étude comparative de nourrissons prématurés et nés à terme et des modes de stimulations qu'ils expérimentent au cours des six premiers mois.

Compared preterm and fullterm infants' temperament and development and to evaluate the physical and social stimulations they experience at 2, 4 and 6 months (correcting for prematurity). Fifty-six mother–infant dyads, including 28 premature and 28 fullterm infants, participated in the study. The groups did not differ on temperament and developmental measures, neither on physical environment (density, toys, accessories). However, significant differences were found regarding social stimulation. Mothers of preterm infants had less optimal sensibility-contingency scores and used more distal stimulation at 2 months than mothers of fullterm infants. During the first 6 months, premature infants spent more time in activities involving the immediate family, whereas fullterm infants went more frequently on outings. At home, fullterm infants interacted more with people from their social network. These stimulations could eventually have an impact on infant development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sleeping position, orientation, and proximity in bedsharing infants and mothers

The impact of mother-infant bedsharing on infant sleeping position, orientation, and proximity to the mother was assessed in 12 breast-feeding Latino mother-infant pairs. Six routinely bedsharing and six routinely solitary-sleeping pairs slept 3 nights in the sleep laboratory. The first night matched the routine home condition, followed by 1 bedsharing night and 1 solitary-sleeping night in random order. During bedsharing infants were never placed prone, regardless of their routine sleeping condition. On the bedsharing night, mothers and infants spent most of the night oriented toward each other; seven of 12 infants remained oriented toward their mothers the entire night. While sleeping in a face-to-face orientation, most pairs slept most of the time less than 30 cm apart with appreciable amounts of time at less than 20 cm. This orientation and proximity should facilitate sensory exchanges between mother and infant which, we hypothesize, influence the infant's sleep physiology and nocturnal behavior. We conclude that bedsharing minimizes the use of the prone infant sleeping position, probably in part to facilitate breast feeding. By promoting nonprone positions, bedsharing may protect some infants from sudden infant death syndrome (SIDS), since prone sleeping is a known risk factor for SIDS. The large percentage of the night that mothers spent oriented toward their infants suggests that a higher degree of maternal vigilance may also result from bedsharing.     

Natural forms of shed tumor gangliosides

Data on activity states were collected from 29 group-housed capuchin monkey (Cebus apella) infants for 3 h each week from birth to 11 weeks of age. The amounts of time spent in sleeping/drowsy, alert-quiet, and alert-active states were measured in these subjects. Videotaped observations of these infants were recorded 3 times/week in the home cage over the first year of life and were scored for a number of social and exploratory behaviors. The extent to which early infant activity state scores predicted later behavior in the home cage was examined. Infant state measures correlated significantly with home cage behavior during months 2-6 in that infants that had been more active in early infancy spent more time alone, with other animals, and in exploration and play and less time with mothers than did quieter infants. Early state measures were less successful in predicting home cage scores beyond 8 months of age, whereas differences in behavior attributable to housing variables became more salient in the latter part of the first year. There was also a negative correlation between mother and infant activity in months 2 and 3, in that more sedentary mothers tended to have more active infants.     

Ontogeny of foraging behavior in wild vervet monkeys (Cercopithecus aethiops): Social interactions and survival.

The ontogeny of feeding behavior was explored by making observations of 32 vervet monkey infants in Amboseli National Park, Kenya. In contrast to adults and juveniles, infants appear to treat all primary food products in their diet as equally valuable. These age-related differences may reflect differences in food preference. To assess social influences, feeding synchrony between mother and infant was explored. From birth to 2 mo, infants typically fed asynchronously with respect to their mother's feeding bouts. From 2–22 mo, however, most infants fed at the same time and on the same food items as their mothers. Among infants there was a significant positive association between the proportion of synchronous, same food bouts and the probability of survival. Variation among infants in access to resources and encounter rates with predators did not, however, have a significant effect on survival. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relations of maternal social support and family structure with maternal responsiveness and child outcomes among African American families.

The social support networks and family structure of 62 low-income African American mothers were related to proximal and distal measures of the mother's parenting style and to the children's social and cognitive development. Women with larger support networks tended to be more responsive in interactions with their infants and to provide more stimulating home environments than mothers with smaller social networks. Activity level was the only infant outcome significantly related to social support. Family structure was not associated with either maternal or child outcomes in these analyses. These results support a systems model of parenting behavior and child development by indicating that maternal caregiving may be positively influenced by supportive social networks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction of infant-father and infant-mother attachment.

The 1st-yr correlations of infant–father and infant–mother attachment were investigated in a longitudinal study of early family development. Mothers and fathers were observed interacting with their 1st-born, 3-mo-old infants. Parents also were interviewed individually at 3 mo child age concerning their time with the infant and their attitudes and reports about the infant and their parental role. Mothers and fathers were seen in the strange situation with their infant at 12 mo. For infants and fathers, security of attachment was predicted from the qualities of interaction at 3 mo, the father's attitudes and reports about the infant and the paternal role, and the father's time with the infant. For infants and mothers, security of attachment was predicted from the qualities of interaction at 3 mo and the mother's time with the infant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-mate or twin sibling: Effects on interactions between monkey mothers and infants.

Examined the effects of the twin sibling relationship upon interactions between mother and infant. 12 rhesus monkey infants were reared with a mother and nonsibling peers; 8 had an age-mate or twin sibling, while 4 control infants did not. The sibling pairs were formed by fostering newborns 2 to a mother; the control infants were fostered 1 to a mother. Findings indicate that the twin infants did not engage in as much interaction with their mothers throughout a 7-mo period of observation on a wide range of indexes, including such basic behaviors as a contact with the mother's ventrum and nipples. The mothers rearing twins spent less time cradling their infants and less frequently rejected them. There were a few additional differences, notably in the area of restrictive behavior, but it is concluded that the differences in maternal behavior were principally a reaction to the differences in infant behavior. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approaching and contacting the object another manipulates: A social skill of the 1-year-old.

Assigned 48 11–23 mo old infants at random to 1 of 4 groups distinguished by how an unfamiliar female adult acted on toys. The infant, in a room containing his or her mother and several toys, observed an adult who did nothing with the toys, periodically approached and sat down beside a predesignated toy either in a repetitive way for 1 group or in a varied manner for another. Contrasting which toys the infants of the different groups contacted indicated that the infants systematically went to and contacted the toy that the adult manipulated. Smiling, vocalizing, and gesturing to the adult, being near her, and contacting her were all reliably linked in time to the infants' contacting her toy. Further, the infants duplicated the adult's actions on the toy reliably more often than expected by a chance matching of activity. The findings suggest that approaching and contacting the object another manipulates is a basic social skill of the 1-yr-old; such behavior functions to facilitate the generation of social interaction. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defining the role of the bladder-neck sling in the surgical treatment of urinary incontinence in children with neurogenic incontinence

Mother squirrel monkeys stop carrying infants at earlier ages in high-demand (HD) conditions where food is difficult to find relative to low-demand (LD) conditions. To characterize these transitions in psychosocial development, from 10- to 21-weeks postpartum we collected measures of behavior, adrenocortical activity, and social transactions coded for initiator (mother or infant), goal (make-contact or break-contact), and outcome (success or failure). Make-contact attempts were most often initiated by HD infants, but mothers often opposed these attempts and less than 50% were successful. Break-contact attempts were most often initiated by LD infants, but mothers often opposed these attempts and fewer LD than HD infant break-contact attempts were successful. Plasma levels of cortisol were significantly higher in HD than LD mothers, but differences in adrenocortical activity were less consistent in their infants. HD and LD infants also spent similar amounts of time nursing on their mothers and feeding on solid foods. By rescheduling some transitions in development (carry-->self-transport), and not others (nursing-->self-feeding), mothers may have partially protected infants from the immediate impact of an otherwise stressful foraging task.     

Behavior of Swedish primary and secondary caretaking fathers in relation to mother's presence.

Parents from 27 Swedish families were observed at home interacting with their infants (aged 8–12 mo) in 2 different social situations—(a) with the father, mother, and infant present and (b) the father alone with infant. 12 of the fathers had been primary caretakers for more than 1 mo (mean?=?3 mo); these families were designated as shared childcare. Men who took little or no parental leave and were never primary caretakers were from families designated as traditional. Results indicate that in the 3-person social context mothers were more likely to engage in distal bidding with their infants (vocalize, smile, laugh) and display affection toward their infants than fathers, regardless of the fathers' past histories of caregiving. By contrast, when the fathers were alone with their infants, effects of the fathers' caregiving histories did occur. In this situation, fathers from traditional families were more likely to display affection toward and play with their infants. In contrast to previous studies, it is suggested that differential involvement in childcare has significant effects in fathers' behavior. (6 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olfactory denervation: its biological and behavioral effects in infant rats

Two-week-old infant rats were treated with intranasal ZnSO4 and compared with littlemate controls 24 hr later. When infants were returned to their mother and littermates, those with olfactory deficits lost weight, had reduced cardiac and respiratory rates and lower body temperatures, and showed increased locomotor behavior in an unfamiliar test area. Subsequent experiments showed that in the absence of the mother and also in isolation, differences between ZnSO4-treated and control infants involved fewer systems were less marked, and presented different patterns. Isolated infants given oral ZnSO4 did not differ from controls on any measures. Olfactory denervation appears to produce these effects by disrupting nursing, by altering littermate interaction, and by other central nervous system effects that are independent of social interaction.     

Distribution and characteristics of poststimulus effects in proximal and distal forelimb muscles from red nucleus in the monkey

We used stimulus-triggered averaging (StTA) of electromyographic (EMG) activity to investigate two major questions concerning the functional organization of the magnocellular red nucleus (RNm) for reaching movements in the macaque monkey. The first is whether the clear preference toward facilitation of extensor muscles we have reported in previous studies for distal (wrist and digit) forelimb muscles also exists for proximal muscles (shoulder and elbow). The second question is whether distal and proximal muscles may be cofacilitated from RNm suggesting the representation of functional muscle synergies for coordinated reaching movements. Two monkeys were trained to perform a prehension task requiring multijoint coordination of the forelimb. EMG activity was recorded from 24 forelimb muscles including 5 shoulder, 7 elbow, 5 wrist, 5 digit, and 2 intrinsic hand muscles. Microstimulation (20 microA at 20 Hz) was delivered throughout the movement task. From 137 microstimulation sites in the RNm, a total of 977 poststimulus effects was obtained including 733 poststimulus facilitation effects (PStF) and 244 poststimulus suppression effects (PStS). Of the PStF effects, 58% were obtained from distal muscles; 42% from proximal muscles. Digit muscles were more frequently facilitated (35%) than the wrist, elbow, or shoulder muscles (20, 24, and 18%, respectively). The intrinsic hand muscles were infrequently facilitated (3%). At all joints tested, PStF was more common in extensor muscles than flexor muscles. This extensor preference was very strong for shoulder (85%), wrist (85%), and digit muscles (94%) and weaker for elbow muscles (60%). Of the PStS effects, 65% were in distal muscles and 35% in proximal muscles. Interestingly, the flexor muscles were more frequently inhibited from RNm than extensor muscles. At 72% of stimulation sites, at least two muscles were facilitated. The majority of these sites (61%) cofacilitated both proximal and distal muscles. At the remaining sites (39%), PStF was observed in either the proximal (17%) or distal muscles (22%). Facilitation most often involved combinations of shoulder, elbow, and distal muscles (30%) or shoulder and distal muscles (26%). Only rarely were intrinsic hand muscles part of the total muscle synergy. Our results show that the RNm 1) controls both proximal and distal muscles but the strength of influence is biased toward distal muscles, 2) preferentially controls extensor muscles not only at distal forelimb joints but also at proximal joints, and 3) output zones cofacilitate synergies of proximal and distal muscles involved in the control of forelimb reaching movements.     

The development toward stereotypic arm kinematics during reaching in the first 3 years of life

We recorded reaching movements from nine infants longitudinally from the onset of reaching (5th postnatal month) up to the age of 3 years. Here we analyze hand and proximal joint trajectories and examine the emerging temporal coordination between arm segments. The present investigation seeks (a) to determine when infants acquire consistent, adult-like patterns of multijoint coordination within that 3-year period, and (b) to relate their hand trajectory formation to underlying patterns of proximal joint motion (shoulder, elbow). Our results show: First, most kinematic parameters do not assume adult-like levels before the age of 2 years. At this time, 75% of the trials reveal a single peaked velocity profile of the hand. Between the 2nd and 3rd year of life, "improvements" of hand- or joint-related movement units are only marginal. Second, infant motor systems strive to obtain velocity patterns with as few force reversals as possible (uni- or bimodal) at all three limb segments. Third, the formation of a consistent interjoint synergy between shoulder and elbow motion is not achieved within the 1st year of life. Stable patterns of temporal coordination across arm segments begin to emerge at 12-15 months of age and continue to develop up to the 3rd year. In summary, the development toward adult forms of multijoint coordination in goal-directed reaching requires more time than previously assumed. Although infants reliably grasp for objects within their workspace 3-4 months after the onset of reaching, stereotypic kinematic motor patterns are not expressed before the 2nd year of life.     

Behavior-state matching and synchrony in mother-infant interactions of nondepressed versus depressed dyads.

Behavior-state matching and synchrony in interactions were assessed in 48 depressed and nondepressed mother–infant dyads when the infants were 3 months old. Attentive/affective behavior states were coded for the infants and mothers on a negative to positive scale. The depressed mothers and their infants matched negative behavior states more often and positive behavior states less often than did the nondepressed dyads. The total percentage of time spent in matching behavior states was less for the depressed than for the nondepressed dyads. Cross-spectral analyses of the mothers' and the infants' behavior-state time series suggested only a trend for greater coherence or synchrony in the interactions of the nondepressed dyads. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Engaging strangers in proximal interaction: Infants' social initiative.

Observed 72 infants aged 12, 18, and 24 mo in the presence of their mothers and 2 adult female strangers to assess their willingness to initiate proximal interaction (PI) with unfamiliar adults. Mothers and strangers were asked to be warmly responsive to infant overtures but not to invite interaction from the infant. A majority of the infants at the 3 ages initiated PI with one or both strangers, often repeatedly. For those who engaged in 2 or more PI bouts with the strangers, a significant upward trend in bout duration and intensity was noted. Older infants gave more toys to the strangers and initiated more mutual play. Stranger–mother distance affected amount of proximity, not PI. Mother–stranger conversation was associated with less PI with the conversing stranger. At all ages infants sought more PI with their mothers than with the strangers. Although infants initiated an appreciable amount of PI with the strangers during the 40-min observation, comparison with other studies indicates that a stranger who takes the initiative by inviting play can establish more rapport much sooner. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infants' responses to facial and vocal emotional signals in a social referencing paradigm

The independent effects of facial and vocal emotional signals and of positive and negative signals on infant behavior were investigated in a novel toy social referencing paradigm. 90 12-month-old infants and their mothers were assigned to an expression condition (neutral, happy, or fear) nested within a modality condition (face-only or voice-only). Each infant participated in 3 trials: a baseline trial, an expression trial, and a final positive trial. We found that fearful vocal emotional signals, when presented without facial signals, were sufficient to elicit appropriate behavior regulation. Infants in the fear-voice condition looked at their mothers longer, showed less toy proximity, and tended to show more negative affect than infants in the neutral-voice condition. Happy vocal signals did not elicit differential responding. The infants' sex was a factor in the few effects that were found for infants' responses to facial emotional signals.     

Modification of study time and grades through self-control procedures.

Evaluated the efficacy of a self-control treatment package to increase daily study time and grades of 44 undergraduates. The additive contribution of individual elements to the treatment package, as well as the potential difference in setting proximal vs distal goals, were also investigated through the use of the following treatment groups: (1) self-monitoring, distal goals, financial contingency, and group meetings; (2) self-monitoring, distal goals, and financial contingency; (3) self-monitoring and distal goals; (4) self-monitoring and proximal goals; (5) self-monitoring alone; (6) waiting-list control. Results show that, without differing from each other, the 1st 3 groups were all superior to self-monitoring and waiting-list control in terms of time spent studying. No significant improvement was found for grades. Results are discussed in terms of implications for potential use in applied settings. (French abstract) (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial integration in infant sable antelope, Hippotragus niger

I studied the relationship between the timing of birth relative to other births in the social group, and the rate of spatial integration into the herd in six cohorts of semi-free-ranging infant sable antelope at the National Zoological Park's Conservation and Research Center near Front Royal, Virginia. All calves spent the initial few days of life resting in seclusion ('hiding'), and interacted with mothers and other conspecifics only during activity bouts. With time, calves became increasingly likely to rest apart from the herd with other calves in crèches, and by 6 weeks of age, calves remained with the herd throughout all resting and activity bouts. The rate of spatial integration for individual calves depended upon the calf's birth date and the availability of peers of similar age (birth clustering). Only the first few calves born in each cohort were observed in crèches, and crèche groups synchronized their entry into the herd. First-born calves remained in crèches longer and began resting with the herd later in life than calves born later in the cohort. Last-born calves typically did not form crèches, but instead rested with the herd from an early age. Other infants may serve as social cover during the time that infants form crèches and when they first begin to accompany the herd. The observed individual differences in the rate of spatial integration may represent individual adjustments in response to the varying degrees of protection offered by the spatial environment. Copyright 1998 The Association for the Study of Animal Behaviour.     

Similarities and differences in infant-mother and infant-father interaction in the strange situation: A component process analysis.

This study examined similarities and differences in infant–mother and infant–father interaction. Previously published data (Belsky, Garduque, & Hrncir, 1984) on infants observed in the Strange Situation with their mothers (N?=?60) and fathers (N?=?50) at 12 and 13 months were reanalyzed using a component process approach to investigate (a) whether the organization of social interactive behavior is relationally based, (b) the factor-analytic structure of social interaction with the two caregivers, (c) the predictive power of crying and social interactive behavior with each caregiver to subsequent behavior with a stranger, and (d) the relative cross-caregiver consistency of crying versus social interaction. Results indicated (a) that the organization of infant social interaction depends on the interactive partner and on the affective context, (b) that infant behavior with the father is more predictive of infant–stranger interaction than is infant–mother interaction, and (c) that crying is more consistent than social interaction across caregivers. Results are interpreted as being consistent with a view of attachment relationships as relationally based and as evidence for the usefulness of the finer-grained analysis provided by the component process approach. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Links between maternal care and persistent infant crying in the early months

A community sample was screened to select three groups of infants and their mothers according to how much the babies cried at 6 weeks of age, the peak age for infant crying. The three groups--of moderate (n = 55), evening (n = 38) and persistent criers (n = 67) and their mothers--were assessed by diary, observation and questionnaire measures of mother and infant characteristics and interactions at 6 weeks and 5 months of infant age. At 6 weeks, mothers of persistent criers spent more time interacting with and physically stimulating their babies. Below-optimum maternal sensitivity/affection was linked to moderately increased crying in the infants overall. However, most mothers of persistent criers showed optimum sensitivity and affection, while no significant links between maternal sensitivity/affection and infant crying were found in the persistent crying group. By 5 months, when infant crying declined, the range and size of differences between mothers of persistent criers and other mothers declined. Home observations and a standard play measure failed to show group differences in maternal sensitivity, affection and intrusiveness at this age. The findings show that persistent infant crying in the early months often occurs in spite of high quality maternal care, so that in most cases the crying is probably not due to inadequate parenting. The need to distinguish general community cases from those at social or medical risk is emphasized and the findings' implications for professionals are discussed.