TY - JOUR
T1 - Grouping in object recognition
T2 - The role of a Gestalt law in letter identification
AU - Pelli, Denis G.
AU - Majaj, Najib J.
AU - Raizman, Noah
AU - Christian, Christopher J.
AU - Kim, Edward
AU - Palomares, Melanie C.
N1 - Funding Information:
We thank Charles Peskin for showing us how to generalize our sinusoidal measure of wiggle to curved stroke paths, Katharine Tillman, Rama Chakravarthi, Dennis Levi, and Athena Vouloumanos for helpful suggestions, Nava Rubin and Jeremy Wolfe for help with historical sources, and Fred Kingdom and Chris Tyler for sharing their wisdom on wiggle. Noah Raizman and Chris Christian participated as undergraduates, and Edward Kim as a high-school student. We thank the NYU Center for Neural Science Summer Undergraduate Research Program, organized by Chiye Aoki, for supporting Noah Raizman’s summer internship during which this project was done. Edward Kim, as a student at Stuyvesant High School, measured thresholds in our lab for snake letters as a function of spacing for his Intel National Talent Search Project, “What makes a letter?” Supported by National Eye Institute Grant R01-EY04432 to Denis Pelli. Najib J. Majaj is now at Brain and Cognitive Science, MIT, Cambridge, MA, USA. Noah Raizman is now at Columbia Medical School, New York, NY, USA. Christopher J. Christian is now at Albert Einstein College of Medicine of Yeshiva University, New York, NY, USA. Edward Kim is now at Stuyvesant High School, New York, NY, USA. Melanie C. Palomares is now at Smith-Kettlewell Eye Research Institute, San Francisco, CA, USA.
PY - 2009
Y1 - 2009
N2 - The Gestalt psychologists reported a set of laws describing how vision groups elements to recognize objects. The Gestalt laws "prescribe for us what we are to recognize 'as one thing'" (Kohler, 1920). Were they right? Does object recognition involve grouping? Tests of the laws of grouping have been favourable, but mostly assessed only detection, not identification, of the compound object. The grouping of elements seen in the detection experiments with lattices and "snakes in the grass" is compelling, but falls far short of the vivid everyday experience of recognizing a familiar, meaningful, named thing, which mediates the ordinary identification of an object. Thus, after nearly a century, there is hardly any evidence that grouping plays a role in ordinary object recognition. To assess grouping in object recognition, we made letters out of grating patches and measured threshold contrast for identifying these letters in visual noise as a function of perturbation of grating orientation, phase, and offset. We define a new measure, "wiggle", to characterize the degree to which these various perturbations violate the Gestalt law of good continuation. We find that efficiency for letter identification is inversely proportional to wiggle and is wholly determined by wiggle, independent of how the wiggle was produced. Thus the effects of three different kinds of shape perturbation on letter identifiability are predicted by a single measure of goodness of continuation. This shows that letter identification obeys the Gestalt law of good continuation and may be the first confirmation of the original Gestalt claim that object recognition involves grouping.
AB - The Gestalt psychologists reported a set of laws describing how vision groups elements to recognize objects. The Gestalt laws "prescribe for us what we are to recognize 'as one thing'" (Kohler, 1920). Were they right? Does object recognition involve grouping? Tests of the laws of grouping have been favourable, but mostly assessed only detection, not identification, of the compound object. The grouping of elements seen in the detection experiments with lattices and "snakes in the grass" is compelling, but falls far short of the vivid everyday experience of recognizing a familiar, meaningful, named thing, which mediates the ordinary identification of an object. Thus, after nearly a century, there is hardly any evidence that grouping plays a role in ordinary object recognition. To assess grouping in object recognition, we made letters out of grating patches and measured threshold contrast for identifying these letters in visual noise as a function of perturbation of grating orientation, phase, and offset. We define a new measure, "wiggle", to characterize the degree to which these various perturbations violate the Gestalt law of good continuation. We find that efficiency for letter identification is inversely proportional to wiggle and is wholly determined by wiggle, independent of how the wiggle was produced. Thus the effects of three different kinds of shape perturbation on letter identifiability are predicted by a single measure of goodness of continuation. This shows that letter identification obeys the Gestalt law of good continuation and may be the first confirmation of the original Gestalt claim that object recognition involves grouping.
KW - Contour integration
KW - Dot lattice
KW - Features
KW - Gestalt
KW - Good continuation
KW - Grouping
KW - Letter identification
KW - Object recognition
KW - Snake in the grass
KW - Snake letters
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U2 - 10.1080/13546800802550134
DO - 10.1080/13546800802550134
M3 - Letter
C2 - 19424881
AN - SCOPUS:67649562561
SN - 0264-3294
VL - 26
SP - 36
EP - 49
JO - Cognitive Neuropsychology
JF - Cognitive Neuropsychology
IS - 1
ER -