Before revision: Overview The introduction of stimuli which were hard to verbalize, and unlikely to be held in long-term memory, revolutionized the study of VSTM in the early 1970s (Phillips, 1974; Phillips Baddeley, 1971) .
After revision: Overview The introduction of stimuli which were hard to verbalize, and unlikely to be held in long-term memory, revolutionized the study of VSTM in the early 1970s .