The effects of repetition on allocation of study time and judgements of learning in Alzheimer’s disease

Greene et al. [12] suggest that Alzheimer’s disease (AD) patients approach repeated trials in a learning test as if they are single unrelated trials. Previous research [7] indicates that AD patients do not have explicit memory for item repetition when asked at test how many times a word was presented, but they do show benefits of repeated presentation in implicit tasks. In this experiment we examine metacognitive judgements made during study for repeated items. It was hypothesised that a lack of awareness of repetition may exacerbate the episodic memory impairment found in AD. To explore this, two measures of metamemory were taken for items presented once, twice or three times in a list: judgements of learning (JOLs), which are a declaration of how well an item has been learned, and recall readiness, which is the study time allocated by participants to ensure proficient learning of an item. With repetition, age matched controls made recall readiness judgements more quickly and reported higher JOLs. The AD patients showed faster recall readiness, but did not alter their JOLs. This suggests a dissociation in the AD group between judgements of learning and the allocation of study time. We discuss the implications for theories of the learning deficit in AD, and the use of metamemory measurements in clinical populations.