Stimulus location probability regulates spatial attention

E. Leslie Cameront, Paul Glimcher

Research output: Contribution to journalArticle

Abstract

Purpose, To test the hypothesis that vbual spatial attention can affect performance on a simple brightness discrimination task. We have quantified attention by measuring performance while manipulating stimulus location probabilities. Methods. Observers (two humans and two monkeys) fixated while a snprathreshold stimulus, on which tl ey were to make a simple brightness discrimination judgement, was briefly pre rented at one of five locations, 12 deg. from fixation. We parametrically manipulated I he distribution of probabilities that governed the trial-by-trial location at which the dis;riminant stimulus would be presented. We determined brightness discrimination thresholds, in a baseline condition, in which the discriminant stimulus occurred 100% of he time at a middle location. Operating at discrimination threshold, we examined four other conditions in blocks; (!) the stimulus appeared 80% of the time at the middle location and 5% at each of four other flanking locations; (2) the stimulus appeared 50% of the time at the middle location and 12 or 13% at the other locations; (3) Itie stimulus appeared with equal probability (20%) at all five locations, and (4) the Uimulus appeared 40% of the time at two flanking locations and 6 or 7% of the tiiru at the three other locations. In Experiment 2 we measured performance using the same distributions of probability but at brightness discriminations above and belt w threshold. Results. In Experiment 1 we found that performance varied as a function ol stimulus location probability. Performance at a given spatial location improved as the probability of stimulus appearance at th it location increased. In Experiment 2 we found that stimulus location probabi ity imposed a smaller effect when the discrimination was performed either abov; or below threshold. Conclusions. We have quantified vhual spatial attention and find that attention affects performance on a simple discrimination task.

Original languageEnglish (US)
JournalInvestigative Ophthalmology and Visual Science
Volume38
Issue number4
StatePublished - 1997

Fingerprint

Haplorhini
Discrimination (Psychology)

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Stimulus location probability regulates spatial attention. / Leslie Cameront, E.; Glimcher, Paul.

In: Investigative Ophthalmology and Visual Science, Vol. 38, No. 4, 1997.

Research output: Contribution to journalArticle

@article{cf444e891b934058a3904d54a65dc404,
title = "Stimulus location probability regulates spatial attention",
abstract = "Purpose, To test the hypothesis that vbual spatial attention can affect performance on a simple brightness discrimination task. We have quantified attention by measuring performance while manipulating stimulus location probabilities. Methods. Observers (two humans and two monkeys) fixated while a snprathreshold stimulus, on which tl ey were to make a simple brightness discrimination judgement, was briefly pre rented at one of five locations, 12 deg. from fixation. We parametrically manipulated I he distribution of probabilities that governed the trial-by-trial location at which the dis;riminant stimulus would be presented. We determined brightness discrimination thresholds, in a baseline condition, in which the discriminant stimulus occurred 100{\%} of he time at a middle location. Operating at discrimination threshold, we examined four other conditions in blocks; (!) the stimulus appeared 80{\%} of the time at the middle location and 5{\%} at each of four other flanking locations; (2) the stimulus appeared 50{\%} of the time at the middle location and 12 or 13{\%} at the other locations; (3) Itie stimulus appeared with equal probability (20{\%}) at all five locations, and (4) the Uimulus appeared 40{\%} of the time at two flanking locations and 6 or 7{\%} of the tiiru at the three other locations. In Experiment 2 we measured performance using the same distributions of probability but at brightness discriminations above and belt w threshold. Results. In Experiment 1 we found that performance varied as a function ol stimulus location probability. Performance at a given spatial location improved as the probability of stimulus appearance at th it location increased. In Experiment 2 we found that stimulus location probabi ity imposed a smaller effect when the discrimination was performed either abov; or below threshold. Conclusions. We have quantified vhual spatial attention and find that attention affects performance on a simple discrimination task.",
author = "{Leslie Cameront}, E. and Paul Glimcher",
year = "1997",
language = "English (US)",
volume = "38",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "4",

}

TY - JOUR

T1 - Stimulus location probability regulates spatial attention

AU - Leslie Cameront, E.

AU - Glimcher, Paul

PY - 1997

Y1 - 1997

N2 - Purpose, To test the hypothesis that vbual spatial attention can affect performance on a simple brightness discrimination task. We have quantified attention by measuring performance while manipulating stimulus location probabilities. Methods. Observers (two humans and two monkeys) fixated while a snprathreshold stimulus, on which tl ey were to make a simple brightness discrimination judgement, was briefly pre rented at one of five locations, 12 deg. from fixation. We parametrically manipulated I he distribution of probabilities that governed the trial-by-trial location at which the dis;riminant stimulus would be presented. We determined brightness discrimination thresholds, in a baseline condition, in which the discriminant stimulus occurred 100% of he time at a middle location. Operating at discrimination threshold, we examined four other conditions in blocks; (!) the stimulus appeared 80% of the time at the middle location and 5% at each of four other flanking locations; (2) the stimulus appeared 50% of the time at the middle location and 12 or 13% at the other locations; (3) Itie stimulus appeared with equal probability (20%) at all five locations, and (4) the Uimulus appeared 40% of the time at two flanking locations and 6 or 7% of the tiiru at the three other locations. In Experiment 2 we measured performance using the same distributions of probability but at brightness discriminations above and belt w threshold. Results. In Experiment 1 we found that performance varied as a function ol stimulus location probability. Performance at a given spatial location improved as the probability of stimulus appearance at th it location increased. In Experiment 2 we found that stimulus location probabi ity imposed a smaller effect when the discrimination was performed either abov; or below threshold. Conclusions. We have quantified vhual spatial attention and find that attention affects performance on a simple discrimination task.

AB - Purpose, To test the hypothesis that vbual spatial attention can affect performance on a simple brightness discrimination task. We have quantified attention by measuring performance while manipulating stimulus location probabilities. Methods. Observers (two humans and two monkeys) fixated while a snprathreshold stimulus, on which tl ey were to make a simple brightness discrimination judgement, was briefly pre rented at one of five locations, 12 deg. from fixation. We parametrically manipulated I he distribution of probabilities that governed the trial-by-trial location at which the dis;riminant stimulus would be presented. We determined brightness discrimination thresholds, in a baseline condition, in which the discriminant stimulus occurred 100% of he time at a middle location. Operating at discrimination threshold, we examined four other conditions in blocks; (!) the stimulus appeared 80% of the time at the middle location and 5% at each of four other flanking locations; (2) the stimulus appeared 50% of the time at the middle location and 12 or 13% at the other locations; (3) Itie stimulus appeared with equal probability (20%) at all five locations, and (4) the Uimulus appeared 40% of the time at two flanking locations and 6 or 7% of the tiiru at the three other locations. In Experiment 2 we measured performance using the same distributions of probability but at brightness discriminations above and belt w threshold. Results. In Experiment 1 we found that performance varied as a function ol stimulus location probability. Performance at a given spatial location improved as the probability of stimulus appearance at th it location increased. In Experiment 2 we found that stimulus location probabi ity imposed a smaller effect when the discrimination was performed either abov; or below threshold. Conclusions. We have quantified vhual spatial attention and find that attention affects performance on a simple discrimination task.

UR - http://www.scopus.com/inward/record.url?scp=33749117762&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749117762&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33749117762

VL - 38

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 4

ER -