A PSYCHOPHYSICAL STUDY OF THE VALIDITY OF ANOMALOSCOPIC ASSESSMENTS OF COLOUR VISION IN THE BLUE-GREEN RANGE
The Roland IF-2 all-colour anomaloscope is used for assessment of genetic or acquired colour vision deficits. The device uses either the Rayleigh (red/green) or Moreland (green/blue) equations and requests forced-choice same-different judgements of the hue of light stimuli on either side of a 2-deg bipartite field. Validating the output of the anomaloscope presents some psychophysical challenges. These were met through the use of a modified same-different signal detection paradigm in which all stimuli within the reported matching range were assumed to be perceptually the same and distinct from all stimuli outside of the matching range. The diagnostic output, at least in the blue-green range with the procedure utilised by the anomaloscope, may not provide accurate assessment of individual differences in colour perception, because performance is likely to be confounded with response bias.