Unit analysis of prose memory in clinical and elderly populations

Interpretation of clinical memory tests generally emphasizes the quantitative aspects of recall. This study presents an additional unit analysis of the Logical Memory subtest of Russell's revision of the Wechsler Memory Scale for a variety of older adult groups. Patients' neuropsychological test data were reviewed, and the paragraphs from the Logical Memory subtest were analyzed using unit analysis (Rubin, 1978). The older adults consisted of a healthy group as well as groups whose diagnoses included Alzheimer's and multi‐infarct dementias, head trauma, and metabolic and affective disorders. Quantitative analyses of recall revealed group differences. Qualitative analysis of which memory units were recalled, however, showed similarities in memory processing among these groups.     

Sensitivity of category cued recall to very mild dementia of the Alzheimer type.

We sought to replicate Buschke, Sliwinski, Kulansky, and Lipton's (1997) finding that the Category Cued Recall portion of the Double Memory Test can discriminate individuals with mild dementia of the Alzheimer type (DAT) and healthy older controls. We then attempted to extend this finding to those with very mild DAT. Finally, we compared these results with those of other tests that discriminate DAT from normal aging. Although we replicated Buschke et al.'s finding that the Category Cued Recall portion of the Double Memory Test discriminates effectively between mildly demented people and controls, it was little more effective in detecting very mild DAT than the WMS Logical Memory subtest nor did it add substantially to the discriminative ability of a brief battery of psychometric tests identified previously.     

Stability of performance on the Hopkins Verbal Learning Test.

Stability of performance on the Hopkins Verbal Learning Test (HVLT) was assessed in 45 healthy elderly subjects over a 9-month period. Stability coefficients were moderate but statistically significant for total recall (r = 0.50), true-positive recognitions (r = 0.66), and false-positive errors (r = 0.42). These correlations are comparable to test-retest correlations reported for other clinical tests of verbal memory (e.g., Logical Memory subtest of the Wechsler Memory Scale-Revised, California Verbal Learning Test) and are sufficient for its clinical use.     

Intrusion errors in the figural memory of patients with Alzheimer's and Huntington's disease.

The tendency of patients with dementia of the Alzheimer type (DAT) and Huntington's disease (HD) to produce prior-item intrusion errors on a figural memory task was assessed. Patients' and elderly control subjects' immediate recall of figures from the Visual Reproduction Test (VRT) of the Wechsler Memory Scale (WMS) was scored for the presence of prior-figure intrusion errors (i.e., characteristics unique to one figure included in the reproduction of a subsequent figure). Results indicate that both patient groups produced more prior-figure intrusion errors than did the NC group, and that DAT patients made significantly more intrusion errors in their reproductions than did HD patients matched for overall severity of dementia. These data suggest that prior-item intrusion errors are evident on figural as well as on verbal memory tasks and that DAT patients are more likely to produce such errors than are equally demented patients with a "subcortical" dementia.     

Factor analysis of the Wechsler memory scale: Is the associate learning subtest an unclear measure?

A factor analysis of the Wechsler Memory Scale (WMS) with 30-minute delayed recall scores (percent retained) for the Logical Memory, Visual Reproduction, and Associate Learning subtests indicated that this variant of the WMS taps different types of learning and memory for new material. With regard to the verbal learning/recall subtests, Logical Memory appears to be related to attention/ concentration ability, while Associate Learning is relatively independent. The results also showed that both the easy and hard items from Associate Learning tap the same ability, providing evidence that this subtest is a measure of rote verbal learning. These results support the clinical utility of the WMS with delayed recalls in neuropsychiatric populations.     

Psychometric construction of the Rey-Osterrieth Complex Figure: methodological considerations and interrater reliability.

Formal scoring criteria for the standard 18 elements of the Rey-Osterrieth Complex Figure were developed and applied to reproductions of 87 healthy young adults. In addition, the effects of immediate recall on delayed performance was investigated. Results indicate (a) the formal scoring criteria can be reliably applied by independent raters; (b) 30-minute recall is significantly higher if immediate reproduction is included compared to 30-minute delay performance without immediate recall; (c) significantly fewer qualitative scoring errors are present at the 30-minute delay if immediate memory is previously assessed; and (d) in addition to an absence of decay over a 30-minute delay, performance significantly improves over this interval. These findings underscore the caution that must be exercised when making specific inferences from test scores alone based upon measures that were obtained in a variety of contexts employing unspecified scoring criteria.     

Association of KIBRA and memory

We report on the association of KIBRA with memory in two samples of older individuals assessed on either memory for semantically unrelated word stimuli (Rey Auditory Verbal Learning Test, n = 2091), or a measure of semantically related material (the WAIS Logical Memory Test of prose-passage recall, n = 542). SNP rs17070145 was associated with delayed recall of semantically unrelated items, but not with immediate recall for these stimuli, nor with either immediate or delayed recall for semantically related material. The pattern of results suggests a role for the T → C substitution in intron 9 of KIBRA in a component of episodic memory involved in long-term storage but independent of processes shared with immediate recall such as rehearsal involved in acquisition and rehearsal or processes.     

Increasing the power for detecting impairment in older adults with the Faces subtest from Wechsler Memory Scale-III: an empirical trial.

Empirical studies have questioned the validity of the Faces subtest from the WMS-III for detecting impairment in visual memory, particularly among the elderly. A recent examination of the test norms revealed a significant age related floor effect already emerging on Faces I (immediate recall), implying excessive difficulty in the acquisition phase among unimpaired older adults. The current study compared the concurrent validity of the Faces subtest with an alternative measure between 16 Alzheimer's patients and 16 controls. The alternative measure was designed to facilitate acquisition by reducing the sequence of item presentation. Other changes aimed at increasing the retrieval challenge, decreasing error due to guessing and standardizing the administration. Analyses converged to indicate that the alternative measure provided a considerably greater differentiation than the Faces subtest between Alzheimer's patients and controls. Steps for revising the Faces subtest are discussed.     

The wechsler memory scale and closed head injury

Compared a sample of Ss from the general population (N = 116) with a sample of head-injured patients (N = 70) whose injuries varied from the mild to the very severe. In a criterion factor analysis it was found that the WMS subtests of Logical Memory and Associate Learning were related closely to the criterion of head injury. Both samples were divided at age 35, and analyses of variance were carried out on the four subsamples. The findings were that the younger head-injured patients had very severe memory deficits, whereas these deficits were much less marked with the older head-injured Ss. The most marked deficits were found on WMS Factor I (verbal learning and immediate recall). WMS Factors II and III displayed significant but less clearly marked cognitive deficits. In this study, analysis in terms of the three WMS Factors enabled group and age differences in memory functioning to be highlighted in an unambiguous manner, which suggested that the present factor system is very useful for describing and identifying some types of memory deficit.     

Neuropsychological dysfunction in patients suffering from end-stage chronic obstructive pulmonary disease.

Few studies have examined the neuropsychological sequelae associated with end-stage pulmonary disease. Neuropsychological data are presented for 47 patients with end-stage chronic obstructive pulmonary disease (COPD) who were being evaluated as potential candidates for lung transplantation. Although patients exhibited a diversity of neurocognitive deficits, their highest frequencies of impairment were found on the Selective Reminding Test (SRT). Specifically, over 50% of the patients completing the SRT exhibited impaired immediate free recall and consistent long-term retrieval deficits, while more than 44% of these individuals displayed deficient long-term retrieval. Deficient SRT long-term storage strategies, cued recall, and delayed recall were exhibited by between 26% and 35% of these patients, while more than 32% of this sample displayed elevated numbers of intrusion errors. Over 31% of the patients completing the Wisconsin Card Sorting Test (WCST) failed to achieve the expected number of categories on this measure, while more than 23% of these individuals demonstrated elevated numbers of perseverative errors and total errors. Clinically notable frequencies of impairment (greater than 20% of the sample) were also found on the Trail Making Test (TMT): Part B and the Wechsler Memory Scale-R (WMS-R) Visual Reproduction II subtest. Minnesota Multiphasic Personality Inventory-2 (MMPI-2) personality assessments indicated that patients were experiencing a diversity of somatic complaints and that they may have been functioning at a reduced level of efficiency. These findings are discussed in light of patients' end-stage COPD and factors possibly contributing to their neuropsychological test performances. Implications for clinical practice and future research are also included.     

Spatial attention and response control in healthy younger and older adults and individuals with Alzheimer's disease: evidence for disproportionate selection impairments in the Simon task

The authors examined the degree to which aging and Alzheimer's disease (AD) influence the ability to control attention when conflict is presented in terms of incongruent mapping between a stimulus and the appropriate response. In a variant of the Simon task, healthy older adults and older adults with mild or very mild AD showed disproportionately larger reaction time (RT) costs when the stimulus and response were in conflict relative to RT costs of healthy younger adults. Analyses of RT distributions provide support for a 2-process model of the Simon effect in which there is a short-lived transient effect of the irrelevant dimension in younger adults and a more sustained influence across the RT distribution in older adults. An analysis of error rates showed that the older adults with mild and very mild AD made more errors on incongruent trials, suggesting that AD leads to increased likelihood of selecting the prepotent pathway. The findings are discussed in terms of the special nature of the response requirements of the Simon task to better illuminate the attentional decrements in both healthy aging and early stage AD.     

The East Boston Memory Test: A clinical screening measure for memory impairment in the elderly

Comparisons between the East Boston Memory Test (EBMT), a brief verbal memory measure used in epidemiological studies with dementia, selected Wechsler Memory Scale-Revised (WMS-R) subtests, and the Mini-Mental State Examination (MMSE) were investigated with 23 geriatric patients diagnosed with dementia. Significant correlations between the EMBT and WMS-R verbal subtests were predicted and occurred (r = .42 to .64). A five minute EBMT recall correlated most highly with the WMS-R Logical Memory subtests. The sensitivity of the EBMT in detecting cognitive impairment was investigated and compared with the sensitivity of the MMSE. The EBMT correctly classified 78% of subjects, compared to a 70% correct classification rate with the MMSE. Implications of these findings and suggestions for future research directions are discussed. © 1996 John Wiley & Sons, Inc.     

Effect of manipulation and irrelevant noise on working memory capacity of patients with Alzheimer's dementia

The effect of manipulation and distracting noise on immediate serial recall was measured in patients with dementia of the Alzheimer type (DAT), neurologically healthy elderly individuals, and young adults. In Experiment 1, the authors compared serial word recall with word recall in alphabetical order. Alphabetical recall requires the active manipulation of the contents of working memory. Findings indicated that DAT patients were severely impaired in the alphabetical recall task, whereas the performance of neurologically healthy elderly participants was comparable with the performance of young adult participants. In Experiment 2, the authors investigated the effect of different irrelevant auditory backgrounds on immediate digit recall. In this task, both elderly participants and DAT patients performed similarly to the group of young adult participants, indicating comparable efficacy to resist auditory distraction.     

Semantic, phonological, and hybrid veridical and false memories in healthy older adults and in individuals with dementia of the Alzheimer type

Five groups of participants (young, healthy old, healthy old-old, very mild dementia of the Alzheimer type [DAT], and mild DAT) studied 12-item lists of words that converged on a critical nonpresented word (cold) semantically (chill, frost, warm, ice), phonologically (code, told, fold, old), or in a hybrid list of both (chill, told, warm, old). The results indicate that (a) veridical recall decreased with age and dementia; (b) recall of the nonpresented items increased with age and remained fairly stable across dementia; and (c) false recall varied by list type, with hybrid lists producing superadditive effects. For hybrid lists, individuals with DAT were 3 times more likely to recall the critical nonpresented word than a studied word. When false memory was considered as a proportion of veridical memory, there was an increase in relative false memory as a function of age and dementia. Results are discussed in terms of age- and dementia-related changes in attention and memory.     

Concurrent validity of abbreviated WAIS-III index scores in geriatric outpatients with suspected dementia.

Assessments of older adults with suspected dementia can be time limited and clinicians might consider using abbreviated versions of measures. The present study examined the concurrent validity of abbreviated WAIS-III index scores in a sample of geriatric patients referred for assessment of suspected dementia (N=43; mean age=63.8 years). All 2-subtest estimates of the Verbal Comprehension, Perceptual Organization, and Working Memory index scores accurately estimated more than 80% of cases within +/-2 standard errors of measurement (S.E.M.), and in most cases, more than 90% of cases were accurate at this level. While none of the 1-subtest estimates of these index scores were as accurate, both of the 1-subtest estimates of the Processing Speed index had high clinical accuracy. Abbreviated versions of the four index scores can be substituted in situations with this clinical population where testing time is limited or a patient fatigues easily.     

Utility of half-credit scoring of Russell's revision of the Wechsler Memory Scale

This study examined interrater reliability of Russell's revision of the Wechsler Memory Scale logical memory using an explicit scoring method in a male medical/psychiatric population. Secondly, it examined whether the ratio of full to half-credit scores can be used to differentiate unimpaired patients from patients with documented cerebral dysfunction. Twenty-five unimpaired and 25 brain-impaired patients matched for age and education were used. Pearson correlations indicate excellent interrater reliability. t-tests indicate that the groups were not significantly different from the ratio of full- to half-credit responses on immediate memory, but were significantly different on delayed memory. A posteriori analyses indicated that a small ratio score (less than 3) on delayed recall classified patients with modest success. Results indicated that brain-impaired and unimpaired patients not only differ in regard to level of recall performance, but also differ in regard to pattern of recall performance. Cross-validation of these results is suggested.     

A semantic contribution to nonword recall? Evidence for intact phonological processes in semantic dementia

Patients with semantic dementia make numerous phonological errors in their immediate serial recall of words that they understand poorly. Previous studies have argued that these errors result from a reduction in the normal contribution made by semantics to the coherence of items in the phonological system. It is possible, however, that the errors might reflect additional subtle phonological deficits. Six patients with semantic dementia were tested on a variety of phonological processing and short-term memory tasks, in order to explore these possibilities. For the most part, the patients showed normal performance in phonological awareness and discrimination tasks and normal effects of phonological similarity and word length in immediate serial recall. The more severely impaired patients, however, showed some weakness on tests of nonword repetition and recall. Every patient showed better recall of words that were still relatively well understood, compared with words that were more semantically degraded. This difference extended to nonwords that were phonologically similar to the known and degraded words, suggesting that the patients' semantic deficits could account for their impairments in nonword recall. The recall advantage for semantically known over degraded items also extended to a nonverbal delayed picture copying task, suggesting that the patients' immediate serial recall impairments were underpinned by a central semantic deficit, and not by a separable lexical deficit.     

A semantic contribution to nonword recall? Evidence for intact phonological processes in semantic dementia

Patients with semantic dementia make numerous phonological errors in their immediate serial recall of words that they understand poorly. Previous studies have argued that these errors result from a reduction in the normal contribution made by semantics to the coherence of items in the phonological system. It is possible, however, that the errors might reflect additional subtle phonological deficits. Six patients with semantic dementia were tested on a variety of phonological processing and short-term memory tasks, in order to explore these possibilities. For the most part, the patients showed normal performance in phonological awareness and discrimination tasks and normal effects of phonological similarity and word length in immediate serial recall. The more severely impaired patients, however, showed some weakness on tests of nonword repetition and recall. Every patient showed better recall of words that were still relatively well understood, compared with words that were more semantically degraded. This difference extended to nonwords that were phonologically similar to the known and degraded words, suggesting that the patients' semantic deficits could account for their impairments in nonword recall. The recall advantage for semantically known over degraded items also extended to a nonverbal delayed picture copying task, suggesting that the patients' immediate serial recall impairments were underpinned by a central semantic deficit, and not by a separable lexical deficit.     

Age effects on response monitoring in a mental-rotation task

A mental-rotation task was presented to young (18-28 years) and old (60-76 years) adults to simultaneously assess age-related changes in performance, response monitoring and adaptive behavior. Relative to young participants, older adults were less inclined to adjust their speed at the expense of accuracy. They displayed a larger number of slow errors, smaller error potentials (Ne and Pe), more immediate corrections of errors when detected, and a larger speed reduction on trials following an error. The data suggest that for older adults an increase of task complexity sometimes caused a radical failure in determining the correct response, rather than a gradual reduction of efficiency.     

Effects of blood pressure on neuropsychological functioning in Alzheimer's disease.

Blood pressure is often lower among patients with Alzheimer's disease (AD) compared to nondemented older adults. Lower blood pressure in AD correlates with reduced cerebral blood flow and cortical atrophy, but its effect on neuropsychological functioning is unclear. We assessed the effects of blood pressure on tests of dementia severity, attention, memory, language, verbal and nonverbal reasoning, motor/psychomotor functioning, and activities of daily living (ADL) among probable AD patients (n=609). As hypothesized, lower systolic blood pressure (SBP) predicted reduced attention (Digits Forward and Backward), memory (Visual Reproduction I), and ADLs. Unexpectedly, lower pulse pressure (SBP-DBP) predicted greater dementia severity (Mini-Mental State Examination, MMSE), attention (Digits Forward and Backward), memory (Logical Memory I and Visual Reproduction I), and ADLs. These findings may reflect a tendency for less severely demented patients to exhibit normal age-related changes in blood pressure, whereas abnormal patterns may develop with increased dementia severity.