EVENT RELATED POTENTIAL SIGNS OF SELECTIVE ATTENTION: THE EFFECT OF CHANNEL PROBABILITY ON PROCESSING NEGATIVITY.
Item
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Title
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EVENT RELATED POTENTIAL SIGNS OF SELECTIVE ATTENTION: THE EFFECT OF CHANNEL PROBABILITY ON PROCESSING NEGATIVITY.
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Identifier
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AAI8629672
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identifier
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8629672
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Creator
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BERMAN, STEVEN MARK.
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Date
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1986
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Clinical
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Abstract
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Event-related potentials have been shown to be a useful tool for investigating mechanisms of selective attention. When auditory, visual, or somatosensory events occur in unpredictable sequences of two possible "channels", stimuli in the channel where subjects are instructed to attend evoke an area of greater negativity than the identical stimuli on runs where they are in the unattended channel. In the auditory modality, this "processing negativity" or "Nd" is thought to reflect an early selection process which may depend on construction of an internal template of the attended perceptual event. One theory proposes that the event represented by the template must be frequently experienced to maintain the Nd effect.;Other electrical correlates of attention have been shown to be sensitive to manipulations of event probability. While current views of the processing negativity propose insensitivity to channel probability, or a difficulty in maintaining the Nd effect as attended channel probability decreases, no previous study was designed to test these predictions.;A systematic manipulation of channel probability was administered to 11 volunteers. Both standard tones consistently show the expected signs of selective attention when the attended channel has a probability of under 70%, but not for probabilities of 70% to 90%. At these higher probabilities, the subtraction Nd (as attended minus as unattended) is greatly reduced or absent. For both high and low tones, this change is due to the appearence of processing-like negativity in the waveform of the unattended standards at high channel probabilities. Low channel probabilities tend to show larger Nds than the 50/50 condition. Deviant long tones show similar early Nds, and also tend to develop late attention-related negativity about 500 msec.;The finding of decreased Nd in high probability channels must be reconciled with current views on the effects of channel probability on processing negativity. In general, the findings are interpreted as representing a changing pattern of adaptive cognitive strategies with sufficiently unequal probability channels. Appendix A presents a general framework developed by the author to integrate ERP work on attention with the work of other scientists.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Psychology
