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Contains fulltext : 167882.pdf (Publisher’s version ) (Closed access) INTRODUCTION: Recognition and visual working memory tasks from the Wechsler Memory Scale-Fourth Edition (WMS-IV) have previously been documented as useful indicators for suboptimal performance. The present study examined the clinical utility of the Dutch version of the WMS-IV (WMS-IV-NL) for the identification of suboptimal performance using an analogue study design. METHOD: The patient group consisted of 59 mixed-etiology patients; the experimental malingerers were 50 healthy individuals who were asked to simulate cognitive impairment as a result of a traumatic brain injury; the last group consisted of 50 healthy controls who were instructed to put forth full effort. RESULTS: Experimental malingerers performed significantly lower on all WMS-IV-NL tasks than did the patients and healthy controls. A binary logistic regression analysis was performed on the experimental malingerers and the patients. The first model contained the visual working memory subtests (Spatial Addition and Symbol Span) and the recognition tasks of the following subtests: Logical Memory, Verbal Paired Associates, Designs, Visual Reproduction. The results showed an overall classification rate of 78.4%, and only Spatial Addition explained a significant amount of variation (p < .001). Subsequent logistic regression analysis and receiver operating characteristic (ROC) analysis supported the discriminatory power of the subtest Spatial Addition. A scaled score cutoff of

Both working memory (WM; a brain system that provides temporary storage and manipulation of the information) and attention-deficit/hyperactivity disorder (ADHD) have been associated with educational deficits. Since WM deficits are prevalent in children with ADHD, the main aim of the present study was to examine whether educational deficits are driven by working memory deficits or driven by the effect of ADHD itself.Participants were referred youth with (N = 276) and without (N = 241) ADHD ascertained from pediatric and psychiatric sources. Assessment included measures of psychiatric, psychosocial, educational, and cognitive functioning. Education deficits were defined as grade retention or placement in special classes and were assessed using interviews and written rating scales. Working memory was assessed using the Wechsler Intelligence Scale for Children-Revised (WISC-R) Freedom from Distractibility (FFD) factor based on Digit Span, Arithmetic, and Coding.Significantly more youth with ADHD had WM deficits than controls (31.9% vs. 13.7%, p.05). In ADHD children, WM deficits were significantly (p.01) associated with an increased risk for grade retention and placement in special classes as well as lower scores on reading and math achievement tests than for ADHD children without WM deficits. In contrast, no other differences were noted in other areas of functioning. Although WM deficits also had some adverse impact on educational and cognitive correlates in non-ADHD controls, these differences failed to attain statistical significance.WM deficits significantly and selectively increase the risk for academic deficits and cognitive dysfunction in children with ADHD beyond those conferred by ADHD. Screening for WM deficits may help identify children with ADHD at high risk for academic and cognitive dysfunction.

Insufficiency of 25-hydroxyvitamin D has been associated with cognitive impairment, particularly worse executive functioning. However, it remains unclear whether supratherapeutic levels (≥100 nmol L(-1)) are associated with even better performance than sufficient levels (defined as ≥50 nmol L(-1) or even ≥75 nmol L(-1)). The current investigation sought to examine this question.Healthy adults (n = 142) were tested on four measures of executive functioning, including verbal fluency, digit span backward, CANTAB® Spatial Working Memory, and One Touch Stockings of Cambridge. A measure of attention (digit span forward) and memory (CANTAB® Verbal Recognition) were also assessed. Based on blood 25-hydroxyvitamin D [25(OH)D] levels, participants were divided into four groups: insufficient (50 nmol L(-1)), low sufficient (50 to75 nmol L(-1)), high sufficient (75 to100 nmol L(-1)), and supratherapeutic (≥100 nmol L(-1)). Relationships between vitamin D status and cognition were assessed by analyses of covariance and hierarchical multiple regression, adjusted for age, education, sex, body mass index, mood, and physical activity level. Multivariate regression spline analyses were utilized to investigate nonlinearity.Performance on verbal fluency, but not other measures, differed by vitamin D status, analysis of covariance (ANCOVA), F(3, 127) = 2.70, p = .048; d = 0.50. Specifically, participants with supratherapeutic levels provided a greater number of words (M = 16.1, SE = 1.0) than those with insufficient (M = 12.0, SE = 1.0; p = .007, d = 0.78), low (M = 13.4, SE = 0.7; p = .026, d = 0.51), and high sufficient levels (M = 13.9, SE = 0.9; p = .080, d = 0.42). Similarly, vitamin D status was a significant independent predictor of verbal fluency (p = .025, d = 0.40). Spline analyses revealed that there is a positive, near-linear association between verbal fluency and 25(OH)D levels up to and exceeding 100 nmol L(-1).Supratherapeutic levels of vitamin D were associated with significantly better performance on verbal fluency. Importantly, commonly used cutoff levels and sufficiency categories have been based on bone health and optimal levels for cognition are unknown. These findings suggest that levels exceeding 100 nmol L(-1) may be optimal for at least some aspects of executive functioning.

The role of memory in the Iowa Gambling Task (IGT) was tested in two experiments that dissociated item memory (memory for losses obtained) from source memory (the deck that produced a given loss). In Experiment 1, participants observed 75 choices that had been made by controls or patients in previous research, followed by memory tests, and then 25 active choices from the participant. In Experiment 2, participants made choices for 75 trials, performed the memory tests, and then made 25 final choices. The data show that item and source memory can diverge within the IGT, and that source memory makes a significant contribution to IGT performance.

We analyzed error patterns during digit span (DS) testing in four experiments. In Experiment 1, error patterns analyzed from a community sample of 427 subjects revealed strong primacy and recency effects. Subjects with shorter DSs showed an increased incidence of transposition errors in comparison with other error types and a greater incidence of multiple errors on incorrect trials. Experiment 2 investigated 46 young subjects in three test sessions. The results replicated those of Experiment 1 and demonstrated that error patterns of individual subjects were consistent across repeated test administrations. Experiment 3 investigated 40 subjects from Experiment 2 who feigned symptoms of traumatic brain injury (TBI) with 80% of malingering subjects producing digit spans in the abnormal range. A digit span malingering index (DSMI) was developed to detect atypical error patterns in malingering subjects. Overall, 59% of malingering subjects with abnormal digit spans showed DSMIs in the abnormal range and DSMI values correlated significantly with the magnitude of malingering. Experiment 4 compared 29 patients with TBI with a new group of 38 control subjects. The TBI group showed significant reductions in digit span. Overall, 32% of the TBI patients showed DS abnormalities and 11% showed abnormal DSMIs. Computerized error-pattern analysis improves the sensitivity of DS assessment and can assist in the detection of malingering.

Twenty-four studies utilizing the Wechsler Adult Intelligence Scale (WAIS) Digit Span subtest--either the Reliable Digit Span (RDS) or Age-Corrected Scaled Score (DS-ACSS) variant--for malingering detection were meta-analytically reviewed to evaluate their effectiveness in detecting malingered neurocognitive dysfunction. RDS and DS-ACSS effectively discriminated between honest responders and dissimulators, with average weighted effect sizes of 1.34 and 1.08, respectively. No significant differences were found between RDS and DS-ACSS. Similarly, no differences were found between the Digit Span subtest from the WAIS or Wechsler Memory Scale (WMS). Strong specificity and moderate sensitivity were observed, and optimal cutting scores are recommended.

We measured digit span (DS) in two experiments that used computerized presentation of randomized auditory digits with performance-adapted list length adjustment. A new mean span (MS) metric of DS was developed that showed reduced variance, improved test-retest reliability, and higher correlations with the results of other neuropsychological test results when compared to traditional DS measures. The MS metric also enhanced the sensitivity of forward versus backward span comparisons, enabled the development of normative performance criteria with sub-digit precision, and elucidated changes in DS performance with age- and education level. Computerized stimulus delivery and improved scoring metrics significantly enhance the precision of DS assessments of short-term verbal memory.

The objective of this study was to compare the coordinative function of the central executive of working memory in matched groups of controls and persons with traumatic brain injury (TBI) with long-term impairments in functioning, using a dual-task paradigm. The dual-task procedure required participants to complete digit span and tracing tasks separately and then together to produce a change index that reflects loss of productivity on the dual trial. A TBI group and a matched group of controls were compared on this task and on ratings of social competency and neuropsychological tests. The two groups were found to differ in social competence, in the number of dysexecutive symptoms, and on dual-task performance, but not on any other measures of cognitive ability. Poor performance on the dual task was found only in persons with initial very severe TBI. There was no evidence that the group difference on the dual task was the consequence of increased task difficulty level, distribution of attention, or other within-task biases. Performance on the dual task was correlated with dysexecutive symptoms and social competency (in particular interpersonal and cognitive competence), but not with other tests of executive functioning. The findings suggest that deficits in the coordinative function persist in long-term survivors of TBI after other deficits in executive functioning may have resolved and are associated with lower ratings of current interpersonal competence.

The n-back task is frequently used as an experimental paradigm in imaging studies of working memory. This study aimed to investigate whether the Bergen 2-back task is suitable for use in desktop assessment of patients with schizophrenia. Looking at the psychometric properties of the task, including the newly added measure of discriminability, d prime (d '), our analyses confirmed that the 2-back d ' is the preferred measure of working memory dysfunction in desktop assessment compared to the Digit Span Backward and the Letter-Number Sequencing subtests from the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III). d ' has the advantage of capturing executive skills needed to perform mental operations in patients with schizophrenia, without being influenced by demographic variables or IQ.

Type 2 diabetes has been associated with a number of physiological consequences including neuropathy, retinopathy, and incidence of vascular disease. Less is known about the effect on cognition of prediabetes, a period when glucose regulation is abnormal. It is not clear which aspect of impaired glucoregulation is most predictive of cognitive deterioration. In the present experiment, we measured cognitive function in 93 healthy male and female nondiabetic older participants who ranged in age from 55 to 88 years. Various biological measures were obtained including a glucose tolerance test during which glucose and insulin were measured. Participants were evaluated twice, once after drinking a saccharin solution and on another occasion after drinking a glucose solution (50 g). The analysis of the correlations between the biological measures and the results of the cognitive tasks revealed that evoked glucose measures such as peak glucose and glucose at 1 hour were most often correlated with cognitive performance. We observed that progressively worse glucose regulation predicted poorer performance on measures of working memory and executive function-that is, on the Arithmetic, Digit Span Backward, Letter-Number Sequencing, Spatial Span Forward, Spatial Span Backward (trend), and Modified Brown-Peterson tasks. Although, there was no significant facilitative effect of glucose on cognitive performance, it reduced the association between glucose regulation and cognition, apparently by slightly improving performance. These results suggest that cognitive functions may be impaired before glucoregulatory impairment reaches levels consistent with a type 2 diabetes diagnosis.

Working memory is the cognitive ability to hold a discrete amount of information in mind in an accessible state for utilization in mental tasks. This cognitive ability is impaired in many clinical populations typically assessed by clinical neuropsychologists. Recently, there have been a number of theoretical shifts in the way that working memory is conceptualized and assessed in the experimental literature. This study sought to determine to what extent the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Working Memory Index (WMI) measures the construct studied in the cognitive working memory literature, whether an improved WMI could be derived from the subtests that comprise the WAIS-III, and what percentage of variance in individual WAIS-III subtests is explained by working memory. It was hypothesized that subtests beyond those currently used to form the WAIS-III WMI would be able to account for a greater percentage of variance in a working memory criterion construct than the current WMI. Multiple regression analyses (n = 180) revealed that the best predictor model of subtests for assessing working memory was composed of the Digit Span, Letter-Number Sequencing, Matrix Reasoning, and Vocabulary. The Arithmetic subtest was not a significant contributor to the model. These results are discussed in the context of how they relate to Unsworth and Engle's (2006, 2007) new conceptualization of working memory mechanisms.

The WAIS-R Digit Span subtests require oral presentation of digits. Older adults with hearing impairments may have reduced recall due to deficits in hearing. It is also possible that older adults' recall is influenced by recall superiority for auditory versus visual information (the auditory superiority effect). Auditory and visual versions of the Digits Forward and Backward tasks were administered to 30 younger adults (18-30 years) and 30 older adults (65-78 years). Although younger adults exhibited marginally better digit recall overall than older adults, all participants' scores were highest for the auditory presentation mode.

Previous research has indicated that patients with a family history of schizophrenia show a greater degree of cognitive and neuropsychological impairment than patients without a family history. We examined the neurocognitive performance, using the WAIS-R, of 51 patients with a family history (familial) and 103 patients without a family history (sporadic) to determine if differences exist that may help to explain the heterogeneous neuropsychological profile of the illness. The family history groups did not differ with respect to gender, diagnosis, ethnicity, age, age of onset, education or duration of illness. Multivariate analyses, covarying for age of onset and education, showed the sporadic group performed significantly better than the familial group on the digit symbol and object assembly subtests, with a trend level difference in overall performance IQ score. Additionally, we identified significant gender differences in favor of males for full scale and verbal IQ, the information, digit span, block design, and arithmetic subtests, and at a trend level, the picture assembly subtest. The family history group differences reflect relative dysfunction in visual attention and scanning, visuomotor control, and spatial processing and reasoning. Overall, the results suggest that sporadic patients have better perceptual-organizational skills and faster speed of processing.

Some studies of elderly individuals with the ApoE-e4 genotype noted subtle deficits on tests of attention such as the WAIS-R Digit Span subtest, but these findings have not been consistently reported. One possible explanation for the inconsistent results could be the presence of subgroups of e4+ individuals with asymmetric cognitive profiles (i.e., significant discrepancies between verbal and visuospatial skills). Comparing genotype groups with individual, modality-specific tests might obscure subtle differences between verbal and visuospatial attention in these asymmetric subgroups. In this study, we administered the WAIS-R Digit Span and WMS-R Visual Memory Span subtests to 21 nondemented elderly e4+ individuals and 21 elderly e4- individuals matched on age, education, and overall cognitive ability. We hypothesized that a) the e4+ group would show a higher incidence of asymmetric cognitive profiles when comparing Digit Span/Visual Memory Span performance relative to the e4- group; and (b) an analysis of individual test performance would fail to reveal differences between the two subject groups. Although the groups’ performances were comparable on the individual attention span tests, the e4+ group showed a significantly larger discrepancy between digit span and spatial span scores compared to the e4- group. These findings suggest that contrast measures of modality-specific attentional skills may be more sensitive to subtle group differences in at-risk groups, even when the groups do not differ on individual comparisons of standardized test means. The increased discrepancy between verbal and visuospatial attention may reflect the presence of “subgroups” within the ApoE-e4 group that are qualitatively similar to asymmetric subgroups commonly associated with the earliest stages of AD.

The Paced Auditory Serial Addition Task (PASAT) is a test of attention and concentration in which participants add each number from a taped list to the one preceding it (Gronwall & Wrightson, 1974). As it requires mental addition at an externally determined pace the task often causes anxiety (Roman, Edwall, Buchanan, & Patton, 1991). We devised the Paced Auditory Serial Opposites Task (PASOT) as a nonnumerical replacement (Deary, 2001). PASOT and PASAT were administered to 40 participants, and the correlation between them was 0.71. The correlations of the PASOT and other cognitive measures did not differ significantly from those of the PASAT (with the exception of Digit Span Backward). Performing the PASOT was significantly less aversive; the PASAT induced more negative feelings of Tense Arousal (t (38) = −4.52, p

This study had two goals. One was to assess whether the WMS-III Spatial Span subtest operates as a visual analogue of Digit Span while the second was to determine whether backward span is a more sensitive measure of working memory than the forward span condition. Analyses based on the WAIS-III-WMS-III standardization and clinical group data revealed some important distinctions between Digit and Spatial Span. The two tasks exhibited differences in patterns of performance on the forward versus backward conditions, in their relationships with age, and in their methodology. Moreover, the backward conditions of both Digit and Spatial Span did not appear more affected by risk factors such as aging or pathology than the forward scores. This runs contrary to the widespread notion that backward span provides differential sensitivity regarding working memory processing.

The aim of this study was to investigate digit span performance in dyslexia. It was hypothesised that differences would be found in accordance with subgrouping by language comprehension and mathematic skills, and by analyses of how the digit span scores were attained. Two digit span tasks were given to a group of dyslexic children and controls (n = 57), mean age 12.62 (SD = 1.43). The tasks were "Digit Span" of the WISC-R, and "Digit Span 2," where the use of back-up strategies like finger counting and lip reading were restricted. As expected, the digit span scores were significantly lower in the dyslexia group than in the control group. Restrictions of back-up strategies did not alter the scores in the control group, while the scores were lowered in the dyslexia group. Further analyses of longest digit span, serial recall, and serial position indicated different retrieval patterns in the subgroups. The subgroup with good language comprehension and mathematic skills (n = 12), showed impaired serial recall especially in backward recall. The subgroup with good language comprehension skills, but with mathematics impairment (n = 9), showed impaired serial recall in both forward and backward recall. The subgroup with language impairments (n = 16), recalled fewer digits than the two other subgroups. The findings were discussed in relation to the "Phonological loop" of the Multi Component Model of Working Memory, and implications for intervention were discussed.

In this study we compared memory performances of 29 probable patients with AD (17 mildly and 12 moderately demented) with those of 39 healthy young subjects, 36 elderly subjects (matched with the AD group for age and years of schooling), and 19 healthy very old subjects. In most of the memory tasks used in the present study, a progressive decline in performance was observed passing from the Young to the Elderly to the Very Old to the AD group. However, patients with AD were selectively impaired in the backward reproduction of verbal and spatial span sequences and in the semantic encoding of verbal material. These data are consistent with the hypothesis of not only quantitative but also a qualitative discontinuity between the process of normal aging and the dementia syndrome.

The verbal working memory abilities of children with stroke related to sickle cell disease (SCD) (n = 20) were compared to those of control children with SCD who had no history of stroke (n = 11). Memory span for one-, two-, and three-syllable words was assessed. For children with anterior infarcts, overall span was comparable to that of controls, but the typical effect of word length on span was reduced. For children with diffuse infarcts, overall span was reduced in comparison to that of controls, but the typical effect of word length on span was observed. For children with posterior infarcts, overall span was comparable to that of controls and the typical effect of word length on span was observed. These results provide preliminary evidence that patterns of working memory performance may vary across children with infarcts affecting different regions of the brain.

Self-appraisal of cognitive difficulties by a sample of 63 male patients with closed-head injury (CHI) was examined in relation to their performance on the Wechsler Memory Scale - Revised (WMS-R; Wechsler, 1987), WAIS-R Digit Span (Wechsler, 1981), and to their scores on MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) measures of anxiety and depression. In an initial step, the Cognitive Difficulties Scale (CDS; McNair & Kahn, 1983), consisting of 39 self-report items, was factor analyzed using a sample of 255 consecutive neuropsychological referrals with documented brain impairment. Seven orthogonal dimensions emerged: Attention and Concentration, Orientation and Memory, Praxis, Domestic Activities, Facial Recognition, Task Efficiency, and Errand and Name Recall. Within a sample subset consisting of 63 patients with CHI, subjective complaints on the CDS were predictive of WMS-R Logical Memory performance (r = -.51, p < .0005). In contrast, CDS scores were generally poor predictors of Digit Span and Visual Reproduction scores (rs < .31). Cognitive complaints were also associated with emotional distress on the MMPI-2. The CDS appears to be a useful measure of self-appraised cognitive difficulties in patients with CHI, and may assist in the assessment of their self-reflective insight.

The most common cognitive impairments in multiple sclerosis (MS) have been documented in specific domains, including new learning and memory, working memory, and information processing speed. However, little attempt has been made to increase our understanding of their relationship to one another. While recent studies have shown that processing speed impacts new learning and memory abilities in MS, the role of working memory in this relationship has received less attention. The present study examines the relative contribution of impaired working memory versus processing speed in new learning and memory functions in MS. Participants consisted of 51 individuals with clinically definite MS. Participants completed two measures of processing speed, two measures of working memory, and two measures of episodic memory. Data were analyzed via correlational and multiple regression analysis. Results indicate that the variance in new learning abilities in this sample was primarily associated with processing speed, with working memory exerting much less of an influence. Results are discussed in terms of the role of cognitive rehabilitation of new learning and memory abilities in persons with MS.

Factor analysis was conducted on attention, information processing, verbal and visual memory scores of 112 patients. Factor structure did not vary as a function of age. The Expanded Paired Associates Test, Verbal Selective Reminding Test, Continuous Recognition Memory Test, and Continuous Visual Memory Test defined a general memory factor. The PASAT, WMS Mental Control, and WAIS-R Digit Span defined an attention/information processing factor. Immediate Visual Reproduction (VR) loaded primarily on visual/nonverbal intelligence, whereas delayed VR loaded primarily with the memory factor. The Trail Making Test, Part B was more closely associated with visual/nonverbal intelligence than with attention/information processing. Serial Digit Learning was more closely associated with attention/information processing than with general memory.

Visuospatial memory was investigated in two groups of patients suffering from senile dementias of the Alzheimer (SDAT) or Lewy body (SDLT) types; a, third, age-matched, healthy control group was also included. The two patient groups were mildly demented and could not be distinguished from each other by traditional tests of cognitive function. A different pattern of performance emerged in the two groups on a computerised test of spatial working memory, which is a self-ordered pointing task requiring the subject to search for hidden tokens. An analysis of the pattern of errors revealed that the SDLT group made more of both possible types of error ("Within Search" and "Between Search") than the SDAT group. Neither patient groups' performance differed from each other when assessed on a computerised Corsi spatial span task. A measure of planning ability was obtained by examining search strategies. Although an index previously developed to measure the subject's use of a particular strategy in the spatial working memory task failed to detect any differences between the three groups, a novel index was calculated which focuses on performance within a search, and this revealed deficits in both demented groups. Since the two patient groups differed from each other in the spatial working memory, but not the Corsi spatial span, task, it is suggested that the differences between the two demented groups are not due to a specific mnemonic impairment, but reflect dysfunctions in non-mnemonic processes mediated by fronto-subcortical circuits, which are more severely damaged in SDLT.

Relationships between performance on the California Verbal Learning Test (CVLT) and executive abilities were examined. In a sample of 115 neurological cases principal components factor analysis produced five theoretically and clinically meaningful CVLT factors. The five CVLT factors reflected general verbal learning (CVLT1), response discrimination (CVLT2), a proactive interference effect or "working memory" (CVLT3), serial learning strategy (CVLT4), and a retroactive interference effect (CVLT5). Canonical correlation between executive function measures and the five CVLT factor scores yielded one significant canonical variable accounting for 29 percent of the variance in the data. Two CVLT factors (CVLT1 and CVLT3), the Trail Making Test Part B, and Digit Span were significantly correlated with the canonical variate. Higher levels of memory performance were associated with better attention and mental tracking. Based on the present findings, attentional aspects of executive abilities appear to play a role in learning and working memory. Other aspects of executive abilities (abstraction, problem-solving, planning) appear to have minimal relationships with memory processes.

Errorless learning represents an important contribution to current neuropsychological rehabilitation. Previous research has mainly explained the benefits of errorless learning through properties of long-term memory. This study aims to explore how errors affect immediate recall performance. A new, supplementary perspective focusing on the role of working memory in errorless learning is introduced. Sixty university students participated in a within-subject design experiment measuring the effect of errors, memory span load, and attentional distractors on a digit recall task. Errors were found to have significant negative impact on immediate recall, while distractors had an effect only in interaction with errors.

Objective: To measure working memory capacity among a cohort of collegiate athletes and to compare results between athletes competing in head-contact-prone sports with those not subject to repeated head contacts. A secondary objective was to determine the effect of sport-related concussion on working memory capacity. Design: Ambidirectional cohort study. Setting: Athletics department at an American university. Participants: Student athletes competing in various sports. Interventions: None. Main outcome measurement: Automated operation span test scores. Results: Working memory capacity is not impaired in student athletes who participate in head-contact-prone sports or in student athletes with a history of diagnosed concussion, even those who are multiconcussed. Our results suggest that athletes competing in sports that impose significant working memory loading score higher on the automated operation span test than do other athletes. Conclusions: Further research is required to determine the value of measur...

Frontal-lobe dysfunction of alcoholic Korsakoff patients was studied by presenting four tasks requiring short-term retention, as well as different degrees and types of control. Digit span forward was considered a measure of passive short-term retention; missing scan measures memory search and comparison, in addition to retention; and two subjective ordering tasks measure active generation of responses in addition to the processes in the other two tasks. The results showed no evidence of reduced performance for any of these tasks, when compared with performance of control subjects. The hypothesis that Korsakoff patients have a frontal-lobe dysfunction in addition to their amnesia needs some qualification because of these results: Frontal-lobe function specific to the ordering of verbal responses seems to be intact in Korsakoff patients

Objective methods for determining clinically relevant neurocognitive change are useful for clinicians and researchers, but the utility of such methods requires validation studies in order to assess their accuracy among target populations. We examined the generalizability of regression equations and reliable change indexes (RCI) derived from a healthy sample to two HIV-infected samples, one similar in demographic makeup to the normative group and the other dissimilar. Measures administered at baseline and follow-up included the Trail Making Test, Controlled Oral Word Association Test (COWAT), Grooved Pegboard, and Digit Span. Frequencies of decline, improvement, or stability were determined for each measure. Among the demographically similar clinical cohort, elevated rates of decline among more immunologically impaired participants were indicated by simple regression method on measures of psychomotor speed and attention, while RCI addressing practice effects (RCI-PE) indicated improvement on most measures regardless of immunostatus. Conversely, among the demographically dissimilar cohort, simple regression indicated high rates of decline across all measures, while RCI-PE indicated elevated rates of decline on psychomotor and attention measures. Thus, the accuracy of the two methods examined for determining clinically significant change among HIV+ cohorts differs depending upon their similarity with the normative sample.

The hypothesized effect of recurrent low-dose manganese (Mn) exposure on neuropsychological function is controversial because of inconsistent findings across three decades of research. We conducted a meta-analysis on 41 variables from nineteen neuropsychological studies of Mn-exposed workers. The results showed: Large effect size (ES) for biological markers of Mn and lead levels; thirteen of 26 neurocognitive measures showing a small average ES; only one of 26 tasks showed a moderate ES; and small to medium ES for confounding/competing variables such as education and aptitude. Tasks with the highest ES included clerical substitution tasks, digit span, tapping endurance, and Swedish Performance Evaluation System "Additions" reaction time, but none exceeded the ES for education or aptitude. The mean ES of dose-response relationships was zero. The data did not support a theory of preclinical ("early") neuromotor or cognitive dysfunction. Overall, the pooled data are more consistent with covariate effect than toxic effect, insofar as the pooled exposure group showed demographics less favorable to neuropsychological performance than the pooled referent groups. Future consideration of demographic and biological covariates is necessary before inferring subtle toxin-induced brain damage because neuropsychological tests are nonspecific.

The developmental sequences of attention and memory were studied by utilizing normative data derived from the neuropsychological battery named NEUROPSI ATTENTION AND MEMORY. A sample of 521 Spanish-speaking individuals, aged 6 to 85 years, participated in this study. In the adult sample, educational level ranged from 0 to 22 years of education. Data from subtests measuring orientation, attention and concentration, executive functions, working memory, immediate and delayed verbal memory, and immediate and delayed visual memory were included. The factor structure of the analyzed battery is presented. The effects of age and education on this structure were analyzed. Results suggested that although attention and memory are related, their developmental sequences are separated from one another. During childhood, the development of selective and sustained attention, attentional-working memory, and executive functions showed a fast improvement in performance. Development of verbal memory and place and person orientation showed a slower increment in scores. In the adult sample it was found that factors related to memory are sensitive to age, whereas those related to attention and executive functions are sensitive to education. The consideration of both the developmental sequence, as well as differential effects of education, can improve the sensitivity and specificity of neuropsychological measures, allowing early diagnosis of cognitive dysfunction and implementation of adequate rehabilitation programs.

The study compared age-related decrements in verbal and visuo-spatial memory across a broad elderly adult age range. Twenty-four young (18-25 years), 24 young-old (65-74 years), 24 middle-old (75-84 years) and 24 old-old (85-93 years) adults completed parallel recall and recognition measures of verbal and visuo-spatial memory from the Doors and People Test (Baddeley, Emslie & Nimmo-Smith, 1994). These constituted 'pure' and validated indices of either verbal or visuo-spatial memory. Verbal and visuo-spatial memory declined similarly with age, with a steeper decline in recall than recognition. Unlike recognition memory, recall performance also showed a heightened decline after the age of 85. Age-associated memory loss in both modalities was largely due to working memory and executive function. Processing speed and sensory functioning (vision, hearing) made minor contributions to memory performance and age differences in it. Together, these findings demonstrate common, rather than differential, age-related effects on verbal and visuo-spatial memory. They also emphasize the importance of using 'pure', parallel and validated measures of verbal and visuo-spatial memory in memory ageing research.

The superiority of the modified 16-item Rey memory test over the original 15-item test has yet to be established in relation to the detection of feigned memory deficits. This study compares the effectiveness of these two versions of the test in combination with a standard memory test. Sixty-four participants, equally divided into "controls" and "simulators", and 32 "memory-impaired" volunteers completed the WAIS-III Digit Span test and either the 15-item or 16-item Rey test. The median scores of the simulators were worse than those of both the controls and the memory-impaired subjects on two types of score on the 16-item test compared to just one on the 15-item test. However, combining the total score from the 16-item test with the digits forward span accurately detected 63% of simulators (with only 6% of nonsimulators wrongly classified as simulators). This performance was better than that obtained from any of the test scores taken singly or from any other combination of a digit span score with a Rey score. It is concluded that the addition of a standard memory test to the Rey memory test improves the detection of individuals feigning memory impairment.

We report Victoria Symptom Validity Test (VSVT) performance in 120 epilepsy patients undergoing neuropsychological assessment as part of their evaluation as epilepsy surgery candidates. Patients were grouped according to their performance on hard VSVT stimuli. Scores of at least 21/24 on the hard VSVT items were classified as valid (n=86), scores of 18/24-20/24 were considered questionably valid (n=20), and scores of 17/24 and below were designated as invalid (n=14). Significant group effects were observed for WAIS-III Full Scale IQ, Verbal IQ, Performance IQ, Digit Span, Rey 3x5 Memory, Selective Reminding Recognition, and Complex Figure Immediate Recall; poorer cognitive scores were associated with lower VSVT scores. Age was also related to VSVT performance, with patients older that 40 years of age (16/42) more likely to fail the VSVT (i.e., hard scores < or = 20/24) than their younger counterparts (8/78) (p=.0006, Fisher's Exact Test). These results indicate that VSVT may identify cases of incomplete effort in patients being evaluated for strictly clinical purposes in which no external incentive to perform poorly has been identified, although the potential confound of low IQ on VSVT cannot be determined from this sample. Older patients also appear to be at increased risk for suboptimal performance, and may need additional encouragement or education regarding the need to perform to the best of their ability, and thereby maximize the likelihood of obtaining valid neuropsychological test results.

Working memory capacity can be conceptualized as the ability to use controlled attention in short term memory (Engle, Tuholski, Laughlin, & Conway, 1999). We tested this idea in young and older adults by combining the task demands of two neuropsychological tests, word span, and Stroop color-naming. Young and older adults were asked to name the colors of a series of congruent and incongruent color-words (between 2 and 6 words/trial). After all the color-words were presented participants attempted to recall the colors in their serial order. This task required inhibition of the prepotent word reading response (i.e., color naming), with a concurrent memory load (caused by the need to maintain already named colors in short-term memory). Older adults showed greater interference effects, and these interference effects increased as a function of memory load. Regression analyses showed that measures of working memory capacity and executive function accounted for unique variance in incongruent color-word errors for older adults. Defining working memory capacity as the ability to use controlled attention in short-term memory may be a fruitful way to think about this concept in studies of executive function.

Performance on the Letter-Number Sequencing (LNS) and Wisconsin Card Sorting Tests (WCST) have been shown to be significantly correlated in patients with schizophrenia, a relationship postulated to be due to working memory demands of the two tests (Gold, Carpenter, Randolph, Goldberg, & Weinberger, 1997). An alternative explanation for the association between these two tests is their sorting demands, in that both require sorting of information albeit in slightly different ways. If the latter explanation is valid, then working memory tasks that do not require sorting or other conceptualization demands should be less predictive of WCST performance than LNS. These hypotheses were examined in 34 poor outcome patients with schizophrenia, one-half of whom were over the age of 65. Patients were evaluated on Digit Span Forward, spatial working memory, LNS, and the WCST. It was found that WCST performance was significantly associated with performance on the LNS but no other working memory task. Age related performance differences were greatest on the WCST Categories and floor effects were noted on this test in one-half of the subjects. Analyses predicting WCST Categories in subjects whose scores were greater than zero (n = 16) also demonstrated that LNS, but not Digit Span or spatial working memory (any delay) predicted WCST performance. These findings indicate that LNS may be an index of executive functioning, particularly in patients who cannot perform the WCST.

Although research examining Auditory-Verbal and Visual Memory Span in adults has failed to provide compelling evidence for the modality specificity of such tasks, Fastenau, Conant, and Lauer (1998) suggested that these processes may be dissociable in children until around the age of 8 years when visuospatial memory span appears to become more verbally mediated perhaps as a function of formal reading training. A subsequent cross-cultural study in Zaire (now Democratic Republic of Congo) by Conant and colleagues (1999) supported that hypothesis. However, other differences in the sociocultural environments of American and rural Zairian children such as nutritional and health care factors could potentially account for the findings. The present study examines the relationships among Auditory-Verbal, Visual, and Cross-Modal Memory Span tasks with 46 Lao and 56 American children. Both samples were divided into younger and older groups, and separate partial correlational analyses were performed on Kaufman Assessment Battery for Children (K-ABC) data from each group. In younger Lao and American children, Auditory-Verbal Memory Span was not significantly correlated with Visual Memory Span or Cross-Modal Memory Span, whereas significant correlations were found between Auditory-Verbal Memory Span and these other tasks in older children from both countries. The similar pattern in both cultures, together with findings from Zaire, supports the hypothesis that the relationship between Auditory-Verbal and Visual Memory Span may change with reading training.

As it is already known that depression can cause a demonstrable impact on cognition in elderly subjects, the objective of this study was to determine whether also the mourning process is associated with any cognitive impairment in this age range. A random and representative sample (a sample with 77 subjects/total county population of oldest-old with 219 subjects = 35%) aged 80 years or more was selected from the county of Veranopolis in the Brazilian rural southern region. Of this group, the cognitive function of subjects without grief and of subjects with the presence of grief were compared. Five neuropsychological tests (the Buschke-Fuld Selective Reminding Test, the word-list from the CERAD battery, the Verbal Fluency Test, and two subtests of the Wechsler memory scale), the Mini-Mental State Examination (MMSE) and two self-perceived memory impairment questionnaires were used. Presence of depressive symptomatology was identified by the Yesavage Geriatric Depression Scale (GDS). The prevalence rates of some psychiatric diagnoses (syndromic general anxiety disorder, major and minor depression) were compared between the bereaved group and the control group. There was not a statistically significant difference between the scores of controls and subjects with grief in the GDS. The frequency of affective disorders in both groups did not differ. However, the recently bereaved elderly subjects presented a mild cognitive impairment when evaluated with the MMSE, with the digit span test and with Word-list neuropsychological memory test. Likewise these bereaved octogenarian subjects presented more frequently a diagnosis of 'aging-associated cognitive decline' when compared with non-bereaved oldest-old. These results suggest that the normal sadness and/or the chronic stress of the grieving process, even without the presence of an identifiable syndromal-level depression, are associated with memory and cognitive differences among the bereaved oldest-old. Cause-effect relationships, however, cannot be established from this cross-sectional correlational study: Grief may influence cognitive functioning in the elderly, but mildly cognitively compromised elderly persons may be more likely to experience strong grief reactions after loss.

We examined the effect of age on working memory with a reading span task (RST) together with other verbal span tasks. Sixty-two participants were divided into three subgroups (young, middle-aged, and elderly). The RST performances were significantly different among all the subgroups. To elucidate which component of the working memory system is affected by age, we performed an analysis of covariance with the scores of simple and complex verbal span tasks as covariates. From the results, we conclude that the difference of the RST performance between the middle-aged and elderly groups reflects a decline in the capacity of the phonological loop, and the difference between the young and middle-aged groups reflects malfunctioning of the central executive system.

Digit span (DS) and visual memory span (VMS) tasks have been shown to be distinct in young children but fail to show modality specificity in older American children and adults (Fastenau, Conant, & Lauer, 1997, 1998). The present study examines the possibility that processing of VMS becomes automatized with written language training. In a sample of 139 Zairian children, separate factor analyses on K-ABC data for younger children (6.1-8.5 years) and older children (8.6-12.8 years) yielded two-factor solutions in both cases, which appear to represent verbal and visual-spatial abilities. Modality specificity of the visual span task is supported in both age groups. Findings of modality specificity in both Zairian age groups provides support for the theoretical distinction between verbal and visual memory span. Continued modality specificity of visual memory span tasks in older Zairian children suggests that the increased verbal loadings of these tasks seen for older American children may reflect differences in written language development.

Longitudinal changes in global cognitive functioning, indexed by the Mini-Mental State Examination (MMSE), in subjects with dementia (Alzheimer's disease and vascular dementia) were examined. The roles of several demographic, psychometric, and biological indices in predicting cognitive deterioration were also examined. The sample consisted of 36 very old (M age at entry = 83.0 years, range = 75-95) adults with dementia from a community-based study. Subjects were tested on two occasions separated by approximately 2.5 years. Results indicated significant longitudinal decline in MMSE scores over the retest interval; the average decline was estimated as 2.43 (SD = 1.81) points per year. Several factors were associated with cognitive deterioration. Higher initial MMSE scores were associated with greater deterioration, whereas superior forward digit span and Block Design at entry were associated with attenuated decline, once differences in baseline severity were accounted for. By contrast, a variety of other putatively important variables exhibited no relationship to decline, including age, gender, education, onset age, dementia type, backward digit span, as well as a number of biological parameters (e.g., vitamin B12, folic acid). The results suggest that although the magnitude of cognitive deterioration in dementia is highly variable, several indicators may be useful predictors of future changes in cognitive functioning.

Eight malingerers (MPs) were identified via significantly below-chance symptom validity testing (SVT) within a sample of 106 consecutive admissions for neuropsychological evaluation. The resulting incidence of 7.5% is seen as a minimal estimate of malingering within the sample. Eight individuals who “passed” SVT but produced neuropsychological data of questionable validity were also identified (QVs). MPs and QVs were compared with matched controls on 14 measures that have been previously suggested as indicators of invalid neuropsychological data. MPs and QVs differed from controls on General Neuropsychological Deficit Scale, Fingertip Number Writing, and Digit Span. CVLT Recognition, Finger Agnosia, and Speech Perception differed for one of the target groups versus controls and had trends toward significance in the other group. However, many of the previously suggested invalidity signs were rare or absent. Reliance on these measures could result in overconfidence in the validity of neuropsycholog...

The construct validity of Wechsler Memory Scale Logical Memory, Paired Associate Learning and Visual Reproduction subtests was evaluated, as well as the validity of the Benton Visual Retention Test, and the two memory factor scales of the Luria-Nebraska Neuropsychological Battery (LNNB). The results of a series of factor analyses based on test performances of 102 subjects indicated that delayed reproduction measures of visual memory were more valid than the traditional immediate reproduction administrations, which were more closely associated with visual-perceptual-motor abilities. Construct validity was also demonstrated for Logical Memory and Paired Associate Learning. Although both LNNB measures loaded on a memory factor, item heterogeneity and brief sampling of items raised serious questions about the clinical utility of these scales.

Fifty-four patients with Alzheimer's disease performed on the Dementia Assessment Battery that comprised of finger tapping, forward digit span, naming, verbal memory, visual memory, Token Test, digit cancellation, word-list generation, symbol-digit substitution, and copying geometric designs. Four forms of the battery were administered at weekly intervals. The equivalence of the forms, the relative difficulty of the tests, retest reliability, and factorial composition of the battery are presented. Performance improved with repetition. Impairments in visuo-spatial and verbal abilities were independent of each other. The fragility of the patients' working memory was identified as a main cause for their poor recall. The importance of "component analysis" in individual assessment is illustrated.

This paper reviews recent neuropsychological studies of primary-memory functioning in early Alzheimer-type dementia (AD) with specific reference to recent research on working memory. The deficits in primary memory follow a fairly distinct pattern with a comparatively unimpaired recency effect in free recall, a moderate impairment in memory span, and a more substantial impairment in short-term retention following distraction. The nature of these deficits is considered in relation to the Working Memory Model (Baddeley & Hitch, 1974). It is suggested that the Articulatory Loop System is functioning normally but that there is an impairment in the control processes of working memory.

Thirty-seven patients with multiple sclerosis (MS) were compared to 26 normal controls of equivalent age, education, and verbal intelligence on measures of verbal learning and memory (Digit Span and Supraspan, Brown-Peterson Distractor Task, Selective Reminding Test, Story Recall, and Free Verbal Recall) and verbal fluency (Letter and Animal Fluency). The MS patients exhibited deficits on measures of secondary (long-term) memory and verbal fluency, but performed normally on measures of primary (short-term) memory, recognition memory, and rate of forgetting from secondary memory. These results suggest that the memory disturbance in MS results primarily from an imparied ability to access information from secondary memory, while encoding and storage capacity is intact. Degree of memory impairment was unrelated to length of illness, severity of disability, or self-reported depression.

Sixteen patients with dementia of the Alzheimer type (AD) and nine patients with Progressive Supranuclear Palsy (PSP) were administered a battery of neuropsy-chological tasks that assessed a cross-section of cognitive abilities. The subjects were equated in terms of overall level of impairment. There was no difference between the groups on the WAIS subtests that were administered (Vocabulary, Digit Span Forward, Similarities, Block Design). There was a striking difference between the AD and PSP patients on tests of verbal and nonverbal memory, as assessed by the Wechsler Memory Scale. The memory performance of the PSP patients did not, in fact, differ from a group of normal controls. In addition, there was a double-dissociation between the AD and PSP patients on tasks that evaluated naming and verbal fluency.