Recall Index Research Articles

Is Basic Memory Structure Invariant Across Epilepsy Patient Subgroups?

It is well known that epilepsy patients often exhibit material-specific deficits in memory for verbal versus nonverbal material. However, it is also apparent that such deficits are not always discernible, and that numerous factors may potentially moderate the degree to which fractionation between verbal and nonverbal material is evident. Using confirmatory factor analysis, we compared the relative fit of one-factor (general) and two-factor (material-specific) models of memory in data from 330 patients with intractable seizure disorder. Data from verbal and nonverbal selective reminding tests, as well as Logical Memory and Visual Reproduction (immediate and delayed recall indices), were used in analyses. The one-factor model fit the data poorly in the full sample, whereas the two-factor model fit the data significantly better. We then assessed the invariance of these two models using multiple-group modeling across subsamples of patients with left versus right sided seizure focus, earlier versus later age of seizure onset, lower versus higher Full Scale IQ, fewer versus more years of education, younger versus older patients, and male versus female patients. In all cases, the two-factor model comprised of verbal and nonverbal memory factors fit the data better than a one-factor (general) model. These findings indicate robust consistency of verbal and nonverbal memory constructs in the epilepsy population, which remain viable in this patient group despite considerable heterogeneity in other respects.

Effects of Part-Set Cuing on Experienced and Novice Chess Players' Reconstruction of a Typical Chess Midgame Position

A typical midgame chess position was presented to participants for 30 sec. Participants then reconstructed the presented position on a second board from memory. Following a brief distraction phase, participants were asked to reconstruct the position a second time with 0, 6, or 12 of the original pieces present. It was hypothesized that cue presentation during second reconstruction would be more disruptive to experienced players' recall than to novices'. Recall was measured in terms of correct pieces placed, new items generated (reminiscence), and previously recalled items omitted (forgetting). Analysis indicated that cues neither facilitated nor inhibited recall: experienced players performed better than novice players across recall indices, with the exception of reminiscence at which both groups performed similarly.

Early patterns of verbal memory impairment in children treated for medulloblastoma.

Children treated for medulloblastoma demonstrate a variety of cognitive deficits in addition to white matter and hippocampal neuropathology. This study examined 40 children treated for medulloblastoma as compared with 40 demographically matched controls on the California Verbal Learning Test-Children's Version (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1994). Results revealed significantly poorer performance on indices of word recall in the patient group as compared with the controls in addition to milder but still significantly poorer recognition memory. These findings suggest that children treated for medulloblastoma demonstrate a mixed profile of memory impairment consisting of both retrieval and recognition deficits. Implications of these findings for understanding neurobehavioral sequelae within pediatric medulloblastoma populations and for designing educational and remediation strategies to be used with these children are discussed.

Construct validity of Hopkins Verbal Learning Test—Revised component process measures in an HIV-1 sample

Executive dyscontrol of episodic verbal learning and memory secondary to prefrontostriatal circuit neuropathophysiology is a common feature of HIV-1 infection. Prior research indicates that standard clinical learning and recall indexes from Hopkins Verbal Learning Test—Revised (HVLT-R) are among the most sensitive indicators of HIV-associated neurocognitive disorders. Emerging data support the validity of qualitative component process measures derived from the HVLT-R (e.g., Semantic Clustering); however, no prior studies have examined these particular indices of performance in an HIV-1-infected population. In the present study, we examined the construct validity of HVLT-R component process indices in a sample of 42 persons with HIV-1 infection and 29 demographically similar seronegative comparison participants. The HIV-1 sample performed significantly below the seronegative group on Total and Delayed Recall, Semantic Clustering, and the Retrieval Index. No between-group differences were observed on Serial Clustering, Pair Frequency, Learning, Repetitions, Semantic False Positive Recognition Errors, or the Recognition Discrimination Index. In addition, the HVLT-R component process measures demonstrated evidence of convergent and divergent validity with standard clinical tests in the HIV-1 sample. Findings support the construct validity of HVLT-R component process measures and are commensurate with prior literature indicating that HIV-1 disease is associated with deficient executive control of encoding and retrieval within verbal episodic memory.

Impacts of meat product recalls on consumer demand in the USA

The impact of meat product recall events on consumer demand (beef, pork, poultry, and other consumption goods) in the USA is tested empirically. Beef, pork, and poultry recall indices are constructed from both the Food Safety Inspection Service's meat recall events and from newspaper reports over the period 1982–1998. Following previous product recall studies, recall indices are incorporated as shift variables in consumers’ demand functions. Estimating an absolute price version of the Rotterdam demand model, findings indicate that Food Safety Inspection Service's meat recall events significantly impact demand, and newspaper reports do not. Moreover, although elasticities related to recall events are significant they are small in magnitude relative to price and income effects. Any favourable effects on the demands of meat substitutes for a recall are offset by a more general negative effect on meat demand. The general negative effect indicates a shift out of meat to non-meat consumption goods.

Disentangling executive functions and memory processes in event‐based prospective remembering after brain damage: A neuropsychological study

Successful prospective remembering (PR) comprises at least two components: one retrospective component that refers to the encoding and retrieval of the content of the intention and a second prospective component that involves the retrieval of the intended action at the appropriate moment. Whereas the retrospective component is very similar to memory skills like learning and retention of new information, the prospective component is thought to rely mainly on executive function. Head injuries can disturb PR during both of these stages. To disentangle the relative impact of executive functions and retrospective memory processes on PR we embedded a PR task in a 2‐back verbal working memory paradigm. Fifty‐six neurological patients with brain damage of various aetiologies were divided pre‐experimentally into four groups on the basis of their delayed recall Index in the Wechsler Memory Scale‐Revised (WMS‐R, indicating absence or presence of deficits in retrospective memory functions) and their age‐corrected score in the Behavioural Assessment of the Dysexecutive Syndrome (BADS, indicating absence or presence of deficits in executive functions). Additionally, 19 controls matched for age and education were examined. We found that patients with deficits in executive functions detected fewer cues than any other group irrespective of their retrospective memory performance. However, eight patients with severe anterograde memory deficits could retain neither the intention nor its content. Thus, intactness of the retrospective component seems to be a necessary but not sufficient prerequisite for successful prospective remembering. For the execution of the intended action itself executive functions play a critical role.

Recall and response of smokers and recent quitters to the Australian National Tobacco Campaign

Objective: To track national population indices of recall and response among smokers and recent quitters to an ongoing national televised anti-smoking campaign in Australia. Method: National cross sectional population telephone...

Relationships Between Eight Measures of Suspect Effort

Previous studies have recommended that multiple measures be employed concurrently to provide converging evidence regarding the presence of suspect effort during neuropsychological assessment. However, if the tests are highly correlated they do not represent independent sources of information. To date, no study has examined correspondence between effort tests. The present study assessed the relationships between eight measures which can be used to assess effort (Rey 15-item, Rey Dot Counting Test, Rey Word Recognition Test, RAVLT recognition trial, Rey-Osterrieth Complex Figure Test effort equation, Digit Span, Warrington Recognition Memory Test-Words, and “b” Test) in a sample of 105 patients in litigation or attempting to obtain/maintain disability compensation and who displayed noncredible symptoms based on psychometric performance and behavioral criteria. Modest to moderate correlations were observed between test summary scores with only two measures sharing more than 50% score variance (Digit Span and Dot Counting). Moderate correlations were also observed between individual test scores reflecting indices of response time, free recall, recognition, and false positive errors, providing possible evidence that patients may use specific strategies when producing noncredible performances. Overall the results suggest that the use of these various tests generally provides nonredundant data regarding patient credibility in neuropsychological evaluations.

A comparison of methods to estimate premorbid intelligence in an Australian sample: data from the Macquarie University Neuropsychological Normative Study (MUNNS)

A variety of methods for estimating premorbid intelligence were compared in an Australian sample participating in the Macquarie University Neuropsychological Normative Study (MUNNS). Predictors included a contextual version of the AUSNART, the WRAT-3 Reading subtest, Spot-the-Word Test and sub-tests from the WAIS-R. The study involved 244 healthy participants aged between 18 and 34 years, with half of them serving as a cross-validation sample. Multiple regression was used for all analyses. When taking into account both the statistical results and clinical utility of the methods, the Sydney Premorbid Intelligence Estimate (SPIE), consisting of Vocabulary and Picture Completion subtests from the WAIS-R, was considered to be the best predictor. Combining all measures into one regression did not substantially increase the amount of variance explained. Base rate tables for predicted IQ versus obtained IQ, and the discrepancy between predicted 10 and Delayed Recall Index of the WMS-R are provided for each of the prediction methods. Further research to examine the clinical utility of these methods is required.

Is the Right Amygdala Involved in Visuospatial Memory? Evidence from MRI Volumetric Measures

Quantitative MRI measurement of hippocampal sclerosis in patients suffering from temporal lobe epilepsy (TLE) have, as yet, failed to evidence any correlation between the right hippocampus and visuospatial memory. In this report, word learning and design learning tasks were carried out as well as MRI volumetric measurements of the hippocampus and amygdala in order to verify possible modality-specific correlations between function and structure. Delayed recall indices in our memory tasks provided significant results. Visuoverbal ratios differed between right and left TLE groups, as did laterality indices of hippocampal and amygdalar volumes. Furthermore, correlations were found between the left hippocampal volume and verbal memory, and between the right amygdala and visuospatial memory. We suggest that the difficulty encountered in establishing a correlation between right temporal structures and visuospatial memory could come both from the type of test employed and the structures considered.

Reliability and clinical usefulness of the short-forms of the Wechsler memory scale (revised) in patients with epilepsy

Purpose: The Wechsler Memory Scale-R (WMS-R) is often used for the evaluation of patients with epilepsy, but is time consuming. Two shortened forms of the WMS-R have been published in an effort to reduce the time involved in the test. The purpose of this study is to cross-validate these abbreviated forms in patients with epilepsy. Methods: We assessed 103 consecutive patients with drug-resistant partial epilepsy being treated in our epilepsy unit. The WMS-R was administered to all patients. The reliability of two shortened versions of the WMS-R were evaluated. The appraisal was performed taking into account the side of the epileptogenic region. The statistical analyses were carried out with the Pearson’s correlation and with the intraclass correlation coefficient. Results: Both shortened formulas showed good reliability coefficients for predicting the General Memory and Delayed Recall Indices. In the overall accuracy of the predictions by both short forms no significant differences were found among the three study, groups (right, left or bilateral). However, when considering the predictive error only the three-subtest formulas comprising logical memory. verbal paired associates and visual reproduction efficiently predicted performance, regardless of the side of the epileptogenic region. Of the predicted scores in the overall sample, 92 and 97% fell below the standard error of measurement for general and delayed memory index, respectively. Both short forms correctly classified 89–94% of the performances at the average or impaired level. Conclusions: The short form of the M-MS-R using three subtests (logical memory, verbal paired associates and visual reproduction) is reliable and time-efficient for estimating the General and Delayed Recall Memory indexes in patients with drug-resistant partial epilepsy.

Generation of protective immune responses to plague by mucosal administration of microsphere coencapsulated recombinant subunits

We have investigated noninvasive immunization to plague. Recombinant subunit antigens, F1 and V from Yersinia pestis, were coencapsulated in biodegradable poly(l-lactide) microspheres and intranasally administered to mice over a range of dose levels. Proteins retained antigenicity during, and postmicroencapsulation as evidenced by immunoblotting and capture enzyme-linked immunosorbent assay protocols. Supporting the rationale that a subunit antigen based vaccine for plague should contain both the F1 and V antigens, we observed that systemic antibody titres to V were improved by concomitant nasal immunization with F1. Conversely, serum titres to F1 were unaffected by the presence of V in the nasal inoculum. Interestingly, intramuscular injection of F1 augmented humoral immunity to nasally applied V antigen, suggesting that F1 adjuvantizes nasally instilled V even when introduced at a spatially distinct location. Although the magnitude of the specific serum response to nasally applied microspheres and equivalent doses of soluble subunits was not always directly proportional to administered dose and frequency of dosing, generally coencapsulated antigens evoked higher titred serum antibody responses. Also, when T-cell recall indices were measured they were found to be maximum in microsphere vaccinees. As few as two appropriately timed nasal inoculations of coencapsulated F1 and V afforded complete protection from >100 LD50’s inhalational challenge with virulent Y. pestis. These data expand on previous findings from our laboratories, providing further insight into the mechanics of safeguarding mice from plague through nasal immunization. Further, these results demonstrate that in a murine model, solid protection from pneumonic plague can be engendered by two intranasal administrations of appropriately formulated recombinant proteins.

Body Image and Appearance-Related Feedback: Recall, Judgment, and Affective Response

Women viewed one of two videotaped vignettes designed to assess the effects of appearance-related feedback on a variety of recall and subjective distress indices. The experimental tape consisted of an interaction between a male and female acquaintance that contained several instances of verbal and nonverbal feedback from the man to the woman regarding physical appearance issues (i.e., attire, exercise, food selection, weight, etc.). The control tape contained the same number of interactions and also maintained the critical tone of the experimental tape; however, the male's commentary targeted issues unrelated to appearance. The results revealed no group or condition influences on free recall of appearance-related feedback. Participants in the experimental condition with high levels of body image anxiety recalled more instances of negative affective responses by the female than in other conditions. The high body image anxiety group also rated their reaction to the specific feedback events as more negative ...

Attention and memory in illicit amphetamine users: comparison with non-drug-using controls

The purpose of this study was to clarify the extent of neuropsychological impairment previously found among amphetamine users (McKetin and Mattick, 1997) by comparing them with a non-drug-using control group. Amphetamine users who were classified as low dependence ( n=15) or high dependence ( n=11) according to the severity of dependence scale (SDS) were compared to non-drug-using control subjects ( n=9) on indices of the Wechsler Memory Scale-Revised (WMS-R). Dependent amphetamine users (high dependence group) performed approximately one half of a standard deviation worse than controls on the verbal memory, attention/concentration and delayed recall indices of the WMS-R but amphetamine users who were less dependent (low dependence group) showed no impairment.

Effects of practice in repeated administrations of the Wechsler Memory Scale Revised in normal adults.

Practice effects were examined over four administrations of the immediate (I) and delayed (II) portions of three subtests of the WMS-R: Logical Memory (LM), Verbal Paired Associates (VPA), and Visual Reproduction (VR). A repeated measures ANOVA revealed that large and significant (p < .001) increases occurred in the General Memory (GM) and Delayed Recall (DR) indices and in the LMI, LMII, and VPAI subtests (Effect Sizes [ESs] = 0.70-0.87). Small but significant (p < .001) increases occurred in VRI (ES = 0.24) and VRII (ES = 0.43). The greatest increase in scores occurred at the first retest session, whereas increases of smaller magnitudes occurred at Sessions 3 and 4. Ceiling effects occur in subtests (VPAII, VRI, and VRII) on which individuals score most of the total possible points at the first testing session; this makes interpretation of practice effects difficult. Test-retest reliability coefficients, mean change scores from Session 1 to Session 2, standard errors of prediction, and 95% confidence intervals are presented. These score changes need to be taken into consideration when interpreting performance at retest.

Short forms of the Wechsler Memory Scale—Revised: Cross-validation and derivation of a two-subtest form.

J. L. Woodard and B. N. Axelrod (1995) and B. N. Axelrod, S. H. Putnam, J. L. Woodard, and K. M. Adams (1996) have presented formulas for estimating the Wechsler Memory Scale-Revised General Memory and Delayed Recall Indexes using the initial and delayed portions of only 3 subtests. The original work found nearly perfect estimates. The present study indicated excellent cross-validation for the original formulas with correlations of.99. Over 85% of the estimated scores were within 6 points of the actual score. Using estimates from only 2 subtests rather than 3, correlations were only slightly lower with 85% of the estimated scores within 10 points of the actual scores. Age, education, diagnosis, and IQ had no effects on the accuracy of these equations. Although the initial 3 test formulas are robust, the results suggest that using only 2 subtests results in higher estimation errors, which can be used when less accurate estimates are acceptable (such as in group research).

Skilled Performance on Software as a Function of Domain Expertise and Program Organization

As part of a study on the recall of skilled and novice programmers, 23 subjects each viewed a 25-line BASIC program organized in one of three ways, executable order, random chunks, and random lines. Subjects performed a perceptual task in which they recopied a 25-line BASIC program on an answer sheet while the program remained in plain view, and a memory task, in which they recalled the BASIC program after a 4-min. exposure to it. For the perceptual task, the number of glances and amount of time per glance between the answer sheet and stimulus material were used as indices of recall. For the memory task, the number of lines recalled as a function of program organization and level of programming skill measured performance. Analysis indicated that skilled programmers encoded more lines of a program per glance and also spent less time examining each line of code than novices when the program was presented in executable order or random chunks. Further, skilled programmers recalled more lines of code than novices when the program was presented in executable order or random chunks but not in random lines. Implication of the results for the design of human-computer interfaces is discussed.

Cross-validation of a method for predicting wechsler memory scale-revised index scores

Equations for prorating Wechsler Memory Scale-Revised General Memory (GM) and Delayed Recall (DR) index scores (Woodward & Axelrod, 1995) were confirmed in clinical samples of patients who were seen for comprehensive neuropsychological testing with (1) moderate or severe closed-head injuries (n = 53); (2) mild head injury/concussion (n = 47); and (3) patients with intractible seizures who were seen for neuropsychological testing prior to neurosurgical resection (n = 24). Fifty-one of the closed-head injury (CHI) patients were involved in litigation related to their injury at the time of this evaluation. Predicted GM and DR index scores fell within 6 points of the obtained scores for 91% and 92%, respectively, of the CHI sample, and 100% of the seizure resection sample. This is well within the standard error of measurement of these index scores. There were no significant differences in accuracy of estimated index scores between litigants and non-litigants or between levels of head injury severity. These findings confirm the earlier cross-validation results reported by Axelrod et al. (1996) in a mixed sample of traumatic brain injury and other neurological insult.

Clinical Utility of Wechsler Memory Scale-Revised and Predicted IQ Discrepancies in Closed Head Injury

Comparisons between Wechsler Memory Scale-Revised (WMS-R) indexes and Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ scores have been proposed to identify severity of memory deficits. However, many neurologic conditions reduce both intellectual and memory functioning, and thus, examining differences between these scores may be of little value. Closed head injured subjects who completed the WMS-R were divided into either mild injury (MI, n = 41) or moderate/severe (SI, n = 41) injury groups based on trauma severity indicators and were matched on age and level of education. The Oklahoma Premorbid Intelligence Estimation (OPIE), a regression formula that takes into account demographic variables as well as IQ performance, was calculated for each subject. Discrepancy scores were calculated between predicted IQ scores and WAIS-R IQ and WMS-R indexes. SI head-injured subjects displayed significantly larger discrepancies (19 points) between OPIE scores and Delayed Recall Indexes from the WMS-R than the MI subjects (10 points). Significantly larger percentages of subjects in the SI group displayed significant (>SD) reductions in many of the WMS-R and WAIS-R scores from estimates than subjects in the MI group. Comparing current memory functioning to estimates of premorbid intellectual ability appears to be a sensitive indicator of presence and degree of intellectual and memory dysfunction in head trauma patients. Results also provide evidence that estimates of premorbid intellectual ability can serve as estimates of premorbid memory functioning. © 1997 National Academy of Neuropsychology. Published by Elsevier Science Ltd

Relationship of iq to verbal learning and memory: Test and retest

The relationship between Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ and performance on measures of memory was examined in 64 adults tested twice at a 2-week interval. Repeated measures analyses of variance revealed that individuals with Low-Average WAIS-R Full Scale IQ scores performed significantly more poorly than did individuals with Average and High-Average Full Scale IQs on memory measures including the Wechsler Memory Scale-Revised (WMS-R) General Memory and Delayed Recall indices, as well as California Verbal Learning Test (CVLT) Total Words, Learning Slope, and Discriminability. Although all three groups demonstrated significant practice effects on each memory measure, group differences in performance persisted at retest. Multiple regression analyses revealed that WAIS-R factor scores Verbal Comprehension and Freedom from Distractibility accounted for up to 42% of the variance in WMS-R and CVLT indices. Moreover, WAIS-R performance at initial testing accounted for 22–41 % of the variance in memory performance at retest These results are discussed in the context of the construct stabilities of intelligence and memory, as well as the psychometric precision of the tests used to measure these constructs.