Representing orientation: A coordinate-system hypothesis and evidence from developmental deficits.

This article concerns how the orientations of objects are represented in the human brain. We propose a coordinate-system hypothesis of orientation representation (COR) and show that the hypothesis provides an explicit basis for interpreting orientation errors. Next, we report results from three studies of individuals with developmental deficits in the processing of orientation information, demonstrating that the COR hypothesis can interpret the error patterns in each study. We conclude by discussing several issues concerning the interpretation of our results, the COR hypothesis, and the use of developmental deficits as a basis for inferences about normal cognition.