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Full-Text Articles in Psychology
Handedness For Unimanual Grasping In 564 Great Apes: The Effect On Grip Morphology And A Comparison With Hand Use For A Bimanual Coordinated Task, A. Meguerditchian, Kimberley A. Phillips, A. Chapelain, L. M. Mahovetz, S. Milne, T. Stoinski, A. Bania, E. V. Lonsdorf, J. Schaeffer, J. Russell, William D. Hopkins
Handedness For Unimanual Grasping In 564 Great Apes: The Effect On Grip Morphology And A Comparison With Hand Use For A Bimanual Coordinated Task, A. Meguerditchian, Kimberley A. Phillips, A. Chapelain, L. M. Mahovetz, S. Milne, T. Stoinski, A. Bania, E. V. Lonsdorf, J. Schaeffer, J. Russell, William D. Hopkins
Psychology Faculty Research
A number of factors have been proposed to influence within and between species variation in handedness in non-human primates. In the initial study, we assessed the influence of grip morphology on hand use for simple reaching in a sample of 564 great apes including 49 orangutans Pongo pygmaeus, 66 gorillas Gorilla gorilla, 354 chimpanzees Pan troglodytes and 95 bonobos Pan paniscus. Overall, we found a significant right hand bias for reaching. We also found a significant effect of the grip morphology of hand use. Grasping with the thumb and index finger was more prevalent in the right …
Handedness Influences Intermanual Transfer In Chimpanzees (Pan Troglodytes) But Not Rhesus Monkeys (Macaca Mulatta), E. R. Boeving, A. Lacreuse, William D. Hopkins, Kimberley A. Phillips, M. A. Novak, E. L. Nelson
Handedness Influences Intermanual Transfer In Chimpanzees (Pan Troglodytes) But Not Rhesus Monkeys (Macaca Mulatta), E. R. Boeving, A. Lacreuse, William D. Hopkins, Kimberley A. Phillips, M. A. Novak, E. L. Nelson
Psychology Faculty Research
Intermanual transfer refers to an effect whereby training one hand to perform a motor task improves performance in the opposite untrained hand. We tested the hypothesis that handedness facilitates intermanual transfer in two nonhuman primate species: rhesus monkeys (N = 13) and chimpanzees (N = 52). Subjects were grouped into one of four conditions: (1) left-handers trained with the left (dominant) hand; (2) left-handers trained with the right (non-dominant) hand; (3) right-handers trained with the left (non-dominant) hand; and (4) right-handers trained with the right (dominant) hand. Intermanual transfer was measured using a task where subjects removed a …
Hand Preference For Tool-Use In Capuchin Monkeys (Cebus Apella) Is Associated With Asymmetry Of The Primary Motor Cortex, Kimberley A. Phillips, C. R. Thompson
Hand Preference For Tool-Use In Capuchin Monkeys (Cebus Apella) Is Associated With Asymmetry Of The Primary Motor Cortex, Kimberley A. Phillips, C. R. Thompson
Psychology Faculty Research
Skilled motor actions are associated with handedness and neuroanatomical specializations in humans. Recent reports have documented similar neuroanatomical asymmetries and their relationship to hand preference in some nonhuman primate species, including chimpanzees and capuchin monkeys. We investigated whether capuchins displayed significant hand preferences for a tool use task and whether such preferences were associated with motor-processing regions of the brain. Handedness data on a dipping tool-use task and high-resolution 3T MRI scans were collected from 15 monkeys. Capuchins displayed a significant group-level left-hand preference for this type of tool use, and handedness was associated with asymmetry of the primary motor …
Performance Asymmetries In Tool Use Are Associated With Corpus Callosum Integrity In Chimpanzees (Pan Troglodytes): A Diffusion Tensor Imaging Study, Kimberley A. Phillips, J. Schaeffer, E. A. Barrett, William D. Hopkins
Performance Asymmetries In Tool Use Are Associated With Corpus Callosum Integrity In Chimpanzees (Pan Troglodytes): A Diffusion Tensor Imaging Study, Kimberley A. Phillips, J. Schaeffer, E. A. Barrett, William D. Hopkins
Psychology Faculty Research
The authors examined the relationship of corpus callosum (CC) morphology and organization to hand preference and performance on a motor skill task in chimpanzees. Handedness was assessed using a complex tool use task that simulated termite fishing. Chimpanzees were initially allowed to perform the task wherein they could choose which hand to use (preference measure), then they were required to complete trials using each hand (performance measure). Two measures were used to assess the CC: midsagittal area obtained from in vivo magnetic resonance images and density of transcallosal connections as determined by fractional anisotropy values obtained from diffusion tensor imaging. …
Hand Preference For Coordinated Bimanual Actions In 777 Great Apes: Implications For The Evolution Of Handedness In Hominins, William D. Hopkins, Kimberley A. Phillips, A. Bania, S. E. Calcutt, M. Gardner, J. Russell, J. Schaeffer, E. V. Lonsdorf, S. R. Ross, S. J. Schapiro
Hand Preference For Coordinated Bimanual Actions In 777 Great Apes: Implications For The Evolution Of Handedness In Hominins, William D. Hopkins, Kimberley A. Phillips, A. Bania, S. E. Calcutt, M. Gardner, J. Russell, J. Schaeffer, E. V. Lonsdorf, S. R. Ross, S. J. Schapiro
Psychology Faculty Research
Whether or not nonhuman primates exhibit population-level handedness remains a topic of considerable scientific debate. Here, we examined handedness for coordinated bimanual actions in a sample of 777 great apes including chimpanzees, bonobos, gorillas, and orangutans. We found population-level right-handedness in chimpanzees, bonobos and gorillas, but left-handedness in orangutans. Directional biases in handedness were consistent across independent samples of apes within each genus. We suggest that, contrary to previous claims, population-level handedness is evident in great apes but differs among species as a result of ecological adaptations associated with posture and locomotion. We further suggest that historical views of nonhuman …
Cross-Sectional Analysis Of The Association Between Age And Corpus Callosum Size In Chimpanzees (Pan Troglodytes), William D. Hopkins, Kimberley A. Phillips
Cross-Sectional Analysis Of The Association Between Age And Corpus Callosum Size In Chimpanzees (Pan Troglodytes), William D. Hopkins, Kimberley A. Phillips
Psychology Faculty Research
The CC is the major white matter tract connecting the cerebral hemispheres and provides for interhemispheric integration of sensory, motor and higher‐order cognitive information. The midsagittal area of the CC has been frequently used as a marker of brain development in humans. We report the first investigation into the development of the corpus callosum and its regional subdivisions in chimpanzees (Pan troglodytes). Magnetic resonance images were collected from 104 chimpanzees (female n = 63, male n = 41) ranging in age from 6 years (pre‐pubescent period) to 54 years (old age). Sustained linear growth was observed in the …