A framework for understanding source monitoring and relevant empirical evidence is described, and several related phenomena are discussed: old-new recognition, indirect tests, eyewitness testimony, misattributed familiarity, cryptomnesia, and incorporation of fiction into fact. Disruptions in source monitoring (e.g., from confabulation, amnesia, and aging) and the brain regions that are involved are also considered, and source monitoring within a general memory architecture is discussed. It is argued that source monitoring is based on qualities of experience resulting from combinations of perceptual and reflective processes, usually requires relatively differentiated phenomenal experience, and involves attributions varying in deliberateness. These judgments evaluate information according to flexible criteria and are subject to error and disruption. Furthermore, diencephalic and temporal regions may play different roles in source monitoring than do frontal regions of the brain.

This experiment was designed to examine the ability of older and younger adults to remember the source of information. Three types of source monitoring tasks were investigated: discriminating between externally derived and internally generated memories, discriminating between two types of internally generated memories, and discriminating between two types of externally derived memories. Relative to younger adults, older adults had more difficulty discriminating between memories of the same class (external-external and internal-internal), but they did not have more difficulty discriminating between memories of different classes (external-internal). These findings indicate that the age-related difficulty in remembering the source of information should not be characterized as a general deficit. Factors that may account for age deficits in source monitoring are discussed drawing upon the Johnson-Raye (1981) reality monitoring framework.

Older and younger adults' memory for perceived and imagined events was examined with a procedure in which everyday situations are simulated in the laboratory. Subjects perceived some situations and imagined others. Later, they were asked to rate their memory for various aspects of these situations (e.g., amount of perceptual detail, thoughts and feelings). A recall test followed the ratings. On the rating scale, for both perceived and imagined events, older subjects reported better memory for their thoughts and feelings than did younger subjects. In addition, on the recall test, older subjects produced more thoughts and feelings than did younger subjects, whereas younger subjects produced more perceptual and spatial information. These results suggest that older subjects may not inhibit personal information (e.g., thoughts and feelings), and this information may interfere with memory for other aspects of information, such as perceptual and contextual details (Hasher & Zacks, 1988).

Subjects heard words originating from 2 speakers and later decided which of the 2 speakers said the words. Older adults had difficulty with source monitoring when perceptual cues from 2 sources were similar (2 female speakers), but this difficulty was overcome when perceptual cues were distinctive (a male and a female speaker) and were the only salient cues to source. Older adults also benefited from distinctive spatial cues when these were the only salient cues to source. Older adults, however, experienced difficulties in using multiple cues (both perceptual and spatial) to source effectively, whereas younger adults were able to use multiple cues to enhance their source-monitoring performance. It is suggested that age differences in source monitoring result from differential cue utilization.

Pairs of young and elderly Ss participated in a short play and were then instructed to talk about factual or affective aspects of the play or to talk about the play without any particular focus suggested. In both the affective and control condition, older adults' ability to discriminate what they had said from what the other person had said was poorer than that of young adults. In contrast, when induced to focus on the factual content of the events, older Ss' source monitoring improved, and the age difference was reduced. The pattern was similar when Ss' ability to discriminate what they had said from what they had thought was examined. Furthermore, affective focus lowered the overall level of recall for both young and older Ss and led older Ss, in particular, to introduce more elaborations into their recall. The possibility that age difference in remembering content and source are related to type of focus is discussed.