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Titolo:
Signal detection theory in the 2AFC paradigm: attention, channel uncertainty and probability summation
Autore:
Tyler, CW; Chen, CC;
Indirizzi:
Smith Kettlewell Eye Res Inst, San Francisco, CA 94115 USA Smith Kettlewell Eye Res Inst San Francisco CA USA 94115 co, CA 94115 USA
Titolo Testata:
VISION RESEARCH
fascicolo: 22, volume: 40, anno: 2000,
pagine: 3121 - 3144
SICI:
0042-6989(2000)40:22<3121:SDTIT2>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
SPATIAL-FREQUENCY; CONTRAST DETECTION; CORTICAL-NEURONS; HUMAN-VISION; PSYCHOMETRIC FUNCTION; THRESHOLD; MODELS; SLOPE; DISCRIMINATION; MONKEY;
Keywords:
psychophysics; summation; probability summation; 2AFC; attention; uncertainty; signal detection theory; additive noise; multiplicative noise;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
31
Recensione:
Indirizzi per estratti:
Indirizzo: Tyler, CW Smith Kettlewell Eye Res Inst, 2318 Fillmore St, San Francisco, CA 94115 USA Smith Kettlewell Eye Res Inst 2318 Fillmore St San Francisco CA USA 94115
Citazione:
C.W. Tyler e C.C. Chen, "Signal detection theory in the 2AFC paradigm: attention, channel uncertainty and probability summation", VISION RES, 40(22), 2000, pp. 3121-3144

Abstract

Neural implementation of classical High-Threshold Theory reveals fundamental flaws in its applicability to realistic neural systems and to the two-alternative forced-choice (2AFC) paradigm. For 2AFC, Signal Detection Theory provides a basis for accurate analysis of the observer's attentional strategy and effective degree of probability summation over attended neural channels. The resulting theory provides substantially different predictions fromthose of previous approximation analyses. Tn additive noise, attentional probability summation depends on the attentional model assumed. (I) For an ideal attentional strategy in additive noise, summation proceeds at a diminishing rate from an initial level of fourth-root summation for the first fewchannels. The maximum improvement asymptotes to about a factor of 4 by a million channels. (2) For a fixed attention field in additive noise, detection is highly inefficient at first and approximates fourth-root summation through the summation range. (3) In physiologically plausible root-multiplicative noise, on the other hand, attentional probability summation mimics a linear improvement in sensitivity up to about ten channels, approaching a factor of 1000 by a million channels. (4) Some noise sources, such as noise from eye movements, are fully multiplicative and would prevent threshold determination within their range of effectiveness. Such results may require reappraisal of previous interpretations of detection behavior in the 2AFC paradigm. (C) 2000 Elsevier Science Ltd. All rights reserved.

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Documento generato il 03/07/20 alle ore 01:30:09