Absolute pitch is disrupted by a memory illusion

An experiment is reported, showing that short-term memory for pitch in absolute pitch (AP) possessors, while substantially more accurate than in AP nonpossessors, is also subject to illusory conjunctions of pitch and time and so can be distorted or enhanced by a single tone embedded in a sequence of six other tones. Both AP possessors and AP nonpossessors performed a short-term memory task. A test tone was presented, then a sequence of six intervening tones, and then a probe tone. The test and probe tones either were identical in pitch or differed by a semitone. The AP nonpossessors judged whether the test and probe tones were the same or different, and the AP possessors identified the test and probe tones by name. In some conditions, a tone of identical pitch to the probe tone or an octave removed from this tone was included in the intervening sequence. In both the AP possessors and AP nonpossessors, this illusion-producing tone increased judgments that the test and probe tones were identical. These results accord with a model of the system underlying short-term memory for pitch proposed earlier and show that this system is bidimensional in nature, involving both pitch height and pitch class.