Hand preference status and reach kinematics in infants

Infants show age-related improvements in reach straightness and smoothness over the first years of life as well as a decrease in average movement speed. This period of changing kinematics overlaps the emergence of handedness. We examined whether infant hand preference status is related to the development of motor control in 53 infants ranging from 11 to 14 months old. Hand preference status was assessed from reaching to a set of 5 objects presented individually at the infant's midline; infants were classified into ‘right preference’ or ‘no preference’ groups. Three-dimensional (3-D) recordings were made of each arm for reaches under two distinct conditions: pick up a ball and fit it into the opening of a toy (grasp-to-place task) or pick up a Cheerio^® and consume it (grasp-to-eat task). Contrary to expectations, there was no effect of hand preference status on reach smoothness or straightness for either task. On the grasp-to-eat task only, average speed of the left hand differed as a function of hand preference status. Infants in the no preference group exhibited higher left hand average speeds than infants in the right preference group. Our results suggest that while behavioral differences in the use of the two hands may be present in some infants, these differences do not appear to be systematically linked to biases in motor control of the arms early in development.     

Infant imitation and the self—A response to Welsh

Talia Welsh (2006 Welsh, T. 2006. Do neonates display innate self-awareness? Why neonatal imitation fails to provide sufficient grounds for innate self and other awareness. Philosophical Psychology, 19: 221–238. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) argues that Shaun Gallagher and Andrew Meltzoff's (1996) application of neonatal imitation research is insufficient grounds for their claim that neonates are born with a primitive body image and thus an innate self-awareness. Drawing upon an understanding of the self that is founded upon a “theory of mind,” Welsh challenges the notion that neonates have the capacity for self-awareness and charges the supposition with an essentialism which threatens to disrupt more social constructionist understandings of the self. In this paper, I initially defend Gallagher and Meltzoff's (1996) application of infant imitation to understandings of neonatal self-awareness by explaining how body image schemas can be understood as non-representational embodied cognitive phenomena that challenge “theory of mind” theory. I then further develop the claim that neonates are born self-aware with reference to my own work in fetal development. I conclude that Welsh's political concerns are unfounded by showing how the conclusion that a neonate is self-aware does not signal a return to an essentialist understanding of self-awareness, but rather introduces into philosophical and psychological discourse possible alternate understandings of an embodied sense of self that are embedded within intersubjective contexts.     

Development of body emotion perception in infancy: From discrimination to recognition

Research suggests that infants progress from discrimination to recognition of emotions in faces during the first half year of life. It is unknown whether the perception of emotions from bodies develops in a similar manner. In the current study, when presented with happy and angry body videos and voices, 5-month-olds looked longer at the matching video when they were presented upright but not when they were inverted. In contrast, 3.5-month-olds failed to match even with upright videos. Thus, 5-month-olds but not 3.5-month-olds exhibited evidence of recognition of emotions from bodies by demonstrating intermodal matching. In a subsequent experiment, younger infants did discriminate between body emotion videos but failed to exhibit an inversion effect, suggesting that discrimination may be based on low-level stimulus features. These results document a developmental change from discrimination based on non-emotional information at 3.5 months to recognition of body emotions at 5 months. This pattern of development is similar to face emotion knowledge development and suggests that both the face and body emotion perception systems develop rapidly during the first half year of life.     

Visual attention control differences in 12-month-old preterm infants

There have been few previous attempts to assess the development of early markers of executive function in infants born preterm despite well-established deficits reported for older preterm children that have been closely linked to poorer academic functioning. The present study investigates early attention control development in healthy 12-month-old age-corrected pre-term infants who were born less than 30 weeks and compares their performance to full-term infants. Eye-tracking methodology was used to measure attention control. Preterm Infants spent less time focused on the target and were slower to fixate attention, with lower gestational age associated with poorer target fixation and slower processing speed. There were no significant group differences observed for inhibition of return or interference control. These findings suggest that specific emerging deficits in attention control may be observed using eye tracking methodology in very preterm infants at this early stage of development, despite scores within the average range on the Bayley Scales of Infant Development.     

Massage therapy improves the development of HIV-exposed infants living in a low socio-economic,peri-urban community of South Africa

The aim of this study was to assess the effect of massage therapy on the growth and development of infants of HIV-infected mothers in a low socio-economic community in Cape Town. It was a prospective, randomised, controlled intervention trial that included massage therapy and control groups of HIV-infected mothers and their normal birth weight infants who were enrolled in the prevention of mother-to-child transmission (PMTCT) programme. Participants were recruited at the 6-week clinic visit and followed up every 2 weeks until their infants were 9 months of age. Mother–infant pairs in the massage therapy and control groups included 73 and 88 at 6 weeks and 55 and 58 at 9 months, respectively. Mothers in the intervention group were trained to massage their infants for 15 min daily. The socioeconomic status, immunity, relationship with the partner and mental pain of mothers; the infants’ dietary intake, anthropometry and development (Griffiths Mental Development Scales); and haematological and iron status of mothers and infants were assessed at baseline and follow-up. Nine infants (5.3%) were HIV-infected on the HIV DNA PCR test at 6 weeks. Despite significantly higher levels of maternal mental pain, infants in the massage therapy compared to control group scored higher in all five of the Griffiths Scales of Mental Development and significantly higher in the mean quotient (p = 0.002) and mean percentile (p = 0.004) for the hearing and speech scale at 9 months. Based on the mean difference in scores, the massage therapy group showed greater improvement for all five scales compared to the control group. The mean difference in scores was significantly greater for the hearing and speech quotient (21.9 vs. 11.2) (p < 0.03) and the general quotient percentile (19.3 vs. 7.7) (p = 0.03) in the massage therapy compared to the control group. These scales remained significant when adjusting for the relationship with the partner and maternal mental pain. Both groups had lower scores in the performance scale at 9 months although this was significantly worse in the control compared to the massage therapy group when adjusting for maternal CD4 count, anaemia, relationship with the partner and mental pain. There were no significant differences in the anthropometric measurements between the two groups. In conclusion, based on the Griffiths Scales, massage therapy improved the overall development and had a significant effect on the hearing and speech and general quotient of HIV-exposed infants in this study.     

Qualitative elements of early motor development that influence reaching of the erect posture. A prospective cohort study

The proposed assessment sheet aims to show in detail, which qualitative elements of motor performance are performed correctly in the 2nd month of life by children who in the 9th month reached the erect posture. Similar analysis was performed for the qualitative assessment in the 6th month. The prospective investigation of motor development involved a group of 109 children (40 girls and 69 boys). The study was based on the previously described quantity and quality assessment sheet of motor performance, validated for the 2nd and 6th month. Final investigation took place in the 9th month of life and was based on a neurological assessment.It could be shown that a completely correct assessment at the age of 2 months precludes future severe motor development disorders, especially cerebral palsy, although it does not rule out a slight delay. Prematurity and the analyzed risk factors, particularly IVH, impair the motor performance. The absence of axial symmetry, the shoulders protraction and improper position of the pelvis are the most important alarming features at the 2nd month. Distal elements observed in the prone position at the 6th month show a good prognosis for the motor performance in the 9th month. Any abnormalities, mainly related to the body axis and symmetry observed at 2 months of age should encourage one to put a child under observation.     

The effect of preterm birth on infant negative affect and maternal postpartum depressive symptoms: A preliminary examination in an underrepresented minority sample

ObjectiveTo examine the effect of preterm birth on maternal postpartum depressive symptoms and infant negative affect in an underrepresented minority sample.MethodParticipants were 102 mothers and their 3- to 10-month-old infants. Mothers completed the Edinburgh Postnatal Depression Scale and the Infant Behavior Questionnaire-Revised.ResultsRelative to normative samples, the current underrepresented minority sample of mostly Hispanics and Blacks displayed high rates of preterm birth (30%) and maternal postpartum depressive symptoms (17%). Preterm birth had a significant direct effect on postpartum depressive symptoms and infant negative affect. Additionally, there was an indirect effect of postpartum depressive symptoms on the relation between preterm birth and infant negative affect. Specifically, lower birth weight and gestational age predicted higher levels of depressive symptoms in the mother, and higher levels of depressive symptoms in the mother, in turn, predicted higher levels of infant negative affect.ConclusionFindings emphasize the importance of screening for postpartum depressive symptoms and infant negative affect among mothers and their preterm infants, especially among families from underrepresented minority backgrounds.     

The influence of a hand preference for acquiring objects on the development of a hand preference for unimanual manipulation from 6 to 14 months

Development of hand preferences for unimanual manipulation of objects was explored in 90 infants (57 males) tested monthly from 6 to 14 months. From a larger sample of 380 infants, 30 infants with a consistent left hand preference for acquiring objects were matched for sex and development of locomotion skills with 30 infants with a consistent right hand preference for acquisition and 30 with no preference. Although frequency of unimanual manipulations increased during 6–14 month period, infants with a hand preference for acquisition did more object manipulations than those without a preference for acquisition. Multilevel modeling of unimanual manipulation trajectories for the three hand-preference groups revealed that hand preferences for unimanual manipulation become more distinctive with age, and the preference is predicted by the hand preference for object acquisition. Infants with a right and left hand preference for object acquisition develop a right and left (respectively) hand preference for unimanual manipulation. However, the majority of infants at each month do not exhibit hand preferences for unimanual manipulation that are unlikely to occur by chance, even by 14 months. The results are consistent with a cascading theory of handedness development in which early preferences (i.e., for acquisition) are transferred to later developing preferences (i.e., for unimanual manipulation).     

Infants' use of category knowledge and object attributes when segregating objects at 8.5 months of age

The current research investigates infants' perception of a novel object from a category that is familiar to young infants: key rings. We ask whether experiences obtained outside the lab would allow young infants to parse the visible portions of a partly occluded key ring display into one single unit, presumably as a result of having categorized it as a key ring. This categorization was marked by infants' perception of the keys and ring as a single unit that should move together, despite their attribute differences. We showed infants a novel key ring display in which the keys and ring moved together as one rigid unit (Move-together event) or the ring moved but the keys remained stationary throughout the event (Move-apart event). Our results showed that 8.5-month-old infants perceived the keys and ring as connected despite their attribute differences, and that their perception of object unity was eliminated as the distinctive attributes of the key ring were removed. When all of the distinctive attributes of the key ring were removed, the 8.5-month-old infants perceived the display as two separate units, which is how younger infants (7-month-old) perceived the key ring display with all its distinctive attributes unaltered. These results suggest that on the basis of extensive experience with an object category, infants come to identify novel members of that category and expect them to possess the attributes typical of that category.