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This prospective study examined the latent growth trajectories of sensory patterns among a North Carolina birth cohort (N = 1517; 49% boys, 87% White) across infancy (6–19 months), preschool (3–4 years), and school years (6–7 years). Change rates of sensory hyper‐ and hyporesponsiveness better differentiated children with an autism diagnosis or elevated autistic traits from those with other developmental conditions, including non‐autistic children with sensory differences. More sensory hyper‐ and hyporesponsiveness at infancy followed by steeper increases differentially predicted more autistic traits at school age. Further, children of parents with higher education tended to show stable or improving trajectories. These findings highlight the importance of tracking sensory patterns from infancy for facilitating early identification of associated challenges and tailored support for families. [ABSTRACT FROM AUTHOR]

Background: Lead is a pervasive neurotoxicant that has been associated with poorer cognitive, behavioral, and motor outcomes in children. The effects of lead on sensory function have not been well characterized. The aim of this study was to assess the effects of prenatal lead exposure on infant sensory function, as measured by auditory brainstem response (ABR) and grating visual acuity (VA).Methods: Lead was measured in maternal blood in mid- and late-pregnancy (mean gestational age = 15.5 and 39.0 weeks, respectively) and umbilical cord blood in a cohort of full-term infants in rural northeastern China. ABR latencies (peaks I, III, V) were measured in newborns during unsedated sleep (n = 315). The ABR central-to-peripheral (C-P) ratio was calculated as the ratio between the III-V and I-III interpeak intervals. VA was measured in 6-week-olds using Teller Acuity Cards (n = 1019) and assigned as the narrowest grid the infant fixated on. Multivariate linear regression was used to evaluate relationships between tertiles of mid-pregnancy, late-pregnancy, or cord lead and newborn ABR or 6-week VA.Results: Higher late-pregnancy lead levels were associated with higher ABR C-P ratios and lower VA. In covariate-adjusted analyses, mean C-P ratios were 4.6 and 3.2 % higher in infants whose mothers had lead > 3.8 μg/dL and lead = 2-3.8 μg/dL, respectively, than for infants whose mothers had lead < 2 μg/dL (p-trend =0.002). In adjusted analyses for VA, mean scores were 8.5 and 7.2 % lower for maternal lead > 3.8 μg/dL and lead = 2-3.8 μg/dL, respectively, compared to lead < 2 μg/dL (p-trend =0.009).Conclusion: Auditory and visual systems maturation appears delayed in infants with higher prenatal lead exposure during late-pregnancy, even at relatively low levels. Both systems start myelinating in late gestation and mature rapidly in infancy. Higher ABR C-P ratio and lower grating VA scores suggest effects of low-level lead exposure on sensory system myelination. [ABSTRACT FROM AUTHOR]

Objective. The aim of this study was to evaluate the effect of gentle tactile stimulation on the fetus in its temperament 3 months after birth. Method. A total of 302 mother-3-month-infant dyads enrolled the retrospective cohort study. 76 mothers had regular gentle tactile stimulation on the fetus in their pregnancy; 62 mothers had irregular tactile stimulation on the fetus, and the rest of 164 mothers who had no tactile stimulation served as nonexposure group. Temperament was assessed using the EITS (a nine-dimensional scale of temperament). Results. Significant difference in temperament type was found among infants in 3 groups at 3 months of age. In the regular practice group, the babies with easy type temperament accounted for 73.7%, which was higher than that in irregular practice group (53.2%, P=0.012) and that in the control group (42.1%, P<0.001). Compared to infants in no practice group, the infants who had received regular gentle tactile stimulation before birth were lower in negative mood (P=0.047) while higher in adaptability (P<0.001), approach (P=0.001), and persistence (P=0.001), respectively. Conclusion. Regular gentle tactile stimulation on fetus may promote the formation of easy type infant temperament. [ABSTRACT FROM AUTHOR]

Research on neonatal cognition has developed very recently in comparison with the long history of research on child behavior. The last sixty years of research have provided a great amount of evidence for infants' numerous cognitive abilities. However, only little of this research concerns newborn infants. What do we know about neonatal cognition? Using a variety of paradigms, researchers became able to probe for what newborns know. Amongst these results, we can distinguish several levels of cognitive abilities. First, at the perceptual or sensory level, newborns are able to process information coming from the social world and the physical objects through all their senses. They are able to discriminate between object shapes and between faces; that is, they are able to detect invariants, remember and recognize them. Second, newborns are able to abstract information, to compare different inputs and to match them across different sensory modalities. We will argue that these two levels can be considered high-level cognitive abilities: they constitute the foundations of human cognition. Furthermore, while some perceptual competencies can stem from the fetal period, many of these perceptual and cognitive abilities cannot be a consequence of the environment surrounding the newborn before birth. [ABSTRACT FROM AUTHOR]

The developing infant learns about the physical and the social world by engaging with objects and with people. In the study reported here, we investigated the relationship between infants' interactions with the physical and the social world. Three-month-old infants were trained for 2 weeks and experienced either actively manipulating objects themselves or passively having objects touched to their hands. Following active or passive experiences, spontaneous orienting towards faces and objects was compared between the trained groups and untrained 3- and 5-month-olds. It is known that the onset of reaching behavior increases infants' interest in objects. However, we report that active, self-produced reaching experiences also increase infants' spontaneous orienting towards faces, while passive experiences do not affect orienting behavior. Regression analyses provide evidence for a link between manual engagement and the development of orienting towards faces. Implications of orienting towards faces for the development of triadic interactions, joint attention, and social cognition in general are discussed. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we examined 4.5-month-old infants'' visual completion of self-occluding three-dimensional objects. A previous study on this topic reported that 6-month-old, but not 4-month-old infants extrapolate a convex, symmetric prism from a limited view of its surfaces (Soska & Johnson, 2008). As of yet, studies on the development of amodal completion of three-dimensional, self-occluding objects are scarce. Given 4-month-old infants'' abilities to derive three-dimensional shape from a variety of visual cues, three-dimensional amodal completion may well depend on the perceptual strength of three-dimensionality in the stimulus displays. The first experiments (1A and 1B) tested this hypothesis by means of a habituation paradigm and showed that 4.5-month-old infants are indeed able to amodally complete the back of a self-occluding object when sufficient three-dimensional cues are available. Further support for volume completion in 4.5-month-old infants was found in a second experiment, again using a habituation paradigm, that measured perceived connectedness between two visually separated, self-occluding, three-dimensional objects. [Copyright &y& Elsevier]

A current theory of attention posits that several micro-indices of attentional vigilance are dependent on activation of the locus coeruleus, a brainstem nucleus that regulates cortical norepinephrine activity (). This theory may account for many findings in the infant literature, while highlighting important new areas for research and theory on infant attention. We examined the visual behaviors of n = 16 infants (6-7 months) while they attended to multiple spatially distributed targets in a naturalistic environment. We coded four measures of attentional vigilance, adapted from studies of norepinergic modulation of animal attention: rate of fixations, duration of fixations, latency to reorientation, and target 'hits'. These measures showed a high degree of coherence in individual infants, in parallel with findings from animal studies. Results also suggest that less vigilant infants showed greater habituation to the trial structure and more attentiveness to less salient stimuli during periods of high attentional competition. This pattern of results is predicted by the Aston-Jones model of attention, but could not be explained by the standard information processing model. [ABSTRACT FROM AUTHOR]

Early development is characterized by a period of exuberant neural connectivity followed by a retraction and reweighting of connections over the course of development. It has been proposed that this connectivity may facilitate arbitrary sensory experiences in infants that are unlike anything experienced by typical adults but are similar to the sensory experiences of adults with synaesthesia, a rare sensory phenomenon that has been associated with exuberant neural connectivity and that is characterized by strong arbitrary associations between different sensations. We provide the first evidence for this infant- synaesthesia hypothesis by showing that the presence of particular shapes influences color preferences in typical 2- and 3-month-olds, but not in 8-month-olds or adults. These results are consistent with the possibility that exuberant neural connectivity facilitates synaesthetic associations during infancy that are typically eliminated during development, but that a failure of the retraction process leads in rare cases to synaesthesia in adults. [ABSTRACT FROM AUTHOR]

Infant brain development is a dynamic process dependent upon endogenous and exogenous stimulation and a supportive environment. A critical period of brain and neurosensory development occurs during the third trimester and into the 'fourth' trimester (first three months of life). Disruption, damage, or deprivation in the infant's social and physical environment can create permanent deficits in the developing neurosensory systems. Implications for infant child care environments are discussed, and a review of quality and standards in infant child care environments leads to a call for improvements to optimize child development. [ABSTRACT FROM AUTHOR]

Abstract: We previously found that young infants spontaneously associate stimuli that they merely see together. Using a sensory preconditioning paradigm with 6- and 9-month-olds, we asked how long such associations remain latent before being forgotten and what exposure conditions affect their persistence. Groups were preexposed to two puppets for 1h/day for 2 days, 1h on 1 day, or 1h on 1 day in two sessions; 1–27 days later, target actions were modeled on one puppet, and infants were tested with the other puppet 1 day later. The longest delay after which infants imitated the actions on the other puppet defined how long they remembered the association. The data revealed that the preexposure regimen determined retention. Regardless of exposure time, both ages remembered the association longer after two sessions, and younger infants remembered longer than older infants – for 4 weeks – after two 30-min sessions on 1 day. [Copyright &y& Elsevier]

We tested 7-month-old infants' sensitivity to others' goals in an imitation task, and assessed whether infants are as likely to imitate the goals of nonhuman agents as they are to imitate human goals. In the current studies, we used the paradigm developed by Hamlin et. al (in press) to test infants' responses to human actions versus closely matched inanimate object motions. The experimental events resembled those from Luo and Baillargeon's (2005) looking-time study in which infants responded to the movements of an inanimate object (a self-propelled box) as goal-directed. Although infants responded visually to the goal structure of the object's movement, here they did not reproduce the box's goal. These results provide further evidence that 7-month-olds' goal representations are sufficiently robust to drive their own manual actions. However, they indicate that infants' responses to inanimate object movements may not be robust in this way. [ABSTRACT FROM AUTHOR]

Pitch perception is critical for the perception of speech and music, for object identification, and for auditory scene analysis, whereby representations are derived for each sounding object in the environment from the complex sound wave that reaches the ears. The perceived pitch of a complex sound corresponds to its fundamental frequency. However, removal of energy at the fundamental does not alter the pitch because adults use the harmonics to derive the pitch (Bendor and Wang, 2005; Trainor, 2008). Although sound frequency is represented subcortically, the integration of harmonics into a representation of pitch does not occur until auditory cortex (Bendor and Wang, 2005). Given that auditory cortex is immature in young infants, we examined the development of cortical representations for pitch by measuring electrophysiological (EEG) responses to pitch changes that required processing the pitch of the missing fundamental. Adults and infants 4 months and older showed a mismatch negativity response to these pitch changes, but 3-month-old infants did not. Thus, cortical representations of the pitch of the missing fundamental emerge between 3 and 4 months of age, indicating that there is a profound change in auditory perception for pitch in early infancy. [ABSTRACT FROM AUTHOR]

Abstract: Reduced sensitivity to naturally occurring and laboratory pain stimuli has been observed in individuals with hypertension, high-normal blood pressure, and a family history of hypertension. The present study sought to extend these findings by examining the relationship between familial history of hypertension and pain responsivity in neonates. Eighty infants had intramuscular (IM) injections of vitamin K performed in the delivery room within 1h of birth as per institutional practice. Video recordings of the injection procedure were used by trained observers to code infant pain responses using facial grimacing and cry duration. Prior to the birth of the child, the infants’ parents each completed a family blood pressure history survey and these responses were used to identify infants with and without a maternal and paternal family history of hypertension. As compared to infants without a maternal family history of hypertension, infants with a maternal family history of hypertension had significantly shorter crying times, F(1,74)=6.96, p =.01, η 2 =.086, and marginally lower facial grimacing scores, F(1,74)=2.68, p =.10, η 2 =.035, during vitamin K injection. The presence of attenuated responses to the IM injection in neonates with a maternal family history of hypertension provides important and novel evidence that reduced pain responding in individuals at risk for hypertension is not a learned response style, but rather may arise from prenatal or genetic influences. [Copyright &y& Elsevier]

Like adults, infants use working memory to represent occluded objects and can update these memory representations to reflect changes to a scene that unfold over time. Here we tested the limits of infants' ability to update object representations in working memory. Eleven-month-old infants participated in a modified foraging task in which they saw 2 quantities of crackers sequentially hidden in buckets and then were allowed to choose between them. We manipulated the working memory demands of the task by either hiding crackers in direct succession (i.e., infants saw all of the crackers hidden in the first location, then saw all of the crackers hidden in the second location), or hiding them in alternation (i.e., infants saw some crackers hidden in the first location, then saw some crackers hidden in the second location, then saw more crackers hidden in the first location). Across 6 experiments we found that infants successfully updated their representations of the hidden arrays when crackers were presented in succession. However, when crackers were hidden in alternation and infants had to reupdate an array that was no longer in the current focus of attention, infants showed a striking pattern of failure. These results suggest that, for infants as well as for adults, the flexibility of working memory is subject to processing constraints. [ABSTRACT FROM AUTHOR]

Abstract: Infants can detect information specifying affect in infant- and adult-directed speech, familiar and unfamiliar facial expressions, and in point-light displays of facial expressions. We examined 3-, 5-, 7-, and 9-month-olds’ discrimination of musical excerpts judged by adults and preschoolers as happy and sad. In Experiment 1, using an infant-controlled habituation procedure, 3-, 5-, 7-, and 9-month-olds heard three musical excerpts that were rated as either happy or sad. Following habituation, infants were presented with two new musical excerpts from the other affect group. Nine-month-olds discriminated the musical excerpts rated as affectively different. Five- and seven-month-olds discriminated the happy and sad excerpts when they were habituated to sad excerpts but not when they were habituated to happy excerpts. Three-month-olds showed no evidence of discriminating the sad and happy excerpts. In Experiment 2, 5-, 7-, and 9-month-olds were presented with two new musical excerpts from the same affective group as the habituation excerpts. At no age did infants discriminate these novel, yet affectively similar, musical excerpts. In Experiment 3, we examined 5-, 7-, and 9-month-olds’ discrimination of individual excerpts rated as affectively similar. Only the 9-month-olds discriminated the affectively similar individual excerpts. Results are discussed in terms of infants’ ability to discriminate affect across a variety of events and its relevance for later social-communicative development. [Copyright &y& Elsevier]

Abstract: Although much is known about the development of object exploration during infancy, it remains to be understood whether and how olfaction can influence infants’ interactions with novel objects. To address these issues, sixteen infants aged 7–15 months were videotaped during two consecutive 5-min free play sessions with a scented or an unscented version of visually similar objects. Results indicate that adding an odor to a novel object influenced the infants’ behavior: the infants exhibited more and longer manipulations and mouthing of the unscented object than of the scented object. The differential responsiveness to the scented, relative to the unscented, object was noted after a 2-min delay following test onset, suggesting that in the present conditions infants do not immediately detect or react to the added odor. It may be concluded that infants do detect an odorant added on a novel object, show odor-based discrimination of visually similar objects, and express withdrawal of the scented, relative to the unscented, object. The implications of these findings for understanding how infants use their senses, namely their olfactory sense, in early exploratory behavior are discussed. [Copyright &y& Elsevier]

The ego - our sense of self - arises out of the body. Sense input from skin and muscles creates the boundary and schema for the body-mind to make sense of itself. The infant's skin ego is bound up with touch, and with the comfort and contact needed for it to feel good inside its skin. The mother's body enables the baby's to regulate itself. As voluntary control of movement develops, the muscle ego, which can deal with the world of objects, and tolerate separateness, emerges. [ABSTRACT FROM AUTHOR]

The study of infant communication during mother–infant interactions has largely focused on infants' distal behaviours, while neglecting their more proximal behaviours, such as touch. Yet, touch is an important modality through which infants and mothers communicate; it is also a vital means through which infants self-regulate and explore their surroundings. The present study was designed to investigate the touching behaviours of 44, 51/2-month-old, healthy, full-term infants during face-to-face mother–infant interactions. A still-face (SF) procedure was used in order to examine differences in the types and locations of infant touch across normal and perturbed interaction periods, when mothers exhibit changes in their emotional availability. Results revealed that infant touch varied with changes in maternal availability. During the SF period, when mothers were unavailable, infants used more active, soothing, and reactive tactile behaviours (stroke, finger, pat, and pull), and they spent more time touching themselves. In contrast, infants used mostly passive touch (static) during the Normal periods, when their mothers were available. They also spent a significant portion of time touching their mothers. The variations in infant touch across periods suggest that infants communicate their affective states through touch. The findings also support the regulatory and exploratory roles of infant touch, especially during periods of maternal unavailability. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Aim: To test the hypothesis that a brief window of time immediately after delivery may be a particularly sensitive period for olfactory learning by human neonates. Methods: Fifty-five vaginally delivered newborns were exposed to an odorant for 30 min beginning 4-37 min after birth (Early exposure) or 12-h post-partum (Late exposure). Several days later, newborns' head orientation responses to the exposure odour versus an unfamiliar odour or an odourless control stimulus were tested. Results: Infants in the Early exposure group spent significantly more time oriented towards the familiar scent rather than a novel odour (Z = 2.869; n = 28; p < 0.01), or an odourless stimulus (Z = 2.550; n = 28; p < 0.01). Infants in the Late exposure condition did not respond differentially to the exposure odour versus a novel odour (Z = 1.105; n = 27, p = 0.27), and spent more time oriented towards an odourless stimulus than to the exposure odour (Z = 2.042; n = 27, p < 0.05). Conclusion: Infants in the Early exposure group, but not in the Late exposure group, became familiar with the exposure odour and retained a memory trace of it during the test trials. [ABSTRACT FROM AUTHOR]

In 3 experiments, the author investigated 16- to 20-month-old infants' attention to dynamic and static parts in learning about self-propelled objects. In Experiment 1, infants were habituated to simple noncausal events in which a geometric figure with a single moving part started to move without physical contact from an identical geometric figure that possessed a single static part. Infants were then tested with an event in which the parts of the objects were switched. In Experiments 2 and 3, infants were habituated and tested with identical events except that the part possessed by each object during habitation was switched relative to the first experiment. Results of the experiments revealed that 16-month-olds failed to encode the relation between an object's part and its onset of motion, 18-month-olds were unconstrained in the relations involving self-propulsion that they would encode, and 20-month-olds were constrained in the relations they would encode. The results are discussed with regard to the developmental trajectory of learning about motion properties and the mechanism involved in early concept acquisition. [ABSTRACT FROM AUTHOR]

Six experiments investigated 7-month-old infants' capacity to learn about the self-propelled motion of an object. After observing 1 wind-up toy animal move on its own and a second wind-up toy animal move passively by an experimenter's hand, infants looked reliably longer at the former object during a subsequent stationary test, providing evidence that infants learned and remembered the mapping of objects and their motions. In further experiments, infants learned the mapping for different animals and retained it over a 15-min delay, providing evidence that the learning is robust and infants' expectations about self-propelled motion are enduring. Further experiments suggested that infants' learning was less reliable when the self-propelled objects were novel or lacked faces, body parts, and articulated, biological motion. The findings are discussed in relation to infants' developing knowledge of object categories and capacity to learn about objects in the first year of life. [ABSTRACT FROM AUTHOR]

Most research on object individuation in infants has focused on the visual domain. Yet the problem of object individuation is not unique to the visual system, but shared by other sensory modalities. This research examined 4.5-month-old infants' capacity to use auditory information to individuate objects. Infants were presented with events in which they heard 2 distinct sounds, separated by a temporal gap, emanate from behind a wide screen; the screen was then lowered to reveal 1 or 2 objects. Longer looking to the 1- than 2-object display was taken as evidence that the infants (a) interpreted the auditory event as involving 2 objects and (b) found the presence of only 1 object when the screen was lowered unexpected. The results indicated that the infants used sounds produced by rattles, but not sounds produced by an electronic keyboard, as the basis for object individuation (Experiments 1 and 2). Data collected with adult participants revealed that adults are also more sensitive to rattle sounds than electronic tones. A final experiment assessed conditions under which young infants attend to rattle sounds (Experiment 3). Collectively, the outcomes of these experiments suggest that infants and adults are more likely to use some sounds than others as the basis for individuating objects. We propose that these results reflect a processing bias to attend to sounds that reveal something about the physical properties of an object—sounds that are obviously linked to object structure—when determining object identity. [ABSTRACT FROM AUTHOR]

Behavioral responses of 3- to 4-day-old newborns to the odors of various human milk (HM) and formula milk (FM) were examined in paired-choice tests. When both stimuli were nonfamiliar, breast-fed, as well as bottle-fed, infants oriented their head and mouthed more vigorously to HM than to FM. When breast-fed infants were exposed to nonfamiliar HM along with the familiar FM, their head-turning responses were undifferentiated although they mouthed more frequently to the human stimulus. When nonfamiliar HM and familiar FM were equalized in intensity, nonfamiliar HM again elicited more head orientation and mouthing responses. These results demonstrate that the odor of HM is more attractive to human newborns than FM and that this preference is independent of postnatal feeding experience. [ABSTRACT FROM AUTHOR]

Provides information on positive touch, an application of the ancient practice of infant massage. Incorporation of massage strokes into ongoing family routines; Simplicity of positive touch; Effects of massage therapy on many functions and medical conditions in varied age groups; Effect of massage on children with a variety of disabilities; Factors to consider in teaching positive touch techniques.

The present research addresses the question of the oblique effect" (better discrimination of the vertical orientation than of an oblique orientation) in manual haptic perception of orientations (without visual control) by 5-noonth-old infants. A familiarization reaction to novelty procedure was used. The results revealed the occurrence of a haptic oblique effect. These Findings are similar to those obtained in infant visual perception. We suggest that 5-month-old infant predominately use vertical orientation as a reference norm to perceive haptically spatial orientations. We discuss the implications of these results for both orientation processing and anatomofunctional level contributing specifically to the haptic oblique effect. [ABSTRACT FROM AUTHOR]

L. Bahrick and R. Lickliter (2000) proposed an intersensory redundancy hypothesis that states that information presented redundantly and in temporal synchrony across two or more sensory modalities selectively recruits infant attention and facilitates perceptual learning more effectively than does the same information presented unimodally. In support of this view, they found that 5-month-old infants were able to differentiate between two complex rhythms when they were presented bimodally, but not unimodally. The present study extended our test of the intersensory redundancy hypothesis to younger infants and to a different amodal property. Three-month-olds' sensitivity to the amodal property of tempo was investigated. Results replicated and extended those of Bahrick and Lickliter, demonstrating that infants could discriminate a change in tempo following bimodal, but not unimodal, habituation. It appears that when infants are first learning to differentiate an amodal stimulus property, discrimination is facilitated by intersensory redundancy and attenuated under conditions of unimodal stimulation. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 41: 352–363, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10049 [ABSTRACT FROM AUTHOR]

The purpose of this study was to observe olfactory detection and discrimination in preterm and full-term newborns. Infants were familiarized for 10 trials with either vanillin or anethole. On each trial, a cotton swab perfumed with one of the odors was slowly moved in front of the baby's nose for 10 sec. For half of the preterm and full-term infants, a new odor was presented after the last familiarization trial (experimental groups). For the other half, the same odor as during familiarization was presented (control groups). Facial and head movements for both populations and heart rates for preterm infants were recorded before, during, and after odor presentation. Preterm infants reacted to the scents by increasing facial actions and heart rate but not head movements. Full-term infants increased facial and head movements. Neither population showed a clear behavioral habituation pattern, but full-term newborns had a significantly reduced facial reactivity on the last familiarization trial compared to preterm infants. Preterm newborns did, however, show cardiac habituation on the last familiarization trial. Preterm and full-term infants presented with a new odor after familiarization increased responding compared to infants presented with the same odor, indicating their ability to discriminate between 2 odors. Infants' reactivity and discrimination to odors indicate preterm and full-term newborns' ability to be attuned to their olfactory environment. [ABSTRACT FROM AUTHOR]

Maturation of tactile sensitivity prior to term was examined in 36 preterm and 13 full-term infants using a fixed-trial, habituation procedure. Each infant was presented with a series of 8 habituation (arm stroke), 2 novel (arm lift), and 2 recovery (arm stroke) stimulus trials while heart rate and body movements were recorded. Maturation was observed with a gradual increase in the magnitude of the stimulus-elicited cardiac acceleration and cardiac-movement coupling from 30 to 40 weeks postconceptional age. The majority of infants displayed habituation—an excitatory response (heart rate acceleration and body movement)—to the initial presentation of a tactile stimulus, response decline with repeated stimulations, and renewed response to a novel stimulus. A substantial number of infants (40%) failed to respond initially to the tactile stimulus, increased responding over several stimulus presentations, and failed to discriminate the presentation of a novel stimulus. We speculate that these differences in response patterns observed over all ages represent individual difference in the perception of stimulus intensity. [ABSTRACT FROM AUTHOR]

The capacity of muscle spindles in adult human extraocular muscles (EOM) to provide effective proprioception was questioned on the grounds of their peculiar morphology. Their appearance could be attributable to ageing and to test this possibility examples of infant muscle spindles have been examined. Forty encapsulated structures from five extraocular muscles removed post mortem from 4 infant patients aged 6 days, 5, 23 and 30 months were examined by means of light microscopy using serial transverse sections. Seven of them were identified as false spindles. The remaining 33 structures, identified as spindles, contained a total of 175 intrafusal fibres varying from 2 to 12 (mean: 6) in each. 130 of these fibres (74.3%) were of nuclear chain type. Unequivocal evidence of bag fibres was not found. Spindles lacked or had a limited equatorial expansion, and the inner capsule was incomplete and irregularly shaped. 45 (25.7%) of the intrafusal fibres had extrafusal features with large diameters, peripherally placed nuclei, no equatorial modification and without associated sensory nerve terminals. Serial sections revealed that a majority of the nuclear chain fibres were interrupted, fragmented or terminated abruptly, and most spindles contained at least one incomplete fibre. These observations show that the atypical features observed in adult human EOM spindles are also present in infants and are therefore not attributable to ageing.Copyright © 2001 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The present series of studies aimed to investigate whether experience with a flavor in mothers' milk modifies the infants' acceptance of similarly flavored foods at weaning. First, we established, using methods developed in our laboratory, that the ingestion of carrot juice by lactating women produced a sensory change in their milk approximately 2 to 3 hr after the ingestion of the beverage. Second, we randomly formed two groups of breast-fed infants who had been fed cereal for a few weeks but had only experienced cereal prepared with water. Their mothers were asked to consume one of two types of beverages (i.e., carrot juice, water) during the exposure period. Each mother was observed feeding her infant cereal during four test sessions. The first two sessions occurred during the 2 days before the exposure period; in counterbalanced order, infants were fed cereal prepared with water on 1 testing day and cereal prepared with carrot juice on the other. These two test sessions were then repeated following the exposure period. The results demonstrated that the infants who had exposure to the flavor of carrots in their mothers' milk during the exposure period consumed less of the carrot-flavored cereal and spent less time feeding when compared to the control infants whose mothers consumed the water. This may be a form of sensory-specific satiety such that the infants become less responsive to a flavor that they have been extensively exposed to in the very recent past. © 1999 John Wiley & Sons, Inc. Dev Psychobiol 35: 197–203, 1999 [ABSTRACT FROM AUTHOR]

LEWIS, MICHAEL, and THOMAS, DAVID. Cortisol Release in Infants in Response to Inoculation. CHILD DEVELOPMENT, 1990, 61, 50-59. Using a cross-sectional design, salivary cortisol was obtained from infants aged 2, 4, and 6 months, prior to and 15 min following an inoculation. Cortisol rose significantly following inoculation. Behavioral responses to inoculation were consistent with the observed patterns of cortisol release. Cortisol base level was significantly and negatively related to the cortisol change score. At 6 months the basal levels also were influenced by an adult-like circadian rhythm; infants tested shortly after awakening had higher basal levels than those tested later in the day. These data provide strong evidence that studies of stress and cortisol release in infants must be sensitive to basal level, circadian rhythm, and behavioral effects, and that appropriate statistical procedures should be employed. [ABSTRACT FROM PUBLISHER]

The present experiments examine acquisition and waning of exposure-induced attraction to a nonnatural odor in rat pups. I found that (1) acquisition of attraction induced by experience of an odor associated with the mother (M-E) and of attraction induced by experience of an odor in the general environment (S-E) had similar time courses and were of similar magnitude in pups < 20 days of age; (2) waning of S-E-induced attraction to a nonnatural odor was far more rapid than waning of M-E-induced attraction; (3) M-E and S-E to an odor were less effective in pups > 20 days of age than in pups < 20 days of age; and (4) although pups > 20 days of age receiving M-E to an odor exhibited enhanced attraction to that odor, pups of equal age receiving S-E to the same odor did not. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study conducted to examine the modification of social responsiveness in institutional babies. Observation of the subjects showed that no person received special attention from the babies. Difference in their responsiveness and their interest in people were also noted. Occasional baby more than 10 months of age who was a favorite of a hospital personnel displayed alertness of facial expression, vocalizations directed to the person, and a reaching of arms. In addition, babies smiled to people in the corridor seen through the windows and to the people who were not looking at them

The article discusses the procedures employed in studying the modification of social responsiveness in institutional babies. Sixteen infants used in the study came from a large urban maternity hospital and orphan asylum which cared for children from birth to three years old. Four pairs of experimental and control babies were studied in the first experiment while the other four pairs constituted a second and parallel experiment. To obtain a difference between the experimental and the control conditions, a separate person took samples on the number of adults on each room and of their activities relative to the babies. Also, a form was posted at the foot of a baby crib on which adult caring for the infant wrote her name to gain additional information.

Examines whether continuous stimulation of sensory modalities decreases the level of arousal in infants. Stimulation of the auditory, visual, proprioceptive-tactile and temperature; Indices of arousal level; Pacification effect.

The article presents beneficial effects of tactile stimulation on early childhood development. Although most parents provide tactile stimulation, recent research underscores the importance of touch in optimizing the development of newborns and growing infants. Infants are all born with the capacity to enjoy tactile stimulation. Numerous benefits of touch have been documented, particularly in regards to newborns with health-related concerns. Nevertheless, professional caregivers can provide normal infants with a variety of tactile stimulation encouraging active exploration through touching and manipulating objects and fostering body awareness. The best kinds of experiences are those intimate moments when caring, loving adults cuddle and nuzzle infants. Some studies provide compelling evidence of the beneficial effects of tactile stimulation on a variety of infants.

The article discusses the design and methods of the experiment conducted to examine the modification of social responsiveness in institutional babies. The chief elements of the study was the substitution of one mother for many mothers. Its primary goal was to bring on an increase in social responsiveness to that one person and to measure the effects of the learning on responsiveness to other persons. After completion of the experiment, it would be possible that an increase in social responsiveness has been demonstrated to assess the effects on the varying components. However, the design of the experiment does not clarify the mechanisms responsible for the learning.

The article presents a study that examined the effect of an experimental modification of the environment on the infants. Infants living in an institution were selected as subjects due to their common background of experience and of the relative ease with which the environmental conditions could be controlled and manipulated. Six-month old infants were also used in the study because they often give clear evidence of a difference in their responses to known and unknown persons. Also, much attention was given to the social behavior of the infant.