| 1. |
- Hopkins, Brian, et al.
(författare)
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Human handedness : developmental, and evolutionary perspectives
- 1998
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Ingår i: The development of sensory, motor and cognitive capacities in early infancy. - Hove, East Sussex, UK : Psychology Press. - 0863775128 ; , s. 191-236
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Bokkapitel (refereegranskat)abstract
- Argues (1) that handedness in humans has a greater evolutionary depth than speech and language and perhaps even habitual bipedalism, (2) that the developmental origins of handedness are based on different mechanisms than for speech and language, (3) that there is no simple task (e.g., reaching) that will provide a valid index of handedness during the 1st year, (4) that studies on the development of handedness need to be more sensitive to the roles of task and S variables, and (5) that the development of handedness should be addressed by models that incorporate hand preference into different modes of bimanual coordination. Topics discussed include: the ontology of handedness, the evolutionary origins of handedness, the developmental origins of human handedness, and the development of handedness in newborns and beyond.
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| 2. |
- Rönnqvist, Louise, 1957-, et al.
(författare)
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Head position preference in the human newborn : a new look
- 1998
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Ingår i: Child Development. - : Blackwell Publishing. - 0009-3920 .- 1467-8624. ; 69:1, s. 13-23
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Tidskriftsartikel (refereegranskat)abstract
- Head position preference was studied in 20 awake newborns who differed in terms of delivery and sex. They were placed supine on a custom-built platform to reduce the effects of gravity and asymmetries in trunk posture and skull shape. A global and a specific scoring method were used, the infants being in State 3 (quiet wakefulness) or 4 (active wakefulness, excluding crying). Delivery and sex did not account for differences in head position. The head turned more often to the right and was maintained longer in this position during State 3, regardless of scoring method. The maintenance of the head in midline was comparable in duration to that reported for infants at 2–3 months when using the global scoring method. This suggests that the neural mechanisms responsible for attaining and maintaining a midline position are present at birth, but are not functionally expressed due to a lack of adequate power in the antigravity muscles of the neck.
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| 3. |
- Rönnqvist, Louise, 1957-, et al.
(författare)
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Lateral biases in head turning and the Moro response in the human newborn : are they both vestibular in origin?
- 1998
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Ingår i: Developmental Psychobiology. - 0012-1630 .- 1098-2302. ; 33:4, s. 339-349
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Tidskriftsartikel (refereegranskat)abstract
- Head turning after release from the midline and the Moro response to a full-body drop in 15 full-term newborns lying supine on a custom-built platform was studied. While the lateral bias for head turning was not as pronounced as for the Moro response, it was still assumed in the ratio of 2 (right):1 (left) as predicted by Previc (1991). Onset latency and time-to-peak acceleration were both significantly shorter in the right arm during the initial phase of the Moro response. For both measures, this right arm bias persisted over four consecutive elicitations in most infants. Vaginally delivered infants and those born by Caesarean section did not differ in terms of head preference and the two measures of arm advantage. Our main finding was that infants with a right-sided head preference had a consistently shorter onset latency for the right arm. We interpret this association as stemming from a common labyrinthine asymmetry that involves different vestibulospinal pathways for the neck and arm muscles. In general, our findings are discussed in the context of Previc's (1991) left-otolithic dominance hypothesis and Grattan, De Vos, Levy, and McClintock's (1992) model of newborn functional asymmetries.
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