Can The Pupillary Responses in Man Provide an Estimate of the Absolute Sensitivity of the Visual Pathway?

Abstract

Previous studies (Birch and Birch, 1987; Trejo and Cicerone, 1982; Schweizer, 1955) have used the pupillary light response to derive relative sensitivity estimates of the afferent visual pathway. The present study examines whether the pupillary response can provide an absolute sensitivity estimate. More specifically, this study addresses two questions: (i) Is a pupillary response elicited by flashes that are detected by the subject only 50% of the time? (ii) Does the pupil response occur on trials that the subject detects the flash, on trials that the subject does not detect the flash, or on both trials that are detected and not detected?