Lateralization of the Grasp Reflex in Male and Female Human Newborns

Tan, Üner; Örs, Rahmi; Kurkcuoglu, Muzaffer; Kutlu, Necíp; Cankaya, A

doi:10.3109/00207459108999768

Cited by 14 publications

(10 citation statements)

References 18 publications

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“…These results conclude that the right brain is most important in determining the facial-width asymmetry in right-handers. In accord with these results, Tan, Ors, Kurkcuoglu, Kutlu, and Cankaya (1992b) have reported that there was a highly significant positive linear correlation between the R -L grasp-reflex strength and the grasp-reflex strength from the right hand in human newborns (r = .74, p = .0000); the correlation between the R -L grasp-reflex strength and the grasp-reflex strength was relatively weaker for the left hand (r = .32, p = .0004) (see also Tan et al, 1992a). These coinciding results (facial asymmetry in adults and grasp reflex in newborns) suggest that the hand skill (brain), the facial asymmetry, and the grasp-reflex asymmetry all may be determined prenatally, having the same origins.…”

Section: Predictability Of Hand Skill By Craniofacial Widthsupporting

confidence: 81%

Predictability of Hand Skill and Cognitive Abilities From Craniofacial Width in Right- And Left-Handed Men and Women: Relation of Skeletal Structure to Cerebral Function

Dayı

Güngörmüş²,

Okuyan³

et al. 2002

International Journal of Neuroscience

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Section: Predictability Of Hand Skill By Craniofacial Widthsupporting

confidence: 81%

Predictability of Hand Skill and Cognitive Abilities From Craniofacial Width in Right- And Left-Handed Men and Women: Relation of Skeletal Structure to Cerebral Function

Dayı

Güngörmüş²,

Okuyan³

et al. 2002

International Journal of Neuroscience

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“…Alternatively, it has been proposed that the behavioral effects of handedness are determined by physiological asymmetries that are present before the opportunity for such experience develops (Annett 1992;Clark et al 1996;Coryell 1985;Drea et al 1995;McManus 1985;Melsbach et al 1996;Tan 1990). According to this idea, handedness emerges from distinctive neural circuits in each hemisphere that are specialized for controlling different aspects of limb movements (Caplan and Kinsbourne 1976;Corryel 1985;Futagi et al 1995;Hepper et al 1991Hepper et al , 1998Konishi et al 1986Konishi et al , 1997Ottaviano et al 1989;Tan et al 1992). It is plausible that the differences in such circuits are related to the facility for modeling and controlling the effects of limb dynamics.…”

Section: Dominant Arm Specialization For Control Of Limb Dynamicsmentioning

confidence: 99%

Handedness: Dominant Arm Advantages in Control of Limb Dynamics

Bagesteiro

Sainburg²

2002

Journal of Neurophysiology

327

262

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Bagesteiro, Leia B. and Robert L. Sainburg. Handedness: dominant arm advantages in control of limb dynamics. J Neurophysiol 88: 2408 -2421, 2002; 10.1152/jn.00901.2001. Recent findings from our laboratory suggest that a major factor distinguishing dominant from nondominant arm performance is the ability by which the effects of intersegmental dynamics are controlled by the CNS. These studies indicated that the dominant arm reliably used more torque-efficient patterns for movements made with similar speeds and accuracy than nondominant arm movements. Whereas, nondominant hand-path curvatures systematically varied with the amplitude of the interaction torques transferred between the segments of the moving limb, dominant hand-path curvatures did not. However, our previous studies did not distinguish whether dominant arm coordination advantages emerged from more effective control of dynamic factors or were simply a secondary effect of planning different kinematics. The purpose of this study was to further investigate interlimb differences in coordination through analysis of inverse dynamics and electromyography recorded during the performance of reaching movements. By controlling the amplitude of intersegmental dynamics in the current study, we were able to assess whether systematic differences in torque-efficiency exist, even when differences in hand-path shape were minimal. Subject's arms were supported in the horizontal plane by a frictionless air-jet system and were constrained to movements about the shoulder and elbow joints. Two targets were designed, such that the interaction torques elicited at the elbow were either large or small. Our results showed that the former produced large differences in hand-path curvature, whereas the latter did not. Additionally, the movements with small differences in hand-path kinematics showed substantial differences in torque patterns and corresponding EMG profiles which implied a more torque-efficient strategy for the dominant arm. In view of these findings we propose that distinct neural control mechanisms are employed for dominant and nondominant arm movements. I N T R O D U C T I O NHandedness, the tendency to prefer the use of a consistent hand in performing selected tasks, is a prominent, yet poorly understood aspect of human motor performance. Whereas it is generally accepted that handedness results from differences in the neural control of each arm, the mechanisms responsible for these differences remain controversial. Previous studies examining handedness have quantified the reaction time, movement time, and final position accuracy of rapid aimed arm movements. Such performance measures were expected to differentiate "open-loop" mechanisms, which by definition are unaffected by sensory feedback, from "closed-loop" mechanisms, which by definition are mediated by sensory feedback. This division was inspired by the ideas of Woodworth (Woodworth 1899) and Fitts (Fitts 1966(Fitts , 1992Fitts and Radford 1966) and is supported by studies contrasting rapid aiming movements ma...

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“…In this context, Tan et al (1992) have quantitatively studied grasp reflex, a primitive spinal reflex, in human neonates. They found that the mean grasp-reflex strength was significantly higher for the right than left hand, but only for the female neonates; the difference between hands was not significant in males.…”

mentioning

confidence: 99%

“…A tendency towards symmetry in males was found to be a result of a stronger grasp reflex from the left hand in males than females; the mean grasp-reflex strengths from the right hand were not significantly different in males and females. Tan et al (1992) had hypothesised that the grasp-reflex asymmetries might foreshadow the development of human hand preference. This argument was recently supported by Hepper, McCartney, and Shannon (1998) as well as by McCartney and Hepper (1999), who observed the left and right arm movements of human foetuses at 10 to 27 weeks gestational age and found that there was a highly significant preference for them to move their right arms (83.3-85%) rather than their left arms.…”

mentioning

confidence: 99%

Testosterone and grasp-reflex differences in human neonates

Tan¹,

Tan²

2001

Laterality

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According to the Geschwind-Behan-Galaburda (GBG) hypothesis, prenatal testosterone (T) causes a slowing in the development of the left brain with a consequent compensatory growth in the right brain, creating a reverse organisation of the cerebral lateralisation. That is, left-and right-handedness might be associated with high and low prenatal T levels, respectively. To test this hypothesis, the relations of T levels (umbilical cord blood) to grasp-reflex strengths were studied in human neonates. Handedness was assessed by measuring the grasp-reflex strengths from the right and left hands in 10 trials from each hand alternatively. There were two handedness groups: right-handers (R-L significantly greater than zero) and left-handers (significantly smaller than zero). Contrary to the GBG model, the mean free T concentration was found to be significantly higher in right-handers than left-handers for males and females. There was no significant difference in the total T levels between right-and left-handers. Free T concentrations positively correlated with R-L grasp-reflex strengths, i.e. righthandedness increased as T increased, and left-handedness increased as T decreased. Contrary to these positive correlations, T negatively correlated with the grasp-reflex strengths from the right and left hands. These results partly supported the GBG hypothesis for this spinal-motor-asymmetry model. Total T did not significantly correlate with grasp-reflex strengths. The results suggest that prenatal T may at least play a role in prenatal determination of spinal motor lateralisation, with a possible consequent upward regulation of cerebral lateralisation.

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Lateralization of the Grasp Reflex in Male and Female Human Newborns

Cited by 14 publications

References 18 publications

Predictability of Hand Skill and Cognitive Abilities From Craniofacial Width in Right- And Left-Handed Men and Women: Relation of Skeletal Structure to Cerebral Function

Predictability of Hand Skill and Cognitive Abilities From Craniofacial Width in Right- And Left-Handed Men and Women: Relation of Skeletal Structure to Cerebral Function

Handedness: Dominant Arm Advantages in Control of Limb Dynamics

Testosterone and grasp-reflex differences in human neonates

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