P. Marshall

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A variant of a sparse distributed memory (SDM) is shown to have the capability of storing and recalling patterns containing rank-order information. These are patterns where information is encoded not only in the subset of neuron outputs that fire, but also in the order in which that subset fires. This is an interesting companion to several recent works in(More)
It is important to establish whether presumed differences among varieties of motor responses are manifested in related differences in performance. In order to determine possible functional distinctions between closed and open kinetic chain tasks, participants' performance in the presence or absence of cognitive distraction on an error-detection task was(More)
Two preliminary investigations were conducted on the error detection and error correction capabilities on a simple motor task of young, middle-aged and elderly adults. The error detection task assessed the subjects' ability to discriminate which of two test movements was the same as a previously presented criterion movement. The error correction task(More)
The purpose of this study was to extend the findings of age-related changes in force fluctuation of musculature of the lower extremity by examining whether accuracy of movement differs between young, middle-aged, and older adults depending on the angular position of the lower leg when completing a continuous tracking task. Participants were 24 healthy young(More)
The purpose of this study was to establish if osteoarthritis in older adults was associated with ability to accurately and continuously track leg movement in a model of therapy to improve age-related impairments of proprioception, kinesthesia, and coordination of muscles at the knee joint. 24 older adults without osteoarthritis and 24 older adults with(More)
Five experiments were conducted to investigate potential structural and functional differences in verbal mediators given by young and elderly adults to CVC material. Experiment 1 found no significant differences in the complexity and flexibility of mediator formation by the two age groups. Experiment 2 replicated these findings using a different sample and(More)
UNLABELLED BACKGROUND/STUDY CONTEXT: Much has been written regarding age-related changes in sensory and motor functions, general slowing of the nervous system, and deficiencies in inhibition. Few studies, however, have attempted to define how each of these factors may contribute to poorer accuracy of motor performance with aging. The purpose of this study(More)
We report rate coefficients for the relaxation of OH(v=1) and OD(v=1) by H2O and D2O as a function of temperature between 251 and 390 K. All four rate coefficients exhibit a negative dependence on temperature. In Arrhenius form, the rate coefficients for relaxation (in units of 10(-12) cm3 molecule-1 s-1) can be expressed as: for OH(v=1)+H2O between 263 and(More)