All participants had normal or corrected-to-normal vision. The ethnic composition in both groups was representative for the New York region, with an approximately equal number of participants in each group in each racial category (patients vs. controls: White 27/24, Black 11/7, Asian 3/4, Native-American 1/0, more than one race 8/8, unknown 7/1). The experimental protocol had been approved by the institutional review board and was undertaken with the understanding and written consent of each participant.
