On the other hand, the inclusion of the English alphabet has limited the use of the test to Western populations. Citing this along with evidence that individuals with less-education/MCI do not perform well on the TMT, researchers devised an alternative version of the TMT (Kim, Baek, & Kim, 2014). The TMT-B&W (black and white) replaces the letters of the original with a second, identical set of numbers which are enclosed in black circles instead of white ones. Instead of alternating between numbers and letters, examinees connect a white-circled number with it's black counterpart before moving onto the next number (see below). Part A is similar to the original TMT-A, but with all of the even numbers enclosed in black circles.
|(from Kim, et al., 2014)|
The authors' goal was to provide a version of the TMT that could be used for non-Western and illiterate populations. The TMT-B&W certainly shows promise in this regard, as participants tolerated the test well and correlations with the original TMT and other measures demonstrated evidence of good construct validity. However, participants level of English fluency was not measured or described, so it's impossible to tell how much of a role this played in the study. Even in Western populations, the test may be useful with illiterate/poorly-educated individuals. A comparison of the two versions of the TMT in an English-speaking population would provide further information on whether this is the case.
Kim, H. J., Baek, M. J., & Kim, S. (2014). Alternative type of the Trail Making Test in nonnative English speakers: The Trail Making Test: Black & White. PloS One 9 (2), 1-6.