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.     

Visual Attention to Dynamic Spatial Relations in Infants and Adults

Previous research has found that kinematic features of interactions, such as spatial proximity, capture adult visual attention. The current research uses online measures of gaze behavior to determine attentional capture to objects with reduced interobject spacing in adults as well as infants at 5 and 12 months. The three age groups observed three identical geometrical shapes that moved randomly. Relative distance between the objects was mapped and intervals of high and low spatial proximity were identified. Findings demonstrate that only adults and 12‐month‐olds look significantly more at the objects that are close during instances of high spatial proximity, while 5‐month‐olds look at chance. The findings speak for a developmental trend in oculomotor processes, where a bias to look at objects with high spatial proximity develops within the first year of life.     

The Development of Selective Attention Orienting is an Agent of Change in Learning and Memory Efficacy

This study examined whether the developmental transition from facilitation‐based orienting mechanisms available very early in life to selective attention orienting (e.g., inhibition of return, IOR) promotes better learning and memory in infancy. We tested a single age group (4‐month‐olds) undergoing rapid development of attention orienting mechanisms. Infants completed a spatial cueing task designed to elicit IOR, in which cat or dog category exemplars consistently appeared in either the cued or noncued locations. Infants were subsequently tested on a visual paired comparison of exemplars from these cued and noncued animal categories. As expected, infants showed either facilitation‐based orienting or the more mature IOR‐based orienting during spatial cueing/encoding. Infants who demonstrated IOR‐based orienting showed memory for both specific exemplars and broader category learning, whereas those who showed facilitation‐based orienting showed weaker evidence of learning. Attention orienting also interacted with previous pet experience, such that the number of pets at home influenced learning only when infants engaged facilitation‐based orienting during encoding. Learning in the context of IOR‐based orienting was stable regardless of pet experience, suggesting that selective attention serves as an online learning mechanism during visual exploration that is less sensitive to prior experience.     

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.     

Neural Correlates of Individual Differences in Infant Visual Attention and Recognition Memory

Past studies have identified individual differences in infant visual attention based upon peak look duration during initial exposure to a stimulus. Colombo and colleagues found that infants that demonstrate brief visual fixations (i.e., short lookers) during familiarization are more likely to demonstrate evidence of recognition memory during subsequent stimulus exposure than infants that demonstrate long visual fixations (i.e., long lookers). This study utilized event‐related potentials (ERPs) to examine possible neural mechanisms associated with individual differences in visual attention and recognition memory for 6‐ and 7.5‐month‐old infants. Short‐ and long‐looking infants viewed images of familiar and novel objects during ERP testing. There was a stimulus type by looker type interaction at temporal and frontal electrodes on the late slow wave (LSW). Short lookers demonstrated an LSW that was significantly greater in amplitude in response to novel stimulus presentations. No significant differences in LSW amplitude were found based on stimulus type for long lookers. These results indicate deeper processing and recognition memory of the familiar stimulus for short lookers.     

Attention during Visual Preference Tasks: Relation to Caregiving and Face Recognition

This research examined how caregiver experience (female primary caregiver or distributed caregiving with mom and dad) influenced 10‐, 14‐, and 16‐month‐olds’ visual preferences and attention toward internal facial features of female–male face pairs, and how these behaviors related to novelty preferences in a face recognition task and speed and accuracy on a visual search task. In the visual preference task, infants visually preferred male faces, regardless of caregiver experience. Despite similarities in visual preferences, infants’ attention toward females and males’ internal facial features was related for infants with distributed caregiving only. Infants’ performance across face processing tasks most often correlated for those with female primary caregivers. Results further our understanding of how infants with female primary caregivers display specialized processing of female faces, and how infants with distributed caregiving show similarities in their attention to female and male facial features.     

Faces Attract Infants' Attention in Complex Displays

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 attention‐grabbing effect of faces is not selective to upright faces (Experiment 2) but does require the presence of internal facial elements, as faces whose interior has been phase‐scrambled did not attract infants' attention (Experiment 3). On the contrary, when the number of fixations is considered, upright faces are scanned more extensively than both inverted and phase‐scrambled faces. The difference in selectivity between the first look measure and the fixation count measure is discussed in light of a distinction between attention‐grabbing and attention‐holding mechanisms.     

The emergence of object‐based visual attention in infancy: A role for family socioeconomic status and competing visual features

The development of spatial visual attention has been extensively studied in infants, but far less is known about the emergence of object‐based visual attention. We tested 3–5‐ and 9–12‐month‐old infants on a task that allowed us to measure infants’ attention orienting bias toward whole objects when they competed with color, motion, and orientation feature information. Infants’ attention orienting to whole objects was affected by the dimension of the competing visual feature. Whether attention was biased toward the whole object or its salient competing feature (e.g., “ball” or “red”) changed with age for the color feature, with infants biased toward whole objects with age. Moreover, family socioeconomic status predicted feature‐based attention in the youngest infants and object‐based attention in the older infants when color feature information competed with whole‐object information.     

The Association Between Infants’ Attention Control and Social Inhibition is Moderated by Genetic and Environmental Risk for Anxiety

Infant social inhibition is associated with increased risk for anxiety later in life. Although both genetic and environmental factors are associated with anxiety, little empirical work has addressed how developing regulatory abilities work with genetic and environmental risk to exacerbate or mitigate problem behaviors. The current study was aimed at addressing this gap in research by investigating an early emerging regulatory behavior, attention control, in association with genetic and environmental risk for anxiety. Participants included 9‐month‐old adopted infants, their birth mothers, and adoptive parents (N = 361). Lifetime diagnosis of birth mother social phobia was obtained using structured interviews. Adoptive parents completed self‐report measures of anxiety symptoms. Infant social inhibition and attention control were coded during a stranger interaction and a barrier task, respectively. Neither adoptive nor birth parent anxiety was directly associated with social inhibition. The association of attention control with social inhibition in infants was moderated by birth and adoptive parent anxiety symptoms. When infants of birth mothers with social phobia were raised by adoptive parents with high self‐reported anxiety symptoms, greater attention control was associated with greater social inhibition. However, when raised by adoptive parents with low self‐reported anxiety, greater attention control was associated with less social inhibition.     

Maternal Talk About Mental States and the Emergence of Joint Visual Attention

Twenty‐four infants were tested monthly for gaze and point following between 9 and 15 months of age and mother‐infant free play sessions were also conducted at 9, 12, and 15 months (Carpenter, Nagell, & Tomasello, 1998). Using this data set, this study explored relations between maternal talk about mental states during mothers' free play with their infants and the emergence of joint visual attention in infants. Contrary to hypothesis, mothers' comments about their infants' perceptual states significantly declined after their infants began to engage in joint visual attention. Comments about other mental states did not change relative to acquisition of joint visual attention skill. We speculate that after infants begin to reliably follow gaze and points, mothers may switch the focus of their conversation from their infants' visual behavior and experiences to the object of their mutual attention.     

The Microstructure of Infants' Gaze as They View Adult Shifts in Overt Attention

We presented infants (5, 6, 9, and 12 months old) with movies in which a female model turned toward and fixated 1 of 2 toys placed on a table. Infants' gaze was measured using a Tobii 1750 eye tracker. Six‐, 9‐, and 12‐month‐olds' first gaze shift from the model's face (after the model started turning) was directed to the attended toy. The 5‐month‐olds performed at random. Following this initial response, 5‐, 6‐, and 9‐month‐olds performed more gaze shifts to the attended target; 12‐month‐olds performed at random. Infants at all ages displayed longer looking times to the attended toy. We discuss a number of explanations for 5‐month‐olds' ability to follow a shift in overt attention by an adult after an initially random response, including the possibility that infants' initial gaze response strengthens the representation of the objects in the peripheral visual field.     

Infants’ Visual Attention to Baby DVDs as a Function of Program Pacing

This study examined the effects of program pacing, defined as the rate of scene and character change per minute, on infants’ visual attention to video presentations. Seventy‐two infants (twenty‐four 6‐month‐olds, twenty‐four 9‐month‐olds, twenty‐four 12‐month‐olds) were exposed to one of two sets of high‐ and low‐paced commercial infant DVDs. Each DVD was approximately 5‐min long, and the order the DVDs were viewed was counterbalanced for pace. Attention was higher during rapidly than slowly paced DVDs, particularly for the 6‐ and 9‐month‐old infants. These results support previous research documenting that attention is initially controlled by exogenous qualities (e.g., rapid pace), but with development and experience becomes more influenced by endogenous factors.     

Relative Color Contrast Drives Competition in Early Exogenous Orienting

Young infants typically orient to a moving object, but the strength of this tendency depends on what else is in the visual field, with some objects competing for attention more effectively than others. This competition was studied in 3.5‐month‐old infants by manipulating the colors and spatial distributions of static elements that appeared with a small moving probe. The hypothesis was that the competition from these static bars would depend on their color contrasts. Three different color pairings were used: red with green, pink with green, and red with pink. The results were generally consistent with the hypothesis that the competition from static elements in the visual field depends on their color contrasts. Orienting at 3.5 months is determined by competition mechanisms that weight motion and color and most probably other stimulus characteristics to produce a directional response.     

Neural Correlates of Encoding Predict Infants’ Memory in the Paired‐Comparison Procedure

The present study used event‐related potentials (ERPs) to monitor infant brain activity during the initial encoding of a previously novel visual stimulus, and examined whether ERP measures of encoding predicted infants’ subsequent performance on a visual memory task (i.e., the paired‐comparison task). A late slow wave component of the ERP measured at encoding predicted infants’ immediate performance in the paired‐comparison task: amplitude of the late slow wave at right‐central and temporal leads decreased with stimulus repetition, and greater decreases at right‐anterior‐temporal leads during encoding were associated with better memory performance at test. By contrast, neither the amplitude nor latency of the negative central (Nc) component predicted infants’ subsequent performance in the paired‐comparison task. These findings are discussed with respect to a biased competition model of visual attention and memory.     

Intention or Attention Before Pointing: Do Infants’ Early Holdout Gestures Reflect Evidence of a Declarative Motive?

Gestures are the first signs of intentional communication within prelinguistic infants and can reflect various motives, including a declarative motive to share attention and interest. The ability to use gestures declaratively has been linked to later language development; therefore, it is important to understand the origins of this motive. Previous research has focused on the use of declarative pointing at around 12 months; however, other potential forms of declarative communication, such as holdout gestures, are yet to be studied in detail. The purpose of this study was to examine whether from 10 months, infants use holdouts declaratively. We elicited holdouts from 36 infants and then reacted to these gestures in four different conditions: (1) joint attention: shared interest; (2) infant attention: attended to infant; (3) toy attention: attended to toy; (4) ignore: gesture was not attended to. Infants’ behavioral responses were recorded. When the experimenter engaged in joint attention, infants were significantly more likely to display a positive attitude and produced fewer re‐engagement attempts. In contrast, the three non‐joint attention conditions displayed significantly higher negative attitudes and attempts to re‐engage the experimenter. We conclude that infants display declarative communication prior to 12 months, resetting the age at which these more complex skills emerge.     

Young Infants' Behavioral Reactivity to Mild Perturbation: Developmental Continuity,Stability, and Organization

This study investigated the developmental continuity, stability, and organization of infants' behavioral response to mild stress from 1 to 3 months of age. Changes in infant stress reactivity were expected to coincide with a suspected neurobiological shift around the 2nd month. A total of 53 infants and their mothers participated in this study. At 1 and 3 months, infants' stress reactivity to mild perturbation was assessed by withdrawing a pacifier during nonnutritive sucking. Infant baseline heart rate activity and maternal reports of infant temperament were also obtained. Focusing on facial and vocal negativity, behavioral measures of infant reactivity to pacifier withdrawal were coded from videos. Results showed that developmental continuity and individual instability characterized changes in infant stress reactivity over the 2nd‐month transition. Developmental reorganization was also evidenced by changes in the direction and magnitude of infant stress reactivity in relation to baseline heart period and maternal temperament ratings, respectively. These findings provide direct supporting evidence for the contention that changes in infant stress reactivity to mild perturbation may be a function of developmental shifts in underlying neurobiological mechanisms in early infancy.     

Developmental Differences in Infants' Attention to Social and Nonsocial Threats

Research has demonstrated that humans detect threatening stimuli more rapidly than nonthreatening stimuli. Although the literature presumes that biases for threat should be normative, present early in development, evident across multiple forms of threat, and stable across individuals, developmental work in this area is limited. Here, we examine the developmental differences in infants' (4‐ to 24‐month‐olds) attention to social (angry faces) and nonsocial (snakes) threats using a new age‐appropriate dot‐probe task. In Experiment 1, infants' first fixations were more often to snakes than to frogs, and they were faster to fixate probes that appeared in place of snakes vs. frogs. There were no significant age differences, suggesting that a perceptual bias for snakes is present early in life and stable across infancy. In Experiment 2, infants fixated probes more quickly after viewing any trials that contained an angry face compared to trials that contained a happy face. Further, there were age‐related changes in infants' responses to face stimuli, with a general increase in looking time to faces before the probe and an increase in latency to fixate the probe after seeing angry faces. Together, this work suggests that different developmental mechanisms may be responsible for attentional biases for social vs. nonsocial threats.     

Categorical Representation of Facial Expressions in the Infant Brain

Categorical perception, demonstrated as reduced discrimination of within‐category relative to between‐category differences in stimuli, has been found in a variety of perceptual domains in adults. To examine the development of categorical perception in the domain of facial expression processing, we used behavioral and event‐related potential (ERP) methods to assess discrimination of within‐category (happy‐happy) and between‐category (happy‐sad) differences in facial expressions in 7‐month‐old infants. Data from a visual paired‐comparison test and recordings of attention‐sensitive ERPs showed no discrimination of facial expressions in the within‐category condition, whereas reliable discrimination was observed in the between‐category condition. The results also showed that face‐sensitive ERPs over occipital‐temporal scalp (P400) were attenuated in the within‐category condition relative to the between‐category condition, suggesting a potential neural basis for the reduced within‐category sensitivity. Together, these results suggest that the neural systems underlying categorical representation of facial expressions emerge during the early stages of postnatal development, before acquisition of language.     

The Emergence and Stability of the Attentional Bias to Fearful Faces in Infancy

Several studies have shown that at 7 months of age, infants display an attentional bias toward fearful facial expressions. In this study, we analyzed visual attention and heart rate data from a cross‐sectional study with 5‐, 7‐, 9‐, and 11‐month‐old infants (Experiment 1) and visual attention from a longitudinal study with 5‐ and 7‐month‐old infants (Experiment 2) to examine the emergence and stability of the attentional bias to fearful facial expressions. In both experiments, the attentional bias to fearful faces appeared to emerge between 5 and 7 months of age: 5‐month‐olds did not show a difference in disengaging attention from fearful and nonfearful faces, whereas 7‐ and 9‐month‐old infants had a lower probability of disengaging attention from fearful than nonfearful faces. Across the age groups, heart rate (HR) data (Experiment 1) showed a more pronounced and longer‐lasting HR deceleration to fearful than nonfearful expressions. The results are discussed in relation to the development of the perception and experience of fear and the interaction between emotional and attentional processes.