title: Versatile grasping ability in power-grip actions by tufted capuchin monkeys (Sapajus spp.).
abstract: OBJECTIVE
  Capuchin monkeys are well known to have a high degree of manual dexterity. In this study, we assessed the variability of capuchin grasping actions involving power grips, i.e., manual actions in which the object is grasped between the palm and one or several parts of the fingers and that do not necessarily involve individually controlled finger movements. Planning abilities in executing actions were also evaluated.
  
  
  METHODS
  Twenty tufted capuchins (Sapajus spp.) were tested in a task requiring individuals to grasp a dowel inserted into a vertical tube. We examined their grasping techniques, focusing on the following aspects: (i) the different hand postures made during grasping, (ii) the frequency of thumb use in opposition to the other fingers, (iii) the asymmetric use of the hands, and (iv) the configuration of the grasping action for the purpose of comfortably bringing the food to the mouth.
  
  
  RESULTS
  Eight power-grip variants were identified, with individual capuchins performing an average of more than five different grips. The use of the thumb in opposition to the other areas of the hand, as reported in studies of precision grips, also appears to be a common feature in power grips. No evidence of group-level manual asymmetries was found. Adult capuchins were better than immature individuals in planning grasping actions in relation to following task demands.
  
  
  CONCLUSIONS
  Overall, these findings clarify the extent to which manual dexterity and cognitive abilities can be expressed in the grasping tasks of highly manually skilled primate species.
authors: Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies, National Research Council (CNR), via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.
authors: Valentina
authors: V
authors: Truppa
authors: Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies, National Research Council (CNR), via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.
authors: Giovanna
authors: G
authors: Spinozzi
authors: Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies, National Research Council (CNR), via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.|School of Veterinary Medicine, University of Teramo, Piazza Aldo Moro 45, 64100 Teramo, Italy.
authors: Tiziana
authors: T
authors: Laganà
authors: Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies, National Research Council (CNR), via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.|Department of Neurobiology, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.
authors: Eva
authors: E
authors: Piano Mortari
authors: Unit of Cognitive Primatology and Primate Center, Institute of Cognitive Sciences and Technologies, National Research Council (CNR), via Ulisse Aldrovandi 16/B, 00197, Rome, Italy.
authors: Gloria
authors: G
authors: Sabbatini
mesh_terms: D000818:Animals; D000885:Anthropology, Physical; D002428:Cebus / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D018737:Hand Strength / Q000502:physiology*; D008297:Male; D013647:Task Performance and Analysis
keywords: action planning; end-state comfort effect; handedness; manual dexterity; platyrrhini