Integration of texture and color cues for visual shape recognition Toni P. Saarela & Michael S. Landy 1,2
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Contact:
[email protected]
Background
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Department of Psychology & Center for Neural Science, New York University 2 Current address: Department of Psychology, University of Pennsylvania
http://www.cns.nyu.edu/~saarela
Experiment 1: Summation 1
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Experiment: Identification thresholds were measured at several relative texture and color contrasts. Texture and color letters were congruent.
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1 Normalized color contrast
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We tested the integration and interaction of texture and color in a simple shape-recognition task.
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How are the cues integrated in visual segmentation and shape recognition?
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There are thus multiple cues available for segmenting figure from background.
Complete independence Complete independence
Figures differ from their backgrounds in several ways (texture, color, luminance, motion...).
Question: Can observers integrate texture and color cues?
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• Observers perform better with two cues, but cue summation is not perfect.
Normalized texture contrast
Experiment 2: Masking Question: Can observers ignore a task-irrelevant cue?
PERFORMANCE
Task & Stimuli Task: Letter identification. Letter templates: Five Sloan letters: D, N, R, S, Z (http://psych.nyu.edu/pelli/software.html)
Stimuli: • Filtered noise • Carrier spatial frequency 1 cycle/deg
Congruent
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Congruent
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Single-cue
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Conflict
Single-cue Conflict
Conflict Mutual masking
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Congruent
Conflict
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Reported texture letter
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Z S N D R
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Conflicting texture letter
Z S N D R
Performance • Task-irrelevant cue facilitates identification when congruent and masks when in conflict with the target. Error analysis: Each dot represents an error on a conflict trial. • When making an error on a conflict trial, the observers were most likely to respond according to the task-irrelevant cue (the dots are concentrated on the main diagonal).
Conclusions R
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Conflicting color letter
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Example: Conflicting letter was `S’ and the observer responded `D’. See all data online: www.cns.nyu.edu/~saarela/VSS2012/SaarelaLandy_VSS2012.php
VSS 2012 Naples, Florida
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Color only
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Congruent
Reported color letter
Texture only
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ERROR RESPONSES
Color only
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Mutual facilitation
0.5 1 Proportion correct: texture
‘Second-order’ cues: 1. Texture (orientation contrast) 2. Color (red-green modulation) Texture only
Proportion correct: color
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Experiment: Identification performance was measured at one texture contrast and one color contrast. Two tasks (blocked): 1. Report texture-defined letter 2. Report color-defined letter Three types of trial (mixed): 1. Single-cue 2. Congruent 3. Conflict
Improved performance with two cues: Observers can integrate texture and color cues. Facilitation and masking by task-irrelevant cue: Observers cannot ignore the other cue even when it is uninformative. Texture and color are not completely independent. Support: NIH EY16165; Swiss National Science Foundation PBELP1-125415
