Why do Infants Look at and Use Positive Information from Some Informants Rather Than Others in Ambiguous Situations?

Three laboratory experiments on social referencing examined whether infants’ tendencies to look at and use positive information from the experimenter could be interpreted from a perspective of novelty or expertise. In Study 1, novelty was manipulated. Forty‐eight 12‐month‐old infants participated. In a between‐subject design, a more novel or a less novel experimenter presented an ambiguous object and provided positive information. The infants looked more at and regulated their behavior more in accordance with information coming from the less novel experimenter. In Study 2, expertise was manipulated. Forty‐eight 12‐month‐old infants were exposed to one experimenter who showed expertise about the laboratory situation and one experimenter who did not show such competence. The infants looked more at and regulated their behavior more in accordance with information coming from the expert. In Study 3, 40 12‐month‐old infants participated. The infants were exposed to a toy‐expert who was either novel or familiar. The infants, in both groups, looked as much at the toy‐experts and used the information regardless of whether the novel or familiar toy‐expert had provided information. The findings suggest that novelty does not increase looking in ambiguous situations. Instead, the results support the expertise perspective of infant looking preferences.     

Infants' Preferences for Familiarity and Novelty During the Course of Visual Processing

At 4 1/2 months, infants were shown a series of brief choice trials between a stimulus that always remained the same and another that was different on every trial. The point when a consistent preference for the novel stimulus commenced was identified for each infant, and their preferences for the familiar and novel stimuli in trials preceding that point were examined. Infants who saw objects or faces as stimuli both exhibited selective attention to the familiar stimulus prior to preferring novel stimuli, although infants shown kaleidoscope patterns did not. These results document a preference for familiarity early in processing with a procedure that is not subject to ambiguities due to individual differences in processing speed or to collapsing data across infants. The results support a nonlinear model for memory formation during infancy and underscore recently voiced concerns that in research on cognitive development, infants' attention to perceptual familiarity‐novelty must be carefully disentangled from conceptual knowledge.     

Exploring the Emergence of Side Biases and Familiarity–Novelty Preferences from the Real‐Time Dynamics of Infant Looking

This study examined how look dynamics contribute to infants’ emerging novelty preferences. Time‐series analyses were used to study the temporal nature of looking displayed by 3‐ to 5‐month‐old infants during a serial paired‐comparison task. Evidence was found only for short‐term stability: Novelty preferences and side biases were not stable from one visit to the next, but looking was consistent from one moment to the next producing stability within trials and temporarily across trials leading to the formation of behavioral runs. Persistence in looking left or right across multiple trials did not change from one visit to the next, but persistence in looking at familiar stimuli declined with age. By Visit 3, familiarity runs occurred less often than did novelty runs. Frequent but highly variable runs, including surprisingly late familiarity preferences, suggest that overall side biases and novelty preferences found during visual preference tasks are emergent phenomena affected by moment‐to‐moment changes in looking.     

Gaze Behaviors of Preterm and Full‐Term Infants in Nonsocial and Social Contexts of Increasing Dynamics: Visual Recognition,Attention Regulation,and Gaze Synchrony

Although research has demonstrated poor visual skills in premature infants, few studies assessed infants’ gaze behaviors across several domains of functioning in a single study. Thirty premature and 30 full‐term 3‐month‐old infants were tested in three social and nonsocial tasks of increasing complexity and their gaze behavior was micro‐coded. In a one‐trial version of the visual recognition paradigm, where novel stimuli were paired with familiar stimuli, preterm infants showed longer first looks to novel stimuli. In the behavior response paradigm, which presented infants with 17 stimuli of increasing complexity in a predetermined “on‐off” sequence, premature infants tended to look away from toys more during presentation. Finally, during mother–infant face‐to‐face interaction, the most dynamic interpersonal context, preterm infants and their mothers displayed short, frequent episodes of gaze synchrony, and lag‐sequential analysis indicated that both mother and infant broke moments of mutual gaze within 2 sec of its initiation. The propotion of look away during the behavior response paradigm was related to lower gaze synchrony and more gaze breaks during mother–infant interactions. Results are discussed in terms of the unique and adaptive gaze patterns typical of low‐risk premature infants.     

Infant Attention to Dynamic Audiovisual Stimuli: Look Duration From 3 to 9 Months of Age

The goal of this study was to examine developmental change in visual attention to dynamic visual and audiovisual stimuli in 3‐, 6‐, and 9‐month‐old infants. Infant look duration was measured during exposure to dynamic geometric patterns and Sesame Street video clips under three different stimulus modality conditions: unimodal visual, synchronous audiovisual, and asynchronous audiovisual. Infants looked longer toward Sesame Street stimuli than geometric patterns, and infants also looked longer during multimodal audiovisual (synchronous and asynchronous) presentations than during unimodal visual presentations. There was a three‐way interaction of age, stimulus type, and stimulus modality. Significant differences were found within and between age groups related to stimulus modality (visual or audiovisual) while viewing Sesame Street clips. No significant interaction was found between age and stimulus type while infants viewed dynamic geometric patterns. These findings indicate that patterns of developmental change in infant attention vary based on stimulus complexity and modality of presentation.     

Picture Perception in Infants: Generalization From Two‐Dimensional to Three‐Dimensional Displays

Two experiments investigated 9‐month‐old infants’ abilities to recognize the correspondence between an actual three‐dimensional (3D) object and its two‐dimensional (2D) representation, looking specifically at representations that did not literally depict the actual object: schematic line drawings. In Experiment 1 , infants habituated to a line drawing of either a doll or a sheep and were then tested with the actual objects themselves. Infants habituated to the sheep drawing recovered to the unfamiliar but not the familiar object, showing a novelty preference. Infants habituated to the doll drawing, however, recovered to both familiar and unfamiliar objects, failing to show any preference between the two. In Experiment 2 , infants habituated to the 3D objects and were then tested with the 2D line drawings. In this case, both groups of infants showed a preference only for the novel displays. Together these findings demonstrate that 9‐month‐old infants recognize the correspondence between 3D objects and their 2D representations, even when these representations are not literal copies of the objects themselves.     

Developmental Changes in Infant Attention to Dynamic and Static Stimuli

This study examined 4‐ and 6‐month‐olds' responses to static or dynamic stimuli using behavioral and heart‐rate‐defmed 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 sustained attention at 4 months, but not at 6 months, was related to stimulus discrimination. These results indicate that the decline in look duration typically observed during the middle of the 1st year for static stimuli does generalize to dynamic stimuli. The results further suggest that the amount of time spent in sustained attention during habituation may be an important indicator of processing in younger infants.     

Infants’ Speed Discrimination: Effects of Different Ratios and Spatial Orientations

This study addressed the question whether 6‐month‐olds’ speed discrimination is ratio dependent and whether an oblique effect (i.e., more accurate discrimination of cardinally as opposed to obliquely oriented objects) affects their speed discrimination skills. Infants were habituated to visual displays showing a ball moving with constant speed and tested with the familiar and a novel speed in the test phase. This ball moved either on a cardinally or obliquely oriented trajectory. Irrespective of orientation, infants looked longer at the novel speed when speeds differed by a ratio of 1:2, whereas they looked indiscriminable at the novel and familiar speeds when they differed by a ratio of 2:3. Our results show remarkable parallels to infants’ ratio‐dependent discrimination behavior in other domains (time, distance, and number), implying that different magnitudes may be processed by the same underlying mechanism. However, our findings also indicate that speed discrimination was not influenced by spatial orientation in a similar way as has been found for other visual perceptual processes.     

Infant Side Biases and Familiarity‐Novelty Preferences During a Serial Paired‐Comparison Task

We monitored changes in looking that emerged when 3‐ to 6‐month‐old infants were presented with 48 trials pairing familiar and novel faces. Graphic displays were used to identify changes in looking throughout the task. Many infants exhibited strong side biases produced by infants looking repeatedly in the same direction. Although an overall novelty preference was found for the group, individual infants exhibited brief novelty runs. Few infants began with a familiarity preference. We argue that variable looking patterns emerged during the task from competition between the infants' preference to look for something novel versus their tendency to look back to previous locations. Our data suggest that looking during paired‐comparison tasks is a dynamic process dependent on perceptual‐motor events happening during the task itself.     

Mental Rotation of Dynamic,Three‐Dimensional Stimuli by 3‐Month‐Old Infants

Mental rotation involves transforming a mental image of an object so as to accurately predict how the object would look if it were rotated in space. This study examined mental rotation in male and female 3‐month‐olds, using the stimuli and paradigm developed by Moore and Johnson (2008) . Infants were habituated to a video of a three‐dimensional object rotating back and forth through a 240° angle around the vertical axis. After habituation, infants were tested both with videos of the same object rotating through the previously unseen 120° angle, and with the mirror image of that display. Unlike females, who fixated the test displays for approximately equal durations, males spent significantly more time fixating the familiar object than the mirror‐image object. Because familiarity preferences like this emerge when infants are relatively slow to process a habituation stimulus, the data support the interpretation that mental rotation of dynamic three‐dimensional stimuli is relatively difficult—but possible—for 3‐month‐old males. Interpretation of the sex differences observed in 3‐ and 5‐month‐olds’ performances is discussed.     

Temporal Sequence of Global‐Local Processing in 3‐Month‐Old Infants

In 3 experiments, the temporal processing sequence of local and global visual properties was investigated with 3‐month‐old infants. Across the experiments, a global pattern was discriminated under conditions of less familiarization than was necessary for local elements to be discriminated, thus indicating a global precedence in the sequence of visual processing at 3 months of age. Patterns of discrimination were also observed to vary as a function of individual differences in infants' look duration. Furthermore, the pattern of novelty and familiarity preferences for short‐looking infants varied in complex ways as a function of familiarization time: Preferences for novel global properties were supplanted by familiarity preferences at the point in familiarization at which infants first became sensitive to local properties.     

Individual Differences in Infants' Recognition of Briefly Presented Visual Stimuli

Infants' recognition memory has been shown to be related to individual differences in look duration and level of heart period variability. This study examined the effect of individual differences in these 2 measures on infants' recognition of briefly presented visual stimuli using a paired‐comparison recognition‐memory paradigm. A sample of 35 full‐term infants was studied longitudinally at 14, 20, and 26 weeks of age. Recognition memory for briefly presented stimuli was tested in 6 experimental conditions, with delays corresponding to different heart‐rate‐defined phases of attention. The 20‐and 26‐week‐old infants, and infants with high levels of heart period variability, generally showed more evidence of recognition memory for briefly presented visual stimuli. Greater evidence of recognition memory was observed when stimuli were presented during sustained attention. Infants with more mature baseline physiological responses show greater evidence of recognition memory, and stimulus and procedural factors may be more important for the study of individual differences in infant visual attention than has previously been suggested.     

Crawling is Associated with Mental Rotation Ability by 9‐Month‐Old Infants

The present experiment examined whether 9‐month‐old infants’ mental rotation ability was related to their crawling ability. Forty‐eight 9‐month‐old infants were tested; half of them crawled for 7.1 weeks on average. Infants were habituated to a video of a simplified Shepard–Metzler object rotating back and forth through a 240° angle around the longitudinal axis of the object. Infants were tested with videos of the same object rotating through the previously unseen 120° angle and with the mirror image of that display. The results showed that the crawlers looked significantly longer at the mirror object than at the familiar object. The results support the interpretation that crawling experience is associated with 9‐month‐old infants’ mental rotation ability.     

Background Television and Infants’ Allocation of Their Attention During Toy Play

The effect of background television on 6‐ and 12‐month‐olds’ attention during 20 min of toy play was examined. During the first or second half of the session, a clip from a variety of commonly available television programs was presented. The duration and frequency of infants’ looks to the toys and to the television indicated that regardless of age or program content, background television frequently got, but did not hold the infants’ attention. An order effect indicated that infants looked longer at the television when it was available in the second half of the session. Examination of infants’ focused attention to the toys showed a reduction in the mean length of focused episodes when the television was on. A follow‐up of the infants at 24 months indicated greater resistance to distraction by the television during play. Data from the three ages showed that individual differences in the amount of viewing were moderately stable across age and across home and lab contexts.     

Infants' ERP Responses to Novel and Familiar Stimuli Change Over Time: Implications for Novelty Detection and Memory

Detection of novelty is an important cognitive ability early in development, when infants must learn a great deal about their world. Work with adults has identified networks of brain areas involved in novelty detection; this study investigated electrophysiological correlates of detection of novelty and recognition of familiarity in 9‐month‐old infants, using event‐related potentials (ERPs). Infants were familiarized with an event in the laboratory, then ERPs were recorded as they viewed repeated presentations of pictures of this familiar event and a novel event, along with single presentations of 30 trial‐unique events. A middle‐latency negative component was sensitive to degree of novelty, differing in amplitude and latency by stimulus condition and across repeated presentations. Long‐latency slow‐wave activity also related to stimulus condition. Findings have implications for our understanding of infants' detection of novel information and the processes that render the novel familiar.     

Cross‐Task Stability in Infant Attention: New Perspectives Using the Still‐Face Procedure

Infant visual attention has been studied extensively within cognitive paradigms using measures such as look duration and reaction time, but less work has examined how infant attention operates in social contexts. In addition, little is known about the stability of individual differences in attention across cognitive and social contexts. In this study, a cross‐sectional sample of 50 infants (4 and 6 months of age) were first tested in a look duration and reaction time task with static visual stimuli. Next, their mothers participated with the infants in the still‐face procedure, a mildly distressing social interaction paradigm that involves violation of expectancy. Individual differences in looking and emotion were stable across the phases of the still‐face task. Further, individual differences in looking measures from the visual attention task were related to the pattern of looking shown across the phases of the still‐face procedure. Results indicate that individual differences in attentional measures show moderate stability within cognitive and social contexts, and that the ability of infants to shift and disengage looks may affect their ability to regulate interaction in social contexts.     

Anticipatory Eye Movements Reveal Infants' Auditory and Visual Categories

We introduce a new paradigm for the assessment of auditory and visual categories in 6‐month‐old infants using a 2‐alternative anticipatory eye‐movement response. Infants were trained by 2 different methods to anticipate the location of a visual reinforcer at 1 of 2 spatial locations (right or left) based on the identity of 2 cuing stimuli. After a training phase, infants were presented with a series of generalization trials in which novel (untrained) stimuli served as the cue to the anticipatory eye movement. Four experiments illustrated that infants can learn the 2‐choice discriminative response during training. Infants also showed anticipatory eye movements to novel stimuli, indicating sensitivity to variations along a variety of stimulus dimensions (e.g., color, shape, orientation, spatial frequency, pitch, and duration). In addition, the paradigm can be used to assess categorization in individual infants, thereby revealing the stimulus dimensions to which infants naturally attend.     

Do 12‐Month‐Old Infants Trust a Competent Adult?

Why infants prefer to look at and use information provided by some informants over others was examined in four experiments. In each experiment, 52 12‐month‐old infants participated. In Experiment 1, a familiar expert and a familiar nonexpert and in Experiment 2, a novel expert and a novel nonexpert presented an ambiguous object and provided positive information. In both experiments, the infants preferred to look at the expert and regulated their behavior more in accordance with positive information provided by the expert, regardless of she was novel or more familiar. In Experiment 3, a familiar expert and a familiar nonexpert and in Experiment 4, a novel expert and a novel nonexpert presented an ambiguous object and provided negative information. In both experiments, the infants looked more at the expert and regulated their behavior more in accordance with negative information provided by the expert, regardless of she was novel or more familiar. The results support an expertise perspective of infant behavior in social‐referencing situations.     

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.     

Relations Among Spontaneous Preferences,Familiarized Preferences,and Novelty Effects: Measurements With Forced‐Choice Techniques

We here describe a discrete trial, forced‐choice, combined spontaneous preference and novelty preference technique. In this technique, spontaneous preferences and familiarized (postfamiliarization) preferences are measured with the same stimulus pairs under closely parallel conditions. A variety of systematic stimulus variations were used in 16‐week‐old infants to explore the interrelations among spontaneous preferences, familiarized preferences, and familiarization (novelty) effects. Infants were exposed to pairs of 10° red and blue disks of varying colorimetric purity generated on a video monitor. Pairs of disks were identified for which spontaneous preferences were balanced at about 50–50 or unbalanced at about 75–25, and the magnitudes of familiarized preferences were determined. When spontaneous preferences were balanced at 50–50, novelty effects increased with increasing chromatic separation between the 2 stimuli, showing the independence of these variables. When spontaneous preferences were unbalanced, novelty effects were asymmetrical, being large after familiarization to the spontaneously preferred stimulus, but small or nonexistent after familiarization to the spontaneously nonpreferred stimulus. The potential uses of combined spontaneous preference and novelty preference techniques are discussed.