Abstract
The present investigation was two-fold in purpose: to test the hypothesis that auditory mental loading would require greater mental effort and larger resultant pupillary dilation than visual mental loading, and to provide evidence for the feasibility of super 8-mm photography for pupillometric research. Subjects were 30 college students. Stimuli to be stored in memory and repeated aloud in reverse order were seven-digit number series. Series were either presented visually from 35-mm slides or auditorily from a taped recording. Pupillary responses were recorded with a super 8-mm movie camera. Pupil diameter was measured to the neatest centimeter on a projected image. Results did not support the hypothesis, but methodologically strong evidence supported 8-mm photography for pupillometry research.