Efficiently Measuring Magnocellular and Parvocellular Function in Human Clinical Studies

Abstract

PURPOSE: Pokorny and Smith (J Opt Soc Am A Opt Image Sci Vis. 1997;14:2477-2486) described a laboratory method to behaviorally measure magnocellular and parvocellular pathway sensitivity. We investigated whether their method may be more efficiently applied to clinical populations by reducing adaptation times. METHODS: We measured contrast detection thresholds to a 30-ms increment on a 30 cd/m2 background every 2 seconds after a 1-minute preadaptation to either a bright (90 cd/m2) or dim (3 cd/m2) luminance, in four observers. We also measured increment thresholds atop a steady 60 cd/m2 luminous pedestal (30 cd/m2 above the background) that remained on for 80 seconds, and tracked thresholds f..