title: Division of labor in hand usage is associated with higher hand performance in free-ranging bonnet macaques, Macaca radiate [corrected].
abstract: A practical approach to understanding lateral asymmetries in body, brain, and cognition would be to examine the performance advantages/disadvantages associated with the corresponding functions and behavior. In the present study, we examined whether the division of labor in hand usage, marked by the preferential usage of the two hands across manual operations requiring maneuvering in three-dimensional space (e.g., reaching for food, grooming, and hitting an opponent) and those requiring physical strength (e.g., climbing), is associated with higher hand performance in free-ranging bonnet macaques, Macaca radiate [corrected]. We determined the extent to which the macaques exhibit laterality in hand usage in an experimental unimanual and a bimanual food-reaching task, and the extent to which manual laterality is associated with hand performance in an experimental hand-performance-differentiation task. We observed negative relationships between (a) the latency in food extraction by the preferred hand in the hand-performance-differentiation task (wherein, lower latency implies higher performance), the preferred hand determined using the bimanual food-reaching task, and the normalized difference between the performance of the two hands, and (b) the normalized difference between the performance of the two hands and the absolute difference between the laterality in hand usage in the unimanual and the bimanual food-reaching tasks (wherein, lesser difference implies higher manual specialization). Collectively, these observations demonstrate that the division of labor between the two hands is associated with higher hand performance.
authors: Department of Psychology, University of Georgia, Athens, Georgia, United States of America.
authors: Madhur
authors: M
authors: Mangalam
authors: Indian Institute of Science Education and Research Pune, Pune, India.
authors: Nisarg
authors: N
authors: Desai
authors: Biopsychology Laboratory, and Institute of Excellence, University of Mysore, Mysore, India; Evolutionary & Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India.
authors: Mewa
authors: M
authors: Singh
mesh_terms: D000818:Animals; D005260:Female; D005502:Food; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000502:physiology*; D008255:Macaca radiata; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*