Benefits of immediate repetition versus long study presentation on memory in amnesia.
OBJECTIVE
This study aimed to resolve discrepant findings in the literature regarding the effects of massed repetition and a single long study presentation on memory in amnesia.


METHODS
Experiment 1 assessed recognition memory in 9 amnesic patients and 18 controls following presentation of a study list that contained items shown for a single short study presentation, a single long study presentation, and three massed repetitions. In Experiment 2, the same encoding conditions were presented in a blocked rather than intermixed format to all participants from Experiment 1.


RESULTS
In Experiment 1, control participants showed benefits associated with both types of extended exposure, and massed repetition was more beneficial than long study presentation, F(2, 34) = 14.03, p < .001, partial eta(2) = .45. In contrast, amnesic participants failed to show benefits of either type of extended exposure, F < 1. In Experiment 2, both groups benefited from repetition, but did so in different ways, F(2, 50) = 4.80, p = .012, partial eta(2) = .16. Amnesic patients showed significant and equivalent benefit associated with both types of extended exposure, F(2, 16) = 5.58, p = .015, partial eta(2) = .41, but control participants again benefited more from massed repetition than from long study presentation, F(2, 34) = 23.74, p < .001, partial eta(2) = .58.


CONCLUSIONS
The findings suggest that previous inconsistencies in the literature were due to procedural differences across studies. We discuss group differences in terms of the mechanisms by which both forms of extended exposure facilitate performance in each group.
Verfaellie
Mieke
M
Memory Disorders Research Center, VA Boston Healthcare System, Boston, MA 02130, USA. verf@bu.edu
LaRocque
Karen F
KF
Rajaram
Suparna
S
D000328:Adult; D000368:Aged; D000647:Amnesia / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011214:Practice, Psychological; D021641:Recognition, Psychology / Q000502:physiology*