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Full-Text Articles in Psychology
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 …
Corpus Callosal Microstructure Influences Intermanual Transfer In Chimpanzees, Kimberley A. Phillips, J. Schaeffer, William D. Hopkins
Corpus Callosal Microstructure Influences Intermanual Transfer In Chimpanzees, Kimberley A. Phillips, J. Schaeffer, William D. Hopkins
Psychology Faculty Research
Learning a new motor skill with one hand typically results in performance improvements in the alternate hand. The neural substrates involved with this skill acquisition are poorly understood. We combined behavioral testing and non-invasive brain imaging to study how the organization of the corpus callosum was related to intermanual transfer performance in chimpanzees. Fifty-three chimpanzees were tested for intermanual transfer of learning using a bent-wire task. Magnetic resonance and diffusion tensor images were collected from 39 of these subjects. The dominant hand showed greater performance benefits than the nondominant hand. Further, performance was associated with structural integrity of the 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. …
Topography Of The Chimpanzee Corpus Callosum, Kimberley A. Phillips, William D. Hopkins
Topography Of The Chimpanzee Corpus Callosum, Kimberley A. Phillips, William D. Hopkins
Psychology Faculty Research
The corpus callosum (CC) is the largest commissural white matter tract in mammalian brains, connecting homotopic and heterotopic regions of the cerebral cortex. Knowledge of the distribution of callosal fibers projecting into specific cortical regions has important implications for understanding the evolution of lateralized structures and functions of the cerebral cortex. No comparisons of CC topography in humans and great apes have yet been conducted. We investigated the topography of the CC in 21 chimpanzees using high-resolution magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Tractography was conducted based on fiber assignment by continuous tracking (FACT) algorithm. We expected …
Evolution Of The Cerebellar Cortex: The Selective Expansion Of Prefrontal-Projecting Cerebellar Lobules, J. H. Balsters, E. Cussans, J. Diedrichsen, Kimberley A. Phillips, T. M. Preuss, J. K. Rilling, N. Ramnani
Evolution Of The Cerebellar Cortex: The Selective Expansion Of Prefrontal-Projecting Cerebellar Lobules, J. H. Balsters, E. Cussans, J. Diedrichsen, Kimberley A. Phillips, T. M. Preuss, J. K. Rilling, N. Ramnani
Psychology Faculty Research
It has been suggested that interconnected brain areas evolve in tandem because evolutionary pressures act on complete functional systems rather than on individual brain areas. The cerebellar cortex has reciprocal connections with both the prefrontal cortex and motor cortex, forming independent loops with each. Specifically, in capuchin monkeys cerebellar cortical lobules Crus I and Crus II connect with prefrontal cortex, whereas the primary motor cortex connects with cerebellar lobules V, VI, VIIb, and VIIIa. Comparisons of extant primate species suggest that the prefrontal cortex has expanded more than cortical motor areas in human evolution. Given the enlargement of the prefrontal …