Use of the Brief Visuospatial Memory Test-Revised (BVMT-R) in neuropsychological evaluation of epilepsy surgery candidates

Nonverbal memory tests revisited: Neuroanatomical correlates and differential influence of biasing cognitive functions

The detection of right temporal lobe dysfunction with nonverbal memory tests has remained difficult in the past. Reasons for this might be the potential influence of other biasing cognitive functions such as executive functions or the verbalisability of nonverbal material. The aim of this study was to investigate three classic nonverbal memory tests by identifying their neuroanatomical correlates with lesion-symptom mapping (LSM) and by probing their independence from verbal encoding abilities and executive functions. In a cohort of 119 patients with first-time cerebrovascular accident, memory performance was assessed in the Nonverbal Learning and Memory Test for Routes (NLMTR), the Rey Complex Figure Test (RCFT), and the Visual Design Learning Test (VDLT). Calculating multivariate LSM, we identified crucial brain structures for these three nonverbal memory tests. Behavioural analyses were performed to assess the impact of executive functions and verbal encoding abilities with regression analyses and likelihood-ratio tests. LSM revealed for the RCFT mainly right-hemispheric frontal, insular, subcortical, and white matter structures and for the NLMTR right-hemispheric temporal (hippocampus), insular, subcortical, and white matter structures. The VDLT did not reach significance in LSM analyses. Behavioural results showed that amongst the three nonverbal memory tests the impact of executive functions was most pronounced for RCFT, and the impact of verbal encoding abilities was most important in VDLT. Likelihood-ratio tests confirmed that only for NLMTR did the goodness of fit not significantly improve by adding executive functions or verbal encoding abilities. These results suggest that amongst the three nonverbal memory tests the NLMTR, as a spatial navigation test, could serve as the most suitable marker of right-hemispheric temporal lobe functioning, with the right hippocampus being involved only in this test. In addition, the behavioural results propose that only NLMTR seems mostly unaffected by executive functions and verbal encoding abilities.

The challenge of neuropsychological assessment of visual/visuo-spatial memory: A critical, historical review, and lessons for the present and future

A proliferation of tests exists for the assessment of auditory-verbal memory processes. However, from a clinical practice perspective, the situation is less clear when it comes to the ready availability of reliable and valid tests for the evaluation of visual/visuo-spatial memory processes. While, at face value, there appear to be a wide range of available tests of visual/visuo-spatial memory, utilizing different types of materials and assessment strategies, a number of criticisms have been, and arguably should be, leveled at the majority of these tests. The criticisms that have been directed toward what are typically considered to be visual/visuo-spatial memory tests, such as (1) the potential for verbal mediation, (2) over-abstraction of stimuli, (3) the requirement of a drawing response, and (4) the lack of sensitivity to unilateral brain lesions, mean that, in reality, the number of readily available valid tests of visual/visuo-spatial memory is, at best, limited. This article offers a critical, historical review on the existing measures and resources for the neuropsychological assessment of visual/visuo-spatial memory, and it showcases some examples of newer tests that have aimed to overcome the challenges of assessing these important aspects of memory. The article also identifies new trends and examples of how technological advances such as virtual reality may add value to overcome previous obstacles to assessment, thereby offering professionals more reliable, accurate means to evaluate visual/visuo-spatial memory in clinical practice.

Prenatal earthquake stress exposure in different gestational trimesters is associated with methylation changes in the glucocorticoid receptor gene (NR3C1) and long-term working memory in adulthood

Prenatal stress exposure is thought to affect the long-term development of the foetal brain via the HPA axis and to change health outcomes in adulthood, including working memory (WM). The potential mechanism is that there is a critical period of brain development of the foetus, which is a result of selective adaptation to the external environment. The human glucocorticoid gene (NR3C1) is associated with memory and cognition. This study investigates the association between earthquake stress during pregnancy and CpG methylation of the NR3C1 exon 1_F promoter and its influence on working memory in adulthood. DNA methylation analysis using bisulfite sequencing PCR was quantified in 176 subjects who were exposed or not exposed to intrauterine earthquake and were divided into three groups based on the pregnancy trimester. The Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R) were used to assess working memory performance. The methylated NR3C1 exon 1_F promoter of the prenatal earthquake exposure (PEE) group was significantly higher than that of the control group (CN). Analysis of subgroups indicated that the subjects in the second trimester of PEE group showed significantly higher methylation than those in the third trimester. Significantly low BVMT-R scores were detected in those who experienced prenatal earthquake in the second trimester of PEE group. Methylated CpG site 1 may play a critical role in contributing to lower BVMT-R scores in the second trimester in the PEE group, and may offer a potential epigenetic mechanism that links prenatal stress and long-term effects on working memory.

The Effect of Repetitive Transcranial Magnetic Stimulation (rTMS) on Cognition in Patients With Traumatic Brain Injury: A Protocol for a Randomized Controlled Trial

Cognitive impairment, defined as a decline in memory and executive function, is one of the most severe complications of traumatic brain injury (TBI). Patients with TBI are often unable to return to work due to cognitive impairment and their overall quality of life is reduced. TBI can bring a serious economic burden to patient's families and to society. Reported findings on the efficacy of repetitive transcranial magnetic stimulation (rTMS) in improving cognitive impairment following TBI are inconsistent. The purpose of the proposed study is to investigate whether rTMS can improve memory and executive function in patients with TBI. Herein, we propose a prospective randomized placebo-controlled (rTMS, sham rTMS, cognitive training), parallel-group, single-center trial. 36 participants with a TBI occurring at least 6 months prior will be recruited from an inpatient rehabilitation center. Participants will be randomly assigned to the real rTMS, sham rTMS, or cognitive training groups with a ratio of 1:1:1. A 20-session transcranial magnetic stimulation protocol will be applied to the left and right dorsolateral prefrontal cortices (DLPFC) at frequencies of 10 Hz and 1 Hz, respectively. Neuropsychological assessments will be performed at four time points: baseline, after the 10th rTMS session, after the 20th rTMS session, and 30 days post-intervention. The primary outcome is change in executive function assessed using the Shape Trail Test (STT). The secondary outcome measures are measures from neuropsychological tests: the Hopkins Verbal Learning Test (HVLT), the Brief Visuospatial Memory Test (BVMT), the Digit Span Test (DST). We report on positive preliminary results in terms of improving memory and executive function as well as beneficial changes in brain connectivity among TBI patients undergoing rTMS and hypothesize that we will obtain similar results in the proposed study.

The modified Ruche visuospatial learning test (RUCHE-M) for the assessment of visuospatial episodic memory in patients with temporal lobe epilepsy: Preliminary evidence for the investigation of memory binding

INTRODUCTION

The Ruche test is a visuospatial form of the Rey auditory verbal learning test (RAVLT), with initial evidence of utility in the diagnosis of temporal lobe epilepsy (TLE)-related memory disorders.

AIMS

To present the translation to Brazilian Portuguese and modification of the Ruche test (RUCHE-M) and compare the RUCHE-M and RAVLT performance between patients with right and left TLE.

METHODS

Twenty-five neuropsychologists participated in instrument adaptation. Thirty-seven patients with right (n = 19) and left (n = 18) TLE participated. Data were compared with the Mann-Whitney U test.

RESULTS

All specialists considered the final RUCHE-M to be adequate. The RUCHE-M forgetting speed index (FSI) score and several RAVLT scores differed significantly between patients with right and left TLE.

CONCLUSION

The RUCHE-M showed limited utility for the assessment of visuospatial episodic memory in patients with TLE. The manipulation of memory binding as demonstrated by FSI score seems to be a promising paradigm for the assessment of right hippocampal function.

The Impact of Right Temporal Lobe Epilepsy On Nonverbal Memory: Meta-regression of Stimulus- and Task-related Moderators

Nonverbal memory tests have great potential value for detecting the impact of lateralized pathology and predicting the risk of memory loss following right temporal lobe resection (TLR) for temporal lobe epilepsy (TLE) patients, but this potential has not been realized. Previous reviews suggest that stimulus type moderates the capacity of nonverbal memory tests to detect right-lateralized pathology (i.e., faces > designs), but the roles of other task-related factors have not been systematically explored. We address these limitations using mixed model meta-regression (k = 158) of right-lateralization effects (right worse than left TLE) testing the moderating effects of: 1) stimulus type (designs, faces, spatial), 2) learning format (single trial, repeated trials), 3) testing delay (immediate or long delay), and 4) testing format (recall, recognition) for three patient scenarios: 1) presurgical, 2) postsurgical, and 3) postsurgical change. Stimulus type significantly moderated the size of the right-lateralization effect (faces > designs) for postsurgical patients, test format moderated the size of the right-lateralization effect for presurgical-postsurgical change (recognition > recall) but learning format and test delay had no right-lateralization effect for either sample. For presurgical patients, none of the task-related factors significantly increased right-lateralization effects. This comprehensive review reveals the value of recognition testing in gauging the risk of nonverbal memory decline.

Teleneuropsychology in the time of COVID-19: The experience of The Australian Epilepsy Project

PURPOSE

Traditional neuropsychological testing carries elevated COVID-19 risk for both examinee and examiner. Here we describe how the pilot study of the Australian Epilepsy Project (AEP) has transitioned to tele-neuropsychology (teleNP), enabling continued safe operations during the pandemic.

METHODS

The AEP includes adults (age 18-60) with a first unprovoked seizure, new diagnosis of epilepsy or drug resistant focal epilepsy. Shortly after launching the study, COVID-related restrictions necessitated adaptation to teleNP, including delivery of verbal tasks via videoconference; visual stimulus delivery via document camera; use of web-hosted, computerised assessment; substitution of oral versions for written tests; online delivery of questionnaires; and discontinuation of telehealth incompatible tasks.

RESULTS

To date, we have completed 24 teleNP assessments: 18 remotely (participant in own home) and six on-site (participant using equipment at research facility). Five face-to-face assessments were conducted prior to the transition to teleNP. Eight of 408 tests administered via teleNP (1.9 %) have been invalidated, for a variety of reasons (technical, procedural, environmental). Data confirm typical patterns of epilepsy-related deficits (p < .05) affecting processing speed, executive function, language and memory. Questionnaire responses indicate elevated rates of patients at high risk of mood (34 %) and anxiety disorder (38 %).

CONCLUSION

Research teleNP assessments reveal a typical pattern of impairments in epilepsy. A range of issues must be considered when introducing teleNP, such as technical and administrative set up, test selection and delivery, and cohort suitability. TeleNP enables large-scale neuropsychological research during periods of social distancing (and beyond), and offers an opportunity to expand the reach and breadth of neuropsychological services.

Intraindividual relative deficits in visual memory to lateralize seizure onset in temporal lobe epilepsy

It is well established that presurgical neuropsychological assessment can assist in lateralizing and localizing focal epileptogenic regions. However, unlike verbal memory impairment, which is a robust and reliable finding in patients with left temporal lobe epilepsy (LTLE), nonverbal memory deficits are less consistently found among patients with right TLE (RTLE). This study aimed to determine whether memory assessment for spatial location in addition to visual content would differentiate patients with RTLE and LTLE. We compared performances between patients with 25 RTLE and 37 patients with LTLE on the Wechsler Advanced Clinical Solutions-Faces (ACS-F) subscales (Faces I, Faces II, Content, and Spatial), verbal-visual memory asymmetry scores, and intelligence quotient (IQ)-visual memory difference scores. Results revealed no significant differences between patients with RTLE and LTLE for any ACS-F memory score. By contrast, groups demonstrated significant differences in memory asymmetry scores (p = .007) and IQ difference scores (p = .006). Thus, visual memory scores in isolation failed to differentiate groups with RTLE and LTLE; however, within-patient differences between visual memory and other cognitive abilities successfully differentiated the groups. These results highlight the importance of using an intraindividual model of neuropsychological assessment to identify relative weaknesses potentially associated with the epileptogenic region.

Standardization of an Arabic-Language Neuropsychological Battery for Epilepsy Surgical Evaluations

OBJECTIVES

This study provides a standardized Arabic language neuropsychological test battery and tests its ability to distinguish patients with left and right hemisphere epileptic foci who are candidates for surgical resection.

METHODS

An Arabic language battery of 15 tests was developed based on the neuropsychological test battery used at the Johns Hopkins Hospital for surgical evaluation of patients undergoing temporal lobe resection. With modifications where culturally required, 11 tests were translated to Arabic by the principal investigator and back-translated by two bilingual health professionals; four tests were available in Arabic and added to the battery. The battery was administered to 21 Arabic-speaking patients with left temporal epileptic foci, 21 with right temporal epileptic foci, and 46 neurologically and psychiatrically healthy adults.

RESULTS

Nearly all the Arabic test versions were capable of differentiating healthy controls and the temporal lobe epilepsy (TLE) groups. Tests known to distinguish left and right temporal lobectomy candidates, such as wordlist memory and prose recall, were able to do so as accurately as the English versions. Also, a roughly "culturally free" task (the Baltimore Board) and a newly developed version of the Boston Naming Test demonstrated some sensitivity to left temporal lobe involvement.

CONCLUSIONS

Arabic-language neuropsychological tests for epilepsy surgical evaluations are made available, demonstrate cultural sensitivity and clinical validity, and require further psychometric property and normative research. (JINS, 2019, 25, 761-771).

Test-specific differences in verbal memory assessments used prior to surgery in temporal lobe epilepsy

OBJECTIVE

To study the relationship between two commonly used verbal memory tests in presurgical evaluation for temporal lobe epilepsy (TLE) in Sweden, the Claeson-Dahl Test for verbal learning and retention (CDT) and the Swedish version of the Rey Auditory Verbal Learning Test (RAVLT).

METHODS

Fifty-nine patients with TLE (male: 41%, mean: age 41.7 ± 12.3 years; epilepsy onset at mean age: 18.3 ± 13.1 years) previously tested with the CDT, the RAVLT, and three nonverbal memory tests on the same occasion were included. We performed (1) a principal component analysis (PCA) on test performances in the CDT and the RAVLT as well as in nonverbal memory tests; (2) a Pearson's correlation analysis for memory components, biological age, education, age at epilepsy onset, and self-rating scores for depression and anxiety; and (3) an estimation of clinically significant verbal memory impairment in patients with left TLE and left-sided hippocampal sclerosis.

RESULTS

The PCAs showed coherence between the learning variables of the CDT and the RAVLT and divergence between the recall variables of the two tests. The RAVLT delayed recall variable was correlated to four out of five nonverbal memory measures. Both tests showed 70-80% clinically significant impairment of verbal memory in patients with left TLE, with or without hippocampal sclerosis, similar to other cohorts with resistant TLE.

CONCLUSIONS

The construct structure of the two verbal memory differs. It was shown that the RAVLT correlated with visuospatial memory, whereas the CDT did not. The study highlights that there are important nonoverlapping features regarding verbal recall of the two tests, indicating that these tests cannot fully replace one another.

Machine learning as a new paradigm for characterizing localization and lateralization of neuropsychological test data in temporal lobe epilepsy

In this study, we employed a kernel support vector machine to predict epilepsy localization and lateralization for patients with a diagnosis of epilepsy (n = 228). We assessed the accuracy to which indices of verbal memory, visual memory, verbal fluency, and naming would localize and lateralize seizure focus in comparison to standard electroencephalogram (EEG). Classification accuracy was defined as models that produced the least cross-validated error (CVϵ). In addition, we assessed whether the inclusion of norm-based standard scores, demographics, and emotional functioning data would reduce CVϵ. Finally, we obtained class probabilities (i.e., the probability of a particular classification for each case) and produced receiver operating characteristic (ROC) curves for the primary analyses. We obtained the least error assessing localization data with the Gaussian radial basis kernel function (RBF; support vectors = 157, CVϵ = 0.22). There was no overlap between the localization and lateralization models, such that the poorest localization model (the hyperbolic tangent kernel function; support vectors = 91, CVϵ = 0.36) outperformed the strongest lateralization model (RBF; support vectors = 201, CVϵ = 0.39). Contrary to our hypothesis, the addition of norm, demographics, and emotional functioning data did not improve the accuracy of the models. Receiver operating characteristic curves suggested clinical utility in classifying epilepsy lateralization and localization using neuropsychological indicators, albeit with better discrimination for localizing determinations. This study adds to the existing literature by employing an analytic technique with inherent advantages in generalizability when compared to traditional single-sample, not cross-validated models. In the future, class probabilities extracted from these and similar analyses could supplement neuropsychological practice by offering a quantitative guide to clinical judgements.

Comparison of the Computer and Hand Administered Versions of the Brown Location Test (BLT)

Objective

The Brown Location Test (BLT) was developed to remedy some of the problems in existing visual-based memory tests. The hand version has demonstrated good psychometric properties, the ability to provide lateralization information for mesial temporal lobe epilepsy patients, and has normative data. The purpose of this study was to compare the hand administered format to the more recently developed computer administered format.

Methods

We used Generalizability Theory analyses to assess the degree of variability in scores across the hand and computer versions of the test, and across alternate test forms, A and B. We also compared the means and standard deviations for the different versions and forms using paired t-tests, and Pearson correlation coefficients.

Results

There was minimal variability and high levels of score similarity across the various test administration formats and forms.

Conclusions

The high degree of comparability between versions allows one to apply the validity findings and normative data collected using the hand administered version to the computer version of the BLT.

Spatial memory for asymmetrical dot locations predicts lateralization among patients with presurgical mesial temporal lobe epilepsy

This study examined the ability of an asymmetrical dot location memory test (Brown Location Test, BLT) and two verbal memory tests (Verbal Selective Reminding Test (VSRT) and California Verbal Learning Test, Second Edition (CVLT-II)) to correctly lateralize left (LTLE) or right (RTLE) mesial temporal lobe epilepsy that was confirmed with video-EEG. Subjects consisted of 16 patients with medically refractory RTLE and 13 patients with medically refractory LTLE who were left hemisphere language dominant. Positive predictive values for lateralizing TLE correctly were 87.5% for the BLT, 72.7% for the VSRT, and 80% for the CVLT-II. Binary logistic regression indicated that the BLT alone correctly classified 76.9% of patients with left temporal lobe epilepsy and 87.5% of patients with right temporal lobe epilepsy. Inclusion of the verbal memory tests improved this to 92.3% of patients with left temporal lobe epilepsy and 100% correct classification of patients with right temporal lobe epilepsy. Though of a limited sample size, this study suggests that the BLT alone provides strong laterality information which improves with the addition of verbal memory tests.

In search of memory tests equivalent for experiments on animals and humans

Older people often exhibit memory impairments. Contemporary demographic trends cause aging of the society. In this situation, it is important to conduct clinical trials of drugs and use training methods to improve memory capacity. Development of new memory tests requires experiments on animals and then clinical trials in humans. Therefore, we decided to review the assessment methods and search for tests that evaluate analogous cognitive processes in animals and humans.

This review has enabled us to propose 2 pairs of tests of the efficiency of working memory capacity in animals and humans.

We propose a basic set of methods for complex clinical trials of drugs and training methods to improve memory, consisting of 2 pairs of tests: 1) the Novel Object Recognition Test – Sternberg Item Recognition Test and 2) the Object-Location Test – Visuospatial Memory Test. We postulate that further investigations of methods that are equivalent in animals experiments and observations performed on humans are necessary.

Influence of anxiety on memory performance in temporal lobe epilepsy

This study examined the degree to which anxiety contributed to inconsistent material-specific memory difficulties among 243 patients with temporal lobe epilepsy from the Multisite Epilepsy Study. Visual memory performance on the Rey Complex Figure Test (RCFT) was poorer for those with high versus low levels of anxiety but was not found to be related to the TLE side. The verbal memory score on the California Verbal Learning Test (CVLT) was significantly lower for patients with left-sided TLE than for patients with right-sided TLE with low anxiety levels but equally impaired for those with high anxiety levels. These results suggest that we can place more confidence in the ability of verbal memory tests like the CVLT to lateralize to left-sided TLE for those with low anxiety levels, but that verbal memory will be less likely to produce lateralizing information for those with high anxiety levels. This suggests that more caution is needed when interpreting verbal memory tests for those with high anxiety levels. These results indicated that RCFT performance was significantly affected by anxiety and did not lateralize to either side, regardless of anxiety levels. This study adds to the existing literature which suggests that drawing-based visual memory tests do not lateralize among patients with TLE, regardless of anxiety levels.

Cognitive approaches to early Alzheimer's disease diagnosis

In this article, cognitive measures in the screening of individuals at risk for Alzheimer disease (AD) are reviewed. Use of cognitive tasks in identifying clinical cases of AD is considered, as well as methods for detecting those in the prodromal stages of the disease, including cognitive screening instruments. Traditional assessments, such as the mini-mental state examination, as well as contemporary computerized screening instruments, are examined. Areas of cognition for investigation in the detection of prodromal AD are recommended. The prospects for general cognitive screening are reviewed, and more engaging technologies to tests individuals at risk for developing AD are recommended.

The NAB shape learning subtest as a predictor of lateralized seizure onset

This study presents the first empirical evaluation of the predictive value of the Neuropsychological Assessment Battery Shape Learning (NAB-SL) subtest in a sample of patients with unilateral temporal lobe epilepsy. Stimulus characteristics of the NAB-SL may improve predictive ability over other commonly used visual memory tests. Forty-nine patients with unilateral temporal lobe epilepsy were compared on measures of non-verbal and verbal memory (NAB-SL and Wechsler Memory Scale-III subtests). Univariate and forward conditional logistic regressions identified predictive values for each memory test individually and in combination. The NAB-SL delayed memory demonstrated consistently stronger predictive power over visual reproduction at the univariate and multivariate levels. The NAB-SL was a good predictor (80% range) of lateralized seizure onset when combined with a verbal memory measure. These preliminary results provide support for the use of the NAB-SL in preoperative epilepsy evaluations as a predictor of non-dominant temporal lobe dysfunction. Potential benefits of this test are discussed.

Verbal and visuospatial memory in lateral onset Parkinson disease: time is of the essence

OBJECTIVE

This investigation sought to study immediate and delayed verbal and visuospatial recall in Parkinson disease (PD) patients with left hemibody (LHO) and right hemibody (RHO) onset of motor symptoms and to examine the role of mental processing speed in recall of this information.

BACKGROUND

Research is mixed regarding material specific memory impairments in LHO and RHO PD. However, earlier research has not used a factorial approach in investigating material specific memory in LHO and RHO PD. We hypothesized that LHO PD patients would exhibit an increase in performance following the delayed verbal free recall trial and either decline or stability in performance on the delayed visuospatial free recall trial. The opposite pattern was hypothesized for RHO PD patients.

METHOD

The Hopkins Verbal Learning Test-revised (HVLT-R) and the Brief Visuospatial Memory Test-revised (BVMT-R) were administered to a sample of 28 LHO PD patients and 36 RHO PD patients. The Stroop Color-word Test was administered as a measure of mental processing speed.

RESULTS

The results indicated that the RHO group experienced a significant decline in performance on verbal free recall from the immediate to the delayed trials and a significant improvement in performance from the immediate to the delayed visuospatial free recall trials. Additionally, a significant negative correlation was found between mental processing speed and changes in recall from the immediate to the delayed conditions for the RHO group.

CONCLUSIONS

These results indicate that the RHO PD group experienced a significant decline in verbal free recall and a significant improvement in visuospatial free recall from the immediate to the delayed trials and that the LHO PD patients experienced no significant changes. Further, mental processing speed appears to influence the recall of information from the immediate to the delayed conditions.

Use of complex three-dimensional objects to assess visuospatial memory in healthy individuals and patients with unilateral amygdalohippocampectomy

Because many visuospatial memory tests do not reliably detect right medial temporal lobe (MTL) dysfunction, we developed a novel object recognition test using complex three-dimensional stimuli. To influence encoding strategy, half the stimuli were multicolored (color towers) and accompanied by verbally based instructions, and half were gray (gray towers) and accompanied by visuospatially based instructions. In Experiment 1, healthy subjects completed the test while performing verbal or visuospatial interference tasks or without interference. In Experiment 2, patients with unilateral amygdalohippocampectomies for intractable epilepsy completed the test without interference. Results suggest that color tower recognition was partially dependent on verbal processing and sensitive to MTL lesions in general. Recognition of gray towers was reliant on visuospatial processing, and the decay in accuracy after a delay was sensitive and specific to right MTL lesions. These findings suggest that test stimuli such as three-dimensional objects can be useful in assessing right MTL dysfunction.

Visual memory in patients after anterior right temporal lobectomy and adult normative data for the Brown Location Test

Several large meta-analytic studies have failed to support a consistent relationship between visual or "nonverbal" memory deficits and right mesial temporal lobe changes. The Brown Location Test (BLT), a recently developed dot location learning and memory test, uses a nonsymmetrical array and provides control over many of the confounding variables (e.g., verbal influence and drawing requirements) inherent in other measures of visual memory. In the present investigation, we evaluated the clinical utility of the BLT in patients who had undergone left or right anterior mesial temporal lobectomy. We also provide normative data of 298 healthy adults for standardized scores. Results revealed significantly worse performance on the BLT in the right as compared to the left lobectomy group and the healthy adult normative sample. The present findings support a role for the right anterior mesial temporal lobe in dot location learning and memory.

Verbal learning in Alzheimer's disease: cumulative word knowledge gains across learning trials

Research regarding learning in Alzheimer's disease (AD) patients has been mixed. Learning capacity might be better indexed using a score that reflects the interaction between the learning slope and total recall, referred to as the Cumulative Word Learning (CWL) score. We compared a group of AD patients to normal participants using a traditional index of learning and the CWL score that were derived from the Hopkins Verbal Learning Test-Revised (HVLT-R). The HVLT-R is a supra-span, list-learning test containing 12 words from three semantic categories. The results indicated that the sample of AD patients performed within the average range, using the traditional learning z score. Although mild AD patients were not found to differ from controls in the traditional learning z score, a significant difference was noted for the CWL score. The moderate AD patients differed from the normal controls in both learning measures. Furthermore, unlike the traditional learning score, the CWL score was a significant predictor of overall cognitive functioning, as indexed using their Mini-Mental State Examination (MMSE) score. Thus, the CWL score might be a more sensitive indicator overall of total learning capacity and may be useful in staging Alzheimer's disease because of increased resilience to floor effects.

Using the MATRICS to guide development of a preclinical cognitive test battery for research in schizophrenia

Cognitive deficits in schizophrenia are among the core symptoms of the disease, correlate with functional outcome, and are not well treated with current antipsychotic therapies. In order to bring together academic, industrial, and governmental bodies to address this great 'unmet therapeutic need', the NIMH sponsored the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative. Through careful factor analysis and consensus of expert opinion, MATRICS identified seven domains of cognition that are deficient in schizophrenia (attention/vigilance, working memory, reasoning and problem solving, processing speed, visual learning and memory, verbal learning and memory, and social cognition) and recommended a specific neuropsychological test battery to probe these domains. In order to move the field forward and outline an approach for translational research, there is a need for a "preclinical MATRICS" to develop a rodent test battery that is appropriate for drug development. In this review, we outline such an approach and review current rodent tasks that target these seven domains of cognition. The rodent tasks are discussed in terms of their validity for probing each cognitive domain as well as a brief overview of the pharmacology and manipulations relevant to schizophrenia for each task.

Changes in individual and group spatial and verbal learning characteristics after anterior temporal lobectomy

PURPOSE

To evaluate the effects of anterior temporal lobectomy (ATL) on individual and group spatial and verbal learning and memory abilities as a function of side of surgery and seizure control outcome.

METHODS

We evaluated pre- and postsurgical learning and memory abilities of 75 left-hemisphere language dominant individuals who underwent ATL (33 left, 42 right) using the 8-trial Nonverbal Selective Reminding test and the 12-trial Verbal Selective Reminding test.

RESULTS

Reliable change index methods indicated that 40.5% of individuals who underwent right-ATL had a clinically significant decline in spatial memory, and 62.5% of individuals who underwent left-ATL had a significant reduction in verbal memory. Growth curve analyses indicated that both side of surgery and poor seizure outcome independently affected the learning slope in the best fitting models. Left-ATL reduced the slope, but did not affect the overall shape, of verbal learning across trials. On the other hand, poor seizure control outcome affected the slope of spatial learning regardless of the side of surgery.

DISCUSSION

Results demonstrate both individual and group declines in spatial memory and learning after ATL. Results suggest that individuals who undergo right-ATL should be counseled regarding the likelihood of a decline in spatial memory and learning abilities after ATL. Results also suggest that individuals with poor seizure control after ATL should be referred for rehabilitation services given the significant declines in spatial and verbal memory that occurred in our sample regardless of side of surgery.

Visual memory deficits in temporal lobe epilepsy: toward a multifactorial approach

Temporal lobe epilepsies (TLE) are associated with material-specific memory deficits depending on the side of seizure origin. However, while verbal memory deficits have been consistently reported in patients with left-sided TLE, the relationship between visual memory deficits and right-sided TLE is more complex. Here, we review factors that influence the pattern of lateralization and the nature of visual memory impairments in TLE and discuss the possible relationship between these deficits and perceptual impairments in TLE patients.

Temporal lobe epilepsy as a model to understand human memory: the distinction between explicit and implicit memory

Decades of research have provided substantial evidence of memory impairments in patients with temporal lobe epilepsy (TLE), including deficits in the encoding, storage, and retrieval of new information. These findings are not surprising, given the associated underlying neuroanatomy, including the hippocampus and surrounding medial temporal lobe structures. Because of its associated anatomic and cognitive characteristics, TLE has provided an excellent model by which to examine specific aspects of human memory functioning, including classic distinctions such as that between explicit and implicit memory. Various clinical and experimental research studies have supported the idea that both conscious and unconscious processes support memory functioning, but the role of relevant brain structures has been the subject of debate. This review is concerned with a discussion of the current status of this research and, importantly, how TLE can inform future studies of memory distinctions.

Memory performance during the intracarotid amobarbital procedure and neuropsychological assessment in medial temporal lobe epilepsy: the limits of material specificity

We investigated the relationship between material-specific memory performance elicited during the Wada test, or intracarotid amobarbital procedure (IAP), and classic neuropsychological assessment in 89 surgical candidates with refractory medial temporal lobe epilepsy (MTLE). The neuropsychological battery included measures of simple and complex verbal and visual memory, whereas the IAP material consisted of verbal and dually encodable stimuli. Neuropsychological testing revealed that reduced verbal memory performance was associated with left-sided MTLE, whereas visual memory tasks revealed no differences between patients with left-sided and right-sided MTLE. During IAP, memory performance was worse with the ipsilesional hemisphere, regardless of lesion side. Most importantly, performance on verbal memory tests was significantly, but moderately, correlated with left hemispheric IAP performance, indicating that memory tasks using verbal material are a valid marker of left hemispheric integrity in left language-dominant MTLE patients and significantly predict left hemispheric memory performance during IAP. In contrast, performance on classic visual memory tests is unrelated to right hemispheric IAP performance, suggesting that the currently used visual memory stimuli do not reflect right hemispheric sensitivity.