Handedness for grasping objects and declarative pointing: A longitudinal study

Abstract

It is still unclear whether infants become right-handed because of their left-hemisphere specialization for language (through gestural communication for instance), whether they speak predominantly with their left hemisphere because of this hemisphere's superiority in controlling sequential actions which first results in right-handedness, or whether the two lateralization processes develop independently. To tackle this question, we followed 26 human infants from 8 to 20 months to evaluate the temporal relationship between the emergence of hand preference for grasping objects and for declarative pointing (communicative gesture). Our results show that when grasping and pointing are compared in similar conditions, with objects presented in several spatial positions, the tendency to use the right hand is significantly larger for pointing than for grasping, and both hand preferences are loosely correlated. This suggests that, at least at the age studied here, hand preferences for grasping and for declarative pointing develop relatively independently.

Manual preferences for visually- and haptically-guided grasping

“…Not surprisingly, vision also plays a critical role in hand preference for grasping. During visually-guided grasping tasks, individuals (even some left-handed) exhibit a clear preference to grasp objects with the right-hand (Bishop, Ross, Daniels & Bright, 1996;Calvert & Bishop, 1998;Gabbard & Rabb, 2000;Gonzalez & Goodale, 2009;Jacquet, Esseily, Rider & Fagard, 2012;Stone & Gonzalez, 2014a;Stone, Bryant & Gonzalez, 2013). The role of haptics in hand preference for grasping however, has been seldom investigated.…”

Handedness as a marker of cerebral lateralization in children with and without autism

“…communicative and non-communicative) have not been previously shown to be correlated in young children [e.g. 17,49,[52][53][54]. In fact, a disparate range of experimental paradigms for assessing handedness in children has resulted in a variety of patterns of asymmetries depending hand action function [e.g.…”

Social encouragement can influence manual preference in 6 month-old-infants

“…It is unlikely that mothers deliberately train their infants to use a particular hand. However, during play it is conceivable that the mother’s own handedness may bias the infant’s hand-use (e.g., placing objects near the infant’s right hand) and activate the ipsilateral hand as we have seen (Fagard et al, 2009; Suzuki et al, 2009; Jacquet et al, 2012). Additionally, Michel (1992) has shown that infants match maternal hand-use and that this matching increases with age.…”

“…This manual preference is quantified in terms of speed and/or performance, and scores of handedness can vary depending on the specificity of the task considered (Fagard and Marks, 2000). For example, symbolic gestures such as signing or pointing – which appear in the second year of life during the period of linguistic explosion – elicit a stronger degree of predominance of right-handedness than non-communicative manual actions in young children (Bates et al, 1986; Vauclair and Imbault, 2009; Cochet and Vauclair, 2010b; Jacquet et al, 2012). Studies on handedness are organized around two axes.…”

“…They also become stable (Michel et al, 2006) with a predominance of right hand-use (McDonnell, 1979; Ramsay, 1980; Michel and Harkins, 1986; Michel et al, 1986) even though all babies display a brief phase of left hand preference between 4 and 6 months (Morange and Bloch, 1996; Morange-Majoux et al, 2000; Rönnqvist and Domellöf, 2006; Morange-Majoux and Dellatolas, 2010; Morange-Majoux, 2011). However, finer motor skills, i.e., manipulations other than reaching or grasping are not consistently lateralized as early as 6 months (Jacquet et al, 2012), indicating that although the direction of hand preference can stabilize from 6 months of age for some activities, the strength of handedness preference may still vary. Additionally, the spatial context of objects influences hand-use until 6/7 months in such a way that objects positioned in the right hemifield lead to more frequent use of the right hand, while objects positioned in the left hemifield lead to more frequent use of the left hand (Provine and Westerman, 1979; Morange and Bloch, 1996; Fagard, 1998; Sacco et al, 2006; Fagard et al, 2009; Souza et al, 2012).…”