This might not be exactly what you're after, but Ackerman, Beier, and Boyle (2002) wrote a paper where they factor analysed various perceptual speed tests along with other tests.
In particlar, the test you are interested in seems to be a member of the sublass of perceptual speed tests that Ackerman et al labelled "Perceptual Speed: Pattern Recognition".
They used the following tests to measure the factor.
- Finding a and t. In this test, participants scan for instances of “a” and “t” in text passages (passages were in Italian).
- Mirror Reading. In this test, participants find target words written in mirrored text.
- Summing to 10. In this test, participants circle pairs of numbers if they sum to 10.
- Finding and ¥. This test is the same as Finding a and t, except the text was random symbols.
- Canceling Symbols. In this test, participants scan a page for a single target figure among other simple target figures.
However, these tests were typically designed for paper and pencil administration and for measuring individual differences. I don't think they used the one-symbol for each trial approach. In particular, I remember a colleague using the Finding A's test in the Ekstrom battery.
- Ackerman, P.L. and Beier, M.E. and Boyle, M.D. (2002).
Individual differences in working memory within a nomological network of cognitive and perceptual speed abilities. Journal of Experimental Psychology: General, 131, 4, 567. PDF
- Ekstrom, R. B., French, J. W., & Harman, H. H. (1976). Manual for kit
o f factor-referenced cognitive tests. Princeton, NJ: Educational Test-