For nonsense syllables, and for most lists of vocabulary words or random sentences, it’s zero: There’s no spontaneous improvement on test scores after a day or two. By contrast, reminiscence is strong for imagery, for photographs, drawings, paintings—and poetry, with its word-pictures. And it takes time to happen. Ballard had identified the “bubbling up” of new verse in the first few days after study, when it’s strongest. Other researchers had looked for it too early, minutes afterward, or too late, after a week or more.
