Using MATLAB with the Psychophysics Toolbox to present the heterochromatic fusion nystagmus stimulus

Abstract

We present a program for MATLAB that generates and presents the heterochromatic fusion nystagmus stimulus. This stimulus allows assessment of isoluminant states through recordings of reflexive eye movements (optokinetic nystagmus). The reflexive nature of the subject's response makes this stimulus especially useful with nonverbal subjects, such as children and animals. Unfortunately, the stimulus is complex and difficult to program. By presenting the present program, we hope to help those who wish to use this tool in their research. The code of the function can be downloaded at www. dal.ca/~mcmullen/downloads.html.

A Web-Based Archive of Norms, Stimuli, and Data

“…Collin and Chaudhuri (2002) offer MatLab source code for generating heterochromatic stimuli for the study of movement perception. Gitelman (2002) provides MatLab source code for offline analysis of eye movement records, and Hornof and Halverson (2002) provide source code for calibration of eye tracking record-ing, and Barabas et al (2004) provide MatLab routines for computing the line of primary gaze in ambulatory eye-tracking studies.…”