title: Is early manual preference in infants defined by intermanual performance asymmetry in reaching?
abstract: In the present study we evaluated the relationship between manual preference and intermanual performance asymmetry in reaching of 5-month-old infants. Manual preference was assessed through frequency of reaches toward toys presented at midline, left or right in egocentric coordinates. Intermanual performance asymmetry was evaluated through kinematic analysis. Results showed that performance was predominantly symmetric between hands. Lateral toy positions induced predominance of ipsilateral reaching, while the midline position led to equivalent distribution between right and left handed reaches. No significant correlation between manual preference and intermanual performance asymmetry was observed. These results converge against the notion that manual preference derives from a genetically determined advantage of movement control favoring the right hand.
authors.affiliation: Human Motor Systems Laboratory, University of São Paulo, São Paulo, Brazil. romasouza@yahoo.com.br
authors.forename: Rosana Machado
authors.initials: RM
authors.lastname: Souza
authors.forename: Raymundo Machado
authors.initials: RM
authors.lastname: de Azevedo Neto
authors.forename: Eloisa
authors.initials: E
authors.lastname: Tudella
authors.forename: Luis Augusto
authors.initials: LA
authors.lastname: Teixeira
mesh_terms: D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007223:Infant; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology