Figure 1.

Schematic of the psychophysical procedure used in the present study. (A) Eccentric locations at which points were located for testing. The black dashed line indicates the 9.5° eccentricity and the red dashed line indicates the 17.5° eccentricity, with the eight points representing locations coincident with test locations within the 30-2 HFA test grid. The black arrow pointer in (A) refers to the pointer used to indicate to the subject the location of the forthcoming stimuli. The arrow was moved around to the different locations matching all of the possible points cued under each condition. The arrow was used prior to the test only, and not during the trial. (B) The sequence of screens during each test of contrast level within the trial.