Rehearsal and Isolation Effect in Recall

The purpose of this study was to test whether (1) the von Restorff effect is eliminated by a vocal repetition which controls a subvocal repetition and (2) the von Restorff effect appears when a vocal repetition is added to a subvocal repetition and the isolation item becomes therefore easier to learn. Four groups were tested in experiments: A, without isolation; B, with isolation of Item 7; C, with vocal repetition of each item during exposition time without isolation; and D, with chromatic isolation of Item 7 and repetition of trigrams. Groups C and D were asked to repeat 5 times each item of a series of 13 CVC trigrams, including a chromatically isolated item. Each trigram was exposed for 5 sec. The significant difference between the recall of the critical item by Groups B and D shows that the isolation effect disappears when the learning level is increased by controlling rehearsal.