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A tale of two stories: Validity of an alternative story memory test in a sample of older adults
Abstract
Objective: Many patients require repeat neuropsychological evaluations to determine change over time. Repeat evaluations lead to practice effects, which can impact the validity of the assessment. The current study assessed, in older adults, the validity of an alternative set of verbal memory stories created by Newcomer and colleagues.
Method: A total 154 of non-demented adults, ages 60–92, completed the WMS-III logical memory (LM) stories and two Newcomer stories (Carson–Jones) as part of a larger battery of neurocognitive tests. The Carson–Jones stories were scored for: (1) verbatim (traditional) and (2) thematic (developed for this study) accuracy. Story memory variables were compared to each other and additional neurocognitive measures using bivariate correlations. A subset of participants (n = 133) completed magnetic resonance imaging (MRI) and various structural regions (e.g. thickness and volume of medial temporal lobe structures) were used to assess external validity of Carson–Jones stories with hierarchical multiple regression analyses.
Results: There was a strong positive correlation between WMS-III LM and Carson–Jones stories for both verbatim and thematic scoring. Both scoring types showed convergent validity with other verbal memory measures (e.g. WMS-III LM and HVLT-R Delay/Learning) and divergent validity with Stroop Word Reading and JOLO. Regarding neuroimaging correlates, Carson–Jones verbatim scoring was significantly associated with left subiculum and left whole hippocampal volume whereas thematic scoring was significantly associated only with left subiculum.
Conclusions: Newcomer stories appear to be a valid alternative to WMS-III LM stories in terms of assessing verbal memory in healthy older adults.
... Nevertheless, since narrative-specificity in brain function may arise at a hemispheric rather than at a regional level 4 , there is a need for validity studies on the role of cerebral laterality of injury in story comprehension and recall, which have been poorly investigated at a hemispheric level. This need arises also in view of the contradictory results regarding laterality and narrative processing, not only from studies on patients with brain impairments 3,6 , and especially on those with temporal lobe epilepsy [7][8][9][10][11][12] , but also from functional or anatomical studies on healthy subjects 4,5,[13][14][15][16][17][18][19][20][21][22][23] . ...
... Bilateral involvement and the (theoretically-subtle) interactions among explicit, implicit, and working memory have been increasingly incorporated into new studies on narrative processing 4,5,16,[24][25][26][27] . In parallel, narratives as whole units, to be understood and/or remembered, have been more frequently examined in natural settings [6][7][8][10][11][12]20,22 . Other than this, they have generally been used as the reference context for interpreting experimental manipulations with the aim of assessing attention to selected story features 14,16,18,23 . ...
... LHI was impaired in relation to non-LHI in both UC and CC, with sensitivity and specificity above 70%. The findings from the present study agree with those of studies that used the narrative as a whole unit, and verbal inputs and outputs [6][7][8]10,12,20,22 , except that the left-lateralization pattern extended beyond the temporal lobe in this study. Also in line with the present findings, concerning the input, activation that was more left-lateralized was previously observed in functional studies for reading than for listening comprehension 13,21 ; and, concerning the output, a UC: uncued condition; CC: cued condition; LHI: patients with left hemisphere injury; RHI: patients with right hemisphere injury; HP: healthy participants. ...
Background:
There are no studies on adults with unilateral brain lesions regarding story reading with incidental/implicit comprehension and memory, in which memory is only assessed through delayed recall. There is a need for validation of cerebral laterality in this type of verbal recall, which includes spontaneous performance (free or uncued condition (UC)), and induced-through-question performance regarding the forgotten units (cued condition (CC)).
Objectives:
To explore the effects of unilateral brain lesions, of oral reading with expression (RE) and comprehension (RC) on delayed recall of a story, as either UC or CC; and to validate the ability of UC and CC to discriminate the side of brain injury.
Methods:
Data were obtained from 200 right-handed volunteers, among whom 42 had left-hemisphere injury (LHI), 49 had right-hemisphere injury (RHI) and 109 were demographically-matched healthy participants (HP). Patients who were unable to read, understand or speak were excluded.
Results:
LHI individuals presented impairment of both UC and CC, in relation to the other two groups (non-LHI) with sensitivity and specificity above 70%. LHI and RHI individuals were not significantly different in RE and RC, but they were both different from HP in all the assessments except CC, in which RHI individuals resembled HP. Despite this lack of abnormality in RHI individuals during CC, about half of this group showed impairment in UC. Additionally, whereas RE had a significant effect on UC, the moral of the story (RC) had a significant effect on both UC and CC.
Conclusions:
The left hemisphere was dominant for this memory task involving implicit processing.
... The LM subtest of the WMS is the most widely known and used neuropsychological test assessing complex verbal memory (Trifilio et al., 2020). Story memory tests were designed to assess everyday learning and remembering of new declarative information, and have been validated in this respect (Squire, 1987). ...
... Requiring episodic memory and performance is associated with left subiculum and hippocampal volume [29] Decreased performance, particularly immediate recall, is observed in temporal lobe resection patients [30]. Variable of interest: total delay recall. ...
Background:
A digital version of the clock drawing test (dCDT) provides new latency and graphomotor behavioral measurements. These variables have yet to be validated with external neuropsychological domains in non-demented adults.
Objective:
The current investigation reports on cognitive constructs associated with selected dCDT latency and graphomotor variables and compares performances between individuals with mild cognitive impairment (MCI) and non-MCI peers.
Methods:
202 non-demented older adults (age 68.79 ± 6.18, 46% female, education years 16.02 ± 2.70) completed the dCDT and a comprehensive neuropsychological protocol. dCDT variables of interest included: total completion time (TCT), pre-first hand latency (PFHL), post-clock face latency (PCFL), and clock face area (CFA). We also explored variables of percent time drawing (i.e., 'ink time') versus percent time not drawing (i.e., 'think time'). Neuropsychological domains of interest included processing speed, working memory, language, and declarative memory.
Results:
Adjusting for age and premorbid cognitive reserve metrics, command TCT positively correlated with multiple cognitive domains; PFHL and PCFL negatively associated with worse performance on working memory and processing speed tests. For Copy, TCT, PCFL, and PFHL negatively correlated with processing speed, and CFA negatively correlated with language. Between-group analyses show MCI participants generated slower command TCT, produced smaller CFA, and required more command 'think' (% Think) than 'ink' (% Ink) time.
Conclusion:
Command dCDT variables of interest were primarily processing speed and working memory dependent. MCI participants showed dCDT differences relative to non-MCI peers, suggesting the dCDT may assist with classification. Results document cognitive construct validation to digital metrics of clock drawing.
Methods
We administered the Global Neuropsychological Assessment (GNA), an abbreviated cognitive battery, to 105 adults aged 73.0 ± 7.1 years, including 28 with probable Alzheimer’s disease, 9 with amnestic mild cognitive impairment, and 68 healthy controls. We examined group differences in baseline performance, test–retest reliability, and correlations with other conventional tests.
Results
Healthy adults outperformed patients on all five GNA subtests. Test–retest intraclass correlation coefficients were significant for all GNA subtests. Among patients with healthy controls, GNA Story Memory correlated best with Wechsler Memory Scale–Revised (WMS-R) Logical Memory for learning and delayed recall, GNA Digit Span correlated most highly with the Wechsler Adult Intelligence Scale–Third Edition (WAIS-III) Digit Span, GNA Perceptual Comparison correlated most highly with the Trail Making Test, and GNA Animal Naming correlated most highly with Supermarket Item Naming.
Conclusions
Preliminary findings suggest that the GNA shows good test–retest validity, clear convergent and discriminant construct validity, and excellent diagnostic criterion validity for dementia and mild cognitive impairment in an American sample.
Two of the most commonly used methods to assess memory functioning in studies of cognitive aging and dementia are story memory and list learning tests. We hypothesized that the most commonly used story memory test, Wechsler's Logical Memory, would generate more pronounced practice effects than a well validated but less common list learning test, the Neuropsychological Assessment Battery (NAB) List Learning test. Two hundred eighty-seven older adults, ages 51 to 100 at baseline, completed both tests as part of a larger neuropsychological test battery on an annual basis. Up to five years of recall scores from participants who were diagnosed as cognitively normal (n = 96) or with mild cognitive impairment (MCI; n = 72) or Alzheimer's disease (AD; n = 121) at their most recent visit were analyzed with linear mixed effects regression to examine the interaction between the type of test and the number of times exposed to the test. Other variables, including age at baseline, sex, education, race, time (years) since baseline, and clinical diagnosis were also entered as fixed effects predictor variables. The results indicated that both tests produced significant practice effects in controls and MCI participants; in contrast, participants with AD declined or remained stable. However, for the delayed—but not the immediate—recall condition, Logical Memory generated more pronounced practice effects than NAB List Learning (b = 0.16, p < .01 for controls). These differential practice effects were moderated by clinical diagnosis, such that controls and MCI participants—but not participants with AD—improved more on Logical Memory delayed recall than on delayed NAB List Learning delayed recall over five annual assessments. Because the Logical Memory test is ubiquitous in cognitive aging and neurodegenerative disease research, its tendency to produce marked practice effects—especially on the delayed recall condition—suggests a threat to its validity as a measure of new learning, an essential construct for dementia diagnosis.
Longitudinal normative data obtained from a robust elderly sample (i.e., believed to be free from neurodegenerative disease) are sparse. The purpose of the present study was to develop reliable change indices (RCIs) that can assist with interpretation of test score changes relative to a healthy sample of older adults (ages 50+). Participants were 4217 individuals who completed at least three annual evaluations at one of 34 past and present Alzheimer’s Disease Centers throughout the United States. All participants were diagnosed as cognitively normal at every study visit, which ranged from three to nine approximately annual evaluations. One-year RCIs were calculated for 11 neuropsychological variables in the Uniform Data Set by regressing follow-up test scores onto baseline test scores, age, education, visit number, post-baseline assessment interval, race, and sex in a linear mixed effects regression framework. In addition, the cumulative frequency distributions of raw score changes were examined to describe the base rates of test score changes. Baseline test score, age, education, and race were robust predictors of follow-up test scores across most tests. The effects of maturation (aging) were more pronounced on tests related to attention and executive functioning, whereas practice effects were more pronounced on tests of episodic and semantic memory. Interpretation of longitudinal changes on 11 cognitive test variables can be facilitated through the use of reliable change intervals and base rates of score changes in this robust sample of older adults. A Web-based calculator is provided to assist neuropsychologists with interpretation of longitudinal change. (
JINS
, 2015,
21
, 1–10)
Background
There is no consensus about which hippocampal subfields become atrophic earliest in the course of Alzheimer's disease (AD).
Methods
Thirty AD patients, 41 mild cognitive impairment (MCI) patients, and 38 healthy controls (HCs) underwent cerebral magnetic resonance imaging (with an automated segmentation protocol for the volumetric analysis of hippocampal subfields) and a test of immediate and delayed recall of a 15-word list.
Results
The volumes of the presubiculum and subiculum presented the most remarkable reduction in the patient's groups. In the MCI group, only the volumes of presubiculum and subiculum predicted performance on the memory tests. In AD patients, the volumes of all hippocampal subfields (with the notable exception of the CA1) predicted memory scores.
Conclusions
Our data point to a prevalent atrophy of the presubicular-subicular complex from the early phases of AD. This finding is consistent with neuropathological observations in AD patients and probably reflects the severe degeneration of the perforant pathway while penetrating the hippocampus through the subicular field in its course from the entorhinal cortex to the dentate gyrus.
Automated analysis of MRI data of the subregions of the hippocampus requires computational atlases built at a higher resolution than those that are typically used in current neuroimaging studies. Here we describe the construction of a statistical atlas of the hippocampal formation at the subregion level using ultra-high resolution, ex vivo MRI. Fifteen autopsy samples were scanned at 0.13 mm isotropic resolution (on average) using customized hardware. The images were manually segmented into 13 different hippocampal substructures using a protocol specifically designed for this study; precise delineations were made possible by the extraordinary resolution of the scans. In addition to the subregions, manual annotations for neighboring structures (e.g., amygdala, cortex) were obtained from a separate dataset of in vivo, T1-weighted MRI scans of the whole brain (1 mm resolution). The manual labels from the in vivo and ex vivo data were combined into a single computational atlas of the hippocampal formation with a novel atlas building algorithm based on Bayesian inference. The resulting atlas can be used to automatically segment the hippocampal subregions in structural MRI images, using an algorithm that can analyze multimodal data and adapt to variations in MRI contrast due to differences in acquisition hardware or pulse sequences. The applicability of the atlas, which we will release as part of FreeSurfer (version 6.0), is demonstrated with experiments on three different publicly available datasets with different types of MRI contrast. The results show that the atlas and companion segmentation method: 1) can segment T1 and T2 images, as well as their combination, 2) replicate findings on mild cognitive impairment based on high-resolution T2 data, and 3) can discriminate between Alzheimer's disease subjects and elderly controls with 88% accuracy in standard resolution (1 mm) T1 data, significantly outperforming the atlas in FreeSurfer version 5.3 (86% accuracy) and classification based on whole hippocampal volume (82% accuracy).
Copyright © 2015. Published by Elsevier Inc.
Previous research has shown that people remember details from emotional events differently than details from neutral events. However, past research suffers from inadequate equating of the details tested in the emotional and neutral events. In the current five experiments, involving a total of 397 subjects, we equated the to-be-remembered detail information. Subjects in these experiments were presented with a thematic series of slides in which the content of one critical slide in the middle of the series varied. When the critical slide was emotional (a woman injured near a bicycle), compared to neutral in nature (a woman riding a bicycle), subjects were better able to remember a central detail but less able to remember a peripheral detail. To determine whether the emotional event led to different performance simply because it was unusual, we included a third condition, in which subjects saw an “unusual” version of the event (a woman carrying a bicycle on her shoulder). Subjects in the unusual condition performed poorly when recalling both the central and the peripheral detail, and thus differently from those in the emotional condition. To determine what subjects were attending to, in Experiment 4 we gathered reports of thoughts that were evoked while subjects viewed the critical slide. Analyses of these reports indicated that differential elaboration occurred when people viewed emotional, unusual, and neutral events.
We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The "Desikan-Killiany-Tourville" (DKT) protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://mindboggle.info/data website.
To evaluate the role of practice and to establish statistically meaningful methods for assessing cognitive outcome after epilepsy surgery, test–retest scores for 47 left (LTL) and 49 right (RTL) temporal lobectomy patients on the Wechsler Adult Intelligence Scale—Revised (WAIS—R) and Wechsler Memory Scale—Revised (WMS—R) were compared with the scores of 40 epilepsy patients who had not received lobectomies (SZCs). Reliable change indexes were calculated to control for measurement error, and base-rate tables for individual change were constructed for each variable before and after adjustment for observed practice effects. More frequent positive Full Scale IQ changes were noted among LTL than among RTL patients following surgery, whereas negative changes on the WMS-R General Memory and Verbal Memory Indexes were more common among the LTL patients than among either the RTL or SZC groups. When practice effects were controlled, the RTL patients also exceeded base-rate expectations for negative outcomes on the Verbal Memory Index. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Practice effects present a challenge for neuropsychological re-assessments. Insufficiently controlled test-learning effects could result in "improved" test scores on re-assessment, which could wrongly be interpreted as recovery when in fact the underlying cognitive function has remained unchanged or deteriorated. Logical memory is highly sensitive to practice effects. Clients often remember the commonly used stimulus stories of the Wechsler Memory Scales (WMS) in subsequent re-assessments. Therefore alternative test stimuli are needed for research and clinical practice. This study undertook the development and statistical evaluation of a new set of logical memory stories, which can be utilised interchangeably with the traditional Wechsler stories. Empirical testing with different client groups (n = 240) confirmed that the newly created test stimuli have highly compatible structural and statistical properties to the WMS stories.
Measuring the entorhinal cortex (ERC) is challenging due to lateral border discrimination from the perirhinal cortex. From a sample of 39 nondemented older adults who completed volumetric image scans and verbal memory indices, we examined reliability and validity concerns for three ERC protocols with different lateral boundary guidelines (i.e., Goncharova, Dickerson, Stoub, & deToledo-Morrell, 2001; Honeycutt et al., 1998; Insausti et al., 1998). We used three novice raters to assess inter-rater reliability on a subset of scans (216 total ERCs), with the entire dataset measured by one rater with strong intra-rater reliability on each technique (234 total ERCs). We found moderate to strong inter-rater reliability for two techniques with consistent ERC lateral boundary endpoints (Goncharova, Honeycutt), with negligible to moderate reliability for the technique requiring consideration of collateral sulcal depth (Insausti). Left ERC and story memory associations were moderate and positive for two techniques designed to exclude the perirhinal cortex (Insausti, Goncharova), with the Insausti technique continuing to explain 10% of memory score variance after additionally controlling for depression symptom severity. Right ERC-story memory associations were nonexistent after excluding an outlier. Researchers are encouraged to consider challenges of rater training for ERC techniques and how lateral boundary endpoints may impact structure-function associations. (JINS, 2010, 16, 846-855.).
Glucocorticoids (GCs) have a variety of effects on the brain including site-preferential, inhibitory effects on hippocampal neurons. In the case of dexamethasone (DEX), extended rather than single-dose treatment in vivo may be required for binding to brain rather than peripheral (e.g., pituitary) GC receptors and for maximizing other biologic effects in hippocampus (e.g., GC receptor downregulation, inhibition of glucose transport). Based on the contributory role of hippocampal neurons in declarative memory performance, we investigated the cognitive consequences of DEX treatment in normal adult human subjects, hypothesizing a decrease in declarative memory performance after extended but not overnight treatment. Double-blind, placebo-controlled treatment with DEX was given at 2300 hr for four consecutive days (0.5, 1, 1, 1 mg, respectively). Plasma sampling (0800 and 1600 hr) and cognitive testing (1600 hr) were performed on study days 0 (baseline), 1, and 4, and 7 d posttreatment. Repeated-measures ANOVA found a significant interaction between study day and treatment condition for correct recall during a paragraph recall task [F(3,51) = 3.52, p = 0.02]. DEX (n = 10) in comparison to placebo (n = 9) treatment decreased correct paragraph recall on study day 4 [F(1,17) = 5.01, p = 0.04] and study day 11 [F(1,17) = 5.82, p = 0.03], with the lowest level of performance occurring on day 4 followed by a return toward baseline performance level by day 11. In the placebo-treated subjects, correct paragraph recall improved over the course of treatment, consistent with practice.(ABSTRACT TRUNCATED AT 250 WORDS)
Previous investigations have found that increasing circulating glucose availability can increase memory performance in rodents, healthy humans, and individuals with dementia of the Alzheimer's type. In this study, patients with schizophrenia, healthy control subjects, and controls with bipolar affective disorder were tested using double-blind treatment with either 50 g anhydrous dextrose plus 4 mg sodium saccharin (for "taste") or 23.7 mg saccharin alone, followed by cognitive testing on a complex battery. At this glucose dose, verbal memory performance on a paragraph recall task was increased during the glucose condition relative to the saccharin condition in the patients with schizophrenia; this effect was not detected in either the psychiatric or normal controls. The results provide preliminary support for the hypothesis that memory performance can be improved in patients with schizophrenia by increasing circulating glucose availability and suggest the importance of further evaluation of therapeutic manipulations of glucose availability.
Several analyses were conducted on data from samples of adults between 18 and 58 years of age who completed the same cognitive tests after an interval ranging from less than 1 week to 35 years. Because the retest interval varied across individuals, it was possible to determine the length of time needed before the gains associated with a retest decreased to 0 and to obtain simultaneous estimates of the magnitude of effects associated with increased age and a prior assessment. The results indicated that for adults within this age range, 7 or more years were needed before positive retest effects were no longer detectable. Age effects in longitudinal comparisons could be interpreted in terms of large positive effects associated with a prior assessment and negative effects associated with age that were comparable in magnitude to those observed in cross-sectional comparisons.
We present a technique for automatically assigning a neuroanatomical label to each location on a cortical surface model based on probabilistic information estimated from a manually labeled training set. This procedure incorporates both geometric information derived from the cortical model, and neuroanatomical convention, as found in the training set. The result is a complete labeling of cortical sulci and gyri. Examples are given from two different training sets generated using different neuroanatomical conventions, illustrating the flexibility of the algorithm. The technique is shown to be comparable in accuracy to manual labeling.
We present a technique for automatically assigning a neuroanatomical label to each voxel in an MRI volume based on probabilistic information automatically estimated from a manually labeled training set. In contrast to existing segmentation procedures that only label a small number of tissue classes, the current method assigns one of 37 labels to each voxel, including left and right caudate, putamen, pallidum, thalamus, lateral ventricles, hippocampus, and amygdala. The classification technique employs a registration procedure that is robust to anatomical variability, including the ventricular enlargement typically associated with neurological diseases and aging. The technique is shown to be comparable in accuracy to manual labeling, and of sufficient sensitivity to robustly detect changes in the volume of noncortical structures that presage the onset of probable Alzheimer's disease.
The paragraphs that compose the Logical Memory subtest of the Wechsler Memory Scale-Revised were examined and alternate paragraphs that were equivalent in structure, affective tone, and number of scorable units were developed. Objective scoring criteria for this alternate form, the Morris Revision, yielded significant interscorer reliability. Concurrent validity for the Moms Revision paragraphs was established using multiple criteria. The correlation between the summed scores for the original paragraphs and the Morris Revision paragraphs was significant, as were the correlations between individual scores for analogous paragraphs across the two forms. The Morris Revision was determined to be a psychometrically equivalent alternate form of the original Logical Memory subtest. Clinical use of the Morris Revision is recommended to eliminate serial testing artifacts when reevaluating verbal memory in neuropsychological patients.
Performed 2 principal factor analyses to examine the construct validity of the Wechsler Memory Scale—Revised (WMS—R) and to determine whether abstraction and memory factors can be extracted from the Halstead-Reitan Neuropsychological Test Battery (HRNB) results. Results from 237 patients support the validity of the verbal memory, delayed recall, and attention and concentration indices of the WMS—R but not the visual memory indices. No separate abstraction factor was found, and none of the HRNB measures loaded substantially on the memory factors defined by WMS—R subtests. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
It has been claimed that emotional arousal causes a narrowing of attention, and, therefore, impoverished memory encoding.
On this view, if details of an emotional event are reported subsequently, these details must be after-the-fact reconstructions
that are open to error. Our study challenges these claims. Using a long-term (2-week), incidental learning procedure, wefound
that emotion promotes memory both for information central to an event and for peripheral detail. This contrasts with the results
of explicit instructions to remember or to attend closely to the event, both of which seem to promote memory for the event’s
gist at the expense of detail. The likely mechanisms underlying these effects are discussed.
Glucocorticoid (GC) exposure can affect brain function, including potential adverse effects on hippocampal physiology and on specific elements of cognitive performance. In a prior study of healthy adult humans, decreased verbal memory performance was detected during four days of double-blind, placebo-controlled dexamethasone (DEX) treatment. Using an identical experimental design and sample size (n = 19), the cognitive effect of DEX treatment was studied in 11 subjects with schizophrenia, compared with 8 receiving placebo. In contrast to the effect in healthy adults, GC treatment with DEX at this dose (cumulative 3.5 mg) and duration did not decrease verbal memory performance or other measures of cognitive function in the patients with schizophrenia. When data from this experiment was compared with data from the previous study of healthy adults, covarying differences in baseline memory performance, a significant 3-way interaction was detected between subject group, treatment condition, and the repeated measurements of verbal memory performance across baseline, treatment and washout (F[3,87] = 4.84, p = .0066), suggesting differential cognitive effects of DEX in the patients versus the previously studied healthy subjects. Baseline plasma cortisol concentrations (0800h) prior to DEX treatment were inversely correlated with baseline delayed (rs = − 0.536, p = .03) verbal recall performance, supporting a previous report. The current results await replication using a larger sample size but provide preliminary evidence for an altered behavioral response to acute GC exposure in schizophrenic versus healthy subjects, and further evidence for a relationship between chronic changes in circulating cortisol and the memory impairments found in this disorder.
FreeSurfer is a suite of tools for the analysis of neuroimaging data that provides an array of algorithms to quantify the functional, connectional and structural properties of the human brain. It has evolved from a package primarily aimed at generating surface representations of the cerebral cortex into one that automatically creates models of most macroscopically visible structures in the human brain given any reasonable T1-weighted input image. It is freely available, runs on a wide variety of hardware and software platforms, and is open source.
Recent advances in neuroimaging have highlighted the interest to differentiate hippocampal subfields for cognitive neurosciences and more notably in assessing the effects of normal and pathological aging. The main goal of the present study is to investigate the effects of normal aging onto the volume of the different hippocampal subfields. For this purpose, we developed a new magnetic resonance sequence together with reliable tracing guidelines to assess the volume of different subfields of the hippocampus using a 3 Tesla scanner, and estimated the validity of a simpler and less time-consuming method based on the widely-used automatic Voxel-Based Morphometry (VBM) technique. Three hippocampal regions of interest were delineated on the right and left hippocampi of 50 healthy subjects between 18 and 68 years old corresponding to the CA1, subiculum and other (including CA2-3-4 and Dentate Gyrus) subfields. A strong effect of age was found on the volume of the subiculum only, with a decrease paralleling that of the global gray matter volume, while CA1 and other subfields seemed relatively spared. Although less precise than the ROI-tracing technique, the VBM-based method appeared as a reliable alternative especially to distinguish CA1 and subiculum subfields. Our findings of a specific effect of age on the subiculum are consistent with the developmental hypothesis ("last-in first-out" theory). This contrasts with the predominant vulnerability of the CA1 subfield to Alzheimer's disease reported in several previous studies, suggesting that the assessment of hippocampal subfields may improve the discrimination between normal and pathological aging.
Operational definitions of cognitive impairment have varied widely in diagnosing mild cognitive impairment (MCI). Identifying clinical subtypes of MCI has further challenged diagnostic approaches because varying the components of the objective cognitive assessment can significantly impact diagnosis. Therefore, the authors investigated the applicability of diagnostic criteria for clinical subtypes of MCI in a naturalistic research sample of community elders and quantified the variability in diagnostic outcomes that results from modifying the neuropsychological definition of objective cognitive impairment.
Cross-sectional and longitudinal study.
San Diego, CA, Veterans Administration Hospital.
Ninety nondemented, neurologically normal, community-dwelling older adults were initially assessed and 73 were seen for follow-up approximately 17 months later.
Participants were classified via consensus diagnosis as either normally aging or having MCI via each of the five diagnostic strategies, which varied the cutoff for objective impairment and the number of neuropsychological tests considered in the diagnostic process.
A range of differences in the percentages identified as MCI versus cognitively normal were demonstrated, ranging from 10-74%, depending on the classification criteria used. A substantial minority of individuals demonstrated diagnostic instability over time and across diagnostic approaches. The single domain nonamnestic subtype diagnosis was particularly unstable (e.g., prone to reclassification as normal at follow up).
Our findings provide empirical support for a neuropsychologically derived operational definition of clinical subtypes of MCI and point to the importance of using comprehensive neuropsychological assessments. Diagnoses, particularly involving nonamnestic MCI, were variable over time. The applicability and utility of this particular MCI subtype warrants further investigation.
Reviews the literature relating arousal and human learning and memory. It is argued that it is important to distinguish between effects of arousal on storage and those on retrieval. The distinction between item arousal and S arousal is also of importance, and more work is needed to consider the conjoint influence of these sources of arousal on performance. Current hypotheses are seen as inadequate because they do not take into account task difficulty in discussing the effects of arousal. A hypothesis is proposed which assumes that high levels of arousal affect storage by focusing attention on physical characteristics of presented information, whereas they affect retrieval by biasing S's search process toward readily accessible sources of stored information. (85 ref)
The authors examined a consecutive series of 50 patients for the presence of apathy, depression, anxiety, and neuropsychological deficits using a neuropsychological battery that included a recently designed apathy scale. This scale was found to be reliable and valid in the diagnosis of apathy in patients with PD. Of patients in the study, 12% showed apathy as their primary psychiatric problem, and 30% were both apathetic and depressed. Patients with apathy (with or without depression), showed significantly more deficits in both tasks of verbal memory and time-dependent tasks. Results suggest that apathy is a frequent finding in PD, is significantly associated with specific cognitive impairments, and may have a different mechanism than depression.
In 1984, Jacobson, Follette, and Revenstorf defined clinically significant change as the extent to which therapy moves someone outside the range of the dysfunctional population or within the range of the functional population. In the present article, ways of operationalizing this definition are described, and examples are used to show how clients can be categorized on the basis of this definition. A reliable change index (RC) is also proposed to determine whether the magnitude of change for a given client is statistically reliable. The inclusion of the RC leads to a twofold criterion for clinically significant change.
The WAIS and Wechsler Memory Scale subtest scores of 256 neurologic and nonneurologic subjects were factor analyzed. The results supported the construct validity of the Wechsler Memory Scale as a measure of verbal learning and memory, attention and concentration, and orientation. Construct validity was not demonstrated for the Visual Reproduction subtest as a measure of visual memory. Suggestions are offered for future development and research on measures of visual memory.
A new Geriatric Depression Scale (GDS) designed specifically for rating depression in the elderly was tested for reliability and validity and compared with the Hamilton Rating Scale for Depression (HRS-D) and the Zung Self-Rating Depression Scale (SDS). In constructing the GDS a 100-item questionnaire was administered to normal and severely depressed subjects. The 30 questions most highly correlated with the total scores were then selected and readministered to new groups of elderly subjects. These subjects were classified as normal, mildly depressed or severely depressed on the basis of Research Diagnostic Criteria (RDC) for depression. The GDS, HRS-D and SDS were all found to be internally consistent measures, and each of the scales was correlated with the subject's number of RDC symptoms. However, the GDS and the HRS-D were significantly better correlated with RDC symptoms than was the SDS. The authors suggest that the GDS represents a reliable and valid self-rating depression screening scale for elderly populations.
Dementia of the Alzheimer type (DAT) is accompanied by disruption in glucose regulation and utilization that may contribute to its characteristic memory impairment. Increasing glucose availability by raising plasma glucose improves memory in patients with DAT. Such memory improvement is associated with a secondary elevation in plasma insulin levels, raising the question of whether improvement is due to changes in insulin levels, independent of hyperglycemia. Distributions of insulin receptors in the hippocampus and insulin-mediated increases in glucose utilization in entorhinal cortex provide potential mechanisms for such improvement. We show that raising plasma insulin through intravenous infusion while keeping plasma glucose at a fasting baseline level produces striking memory enhancement for patients with DAT. Previous findings of hyperglycemic memory enhancement were also replicated. Patients with DAT also showed abnormal plasma levels of glucoregulatory hormones and metabolites at baseline and during metabolic manipulations. Our findings suggest that neuroendocrine factors play an important role in the pathophysiology of DAT.
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.
Glucocorticoids (GCs) can regulate hippocampal metabolism, physiologic functions, and memory. Despite evidence of memory decreases during pharmacological GC treatment, and correlations between memory and cortisol levels in certain disease conditions, it remains unclear whether exposure to the endogenous GC cortisol at levels seen during physical and psychological stress in humans can inhibit memory performance in otherwise healthy individuals.
Randomized, double-blind, placebo-controlled comparison of 2 fixed oral doses of cortisol (40 mg/d and 160 mg/d using split doses to approximate circadian rhythm) given for 4 days to matched groups of healthy subjects (n = 51). Lower-dose treatment approximated cortisol exposure during mild stress, whereas the higher dose approximated cortisol exposure during major stress. Cognitive testing and plasma sampling were done at baseline, after 1 and 4 days of treatment, and after a 6-day washout period, hypothesizing dose-dependent decreases in verbal declarative memory.
Cortisol treatment at the higher dose produced reversible decreases in verbal declarative memory without effects on nonverbal memory, sustained or selective attention, or executive function. A significant interaction between time and treatment condition for paragraph recall was explained by treatment-induced differences in performance after 4 treatment days, with lower immediate and delayed recall performance during higher-dose cortisol treatment compared with lower-dose treatment and placebo.
Several days of exposure to cortisol at doses and plasma concentrations associated with physical and psychological stress in humans can-similar to pharmacological GC treatment-reversibly decrease specific elements of memory performance in otherwise healthy individuals.
Evaluation of patients with suspected Alzheimer's disease (AD) often involves clinicians of multiple disciplines working in collaboration to maximize diagnostic accuracy. Accordingly, repeated administrations of some common tests of mental status may occur within a relatively brief time period. The effect of such retesting on subsequent results is largely unknown for many cognitive tasks, despite the possibility that repeated administrations may artificially inflate scores. To assess the potential impact of practice effects on a commonly administered verbal fluency task, animal naming was administered twice within a 1-week period to 111 patients with probable AD and 12 persons without dementia. Non-demended subjects were the only group to demonstrate a small (3 point), but statistically significant practice effect. Regardless of level of cognitive impairment, patients with AD did not show significant practice effects over repeated administrations of animal naming after a relatively brief test-retest interval, suggesting the robust nature of this task in AD.
During the standardization of the Wechsler Adult Intelligence Scale (3rd ed.; WAIS-III) and the Wechsler Memory Scale (3rd ed.; WMS-III) the participants in the normative study completed both scales. This "co-norming" methodology set the stage for full integration of the 2 tests and the development of an expanded structure of cognitive functioning. Until now, however, the WAIS-III and WMS-III had not been examined together in a factor analytic study. This article presents a series of confirmatory factor analyses to determine the joint WAIS-III and WMS-III factor structure. Using a structural equation modeling approach, a 6-factor model that included verbal, perceptual, processing speed, working memory, auditory memory, and visual memory constructs provided the best model fit to the data. Allowing select subtests to load simultaneously on 2 factors improved model fit and indicated that some subtests are multifaceted. The results were then replicated in a large cross-validation sample (N = 858).
The degree of practice effects with the Brief NIMH Neuropsychological Battery for HIV Infection and AIDS is reported using a 7-10 day test-retest interval. The patient groups were asymptomatic and symptomatic of HIV while the control group was made up of "at risk" volunteers. Statistically significant practice effects were obtained on the California Verbal Learning Test, the Paced Auditory Serial Addition Task and the Visual Search Test among the infected individuals. The controls subjects demonstrated statistically significant practice effects on all of the neuropsychological tests. The implications of these findings in prospective studies are discussed.
Clinicians should note that there is considerable variability in the reliabilities of the index and subtest scores derived from the third editions of the Wechsler Adult Intelligence Scale (WAIS-III) and the Wechsler Memory Scale (WMS-III). The purpose of this article is to review these reliabilities and to illustrate how they can be used to interpret change in patients' performances from test to retest. The WAIS-III IQ and Index scores are consistently the most reliable scores, in terms of both internal consistency and test-retest reliability. The most internally consistent WAIS-III subtests are Vocabulary, Information, Digit Span, Matrix Reasoning, and Arithmetic. Information and Vocabulary have the highest test-retest reliability. On the WMS-III, the Auditory Immediate Index, Immediate Memory Index, Auditory Delayed Index, and General Memory Index are the most reliable, in terms of both internal consistency and test-retest reliability. The Logical Memory I and Verbal Paired Associates I subtests are the most reliable. Data from three clinical groups (i.e., Alzheimer's disease, chronic alcohol abuse, and schizophrenia) were extracted from the Technical Manual [Psychological Corporation (1997). WAIS-III/WMS-III Technical Manual. San Antonio: Harcourt Brace] for the purpose of calculating reliable change estimates. A table of confidence intervals for test-retest measurement error is provided to help the clinician determine if patients have reliably improved or deteriorated on follow-up testing.
The effects of repeated administrations of neuropsychological instruments were evaluated in a group of chronic cigarette smokers
who served as control subjects in a larger research project. Subjects performance on 13 neuropsychological variables across
four assessments was evaluated using trend analyses. Statistically significant results were obtained on the Logical and Figurai
Memory Subtests of the Wechsler Memory Scale (Form I — Russell's Revision) Part B of the Trail Making Test and the Grooved
Pegboard Test (preferred hand). Of the remaining seven variables the Speech Sounds Perception Test, the Seashore Rhythm Test
and Simple Auditory Reaction Time were highly consistent across all four assessments. The implications of these findings in
clinical practice and research settings are addressed.
To develop a 10-minute cognitive screening tool (Montreal Cognitive Assessment, MoCA) to assist first-line physicians in detection of mild cognitive impairment (MCI), a clinical state that often progresses to dementia.
Validation study.
A community clinic and an academic center.
Ninety-four patients meeting MCI clinical criteria supported by psychometric measures, 93 patients with mild Alzheimer's disease (AD) (Mini-Mental State Examination (MMSE) score > or =17), and 90 healthy elderly controls (NC).
The MoCA and MMSE were administered to all participants, and sensitivity and specificity of both measures were assessed for detection of MCI and mild AD.
Using a cutoff score 26, the MMSE had a sensitivity of 18% to detect MCI, whereas the MoCA detected 90% of MCI subjects. In the mild AD group, the MMSE had a sensitivity of 78%, whereas the MoCA detected 100%. Specificity was excellent for both MMSE and MoCA (100% and 87%, respectively).
MCI as an entity is evolving and somewhat controversial. The MoCA is a brief cognitive screening tool with high sensitivity and specificity for detecting MCI as currently conceptualized in patients performing in the normal range on the MMSE.
Logical memory (LM) is the most frequently administered subtest from the Wechsler Memory Scale; however, the lack of alternate equivalent forms for this subtest may limit its clinical utility. Six new paragraphs modelled on LM stories were developed. Stories were matched on attributes such as number of words and readability. Passage attributes for the six stories were compared with those of standard LM stories (WMS-R and WMS-III versions) to examine story equivalence. The psychometric properties of new passages were also calculated to assess task difficulty and interrater reliability. Results from these analyses suggest a high degree of overlap between the attributes of the new stories and some interesting discrepancies between passage attributes of WMS-R and WMS-III LM stories. In addition, interrater reliability of new passages was found to be excellent (at least .97), and when combined into three sets of passage-pairs, these pairs were found have equivalent difficulty. To reduce the potential for practice effects by use of alternate forms, these new logical memory-style passages may facilitate repeat assessment of auditory-verbal memory.
In this study, we have assessed the validity and reliability of an automated labeling system that we have developed for subdividing the human cerebral cortex on magnetic resonance images into gyral based regions of interest (ROIs). Using a dataset of 40 MRI scans we manually identified 34 cortical ROIs in each of the individual hemispheres. This information was then encoded in the form of an atlas that was utilized to automatically label ROIs. To examine the validity, as well as the intra- and inter-rater reliability of the automated system, we used both intraclass correlation coefficients (ICC), and a new method known as mean distance maps, to assess the degree of mismatch between the manual and the automated sets of ROIs. When compared with the manual ROIs, the automated ROIs were highly accurate, with an average ICC of 0.835 across all of the ROIs, and a mean distance error of less than 1 mm. Intra- and inter-rater comparisons yielded little to no difference between the sets of ROIs. These findings suggest that the automated method we have developed for subdividing the human cerebral cortex into standard gyral-based neuroanatomical regions is both anatomically valid and reliable. This method may be useful for both morphometric and functional studies of the cerebral cortex as well as for clinical investigations aimed at tracking the evolution of disease-induced changes over time, including clinical trials in which MRI-based measures are used to examine response to treatment.
Practice effects, defined as improvements in cognitive test performance due to repeated exposure to the test materials, have
traditionally been viewed as sources of error. However, they might provide useful information for predicting cognitive outcome.
The current study used three separate patient samples (older adults with mild cognitive impairments, individuals who were
HIV+, individuals with Huntington's disease) to examine the relationship between practice effects and cognitive functioning
at a later point. Across all three samples, practice effects accounted for as much as 31–83% of the variance in the follow-up
cognitive scores, after controlling for baseline cognitive functioning. If these findings can be replicated in other patients
with neurodegenerative disorders, clinicians and researchers may be able to develop predictive models to identify the individuals
who are most likely to demonstrate continued cognitive decline across time. The ability to utilize practice effects data would
add a simple, convenient, and non-invasive marker for monitoring an individual patient's cognitive status. Additionally, this
prognostic index could be used to offer interventions to patients who are in the earliest stages of progressive neurodegenerative
disorders.
We present a technique for automatically assigning a neuroanatomical label to each location on a cortical surface model based on probabilistic information estimated from a manually labeled training set. This procedure incorporates both geometric information derived from the cortical model, and neuroanatomical convention, as found in the training set. The result is a complete labeling of cortical sulci and gyri. Examples are given from two different training sets generated using different neuroanatomical conventions, illustrating the flexibility of the algorithm. The technique is shown to be comparable in accuracy to manual labeling.
The hippocampus is the brain structure of highest and earliest structural alteration in Alzheimer's disease (AD). New developments in neuroimaging methods recently made it possible to assess the respective involvement of the different hippocampal subfields by mapping atrophy on a 3D hippocampal surface view. In this longitudinal study on patients with mild cognitive impairment (MCI), we used such an approach to map the profile of hippocampal atrophy and its progression over an 18-month follow-up period in rapid converters to AD and "non-converters" compared to age-matched controls. For the sake of comparison, we also assessed the profile of hippocampal atrophy associated with AD and with increasing age in a healthy control population ranging from young adult to elderly. We found major involvement of the lateral part of the superior hippocampus mainly corresponding to the CA1 subfield in MCI and AD while increasing age was mainly associated with subiculum atrophy in the healthy population. Moreover, the CA1 subfield also showed highest atrophy rates during follow-up, in both rapid converters and "non-converters" although increased effects were observed in the former group. This study emphasizes the differences between normal aging and AD processes leading to hippocampal atrophy, pointing to a specific AD-related CA1 involvement while subiculum atrophy would represent a normal aging process. Our findings also suggest that the degree of hippocampal atrophy, more than its spatial localization, predicts rapid conversion to AD in patients with MCI.