The contribution of recollection and familiarity to yes-no and forced-choice recognition tests in healthy subjects and amnesics.

Recent reports suggest that some amnesic patients perform relatively normally on forced-choice recognition memory tests. Their preserved performance may reflect the fact that the test relies more heavily on assessments of familiarity, a process that is relatively preserved in these patients, than do other recognition tests such as yes-no tests, which may rely more on recollection. The current study examined recognition memory using yes-no and forced-choice procedures in control and amnesic patients in order to determine whether the two tasks differentially relied on recollection and familiarity, and whether the extent of the recognition memory deficit observed in amnesia was dependent upon the type of recognition test used to measure performance. Results using the remember-know procedure with healthy subjects showed that there were no substantial differences in recognition accuracy or in the contribution of recollection to these two tasks. Moreover, amnesic patients were not found to perform better on a forced-choice test than on a yes-no test, suggesting that familiarity contributed equally to these two types of recognition test.