Henkel, L.A., Jonhson, M.K. & De Leonardis, D.M. (1998). Aging and source monitoring: Cognitive processes and neuropsychological correlates. Journal of Experimental Psychology, 127, 251-268.

Background:

-Older adults tend to show less accurate reality monitoring ( the processes involved in discriminating between external and internal sources of information) than younger adults

-Reality monitoring errors increase when:

• Memory of an imagined event has features that are typical of the class of perceptually derived memories
• Features of an imaginally derived memory increase in similarity to a specific perceptually derived memory

Older adults are less efficient at binding or integrating contextual information with a target memory and have reduced accessibility of source-specifying attributes in memory (e.g. perceptual detail, spatial and temporal information, cognitive operations info.)

This study focuses on whether or not older adults have more impaired source accuracy as the similarity between specific individual imagined and perceived memories increases

This study also expected that there would be differences in the phenomenal features of memories correctly attributed to their source and those falsely attributed to a source and that such differences were expected to be less in older adults, along with their expected decline in source accuracy

This study also looks at memory performance in relation to neuropsychological measures of brain function in older adults

• Evidence shows that normal aging is associated with neuroanatomic and neurochemical changes in frontal lobe areas (which are implicated in such activities as planning, strategic retrieval, organizing events, etc.)
• Therefore, it has been hypothesized that age-related declines in frontal lobe functioning may contribute to age-related deficits in source monitoring
• Also, in older adults, low scores on neuropsychological tests used to assess frontal lobe function were associated with a reduction in the subjective vividness of source-specifying features for remembered events

To sum it all up: "on the basis of the source monitoring framework, relative to younger adults, older adults were expected to show greater deficits in judging the source of related that unrelated items and to show greater similarity in the phenomenal characteristics if correctly and incorrectly attributed memories...and that older adults' source monitoring accuracy should be related to neuropsychological test scores assessing both frontal and medial temporal function.

Method

-24 younger adults (ages 19-23), 48 older adults (24/two delay conditions) (ages 64-83)

-mean scores for younger adults did not differ on the vocab subscale of the Wechsler Adult Intelligence Scale-Revised from that of older adults, also, mean number of years of formal education did not differ

-only 36 of the 48 older adults completed the neuropsycological tests

-participants were shown 84 slides, half perceived, half imagery

-perceived trials: shown a simple black-and-white drawing of a common object with its name below it

-imagery trials: shown just the name of the object at the bottom of the slide

-three types of stimulus pairs were used where one item was perceived and one imagined

-participants had to estimate how many seconds it took to draw each picture or how many seconds it would take to draw each imagined item

-all participants then completed the vocabulary test

-half of the older adults were give a surprise memory test (were items pics, imagined, or new) 15 minutes after the slide presentation

-the other half of the older adults and all of the younger adults were given a surprise source monitoring test 2 days later

-they were then given an abbreviated memory characteristics questionnaire and then two standardized imagery questionnaires

-older participants returned later for the neuropsychological tests

Results

-old-new recognition: recognition was significantly higher for imagined than for perceived items for all three groups, recognition was lower for older than for younger adults after a 2-day delay, but older adults tested 15 minutes later did not differ in recognition from younger adults

-source identification: given equivalent levels of recognition, both younger and older adults showed a greater likelihood of erroneously claiming to have perceived an item that was imagined when a different object with similar perceptual features had been seen; older adults were likely to mistakenly claim that an imagined item had been perceived when it was conceptually related to something they did actually see compared to when there was no conceptual relation

-memory characteristics: the features of a memory incorrectly attributed to a source were less vivid than if its source had been correctly judged

-recognition and source accuracy in relation to neuropsychological test scores: a relation was found between the frontal battery and source monitoring, but only in the condition when overall source accuracy was extremely low; source accuracy was also shown to be related to scores on the medial temporal battery

Discussion

-results showed that older adults are even more susceptible to source errors as the similarity between specific imagined and perceived memories is increased

-older adults are more likely to be influenced by similar features from another perceived memory in judging an imagined memory's source

-over time, older adults' source monitoring difficulty becomes more general and severe

-both medial temporal and frontal battery scores were positively associated with older adults' source accuracy

-to think about: when older adults are encouraged to focus on factual rather than affective features of their memories or more personally engaging information, the age deficit in source accuracy is diminished

-age related source deficits can also be reduced when older people are induced to rely on more stringent or specific criteria to evaluate the source of their memories