On the acquisition of new declarative knowledge in amnesia.

In 2 experiments, the acquisition of new declarative knowledge was examined in amnesic patients and in 7 groups of controls, with a study-only procedure that delayed testing until the conclusion of training. The study-only procedure was compared with a standard procedure in which study and test trials alternated (study-test). The amnesic patients acquired new factual (declarative) knowledge at an abnormally slow rate, learning more with the study-only procedure than with the study-test procedure. Controls exhibited the opposite pattern. The advantage of the study-only procedure for amnesic patients was related to the presence of frontal lobe dysfunction. The 2 groups exhibited a similar ability to use their knowledge flexibly, suggesting that the information acquired by amnesic patients was based on their residual capacity for declarative memory. In addition, the capacity for factual learning in amnesia was proportional to the capacity to recollect specific events in the learning session.