For detailing added to break up a surface, see Greeble.
The Greebles come in two genders and five families.
The Greebles refers to an invented category of novel objects used as stimuli in psychological studies of object and face recognition. They were named by the psychologist Robert Abelson. The greebles were created for Isabel Gauthier'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, and in more than 25 scientific articles on perception (see below). They are often used in mental rotation task experiments.
Isabel Gauthier (1998). Dissecting face recognition: The role of expertise and level of categorization in object recognition (Ph.D.). Yale University.
Williams, P., Gauthier, I., & Tarr, M. J. (1998). "Feature learning during the acquisition of perceptual expertise" [Commentary on Schyns, Goldstone & Thibault. The development of features in object concepts]. Behavioral and Brain Sciences, 21(1), 40-41.
Rossion, B., Gauthier, I, Goffaux, V., Tarr, M.J., Crommelinck, M. (2002). "Expertise training with novel objects leads to left lateralized face-like electrophysiological responses". Psychological Science. 13(3): 250-257. doi:10.1111/1467-9280.00446.
Lahaie, A., Mottron, L., Arguin, M., Berthiaume, C., Jemel, B., Saumier, D. (2006). "Face perception in high-functioning autistic adults: evidence for superior processing of face parts, not for a configural face-processing deficit". Neuropsychology, 20(1): 30-41.
Richler, J.J., Tanaka, J.W., Brown, D.D. & Gauthier, I. (2008). Why does selective attention to parts fail in face processing? Journal of Experimental Psychology: Learning, Memory, and Cognition. 34(6): 1356-1368. doi:10.1037/a0013080.