Ten amnesic patients of various etiologies and 10 matched normal
controls participated in this study. On 2 consecutive days, subjects
studied 30 novel word–word associations 6 times. Using a cued recall
task, we assessed episodic learning and delayed retention of the study
material immediately after each study phase and again 24 hr after the
final study phase. Further, we evaluated implicit memory for new
between-word associations by means of an automatic relational priming
paradigm immediately after the delayed cued recall trial. Amnesic patients
performed poorly on the cued recall task. Moreover, in the overall group
of amnesics the priming effect failed to reach statistical significance.
When the overall group of amnesics was split according to mean performance
on the cued recall task, those in the low performer
subgroup—comprised of 6 patients with direct or indirect involvement
of the hippocampi—were particularly poor at episodically remembering
the associations and did not reveal any relational priming. These data
support the hypothesis of similar impairment of new episodic and implicit
learning in amnesic patients and suggest that the hippocampus is crucial
for both kinds of new learning. (JINS, 2005, 11,
566–573.)