Introduction Both animals and humans manifest social qualities. Dogs recognize dominance and submission, stand corrected by their superiors, demonstrate consistent personalities, and so forth. On the other hand, only humans communicate using language, and carry on conversations with one another. And the skills of conversation have developed in humans in such a way as to exploit all of the uniqu...

Gorillas are more closely related to each other than to any other extant primate and are all terrestrial knuckle-walkers, but taxa differ along a gradient of dietary strategies and the frequency of arboreality in their behavioral repertoire. In this study, we test the hypothesis that medial cuneiform morphology falls on a morphocline in gorillas that tracks function related to hallucial abducti...

This study investigated the effects of a specific regimen of resistance training on coordinated actions of human hand digits during grasping. Participants were instructed to hold a rectangular object with all five digits and to maintain the orientation of the object against transient perturbation. Indices of co-varied actions (i.e., synergies) among multi-digit grasping and rotational actions w...

This study questions the validity of the principle of a proximo-distal direction of motor development and the idea that distal skill emerges out of and is dependent upon proximal control. To determine the relationship between proximal and distal motor function, 12 normal infants (9 girls, 3 boys), 30-weeks of age, were recorded on videotape while reaching for a one-inch red cube contained in a ...

Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overl...

Because the way we grasp an object varies depending on the intention with which the object is grasped, monitoring the properties of prehensile movements may provide access to a person's intention. Here we investigate the role of visual kinematics in the implicit coding of intention, by using functional brain imaging while participants observed grasping movements performed with social versus ind...

The modern primates are a diverse order of mammals that includes lemurs, lorises, tarsiers, monkeys, apes and humans. They are united by a 65 My evolutionary history originally built on an adaptive foundation of tropical arboreality and so they share a collection of traits that are unique among mammals, such as an excellent sense of balance, acute vision, good hand–eye coordination, a large gra...

Kinematic studies to date have not considered in what ways surface markers may affect the performance of the analyzed motion. This neglect is particularly apparent in studies of prehensile movements involving surface markers attached to the fingers. In order to specify any such effects, a range of kinematic parameters derived from simple reach-to-grasp movements, both with and without finger ma...