An example of exceptional practice effects in the verbal domain.

XY, a 20-year-old mnemonist (current world ranking within the top 50) was tested with standard neuropsychological tests. XY recalled all words on all trials on the Rey Auditory Verbal Learning Test (RAVLT, 15 words) and scored above the 99.9th percentile on the Wechsler Memory Scales R, Logical Memory (WLM, 2 short stories, 25 units per story, 50 units total). XY had not been previously tested with neuropsychological tests, but had trained memory techniques for approximately 8 years. We suggest that training on similar tasks resulted in substantial practice effects in the verbal memory domain, with no measurable transfer effects to the visual domain. In addition to previous findings, we present a practice effect on RAVLT and WLM exceeding previously documented test-retest effects by 2-3 standard deviations.