Effect of large spatial uncertainty on foveal luminance increment detectability

Cohn, Theodore E.; Wardlaw, James C.

doi:10.1364/josaa.2.000820

Cited by 26 publications

(17 citation statements)

References 16 publications

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“…First, however, we must dispose of the expectancy hypothesis. certainty leads to deteriorating performance (Cohn & Wardlaw, 1985;Davis & Graham, 1981). It is possible that an observer's expectancy ofa target color may be responsible for the very large difference in performance seen here.…”

Section: Short-term Memorymentioning

confidence: 79%

Priming of pop-out: I. Role of features

1994

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We examined a visual search task, in which observers responded to the high-acuityaspect of a popout target (shape of an odd-colored diamond or vernier offset of an odd spatial-frequency patch). Repetition of the attention-driving feature (color or spatial frequency) in this task primes the popout; repetition of the high-acuity aspect (shape, vernier offset) does not. Priming of pop-out is due to a decaying memory trace of the attention-focusing feature laid down with each trial. The trace exerts a diminishing effect over the following five to eight trials (-30 sec), and its influence over this time is cumulative. Observers cannot willfully overcome the priming, which suggests that it is passive and autonomous. Both target facilitation and distractor inhibition are evident; the former has a greater effect. The phenomenon shows complete binocular transfer.In a typical visual search experiment, the observer's task is to detect the presence of the odd target within a field of distractors. Two well-known effects have been observed. Serial search is the term attributed to the finding that an increasing number ofdistractors increases the time necessary to find the target, yielding positive slope functions (Sagi & Julesz, 1985;Treisman & Gelade, 1980). Parallel search is the term attributed to the finding that the target is detected equally quickly regardless of the number of distractors, yielding flat reaction time versus distractor number functions. In this situation, the target also "pops out"; that is, attention is automatically drawn to the odd item. The flat functions and the presence of"pop-out" were generally assumed to be causally related. Bravo and Nakayama (1992), however, dissociated these two aspects by adding an additional requirement to the task, which tapped into its attention-focusing aspect. They asked observers to respond to the shape of the odd-colored target, not its presence or absence. It was their claim that responding to the shape necessitates the spatial focusing of attention to the odd target. As such, this task examines the characteristics of attention focusing in pop-out. In contrast, the previously used presence versus absence task does not require the focusing of attention and is not informative regarding the deployment of focal attention.Drawing on theoretical accounts of attentional guidance, Bravo and Nakayama (1992) made a number of experimental predictions. To start, they reviewed two general processes that would be useful for focusing atThis work was supported by AFOSR Grant F49620-92-J-0016 to K.N. We thank Shinsuke Shimojo for his comments on an earlier version of this manuscript. V.Maljkovic is now in the Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology. Correspondence should be addressed to K. Nakayama,

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Section: Short-term Memorymentioning

confidence: 79%

Priming of pop-out: I. Role of features

1994

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“…One recent idea, is that there is a high degree of positional uncertainty in the amblyepic visual system (Cohn & Wardlaw, 1985). Increased positional uncertainty might be expected to produce elevated contrast detection thresholds for localized stimuli (such as thin lines), because the observers would not be able to appropriately direct their attention to the target; however, it would not be expected to have as large an effect upon resolution or spatial interval discrimination thresholds for stimuli that were suprathreshold.…”

Section: Kfodelling the Umblyopic Lossmentioning

confidence: 99%

“…However, there is little agreement on how to model the losses (although there is no shortage of ideas). Among the many (not necessarily distinct) explanations which have been proposed to account for the losses are: (1) intrinsic positional uncertainty (Cohn & Wardlaw, 1985); (2) spatial scrambling (Hess, 1982;Watt & Hess, 1987); (3) reduced sensitivity of the putative spatial filters (Bradley & Freeman, 1985;Levi 8z Klein, 1985;Levi et al, 1987;Wilson, 1986b); (4) spatial undersampling (Levi & Klein, 1986;Levi et al, 1987;Wilson, 1986b); and (5) intrinsic blur (Levi & Klein, 1982Flom, Bedell & Barbeito, 1986).…”

Section: Introductionmentioning

confidence: 99%

Equivalent intrinsic blur in amblyopia

Levi

Klein

1990

Vision Research

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“…However, when we lose track of a cursor's position, it can be difficult to detect because we must now consider hundreds or even thousands of nonoverlapping positions for the cursor. This position uncertainty can reduce the detectability of the target by more than an order of magnitude (Cohn & Wardlaw, 1985). …”

Section: Introductionmentioning

confidence: 99%

“…When eccentricity effects are controlled, researchers have found that performance in a variety of detection and discrimination tasks involving multiple potential target locations is explained largely by the uncertainty that the added locations contribute to the task (e.g., Baldassi & Burr, 2000; Burgess & Ghandeharian, 1984; Cameron et al, 2004; Cohn & Wardlaw, 1985; Cohn & Lasley, 1974; Eckstein & Whiting, 1996; Eckstein, 1998; Eckstein, Thomas, Palmer, & Shimozaki, 2000; Palmer, 1994; Palmer, Ames, & Lindsey, 1993; Shaw, 1982; Swensson & Judy, 1981). …”

Section: Introductionmentioning

confidence: 99%

Intrinsic position uncertainty explains detection and localization performance in peripheral vision

Michel

Geisler

2011

Journal of Vision

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Efficient performance in visual detection tasks requires excluding signals from irrelevant spatial locations. Indeed, researchers have found that detection performance in many tasks involving multiple potential target locations can be explained by the uncertainty the added locations contribute to the task. A similar type of Location Uncertainty may arise within the visual system itself. Converging evidence from hyperacuity and crowding studies suggests that feature localization declines rapidly in peripheral vision. This decline should add inherent position uncertainty to detection tasks. The current study used a modified detection task to measure how intrinsic position uncertainty changes with eccentricity. Subjects judged whether a Gabor target appeared within a cued region of a noisy display. The eccentricity and size of the region varied across blocks. When subjects detected the target, they used a mouse to indicate its location. This allowed measurement of localization as well as detection errors. An ideal observer degraded with internal response noise and position noise (uncertainty) accounted for both the detection and localization performance of the subjects. The results suggest that position uncertainty grows linearly with visual eccentricity and is independent of target contrast. Intrinsic position uncertainty appears to be a critical factor limiting search and detection performance.

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Effect of large spatial uncertainty on foveal luminance increment detectability

Cited by 26 publications

References 16 publications

Priming of pop-out: I. Role of features

Priming of pop-out: I. Role of features

Equivalent intrinsic blur in amblyopia

Intrinsic position uncertainty explains detection and localization performance in peripheral vision

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