Three Randomized Controlled Trials of Early Long-Chain Polyunsaturated Fatty Acid Supplementation on Means-End Problem Solving in 9-Month-Olds

This study examines whether feeding infants formula supplemented with long-chain polyunsaturated fatty acids (LCPUFA) improves cognitive function of 9-month-olds. Participants included 229 infants from 3 randomized controlled trials. Children received either formula supplemented with docosahexaenoic acid and arachidonic acid, or a control formula beginning at 1–5 days (12-month feeding study), or following 6 weeks (6-week-weaning study) or 4–6 months of breastfeeding (4-to 6-month weaning study). Infants were assessed with a 2-step problem solving task. In the 12-month feeding and 6-week weaning studies, supplemented children had more intentional solutions (successful task completions) and higher intention scores (goal-directed behaviors) than controls. These results suggest that LCPUFA supplementation improves means-end problem solving.     

Infant Auditory Temporal Acuity: Gap Detection

The development of auditory temporal acuity during infancy was examined in 3-, 6-, and 12-month-old infants and in adults using the gap detection paradigm. Listeners detected a series of gaps, or silent intervals, or variable duration in a broadband noise. In order to vary the acoustic frequencies available to the listener, a high-pass noise was used to mask frequencies above specified cutoffs. High-pass maskers with cutoffs of 500, 2,000, and 8,000 Hz were used. The minimum detectable gap was determined using the Observer-based Psychoacoustic Procedure. The thresholds of 3- and 6-month-olds were considerably poorer than those of the adults, although the effect of masker condition was about the same for these 3 groups. The thresholds of 12-month-olds were significantly worse than the adults when the stimulus was unmasked or when the masker cutoff frequency was 2,000 or 8,000 Hz. When the masker cutoff frequency was 500 Hz, 12-month-olds fell into 2 groups: some had gap thresholds that were about the same as 3- and 6-month-olds, while some had gap thresholds that approached those of adults. In a second experiment, a larger group of 12-month-olds were tested with a 500-Hz masker cutoff. Average performance of 12-month-olds was about the same as that of 3- and 6-month-olds in Experiment 1. Some infants attained thresholds close to those of adults. Thus, gap detection thresholds are quite poor in infants, although the similarity of the effect of frequency on performance in infants and adults suggests that the mechanisms governing temporal resolution in infants operate qualitatively like those in adults.     

Emerging Integration of Sequential and Suprasegmental Information in Preverbal Speech Segmentation

5 studies examined contributions of syllable-ordering and rhythmic properties of syllable strings to 6- and 9-month-old infants' speech segmentation. A pair of methods measuring complementary properties of representational units was used: a noise detection task sensitive to perceived cohesiveness of pairs of syllables, and a discrimination maintenance task sensitive to compactness of representations of syllable pairs. For 9-month-olds, results show that a key pair of syllables was represented as a unit when the grouping of these syllables was supported by correlated regularities of ordering and rhythm in the set of stimulus strings, but not when such grouping was supported by only rhythmic or only syllable-ordering regularity. For 6-month-olds, results show that a key pair of syllables was represented as a unit whenever grouping was supported by rhythmic regularity in the stimulus strings, regardless of whether syllable-ordering regularity was also present. Thus, whereas 9-month-olds appear to be capable of integrating sequential and suprasegmental information in forming wordlike (multisyllabic) phonological percepts, 6-month-olds are not. The emergence of integrative abilities portends increased efficiency in speech processing and may contribute to the formation and use of an initial lexicon.     

Evaluation of a Practice-Development Initiative to Improve Breastfeeding Rates

The benefits of breastfeeding for infant, mother, family, and community are well recognized, and increasing breastfeeding rates is considered an important health-promotion strategy. Improving breastfeeding knowledge and practice among individuals caring for breastfeeding women is considered an important aspect of this strategy. The practice-development initiative described in this article aimed to improve hospital-based breastfeeding rates through the implementation of The Ten Steps to Successful Breastfeeding. The initiative included the development and implementation of an education program aimed at changing and improving breastfeeding practices. The program was evaluated in three ways: changes in breastfeeding rates at hospital discharge; client preparation for breastfeeding and satisfaction during the postnatal period; and staff knowledge and skills.     

Developmental and Temperamental Differences in Emotion Regulation in Infancy

One of the major adaptations during the infancy period is the development of the ability to cope with arousing or uncertain events. The following study was designed to examine emotion regulation strategy use between 6 and 18 months. 75 infants (25 each of 6-, 12-, and 18-month-olds) were videotaped interacting with 3 female strangers. Coping strategies were coded using a portable computer with a continuous sampling program, enabling coders to record both frequencies and durations of behaviors. Results indicated that 6-month-olds were more likely than 12- or 18-month-olds to use gaze aversion and fussing as their primary emotion regulation strategies, and were less likely than the older infants to use self-soothing and self-distraction. 18-month-olds were more likely than the younger infants to attempt to direct their interactions with the strangers. Infants' strategy use also differed as a function of their wariness of strangers, particularly at 12 months of age.     

Preverbal infants anticipate that food will be brought to the mouth: an eye tracking study of manual feeding and flying spoons

This study relies on eye tracking technology to investigate how humans perceive others' feeding actions. Results demonstrate that 6-month-olds (n = 54) anticipate that food is brought to the mouth when observing an adult feeding herself with a spoon. Still, they fail to anticipate self-propelled (SP) spoons that move toward the mouth and manual combing actions directed toward the head. Ten-month-olds (n = 54) and adults (n = 32) anticipate SP spoons; however, only adults anticipate combing actions. These results suggest that goal anticipation during observation of feeding actions develops earlier and is less dependent on directly perceived actions than goal anticipation during observation of other manual actions. These results are discussed in relation to experience and a possible phylogenetic influence on perception and understanding of feeding.     

Visual Guidance in Infants' Reaching toward Suddenly Displaced Targets

This experiment evaluated the role of visual input about the location of a target object and the location of the hand in reaching by infants and adults. 5- and 9-month-old infants were presented with illuminated toys to reach for in a dark room. On no-switch trials, the toy remained illuminated throughout the infant's reach, whereas on switch trials the first-lit toy was replaced during the reach by a second-lit toy at a different position. On approximately half of the trials of each type a luminescent marker was attached to the reaching hand. Adult subjects (tested without the hand marker) fully compensated to the second-lit toy on switch trials, during a second reaching segment. On switch trials, 9-month-olds partially adjusted to the second-lit toy when wearing the hand marker and did not adjust without it. On no-switch trials, 9-month-olds reached just as accurately with or without the hand marker. 5-month-olds were generally inaccurate in their reaching and were unaffected by the presence or absence of the hand marker. The findings suggest that during the development of reaching there is an increase in visual guidance during the approach phase of reaches.     

Pointing at objects in other rooms: young children's sensitivity to perspective after walking with and without vision

Locomotion alters the spatial structure of an observer's perspective, that is, the network of observer to environment distances and directions. The purpose of the present 6 experiments was to investigate the sensitivity of 12-48-month-olds to changes in perspective that are occluded from view by walls and by darkness. To assess sensitivity, children were shown a target object in one room, walked into an adjacent room and asked to point in the straight-line direction at the target. In Experiment 1, 42 12-48-month-olds were tested and results indicated that children older than 36 months responded by pointing straight at the occluded target, whereas younger children tended to point in the direction of their route away from the target. In Experiments 2-4, 24- and 48-month-olds were tested and results demonstrated that 48-month-olds were sensitive to the proprioceptive and to the visual-environmental cues for the changes in perspective structure. The 24-month-olds, however, responded by pointing straight toward the target when visual-environmental cues were absent, whereas they pointed in the direction of their route when they were present. In Experiments 5 and 6 additional 24-month-olds were tested to assess the effects of short-term training and of a continuous view of the target on responding in the presence of visual-environmental cues. The results indicated relatively early sensitivity to proprioceptive cues for changes in perspective and somewhat later sensitivity to appropriate visual-environmental cues under these conditions.     

Factors associated with exclusive breastfeeding 2 to 4 weeks following discharge from a large, urban, academic medical center striving for baby-friendly designation

Substantial evidence documents the superiority of breastfeeding for mothers and breastmilk for babies. Although the American Academy of Pediatrics and the U.S. Healthy People 2010 initiative promote breastfeeding, current breastfeeding rates often fall short of recommendations. This study determined factors associated with exclusive breastfeeding 2 to 4 weeks following discharge from a large, urban, academic medical center striving for Baby-Friendly designation. Results indicated that mothers who breastfed within the first hour of birth (61%) were significantly more likely to be exclusively breastfeeding 2 to 4 weeks after discharge. Incorporating care practices that include a number of the "Ten Steps to Successful Breastfeeding," as recommended by the Baby-Friendly Hospital Initiative, may increase the duration of exclusive breastfeeding after discharge.     

Analysis and Application of the Concept of Modesty to Breastfeeding

Modesty may be a significant variable impacting breast- feeding outcomes in western cultures, yet this term has received minimal attention in the breastfeeding literature. An analysis of the concept of modesty was conducted to gain greater understanding of the potential impact of modesty on breastfeeding outcomes. Various uses of the term modesty and particularly modesty in the context of breastfeeding are discussed in this paper. The defining attributes of breastfeeding modesty are identified and examples are provided. Implications for research and clinical practice are suggested.     

The early childhood aggression curve: development of physical aggression in 10- to 50-month-old children

This study examines the prevalence, stability, and development of physical aggression, as reported by mothers and fathers, in a sample of children initially recruited at 12, 24, and 36 months (N=2,253) and in a subsample followed up 1 year later (n=271) in a cross-sequential design. Physical aggression occurred in 12-month-olds, but significantly more often in 24- and 36-month-olds. The rates of physically aggressive behaviors increased in the 2nd year of life, and declined from the 3rd birthday onward. Stabilities were moderate for 12-month-olds and high for 24- and 36-month-olds. At the ages of 24 and 36 months, boys were more aggressive than girls. The results confirm and extend R.E. Tremblay's (2004) hypothesis about the early development of physical aggression.     

Predicting breastfeeding duration related to maternal attitudes in a taiwanese sample

The purpose of this study was to examine maternal attitudes and sociodemographic variables associated with Taiwanese mothers' continuation of breastfeeding at 6 weeks postpartum. A sample of 140 in-hospital breastfeeding mothers was recruited in Taiwan. Participants completed the Iowa Infant Feeding Attitude Scale (IIFAS) in the hospital prior to discharge. Postdischarge participants were contacted by telephone at 3 and 6 weeks postpartum to obtain information regarding their feeding method and duration. Findings revealed that in-hospital maternal breastfeeding attitudes are predictive of breastfeeding duration. Insufficient milk supply was the reason most often given for discontinuing breastfeeding. Women's husband/partner was found to be the main source of breastfeeding support. We recommend health-care professionals add the IIFAS to their assessment to identify mothers at high risk for discontinuing breastfeeding and to develop and better evaluate breastfeeding promotion programs.     

Two-year-olds use the generic/nongeneric distinction to guide their inferences about novel kinds

These studies investigated two hundred and forty-four 24- and 30-month-olds' sensitivity to generic versus nongeneric language when acquiring knowledge about novel kinds. Toddlers were administered an inductive inference task, during which they heard a generic noun phrase (e.g., "Blicks drink milk") or a nongeneric noun phrase (e.g., "This blick drinks milk") paired with an action (e.g., drinking) modeled on an object. They were then provided with the model and a nonmodel exemplar and asked to imitate the action. After hearing nongeneric phrases, 30-month-olds, but not 24-month-olds, imitated more often with the model than with the nonmodel exemplar. In contrast, after hearing generic phrases, 30-month-olds imitated equally often with both exemplars. These results suggest that 30-month-olds use the generic/nongeneric distinction to guide their inferences about novel kinds.     

Two- to eight-month-old infants' perception of dynamic auditory-visual spatial colocation

From birth, infants detect associations between the locations of static visual objects and sounds they emit, but there is limited evidence regarding their sensitivity to the dynamic equivalent when a sound-emitting object moves. In 4 experiments involving thirty-six 2-month-olds, forty-eight 5-month-olds, and forty-eight 8-month-olds, we investigated infants' ability to process this form of spatial colocation. Whereas there was no evidence of spontaneous sensitivity, all age groups detected a dynamic colocation during habituation and looked longer at test trials in which sound and sight were dislocated. Only 2-month-olds showed clear sensitivity to the dislocation relation, although 8-month-olds did so following additional habituation. These results are discussed relative to the intersensory redundancy hypothesis and work suggesting increasing specificity in processing with age.     

Location, location, location: development of spatiotemporal sequence learning in infancy

We investigated infants' sensitivity to spatiotemporal structure. In Experiment 1, circles appeared in a statistically defined spatial pattern. At test 11-month-olds, but not 8-month-olds, looked longer at a novel spatial sequence. Experiment 2 presented different color/shape stimuli, but only the location sequence was violated during test; 8-month-olds preferred the novel spatial structure, but 5-month-olds did not. In Experiment 3, the locations but not color/shape pairings were constant at test; 5-month-olds showed a novelty preference. Experiment 4 examined "online learning": We recorded eye movements of 8-month-olds watching a spatiotemporal sequence. Saccade latencies to predictable locations decreased. We argue that temporal order statistics involving informative spatial relations become available to infants during the first year after birth, assisted by multiple cues.     

Individual and Developmental Differences in Disengagement of Fixation in Early Infancy

The current study investigated whether individual and developmental differences in look duration are correlated with the latency for infants to disengage fixation from a visual stimulus. Ninety-four infants (52 3-month-olds, 42 4-month-olds) were tested in a procedure that measured ocular reaction time to shift fixation from a central target to a peripheral target under conditions in which the central-target either remained present ("competition" condition) or was removed from the display ("noncompetition" condition). Look duration was correlated with disengagement latency; longer-looking infants were slower than shorter-looking infants to shift fixation to the peripheral target on competition trials, but not noncompetition trials. Results were similar for 3- and 4-month-olds, although 3-month-olds showed slower latencies on all trials. Furthermore, long-looking infants were not consistently slower, but rather showed greater variability in their response latencies under conditions that required disengagement of fixation. The results support the position that developmental and individual differences in look duration are linked to the development of the neural attentional systems that control the ability to disengage, or inhibit, visual fixation.     

Vagal Regulation in Breastfeeding Infants and Their Mothers

Consistent with the gustatory–vagal hypothesis, vagal stimulation during breastfeeding may contribute to infants' physiological regulatory development independent of caregiving effects. This study examined whether breastfeeding predicted 6‐month‐old infants' (N = 151) and their mothers' vagal regulation during the face‐to‐face still‐face (FFSF). Although breastfed and nonbreastfed infants showed expected vagal withdrawal during the Still‐Face episode, only breastfed infants showed continued withdrawal during the reunion episode, suggesting greater physiological mobilization to repair the interaction. Breastfeeding mothers showed higher vagal tone than nonbreastfeeding mothers at baseline, suggesting greater capacity for regulation, and throughout the FFSF, suggesting calmer states. Breastfeeding effects were independent of maternal sensitivity. Findings suggest that infants' and mothers' physiological regulation may be shaped by breastfeeding independently of associated social factors.     

Parameters of remembering and forgetting in the transition from infancy to early childhood

The ability to recall is something that most intact adults take for granted. For much of the last century, this feature of mental life was not considered to extend to very young children. There now is evidence that 1- to 2-year-olds are able to recall specific events after delays of several months. Over the short term, 1- to 2-year-olds' recall is affected by the same factors that affect older children's recall; it is not clear whether similar effects are apparent over the long term. Moreover, although age-related increases in long-term recall are assumed, there have been few empirical tests of the question. We examined recall by 14- to 32-month-olds for events experienced at 13 to 20 months. Using elicited imitation of novel multistep event sequences we examined effects of (a) delay length, (b) age at the time of experience, (c) temporal structure of events, (d) mode of experience of events, and (e) availability of verbal reminders, on long-term recall. Participants were 360 children enrolled at 13 (n = 90), 16 (n = 180), and 20 (n = 90) months. All of the 13-month-olds and half of the 16-month-olds were tested on 3-step event sequences; all of the 20-month-olds and half of the 16-month-olds were tested on 4-step event sequences. Within each age and step-length group, equal numbers of children were tested after intervals of 1, 3, 6, 9, and 12 months (n = 18 per cell). Children were tested on a variety of sequence types. For half of the events, imitation was permitted prior to the delay; for the other half, children were not permitted imitation. At delayed testing, children experienced a recall period during which they were cued by the event-related props alone, followed by a period in which recall was cued both by the event-related props and by verbal labels for the event sequences. Within step-length groups, the length of time for which older and younger children showed evidence of memory did not differ. Nevertheless, when the children were prompted by the event-related props alone, there were age-related differences in the robustness of children's memories (as indexed by higher levels of recall for older children relative to younger children). When the children were prompted by the props and by verbal labels for the event sequences, at the longer retention intervals, there were age-related differences in the robustness of children's memories and in the reliability with which recall was evidenced (as indexed by the larger numbers of older children evincing recall). Age-related effects were particularly apparent on children's ordered recall. Across the entire age range, the children were similarly affected by the variables of sequence type, opportunity for imitation, and verbal reminding.     

The infant as onlooker: learning from emotional reactions observed in a television scenario

Two studies investigated whether 10- and 12-month-olds can use televised emotional reactions to guide their behavior. Infants watched an actress orient toward 1 of 2 novel objects and react with neutral affect during baseline and with positive or negative affect during test. Infants then had 30 s to interact with the objects. In Study 1, 12-month-olds (N = 32) avoided the target object and showed increases in negative affect after observing the negative-emotion scenario. Twelve-month-olds' responses to positive vs. neutral signals did not differ significantly. In Study 2, 10-month-olds (N = 32) attended to the televised presentations but showed no consistent changes in their object interactions or affect. Thus, 12-month-olds used social information presented on television and associated emotional signals with the intended target.