Brain Advance Access originally published online on January 28, 2004
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Brain, Vol. 127, No. 4, 825-834, 2004
© 2004 Guarantors of Brain
doi: 10.1093/brain/awh107
Verbal recall in amnesiacs under conditions of diminished retroactive interference
1 Department of Psychological Sciences, 18 McAlester Hall, University of Missouri, Columbia, MO 65211, USA, 2 Dipartimento di Riabilitazione, Ospedale Somma Lombardo, Italy and 3 Human Cognitive Neuroscience, Department of Psychology, University of Aberdeen, UK
Correspondence to: Nelson Cowan, 18 McAlester Hall, Department of Psychological Sciences, University of Missouri, Columbia, MO 65211, USA E-mail: CowanN{at}missouri.edu
In amnesiacs, stimuli that at first can be recalled are usually forgotten within 1 min, but the conditions required for this severe forgetting have remained unknown. To examine this, six patients with amnesia due to head injury or stroke and six normal controls heard lists of words (Experiment 1) and stories (Experiment 2). These stimuli were to be recalled immediately or after an extended test delay (10 min in Experiment 1; 1 h in Experiment 2). Although severe forgetting occurred in the amnesiacs following activity-filled delays, much less forgetting occurred in four of these patients after delays spent in a dark, quiet room. This was true even when the patients appeared to sleep during the delays. The results show, in a novel manner, that one deficit underlying their amnesias is vulnerability to retroactive interference.
Key Words: retroactive interference; amnesia; anterograde amnesia; memory; interference
Received March 20, 2003. Accepted December 9, 2003.