. non-human in Experiment 1) subordinate category (individual identity in Experiment 2) or by race (White vs. Black, Experiments 1 & 2). We assessed individuation by quantifying the difference in infants' duration of reaching within an empty box between trials when the box was unexpectedly empty and expectedly empty. We found evidence of individuation across all ages and conditions, but with within-infant variation. On average, infants individuated face from non-face stimuli (Experiment 1), individual face identities (Experiment 2), and White versus Black faces (Experiments 1 & 2). These findings suggest that 1- to 2-year-old infants use distinct human face features to represent individuals across time and space. We discuss this evidence for race-based individuation and related complexities of face identity in terms of implications for conceptual development for faces in the first years of life.

Infants' Individuation of Faces by Gender.

By 3 months of age, infants can perceptually distinguish faces based upon differences in gender. However, it is still unknown when infants begin using these perceptual differences to represent faces in a conceptual, kind-based manner. The current study examined this issue by using a violation-of-expectation manual search individuation paradigm to assess 12- and 24-month-old infants' kind-based representations of faces varying by gender. While infants of both ages successfully individuated human faces from non-face shapes in a control condition, only the 24-month-old infants' reaching behaviors provided evidence of their individuating male from female faces. The current findings help specify when infants begin to represent male and female faces as being conceptually distinct and may serve as a starting point for socio-cognitive biases observed later in development.

Learning to Individuate: The Specificity of Labels Differentially Impacts Infant Visual Attention.

This study examined differences in visual attention as a function of label learning from 6 to 9 months of age. Before and after 3 months of parent-directed storybook training with computer-generated novel objects, event-related potentials and visual fixations were recorded while infants viewed trained and untrained images (n = 23). Relative to a pretraining, a no-training control group (n = 11), and to infants trained with category-level labels (e.g., all labeled "Hitchel"), infants trained with individual-level labels (e.g., "Boris," "Jamar") displayed increased visual attention and neural differentiation of objects after training.

Follow My Gaze: Face Race and Sex Influence Gaze-Cued Attention in Infancy.

Using the eye gaze of others to direct one's own attention develops during the first year of life and is thought to be an important skill for learning and social communication. However, it is currently unclear whether infants differentially attend to and encode objects cued by the eye gaze of individuals within familiar groups (e.g., own race, more familiar sex) relative to unfamiliar groups (e.g., other race, less familiar sex). During gaze cueing, but prior to the presentation of objects, 10-month-olds looked longer to the eyes of own-race faces relative to 5-month-olds and relative to the eyes of other-race faces. After gaze cueing, two objects were presented alongside the face and at both ages, infants looked longer to the uncued objects for faces from the more familiar-sex and longer to cued objects for the less familiar-sex faces. Finally, during the test phase, both 5- and 10-month-old infants looked longer to uncued objects relative to cued objects but only when the objects were cued by an own-race and familiar-sex individual. Results demonstrate that infants use face eye gaze differently when the cue comes from someone within a highly experienced group.

The lasting effects of process-specific versus stimulus-specific learning during infancy.

The capacity to tell the difference between two faces within an infrequently experienced face group (e.g. other species, other race) declines from 6 to 9 months of age unless infants learn to match these faces with individual-level names. Similarly, the use of individual-level labels can also facilitate differentiation of a group of non-face objects (strollers). This early learning leads to increased neural specialization for previously unfamiliar face or object groups. The current investigation aimed to determine whether early conceptual learning between 6 and 9 months leads to sustained behavioral advantages and neural changes in these same children at 4-6 years of age. Results suggest that relative to a control group of children with no previous training and to children with infant category-level naming experience, children with early individual-level training exhibited faster response times to human faces. Further, individual-level training with a face group - but not an object group - led to more adult-like neural responses for human faces. These results suggest that early individual-level learning results in long-lasting process-specific effects, which benefit categories that continue to be perceived and recognized at the individual level (e.g. human faces).