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M C Polson

Publications and source records attributed to M C Polson.

4 recordsLinked to original sources
PubMed1982

Dividing attention within and between hemispheres: testing a multiple resources approach to limited-capacity information processing.

Two experiments tested the limiting case of a multiple resources approach to resource allocation in information processing. In this framework, the left and right hemispheres are assumed to have separate, limited-capacity pools of undifferentiated resources that are not mutually accessible, so that tasks can overlap in their demand for these resources either completely, partially, or not at all. We tested all three degrees of overlap in demand for left hemisphere supplies, using dual-task methodology in which subjects were induced to pay different amounts of attention to each task. Experiment 1 compared complete and partial overlap by combining a verbal memory load with a task in which subjects named nonsense syllables briefly presented to either the left or right visual field (LVF and RVF, respectively). Experiment 2 compared complete versus no overlap by using the same verbal memory load combined with a laterally presented same-different judgment task that did not require a spoken response. Decrements from single-task performance were always more severe when the visual field task stimulus was presented to the RVF. Further, subjects in Experiment 1 were able to trade performance between tasks on both LVF and RVF trials because there was always at least some overlap in left hemisphere demand. In Experiment 2, performance trade-offs were observed on RVF (complete overlap) trials, but not on LVF trials, where no overlap in demand existed. These results contradict a single-capacity model, but they support the idea that the hemispheres' resource supplies are independent and have implications for both cerebral specialization and divided attention issues.

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PubMed1981

Hemispheres as independent resource systems: limited-capacity processing and cerebral specialization.

In this article, we develop as framework for understanding how cerebral specialization of function contributes to the flexibility of human information processing. We propose that the left and right hemispheres together form a system of two mutually inaccessible and finite pools of resources. Further, we propose that these two types of resources cannot be made available in different amounts at any given time. This framework is essentially a special case of a multiple-resources model of limited-capacity information processing. It accounts for a broad range of data from experiments involving perceptual and cognitive information processing, control of motor performance, and changes in electrical activity of the brain. It also provides insights into why the cerebral specialization literature has been plagued with problems that have made theorizing so difficult. In addition, the theory provides insights into mechanisms that might be responsible for patterns of task interference that are not easily handled by an information-processing model in which processes compete for supplies from a single pool of undifferentiated resources. Thus, the framework we are proposing has important theoretical and methodological implications for researchers in both divided attention and cerebral specialization.

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