The greebles are artificial objects designed to be used as stimuli in psychological studies of object and
face recognition. They were named by the American psychologist
Robert Abelson Robert Paul Abelson (September 12, 1928 – July 13, 2005) was a Yale University psychologist and political scientist with special interests in statistics and logic.
Biography
He was born in New York City and attended the Bronx High School of Scien ...
. The greebles were created for
Isabel Gauthier
Isabel Gauthier is a cognitive neuroscientist currently holding the position of David K. Wilson Professor of Psychology and head of the Object Perception Lab at Vanderbilt University’s Department of Psychology. In 2000, with the support of the J ...
's dissertation work at Yale, so as to share constraints with faces: they have a small number of parts in a common configuration. Greebles have appeared in psychology textbooks,
[ Here: sect.4.5 on evolution and plasticity] and in more than 25 scientific articles on perception. They are often used in
mental rotation
Mental rotation is the ability to rotate mental representations of two-dimensional and three-dimensional objects as it is related to the visual representation of such rotation within the human mind. There is a relationship between areas of the bra ...
task experiments.
Twelve undergraduates of
Oberlin College were offered participation in the initial facial rotation experiment, wherein they took part in a rigorous training exercise, with the goal being the creation of experts in recognizing Greebles. For the second test, the "Brightness-Reversal Test," ten of the original participants were joined with twelve undergraduates of
Brown University. 30 Greebles were employed in the initial experiment. Each Greeble was assigned a meaningless name, each starting with a unique letter. The Greebles were viewed on Macintosh computer monitors of 72 pixels per inch. Experimentation was divided into one-hour sessions over the course of two weeks, for a total time of 9 hours. Results found the process of Greeble recognition differed from that of facial recognition. Two subjects bearing
prosopagnosia
Prosopagnosia (from Greek ''prósōpon'', meaning "face", and ''agnōsía'', meaning "non-knowledge"), also called face blindness, ("illChoisser had even begun tpopularizea name for the condition: face blindness.") is a cognitive disorder of f ...
proved to be far more capable at the recognition of Greebles than human faces, the latter faculty being a severe disability. Consequently, the study evinced questions regarding the mechanisms of human facial recognition, and whether this facility applies to faces alone, or other object classes.
The study is remarkable because Gauthier
demonstrated that, after training participants on the many aspects of greebles, the
fusiform face area
The fusiform face area (FFA, meaning spindle-shaped face area) is a part of the human visual system (while also activated in people blind from birth) that is specialized for facial recognition. It is located in the inferior temporal cortex ( ...
in the participants' brains responded just as well to greebles as it did to human faces. This suggests that people can improve their ability to recognize faces and objects, and that the fusiform face area is not strictly used for recognizing human faces.
Footnotes
References
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
{{commons category, Greeble
Scott Yu's original Greebles(under the dropdown titled "Novel Objects")
Vision