Emergence of Global Shape Processing Continues Through Adolescence


  • The research reported in this article was supported by National Institutes of Health Grants PO1/U19 to Marlene Behrmann and Beatriz Luna (PI: Nancy Minshew), which is part of the Collaborative Programs for Excellence in Autism (CPEA), and T32 HD049354 to Ron Dahl and Robert Noll, as well as a postdoctoral fellowship from the National Alliance for Autism Research to K. Suzanne Scherf and Beatriz Luna. We are grateful to the work of the staff in the CPEA for their help recruiting participants for this project and to our study families for making this research possible.

concerning this article should be addressed to K. Suzanne Scherf, Department of Psychology, 330 Baker Hall, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213. Electronic mail may be sent to suzyscherf@cmu.edu.


The developmental trajectory of perceptual organization in humans is unclear. This study investigated perceptual grouping abilities across a wide age range (8–30 years) using a classic compound letter global/local (GL) task and a more fine-grained microgenetic prime paradigm (MPP) with both few- and many-element hierarchical displays. In the GL task, contrary to adults, both children and adolescents exhibited a classic local bias. In the MPP, all 3 age groups evinced a bias to individuate the few-element displays; however, the ability to encode the global shape of the many-element displays at the short prime durations increased with age. These results indicate that the full process of garnering shape information from perceptual grouping, which is essential for the ability to do fast and efficient object recognition and identification, develops late into adolescence.