Do color-deficient observers take longer to complete a color-related task?

Purpose: Previous research has shown that observers with congenital red-green color vision deficiencies (color-deficient) have longer reaction and response times in making color-related judgments compared with individuals with normal color vision (color-normals). The objectives of this study were to determine how much longer color-deficient observers take to complete a visual display terminal (VDT) based color naming test without imposed time constraints, whether there was any correlation between error rate and time to complete the task, to determine the effect of familiarity on the time to complete the task, and whether the completion times were correlated with the anomaloscope or Farnsworth D-15.

Methods: The VDT task requires individuals to identify colors used to code information in a railway dispatcher display. The test typically takes 8 to 10 min to complete. Eighty-one color-normals and 41 color-deficient observers participated. The total number of errors and time to complete the test were recorded. There were two sessions separated by approximately 2 weeks. The color-deficient group was divided into those that passed the test and those that failed. Pass/fail criteria for the color naming test was established based on the number and types of color-normal errors.

Results: The time to complete the task for the color-deficient group who passed was 14% longer than color-normals. Color-deficient observers who failed took 29% longer than color-normals. Mean times to complete the task at the second session were significantly faster (18%) for all three groups with the reduction in time approximately equal across the groups. There was no significant correlation between the number of errors and time to complete or the clinical tests and completion times for any of the three groups.

Conclusions: In general, color-deficient observers required more time to the complete the color identification test than color-normals. Although color-deficient observers who failed the VDT test took the longest, there was no correlation between time and the number of errors for any of the subject groups.