Exceptional Color Vision in Jewelry Appraisers: A Potential Effect of Perceptual Learning and Neural Plasticity

Abstract

Purpose : The National Association for Jewelry Appraisers (NAJA) require periodic testing of color vision with the FM 100 Hue arrangement test. Since the 100 Hue can be time consuming to complete and score, alternate tests may be preferable. Our purpose was to compare the efficacy of the FM 100 Hue to the Cone Contrast Test (CCT, Innova Systems, Inc.) and desaturated D15 to assess color vision in a cohort of NAJA employees.

Methods : NAJA employees requiring color certification (NAJA, Dallas, TX, 2019) were invited to participate in our IRB approved protocol to assess performance on the Ishihara test, FM 100 Hue, desaturated D15 and CCT, a computer-based test which determines L, M and S cone contrast thresholds. The Ishihara was used to detect hereditary color deficiency while all other testing quantified color vision ability.
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Results : 18 subjects (mean age 57 ± 12 SD, range 34 - 76 YO, 14 females, 4 males) participated after signed informed consent in accord with our IRB approved protocol. All subjects passed the Ishihara and desaturated D15 tests. CCT scores (L, M & S cone average) were predictive of FM 100 Hue total error score (TES; F = 6.02, P < .03; r² = 0.27). Interestingly, all 18 subjects had 100 Hue TES scores which were at least 2SDs below age-matched normal values¹ indicating exceptional performance. the TES scores were significantly lower than age-matched norms. Moreover, regression analysis of TES Z-scores vs. age revealed a significant inverse relationship: the older the subject, the better the performance (F = 29.54, P < 0.0001; r² = 0.66).

Conclusions : The correlation between CCT and 100 Hue scores indicates that the CCT may be utilized as an alternate test for jewelry appraisers. Benefits include the rapid CCT test time (5 min.) vs. 20-30 min. for the 100 Hue and often tedious scoring. Yet the CCT and 100 Hue measure different aspects of color vision with the 100 Hue more representative of the primary task of appraisers: discriminating subtle hue difference which significantly impact gemstone value. The novel finding of significantly lower TES scores among appraisers, coupled with the inverse relation between performance and age, indicates a learning effect which may reflect perceptual learning known to enhance neuroplasticity even in adulthood.
¹Kinnear & Sahraie (2002). British Journal of Ophthalmology, 86, 1408-1411.

This is a 2020 ARVO Annual Meeting abstract.