Showing papers in "Infancy in 2007"
TL;DR: Two experiments investigated the proclivity of 14-month-old infants to altruistically help others toward individual goals, and to cooperate toward a shared goal, which is integrated into a model of cooperative activities as they develop over the 2nd year of life.
Abstract: Two experiments investigated the proclivity of 14-month-old infants (a) to altruistically help others toward individual goals, and (b) to cooperate toward a shared goal. The infants helped another person by handing over objects the other person was unsuccessfully reaching for, but did not help reliably in situations involving more complex goals. When a programmed adult partner interrupted a joint cooperative activity at specific moments, infants sometimes tried to reengage the adult, perhaps indicating that they understood the interdependency of actions toward a shared goal. However, as compared to 18- and 24-month-olds, their skills in behaviorally coordinating their actions with a social partner remained rudimentary. Results are integrated into a model of cooperative activities as they develop over the 2nd year of life.
580 citations
TL;DR: This paper used a visual preference procedure 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.
Abstract: 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 exposed only to Caucasian faces prefer same-race faces (Kelly et al., 2005) and that Caucasian and African infants exposed only to native faces prefer the same over the other-race faces (Bar-Haim, Ziv, Lamy, & Hodes, 2006), the findings reported here (a) extend the same-race preference observed in young infants to a new race of infants (Chinese), and (b) show that cross-race preferences for same-race faces extend beyond the perceptually robust contrast between African and Caucasian faces.
165 citations
TL;DR: The most robust predictors of maternalPostnatal efficacy included both prenatal efficacy, which significantly predicted postnatal efficacy independent of all other predictors including the current parenting context, and perceived infant temperamental reactivity as both a main effect and as buffered by social support.
Abstract: Predictors of prenatal and postnatal parenting efficacy were examined in a sample of 115 primiparous mothers and 73 fathers in an effort to examine the association between preexisting parental characteristics and prenatal efficacy and the association between prenatal characteristics and postnatal efficacy when aspects of the current parenting context are taken into account. The most robust predictors of maternal postnatal efficacy included both prenatal efficacy, which significantly predicted postnatal efficacy independent of all other predictors including the current parenting context, and perceived infant temperamental reactivity as both a main effect and as buffered by social support. This was not the case for fathers, whose postnatal efficacy was primarily a function of their amount of involvement in parenting tasks and social support. The differential predictors of mother and father efficacy as well as their implications for future research are discussed.
119 citations
TL;DR: In this paper, the authors explored the impact of infant-directed speech (IDS) versus AD on neural activity to familiar and unfamiliar words in 6- and 13-month-old infants.
Abstract: This study explored the impact of infant-directed speech (IDS) versus adult-directed speech (ADS) on neural activity to familiar and unfamiliar words in 6- and 13-month-old infants. Event-related potentials were recorded while infants listened to familiar words in IDS, familiar words in ADS, unfamiliar words in IDS, and unfamiliar words in ADS. The results indicated that IDS elicited increased neural activity compared to ADS for both age groups. Six-month-olds showed a boost in neural activity to IDS for familiar words only. Thirteen-month-olds exhibited increased brain activity to IDS for both familiar and unfamiliar words. The results suggested that IDS changed as a function of development and word familiarity and served as an attentional spotlight to increase brain activity to potentially meaningful words.
104 citations
TL;DR: Children in higher SES families, whose mothers worked fewer hours and attributed their parenting failures to internal causes, and who themselves used more vocabulary were observed to be more responsive in their interactions with their mothers.
Abstract: This study examined unique associations of multiple distal context variables (family socioeconomic status [SES], maternal employment, and paternal parenting) and proximal maternal (personality, intelligence, and knowledge; behavior, self-perceptions, and attributions) and child (age, gender, representation, language, and sociability) characteristics with maternal sensitivity and child responsiveness in 254 European American mothers and their firstborn 20-month-olds. Specific unique relations emerged in hierarchical regression analyses. Mothers who worked fewer hours per week and reported less dissonance in their husbands' didactic parenting, whose children spoke using more vocabulary, and who reported less limit setting in their parenting and attributed their parenting failures to internal causes were observed to be more sensitive in their interactions with their children. Children in higher SES families, whose mothers worked fewer hours and attributed their parenting failures to internal causes, and who themselves used more vocabulary were observed to be more responsive in their interactions with their mothers. Although potential associations are many, when considered together, unique associations with maternal sensitivity and child responsiveness are few, and some are shared whereas others are unique.
100 citations
TL;DR: Overall, infants accumulated more looking when visual stimuli were accompanied by sounds or labels; however, infants were more likely to categorize when the visual images were presented without an auditory stimulus.
Abstract: Although it is generally accepted that labels facilitate categorization in infancy, recent evidence suggests that infants and young children are more likely to process visual input when presented in isolation than when paired with nonlinguistic sounds or linguistic labels. These findings suggest that auditory input (when compared to a no-auditory baseline) may hinder rather than facilitate categorization. This study assessed 8-month-olds' (n = 191) and 12-month-olds' (n = 81) abilities to form categories when images were paired with nonlinguistic sounds, linguistic labels, and when presented in isolation. Overall, infants accumulated more looking when visual stimuli were accompanied by sounds or labels; however, infants were more likely to categorize when the visual images were presented without an auditory stimulus.
93 citations
TL;DR: In this article, European American, Chinese, and Japanese 11-month-olds were videotaped during procedures designed to elicit mild anger or frustration and fear, and facial behavior was coded using Baby FACS, an anatomically based scoring system.
Abstract: Do infants show distinct negative facial expressions for different negative emotions? To address this question, European American, Chinese, and Japanese 11-month-olds were videotaped during procedures designed to elicit mild anger or frustration and fear. Facial behavior was coded using Baby FACS, an anatomically based scoring system. Infants’ nonfacial behavior differed across procedures, suggesting that the target emotions were successfully elicited. However evidence for distinct emotion-specific facial configurations corresponding to fear versus anger was not obtained. Although facial responses were largely similar across cultures, some differences also were observed. Results are discussed in terms of functionalist and dynamical systems approaches to emotion and emotional expression.
79 citations
TL;DR: Toddler toy play evolves in a predictable manner and provides a valid, nonverbal measure of cognitive function unbiased by social behaviors, and PNMS appears to affect functional play development in toddlers negatively.
Abstract: Toddler toy play evolves in a predictable manner and provides a valid, nonverbal measure of cognitive function unbiased by social behaviors. Research on prenatal maternal stress (PNMS) indicates that exposure to stress in utero results in developmental deficits. We hypothesized that children exposed to high objective PNMS from a natural disaster early in pregnancy would exhibit higher rates of stereotypical play and lower rates of mature functional play than their low-stress counterparts would. We examined the functional play abilities of 52 2-year-olds exposed to low or high objective PNMS from a natural disaster within a nonstructured play session. Toddlers exposed to high objective PNMS, subjective PNMS, or both exhibited less functional and more stereotypical toy play, with less diversity, compared to toddlers exposed to low PNMS. PNMS appears to affect functional play development in toddlers negatively. These results replicate delays in language and intellectual functioning observed in these toddlers using the Bayley Scales.
79 citations
TL;DR: Most striking in this research was the consistency with which particular maternal pretend behaviors were associated with children engaging in pretense behaviors and smiling.
Abstract: Participation in imagined worlds is a hallmark of the human species, and yet we know little about the context of its early emergence. The experiments reported here replicated and extended in 2 directions Lillard and Witherington's (2004) study of how mothers pretend to have snacks, across different ages of children (15- to 24-month-olds, Experiment 1) and to a different scenario (personal grooming, Experiment 2). Mothers' pretend behaviors changed little as infants aged, but there were some scenario differences. Most striking in this research was the consistency with which particular maternal pretend behaviors were associated with children engaging in pretense behaviors and smiling. The findings are discussed with reference to the child's emerging skills in joint attention and social referencing.
75 citations
TL;DR: The authors investigated the infant-directed action features of interactiveness and simplification by quantifying eye gaze, object exchanges, and action units enacted between exchanges in 42 mothers' demonstrations of novel objects to infants (6-8 months or 11-13 months) or adults.
Abstract: Mothers modify their actions when demonstrating objects to infants versus adults. Such modifications have been called infant-directed action (IDA) or motionese (Brand, Baldwin, & Ashburn, 2002). We investigated the IDA features of interactiveness and simplification by quantifying eye gaze, object exchanges, and action units enacted between exchanges in 42 mothers’ demonstrations of novel objects to infants (6–8 months or 11–13 months) or adults. We found more eye gaze, more object exchanges, and fewer action types per turn in demonstrations to infants relative to adults. Unlike prior research using global measurements, we detected differences in behavior directed at infants of different ages: Shorter, more frequent gazes and more exchanges characterized demonstrations to older versus younger infants. These findings indicate the fruitfulness of fine-grained analysis of IDA, and further clarify how adults may support infants’ processing of human motion.
72 citations
TL;DR: Results indicate that at least by 3.5 months of age, infants have attained enough face processing expertise to process familiar- race faces in a different manner than unfamiliar-race faces.
Abstract: Human adults are more accurate at discriminating faces from their own race than faces from another race. This other-race effect (ORE) has been characterized as a reflection of face processing specialization arising from differential experience with own-race faces. We examined whether 3.5-month-old infants exhibit ORE using morphed faces on which adults had displayed a crossover ORE (i.e., Caucasians performed better on Caucasian faces and Asians performed better on Asian faces). In this experiment, Caucasian infants who had grown up in a predominantly Caucasian environment discriminated 100% Caucasian faces from 70% Caucasian/30% Asian morphed faces but failed to discriminate between the corresponding 100% Asian and 70% Asian/30% Caucasian faces. Thus, 3.5-month-olds exhibited evidence of ORE. These results indicate that at least by 3.5 months of age, infants have attained enough face processing expertise to process familiar-race faces in a different manner than unfamiliar-race faces.
TL;DR: It is suggested that sensitivity to the relationship between functional morphemes and content words, rather than sensitivity to either independently, drives the development of early grammatical knowledge.
Abstract: This study examines 16-month-olds' understanding of word order and inflectional properties of familiar nouns and verbs. Infants preferred grammatical sentences over ungrammatical sentences when the ungrammaticality was cued by both misplaced inflection and word order reversal of nouns and verbs. Infants were also sensitive to inflection alone as a cue to grammaticality, but not word order alone. The preference for grammatical sentence forms was also disrupted when adjacent function word cues were removed from the stimuli, and when familiar content words were replaced by nonce words. These results suggest that sensitivity to the relationship between functional morphemes and content words, rather than sensitivity to either independently, drives the development of early grammatical knowledge. Furthermore, infants showed some ability to generalize from familiar to nonce content word contexts.
TL;DR: In this paper, the form and recognizability of neonatal smiling were investigated in 32 newborns (14 girls; M = 25.6hr) who were videorecorded in the behavioral states of alertness, drowsiness, active sleep, and quiet sleep.
Abstract: To better understand the form and recognizability of neonatal smiling, 32 newborns (14 girls; M = 25.6 hr) were videorecorded in the behavioral states of alertness, drowsiness, active sleep, and quiet sleep. Baby Facial Action Coding System coding of both lip corner raising (simple or non-Duchenne) and lip corner raising with cheek raising (Duchenne smile) was followed by a smile recognition task using 48 naive observers. Both types of smiles were detected in all behavioral states. Lip corner raising with cheek raising (Duchenne smiling) tended to predominate in active (rapid eye movement) sleep, suggesting a potential tie to early constituents of emotion. A significant portion of the typically briefer lip corner raising distinguished by expert coders was not recognized as smiling by the naive observers. These briefer actions may represent a motor phenomenon idiosyncratic to the neonatal period.
TL;DR: The hybrid variant proved to be the most successful in detecting statistically significant discrimination inindividual infants (8 out of 10), suggesting that both the oddity and the stimulus alternation features contribute to providing a robust methodology for assessing discrimination in individual infants.
Abstract: Assessing speech discrimination skills in individual infants from clinical populations (e.g., infants with hearing impairment) has important diagnostic value. However, most infant speech discrimination paradigms have been designed to test group effects rather than individual differences. Other procedures suffer from high attrition rates. In this study, we developed 4 variants of the Visual Habituation Procedure (VHP) and assessed their robustness in detecting individual 9-month-old infants' ability to discriminate highly contrastive nonwords. In each variant, infants were first habituated to audiovisual repetitions of a nonword (seepug) before entering the test phase. The test phase in Experiment 1 (extended variant) consisted of 7 old trials (seepug) and 7 novel trials (boodup) in alternating order. In Experiment 2, we tested 3 novel variants that incorporated methodological features of other behavioral paradigms. For the oddity variant, only 4 novel trials and 10 old trials were used. The stimulus alter...
TL;DR: This article examined how these factors interact on the moment-to-moment time scale of the training children receive and the sequence of stimuli they are shown, and found that children's generalizations on individual trials are influenced by what they have seen and done on previous trials.
Abstract: Recent research on early word learning suggests that children's behavior when-generalizing novel nouns integrates their prior vocabulary knowledge with the specifics of the task. This study examines how these factors interact on the moment-to-moment time scale of the training children receive and the sequence of stimuli they are shown. In ***1 condition, we used a combination of training and stimulus factors predicted to produce a bias to generalize nouns by shape similarity. We then reduced this shape bias and amplified a bias to generalize nouns by material similarity via manipulations of training and stimuli across 3 other conditions. Additional analyses suggest that children's generalizations on individual trials are influenced by what they have seen and done on previous trials. These results highlight the importance of the task and stimuli in bringing children's prior knowledge to bear in early word learning.
TL;DR: This article examined toddlers' performance on a new task designed to examine the development of body self-awareness and found significant improvement with age in performance for the self-version of the task that was not matched by similar age differences in the weight task.
Abstract: Two experiments examined toddlers’ performance on a new task designed to examine the development of body self-awareness. The new task was conceived from observations by Piaget (1953/1977) and theoretical work from Povinelli and Cant (1995) and involved a toy shopping cart to the back of which a small mat had been attached. Children were asked to push the cart to their mothers but in attempting to do so they had to step on the mat and in consequence, their body weight prevented the cart from moving. In the first experiment, performance on the shopping cart task was examined in children of 16 and 21 months both when the self was the obstacle and when a heavy weight was the obstacle. Results showed significant improvement with age in performance for the self-version of the task that was not matched by similar age differences in the weight task. In the second experiment, children's performance on both the self-version of the shopping cart and on a standard mirror self-recognition task was assessed. R...
TL;DR: This study investigated whether acoustic input, in the form of infant-directed speech, influenced infants' segmenting of action sequences, and heard during familiarization influenced how infants viewed the action units.
Abstract: This study investigated whether acoustic input, in the form of infant-directed speech, influenced infants' segmenting of action sequences. Thirty-two 7.5- to 11.5-month-old infants were familiarized with video sequences made up of short action clips. Narration coincided with portions of the action stream to package certain pairs of clips together. At test, packaged and nonpackaged pairs of actions were presented side by side in silence. Narration heard during familiarization influenced how infants viewed the action units, such that at test, infants older than 9.5 months (but not younger) looked longer at the nonpackaged than the packaged action sequences. The role of infant-directed speech as well as other types of acoustic input in assisting infants' processing of action is discussed.
TL;DR: Investigation of characteristics of vocalizations associated with mouthing in 6- to 9-month-old infants during play with a primary caregiver suggests that mOUthing may influence the phonetic characteristics ofocalizations by introducing vocal tract closure and variation in consonant production.
Abstract: Although vocalization and mouthing are behaviors frequently performed by infants, little is known about the characteristics of vocalizations that occur with objects, hands, or fingers in infants' mouths. The purpose of this research was to investigate characteristics of vocalizations associated with mouthing in 6- to 9-month-old infants during play with a primary caregiver. Results suggest that mouthing may influence the phonetic characteristics of vocalizations by introducing vocal tract closure and variation in consonant production.
TL;DR: For instance, the authors found that infants preferred to look at the experimenter in almost all conditions and they regulated their behavior in accordance with information obtained from the experimenters. But none of the studies lends support for an explanation in terms of behaviors deriving from the attachment system, and they raise questions concerning social referencing interpretations of infants' looking behavior.
Abstract: Is infant looking behavior in ambiguous situations best described in terms of information seeking (social referencing) or as attachment behavior? Twelve-month-old infants were assigned to 1 of 2 conditions (Study 1); each infant's mother provided positive information about an ambiguous toy and an experimenter provided positive information. In Study 2, 12-month-old infants were assigned to 1 of 3 conditions: mother provided positive information about the toy, mother was inattentive, or mother provided negative information; the experimenter was inattentive. The infants preferred to look at the experimenter in almost all conditions and they regulated their behavior in accordance with information obtained from the experimenter. None of the studies lends support for an explanation in terms of behaviors deriving from the attachment system, and they raise questions concerning social referencing interpretations of infants’ looking behavior. Other alternatives for explaining infant looking behavior in soc...
TL;DR: In this paper, the authors evaluated the acoustic properties of 14 infants at both 2 and 4 weeks of age when lying in a supine position and when they were sitting upright in a car seat.
Abstract: Acoustic properties of the cries of 14 infants were evaluated at both 2 and 4 weeks of age when the infants were lying in a supine position and when they were sitting upright in a car seat. In the upright position, infants’ breathing was more rapid and showed less individual variability. The fundamental frequency of their cries increased in the upright position, but this increase was likely attributable to increased arousal or distress, not to posture per se. There were no differences in acoustic measures related to vocal tract shape in the supine versus upright positions. Across age, there was a decline in fundamental frequency. Individual difference stability of most acoustic measures was moderate to high. The importance of postural effects on the acoustic features of cries was discussed.
TL;DR: Infants' object recognition is enhanced by experience with multiple views, even when that experience is around an orthogonal axis of rotation, and infants are sensitive to even subtle shape differences between components of similar objects.
Abstract: This work examined predictions of the interpolation of familiar views (IFV) account of object recognition performance in 5-month-olds. Infants were familiarized to an object either from a single viewpoint or from multiple viewpoints varying in rotation around a single axis. Object recognition was then tested in both conditions with the same object rotated around a novel axis. Infants in the multiple-views condition recognized the object, whereas infants in the single-view condition provided no evidence for recognition. Under the same 2 familiarization conditions, infants in a 2nd experiment treated as novel an object that differed in only 1 component from the familiar object. Infants' object recognition is enhanced by experience with multiple views, even when that experience is around an orthogonal axis of rotation, and infants are sensitive to even subtle shape differences between components of similar objects. In general, infants' performance does not accord with the predictions of the IFV model of object recognition. These findings motivate the extension of future research and theory beyond the limits of strictly interpolative mechanisms.
TL;DR: The results of this study indicate that infants whose mothers showed a greater contribution to reducing their distress at 2 months showed a shorter duration of crying 4 months later, suggesting a possible longitudinal influence of maternal regulation on infants' distress responses.
Abstract: This study investigates individual differences in the contribution of specific maternal regulatory behaviors to the mother-infant dyad's regulation of infant distress response. Additionally, we examined the stability of infants' stress responses and the stability of specific maternal soothing behaviors. The sample included 128 mother-infant dyads that were observed during an inoculation at 2 and 6 months. The average intensity of infant cry response showed modest stability across age only before controlling for the infant's general state of irritability, and the duration of crying was not stable. Of the 8 specific maternal regulatory behaviors studied, affection, touching, and vocalizing showed the strongest stability across infant age. Finally, an index of the contingency between maternal soothing and infant cry reduction at 2 months predicted shorter cry duration but not cry intensity at 6 months. The results of this study indicate that infants whose mothers showed a greater contribution to reducing their distress at 2 months showed a shorter duration of crying 4 months later. This suggests a possible longitudinal influence of maternal regulation on infants' distress responses.
TL;DR: Results indicated that, on average, infants who were exposed to higher levels of prenatal smoking exhibited less positive affect and greater irritability, and there was no evidence that the effects of prenatal exposure to smoking on infant neurobehavioral functioning were mediated by physical growth paramete...
Abstract: Between 400,000 and 800,000 infants are born in the United States each year to women who smoked cigarettes during their pregnancy. Whereas the physical health consequences to infants of prenatal exposure to smoking are well established, the early neurobehavioral consequences are less well understood. This study investigated the neurobehavioral consequences of prenatal exposure to smoking using an epidemiologically derived sample of 454 infants who were drawn from a larger sample of 1,292 infants whose families were recruited at birth. Results indicated that, on average, infants who were exposed to higher levels of prenatal smoking exhibited less positive affect and greater irritability. Moreover, among male infants, elevated levels of prenatal exposure to smoking were associated with lower levels of approach, gross motor movement, reactivity, and attention. There was no evidence that the effects of prenatal exposure to smoking on infant neurobehavioral functioning were mediated by physical growth paramete...
TL;DR: The hypothesis that toddlers interpret an adult's head turn as evidence that the adult was looking at something, whereas younger infants interpret gaze based on an expectancy that an interesting object will be present on the side to which the adult has turned is examined.
Abstract: This study examined the hypothesis that toddlers interpret an adult's head turn as evidence that the adult was looking at something, whereas younger infants interpret gaze based on an expectancy that an interesting object will be present on the side to which the adult has turned. Infants of 12 months and toddlers of 24 months were first shown that an adult head turn to the side predicted the activation of a remote-controlled toy on that side of the room. After this connection had been demonstrated, participants were assigned to 2 conditions. In the head turn condition the toys were removed but the adult continued to produce head turns to the side. In the toy condition the adult stopped turning but the toys continued to be activated when the participant turned toward them. Results showed that, compared to 12-month-olds, 24-month-olds were more likely to continue to turn to the side when the adult continued to turn even though there was no longer anything of interest to see. In contrast, compared to 24-month-olds, 12-month-olds were, if anything, more likely to continue to turn to the side in the condition in which the adult stopped turning. The latter result was replicated in a condition in which the activation of the toy was not contingent on the child's own head turn. These results imply that the meaning of gaze following may change significantly over the 2nd year of life. For 12-month-olds, gaze is a useful predictor of where interesting sights may occur. In contrast, for 24-month-olds, gaze may be a signal that the adult is looking at something.
TL;DR: Investigating the relation among vocabulary size, object recognition, and 24-month-olds' willingness to accept potentially surprising testimony about the category to which an object belongs showed that children with larger vocabularies were better able to recognize atypical exemplars of familiar categories than children with smaller vocABularies.
Abstract: Children must be willing to accept some of what they hear “on faith,” even when that testimony conflicts with their own expectations. The study reported here investigated the relation among vocabulary size, object recognition, and 24-month-olds' (N = 40) willingness to accept potentially surprising testimony about the category to which an object belongs. Results showed that children with larger vocabularies were better able to recognize atypical exemplars of familiar categories than children with smaller vocabularies. However, they were also most likely to accept unexpected testimony that an object that looked like a member of one familiar category was actually a member of another. These results indicate that 24-month-olds trust classifications provided by adult labeling patterns even when they conflict with the classifications children generate on their own.
TL;DR: It is found that 4- to 5-month-old infants do indeed discriminate hits versus misses, and a novel result regarding the path of the approaching object is found.
Abstract: This experiment investigated the impact of the path of approach of an object, from head on versus from the side, and the type of imminent contact with that object, a hit versus a miss, on young infants' perceptions of object looming. Consistent with earlier studies, we found that 4- to 5-month-old infants do indeed discriminate hits versus misses. We also found a novel result regarding the path of the approaching object. The discrimination of hits from misses was modified by whether or not the approaching objects passed in front of the infants' faces; objects crossing the line of sight evoked more frequent defensive reactions than objects that did not cross the line of sight, regardless of whether or not such objects were on a collision course. These findings are discussed within the context of the development of visually guided locomotion and linear versus nonlinear paths of translation through the world.
TL;DR: Infants as young as 3 to 4 months of age are not only sensitive to regions in visual images, but also use these regions to group elements in accord with the principle of common region, which is critical to such basic visual functions as figure-ground and object segregation.
Abstract: We examined whether infants organize information according to the newly proposed principle of common region, which states that elements within a region are grouped together and separated from those of other regions. In Experiment 1, 6- to 7-month-olds exhibited sensitivity to regions by discriminating between the displacement of an element within a region versus across regions. In Experiments 2 (6- to 7-month-olds) and 3 (3- to 4-month-olds), infants who were habituated to 2 elements in each of 2 regions subsequently discriminated between a familiar and novel grouping in familiar and novel regions. Thus, infants as young as 3 to 4 months of age are not only sensitive to regions in visual images, but also use these regions to group elements in accord with the principle of common region. Because common region analysis is critical to such basic visual functions as figure-ground and object segregation, these results suggest that the organizational mechanism that underlies many vital visual functions is already operational by 3 to 4 months of age.
TL;DR: This study examined infants' use of object knowledge for scaling the manipulative force of object-directed actions by outfitted with motion-analysis sensors on their arms and presented with stimulus objects to examine individually over a series of familiarization trials.
Abstract: This study examined infants' use of object knowledge for scaling the manipulative force of object-directed actions. Infants 9, 12, and 15 months of age were outfitted with motion-analysis sensors on their arms and then presented with stimulus objects to examine individually over a series of familiarization trials. Two stimulus objects were used in the familiarization phase, and were identical in size, shape, and material, but different in color and weight. Following familiarization, two test objects that had been hidden from view were presented. The test objects were identical in appearance to the familiarization objects, but their color-weight correspondence was reversed. Infants' actions on the test objects revealed selective, differential preparation for the specific weights experienced during familiarization. Because the objects were equivalent in their visual affordances for action, the differential preparation and coordination of manipulative force was based on knowledge acquired during the familiar...
TL;DR: In this paper, 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 conditions varying whether motion or feature information about the faces was available.
Abstract: 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 conditions varying whether motion or feature information about the faces was available. The faces were presented in a still or dynamic video image with either a positive or a negative contrast. In each condition, infants habituated to a stranger's face and then viewed, in 3 pairs of alternating novelty test trials, either a new stranger or their mother's face. Results show that motion information contributes to the 8-month-old infants', but not the 4-month-old infants' discrimination of maternal faces. These results are interpreted in relation to recent findings and models in the adult literature suggesting that there is an enhanced contribution of dynamic informa...
TL;DR: This paper found that individual differences in infants' proximity-seeking behaviors during interactions with the mother correlate with their neurophysiological responses to the mother's face as opposed to an unfamiliar face for the Nc component of t...
Abstract: 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 age is frequently noted in the behavioral and neurophysiological literature as a time of transition in which infants begin to discriminate more readily between caregivers and unfamiliar adults. We used infants' behavioral responses to an original behavioral paradigm to predict event-related potential (ERP) responses to pictures of the mother's face and a stranger's face in the same group of participants. Our results suggest that individual differences in infants' proximity-seeking behaviors during interactions with the mother correlate with their neurophysiological responses to the mother's face as opposed to an unfamiliar face for the Nc component of t...