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Spatial probability AIDS visual stimulus discrimination.

Druker M, Anderson B - Front Hum Neurosci (2010)

Bottom Line: Recent results have suggested that spatial probability can be a cue for the allocation of attention in visual search.This produced fewer spatial repeats and allowed us to dissociate the effect of a high-probability location from that of short-term spatial repetition.These two experiments suggest that inhomogeneities in spatial probability can be learned and used by participants on-line and without prompting as an aid for visual stimulus discrimination and that spatial repetition priming is not a sufficient explanation for this effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Waterloo Waterloo, ON, Canada.

ABSTRACT
We investigated whether the statistical predictability of a target's location would influence how quickly and accurately it was classified. Recent results have suggested that spatial probability can be a cue for the allocation of attention in visual search. One explanation for probability cuing is spatial repetition priming. In our two experiments we used probability distributions that were continuous across the display rather than relying on a few arbitrary screen locations. This produced fewer spatial repeats and allowed us to dissociate the effect of a high-probability location from that of short-term spatial repetition. The task required participants to quickly judge the color of a single dot presented on a computer screen. In Experiment 1, targets were more probable in an off-center hotspot of high-probability that gradually declined to a background rate. Targets garnered faster responses if they were near earlier target locations (priming) and if they were near the high-probability hotspot (probability cuing). In Experiment 2, target locations were chosen on three concentric circles around fixation. One circle contained 80% of targets. The value of this ring distribution is that it allowed for a spatially restricted high-probability zone in which sequentially repeated trials were not likely to be physically close. Participant performance was sensitive to the high-probability circle in addition to the expected effects of eccentricity and the distance to recent targets. These two experiments suggest that inhomogeneities in spatial probability can be learned and used by participants on-line and without prompting as an aid for visual stimulus discrimination and that spatial repetition priming is not a sufficient explanation for this effect. Future models of attention should consider explicitly incorporating the probabilities of targets locations and features.

No MeSH data available.


Related in: MedlinePlus

Mean reaction time as a function of target location and probability; error bars are 95% confidence intervals for each location × probability condition. Targets were either on the inner, middle, or outer circle. For each circle, the right (red) point is for the trials where that circle was the high-probability location, and the left (black) point is for trials where the circle was a low-probability location. This graph is intended to visualize the magnitude and directions of the effects and thus excludes the data from two participants who had mean RTs two standard deviations away from the sample mean. Statistical analyses reported in the text include the data from all participants.
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Figure 6: Mean reaction time as a function of target location and probability; error bars are 95% confidence intervals for each location × probability condition. Targets were either on the inner, middle, or outer circle. For each circle, the right (red) point is for the trials where that circle was the high-probability location, and the left (black) point is for trials where the circle was a low-probability location. This graph is intended to visualize the magnitude and directions of the effects and thus excludes the data from two participants who had mean RTs two standard deviations away from the sample mean. Statistical analyses reported in the text include the data from all participants.

Mentions: To visualize these effects we plotted the mean RTs for all three circles in Figure 6, with targets subdivided by whether the condition had the circle as the high-probability circle. Figure 6 can be viewed in two different ways. One can compare across the circle locations within a probability condition or by focusing on the effect of probability condition for each circle position. The basic pattern suggests that the middle condition was the least affected by the probability manipulation while the rings on the edge of the target location zone, the inner most and outer most, were most affected by being high- and low-probability locations. The slowest location, the outer circle, benefited the most from being the high-probability location.


Spatial probability AIDS visual stimulus discrimination.

Druker M, Anderson B - Front Hum Neurosci (2010)

Mean reaction time as a function of target location and probability; error bars are 95% confidence intervals for each location × probability condition. Targets were either on the inner, middle, or outer circle. For each circle, the right (red) point is for the trials where that circle was the high-probability location, and the left (black) point is for trials where the circle was a low-probability location. This graph is intended to visualize the magnitude and directions of the effects and thus excludes the data from two participants who had mean RTs two standard deviations away from the sample mean. Statistical analyses reported in the text include the data from all participants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2927278&req=5

Figure 6: Mean reaction time as a function of target location and probability; error bars are 95% confidence intervals for each location × probability condition. Targets were either on the inner, middle, or outer circle. For each circle, the right (red) point is for the trials where that circle was the high-probability location, and the left (black) point is for trials where the circle was a low-probability location. This graph is intended to visualize the magnitude and directions of the effects and thus excludes the data from two participants who had mean RTs two standard deviations away from the sample mean. Statistical analyses reported in the text include the data from all participants.
Mentions: To visualize these effects we plotted the mean RTs for all three circles in Figure 6, with targets subdivided by whether the condition had the circle as the high-probability circle. Figure 6 can be viewed in two different ways. One can compare across the circle locations within a probability condition or by focusing on the effect of probability condition for each circle position. The basic pattern suggests that the middle condition was the least affected by the probability manipulation while the rings on the edge of the target location zone, the inner most and outer most, were most affected by being high- and low-probability locations. The slowest location, the outer circle, benefited the most from being the high-probability location.

Bottom Line: Recent results have suggested that spatial probability can be a cue for the allocation of attention in visual search.This produced fewer spatial repeats and allowed us to dissociate the effect of a high-probability location from that of short-term spatial repetition.These two experiments suggest that inhomogeneities in spatial probability can be learned and used by participants on-line and without prompting as an aid for visual stimulus discrimination and that spatial repetition priming is not a sufficient explanation for this effect.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Waterloo Waterloo, ON, Canada.

ABSTRACT
We investigated whether the statistical predictability of a target's location would influence how quickly and accurately it was classified. Recent results have suggested that spatial probability can be a cue for the allocation of attention in visual search. One explanation for probability cuing is spatial repetition priming. In our two experiments we used probability distributions that were continuous across the display rather than relying on a few arbitrary screen locations. This produced fewer spatial repeats and allowed us to dissociate the effect of a high-probability location from that of short-term spatial repetition. The task required participants to quickly judge the color of a single dot presented on a computer screen. In Experiment 1, targets were more probable in an off-center hotspot of high-probability that gradually declined to a background rate. Targets garnered faster responses if they were near earlier target locations (priming) and if they were near the high-probability hotspot (probability cuing). In Experiment 2, target locations were chosen on three concentric circles around fixation. One circle contained 80% of targets. The value of this ring distribution is that it allowed for a spatially restricted high-probability zone in which sequentially repeated trials were not likely to be physically close. Participant performance was sensitive to the high-probability circle in addition to the expected effects of eccentricity and the distance to recent targets. These two experiments suggest that inhomogeneities in spatial probability can be learned and used by participants on-line and without prompting as an aid for visual stimulus discrimination and that spatial repetition priming is not a sufficient explanation for this effect. Future models of attention should consider explicitly incorporating the probabilities of targets locations and features.

No MeSH data available.


Related in: MedlinePlus