Infants search for an object hidden by an occluder in the light months later than one hidden by darkness. One explanation attributes this decalage to easier action demands in darkness versus occlusion, whereas another attributes it to easier representation demands in darkness versus occlusion. However, search tasks typically confound these two…

Infant's face preferences have previously been assessed in displays containing 1 or 2 faces. Here we present 6-month-old infants with a complex visual array containing faces among multiple visual objects. Despite the competing objects, infants direct their first saccade toward faces more frequently than expected by chance (Experiment 1). The…

In 2 experiments, the interplay of action perception and action production was investigated in 6-month-old infants. In Experiment 1, infants received 2 versions of a means-end task in counterbalanced order. In the action perception version, a preferential looking paradigm in which infants were shown an actor performing means-end behavior with an…

There is evidence that, from an early age, humans are sensitive to spatial information such as simple landmarks and the size of objects. This study concerns the ability to represent a particular kind of spatial information, namely, the "geometry" of an enclosed layout--an ability present in older children, adults, and nonhuman animals (e.g.,…

During the second year of life, infants develop a preference to attach novel labels to novel objects. This behavior is commonly known as "mutual exclusivity" (Markman, 1989). In an intermodal preferential looking experiment with 19.5- and 22.5-month-olds, stimulus repetition was critical for observing mutual exclusivity. On the first…

The contribution of motion and feature invariant information in infants' discrimination of maternal versus female stranger faces was assessed. Using an infant controlled habituation--dishabituation procedure, 4- and 8-month-old infants (N = 62) were tested for their ability to discriminate between their mother and a female stranger in 4 different…

A visual preference procedure was used to examine preferences among faces of different ethnicities (African, Asian, Caucasian, and Middle Eastern) in Chinese 3-month-old infants exposed only to Chinese faces. The infants demonstrated a preference for faces from their own ethnic group. Alongside previous results showing that Caucasian infants…

Six experiments investigated 7-month-old infants' capacity to learn about the self-propelled motion of an object. After observing 1 wind-up toy animal move on its own and a second wind-up toy animal move passively by an experimenter's hand, infants looked reliably longer at the former object during a subsequent stationary test, providing evidence…

We investigated how within-stimulus heterogeneity affects the ability of rhesus monkeys to order pairs of the numerosities 1 through 9. Two rhesus monkeys were tested in a touch screen task where the variability of elements within each visual array was systematically varied by allowing elements to vary in color, size, shape, or any combination of…

Developmental studies of face processing have revealed age-related changes in how infants allocate neurophysiological resources to the face of a caregiver and an unfamiliar adult. We hypothesize that developmental changes in how infants interact with their caregiver are related to the changes in brain response. We studied 6-month-olds because this…

Eye gaze has been shown to be an effective cue for directing attention in adults. Whether this ability operates from birth is unknown. Three experiments were carried out with 2- to 5-day-old newborns. The first experiment replicated the previous finding that newborns are able to discriminate between direct and averted gaze, and extended this…

This study examined 4- and 6-month-olds' responses to static or dynamic stimuli using behavioral and heart-rate-defined measures of attention. Infants looked longest to dynamic stimuli with an audio track and least to a static stimulus that was mute. Overall, look duration declined with age to the different stimuli. The amount of time spent in…