Hue discrimination in jewellery appraisers exceeds normal performance.

Abstract

The FM-100 Hue test is used for vocational purposes where hue discrimination is of the upmost importance, such as in jewellery appraisals where small errors in hue discrimination can lead to significant differences in gemstone valuation. The purpose of this study was to determine if the cone contrast test (CCT) could predict performance on the FM-100 Hue, providing a potential alternative test for screening of jewellery appraisers. Members of the National Association of Jewelry Appraisers (NAJA; n=18, ages 34 to 76years) requiring colour vision certification with the FM-100 Hue were invited to participate in a study to assess performance on the Ishihara test, FM-100 Hue, Lanthony Desaturated D-15 and the CCT. The FM-100 Hue test was administered to award or renew NAJA certification, while the CCT was included as a possible alternative certification test. Average CCT M and S cone scores were predictive of FM-100 Hue total error score (TES: F1,16 =7.77, p<0.02; r2 =0.33). The regression equation indicates that a CCT score of <60 is 3SD below the mean TES in our cohort of jewellery appraisers. Seventeen of 18 jewellery appraisers had FM-100 Hue TES scores significantly below the lower limit for age-matched normal values, indicating exceptional performance (p<0.001). Results indicate the CCT may be an effective substitute for the FM-100 Hue to provide certification of jewellery appraisers, but the small sample size warrants additional comparative validation to support sole utilisation of the CCT. It is of interest that this sample of jewellery appraisers showed lower (i.e., better) than normal TES scores despite mitigating senescence factors. It is conceivable that the enhanced jewellery appraisers' hue discrimination reflects perceptual learning, wherein reward-based repetition on specific tasks can improve performance, even in adulthood beyond critical periods.