Batsmen Mike Hussey and Brad Hodge made their Test debuts aged 30 during the series against the West Indies and bowler Nathan Bracken (three previous tests) and all-rounders Andrew Symonds (two) and Shane Watson (one) were recalled.
According to research compiled by the U.S. Agency for Healthcare Research and Quality, the percentage of false-positive readings is between 7% and 8% for women aged 40 to 59 who took the test.
Masakadza's hundred was his first for Zimbabwe since 2001, when he became the then youngest player in history to make a century in his debut Test by hitting 119 against West Indies aged just 17 years and 354 days.
They outperformed 10 typical healthy older folk (average age 83) on a test that involved recalling lists of words, and they matched the performance of 14 healthy middle-aged volunteers (average age 58).