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C F Tyner

Publications and source records attributed to C F Tyner.

13 recordsLinked to original sources
PubMed1989

Performance of a weight-lifting task by normal and deafferented monkeys.

The role of topographic information from a moving limb in controlling the trajectory of the limb was explored by comparing the ability of 3 normal and 2 unilaterally deafferented monkeys to generate criterion elbow flexions when opposed by different weights. When lifting initially unknown weights, both groups of monkeys reached maximum positions that were inversely related to load. The performance of the deafferented monkeys approached that of the normal monkeys on these first lifts of initially unknown weights. The preceding load had a greater effect on the initial lifts of the deafferented monkeys than on those of the normal monkeys. When allowed to repeatedly lift the same weight, both groups obtained a high density of reinforcement, but the responses of the deafferented monkeys were more dependent on the weight. The results are consistent with the hypothesis that the mechanical properties of muscle make an important contribution to compensation.

Afferent Pathways↗
PubMed1981

Weight-lifting by normal and deafferented monkeys: evidence for compensatory changes in ongoing movements.

When trained in a weight-lifting paradigm, both normal and deafferented monkeys achieved high reinforcement densities at all test weights employed. Recordings of acceleration on the first lift of an unknown weight reveal that at some delay after the start of movement deafferented monkeys can alter the subsequent trajectory by a sudden change in applied torque. Comparison with normal animals indicates that short latency feedback pathways in normal animals contribute to the smoothness of movements made in the face of unknown external loads.

Afferent Pathways↗
PubMed1975

The naming of neurons: applications of taxonomic theory to the study of cellular populations.

For many purposes, biologists must study large brains through groups of similar neurons, since these populations - not individual cells - are the smallest units for which exact counterparts can be recognized unequivocally across a series of brains. One who surveys singel neurons, by whatever techniques, may discern major aspects of a tissue's organization by classifying the elements studied, thereby performing an exercise in taxonomy at the cellular level. The discovery of neuronal types is best achieved by imitating the naturalist who seeks new biological species: a large sample of cells is gathered by a regular, widely effective method, and an effort is made to understand the biases in the sampling procedure; a numerous and diverse set of features is observed for each neuron encountered; and the cell sets recognized are described in agreement with the polythetic concept of natural groups. The resulting multidimensional population descriptions, the most useful of which include the temporal information available through electrophysiologic recording, may be quite powerful for testing circuit hypotheses about the large nervous system.

Classification↗