Query: WAIS digit span task

title: Verbal working memory impairment in schizophrenia patients and their first degree relatives: evidence from the digit span task.
abstract: The evidence for verbal working memory deficits in schizophrenia has been inconsistent. Few studies have evaluated verbal working memory in the first degree relatives of schizophrenia patients, who likely share the genetic diathesis for schizophrenia but not the potential confounds associated with chronic mental illness.  The Wechsler Digit Span Task was used to investigate verbal working memory in 52 schizophrenia patients, 56 of their first degree relatives, and 73 nonpsychiatric comparison subjects.  The nonpsychotic relatives showed no impairment on the forward digit span task, a measure of general attention, but did show impairment on the backward digit span task, a measure of verbal working memory. Schizophrenia patients showed impairment on both the forward and backward digit span tasks.  These results indicate that the forward and backward digit span tasks tap different cognitive abilities that are differentially associated with the diathesis for schizophrenia. Working memory deficits associated with schizophrenia appear to be generalized and not limited to the spatial modality.

title: Effects of acute subcutaneous nicotine on attention, information processing and short term memory in alzheimer's disease
abstract: This single blind, placebo controlled study reports on the effects of administering three acute doses of nicotine (0.4, 0.6 and 0.8 mg) subcutaneously to a group of Alzheimer's disease (DAT) patients (n=22) young adult controls (n=24) and normal aged controls (n=24) The study extends our previous findings obtained using smaller groups of subjects. Drug effects were examined on three computerised tests: the first measuring rapid visual information processing, sustained visual attention and reaction time (RVIP task) a delayed response matching to location order task measuring sustained visual attention and visual short term memory (DRMLO task) and a finger tapping test measuring simple reaction time (FT task) The critical flicker fusion test (CFF) was used as a measure of perception and the WAIS digit span forwards (DS) of auditory short term memory. Tests were graded in difficulty, titrated to avoid floor and ceiling effects so that meaningful, direct comparisons between groups could be made. Nicotine significantly improved sustained visual attention (in both RVIP and DRMLO tasks) reaction time (in both FT and RVIP tasks) and perception (CFF task both ascending and descending thresholds) Nicotine administration did not improve auditory and visual short term memory. There were no consistent, overall patterns of difference in performance between smokers and non smokers in the control groups, or between males and females in any group. Despite the absence of change in memory functioning, these results demonstrate that DAT patients have significant perceptual and visual attention deficits which are improved by nicotine administration. The importance of measuring multiple abilities in future drug studies is emphasized and results are discussed in terms of nicotine's actions on attention, information processing and short term memory.

title: Visuospatial imagery is a fruitful strategy for the digit span backward task: a study with near infrared optical tomography.
abstract: Our newly developed 64 channel time resolved optical tomographic imaging system using near infrared light enables us to obtain a quantitative image of hemoglobin concentration changes associated with neuronal activation in the human brain ?H. Eda, I. Oda, Y. Ito, Y. Wada, Y. Oikawa, Y. Tsunazawa, M. Takada, Y. Tsuchiya, Y. Yamashita, M. Oda, A. Sassaroll, Y. Yamada, M. Tamura, Multi channel time resolved optical tomographic imaging system,  (1999) 3595 3602. Here, we used this optical imaging system to demonstrate that the backward digit span (DB) task activated the dorsolateral prefrontal cortex (DLPFC) of each hemisphere more than the forward digit span (DF) task in healthy adult volunteers, and higher performance of the DB task was closely related to the activation of the right DLPFC. These results suggest that visuospatial imagery is a useful strategy for the DB task. Optical tomography described here is a new modality of neuropsychological studies.

title: The Backward Span of the Corsi Block Tapping Task and Its Association With the WAIS III Digit Span
abstract: The Corsi Block Tapping Task measures visuospatial short term and working memory, but a standardized backward condition is lacking. The authors present a standardized backward procedure that was examined in 246 healthy older adults (ages 50 to 92) comparing the results with the Digit Span subtest of the Wechsler Adult Intelligence Scale Third Edition. Principal component analysis resulted in a two factor model, dissociating a verbal and a spatial working memory factor. Also the Corsi backward is not more difficult than the Corsi forward, in contrast to the Digit Span backward that is more difficult than the Digit Span forward. This may suggest that the Corsi Block Tapping Task backward task relies on processing within working memory's slave systems, whereas the Digit Span backward also relies on the central executive component of working memory. Finally, regression based normative data and cutoff scores for older adults are presented for use in clinical practice.

title: Theory of mind disability in major depression with or without psychotic symptoms: A componential view
abstract: Previous reports have conceptualized theory of mind (ToM) as comprising two components and questioned whether ToM deficits are associated with psychotic symptoms. We investigated 33 nonpsychotic depressed inpatients, 23 psychotic depressed inpatients, and 53 normal controls with the following measures: Eyes Task, Faux pas Task, Verbal Fluency Test (VFT) Digit Span Test (DST) and WAIS IQ. The depressed patients were also evaluated with the Beck Depression Inventory II (BDI II) and the Brief Psychiatric Rating Scale (BPRS) The nonpsychotic depressed patients and the psychotic depressed individuals were significantly impaired on tasks involving ToM social perceptual and social cognitive components, as well as the VFT. The psychotic depressed patients performed significantly worse than nonpsychotic depressed patients on ToM tasks. An association was found between ToM performances and both BPRS total and hostile suspiciousness scores in the depressed group. Both of the ToM components were impaired in depressed patients. Similar mechanisms and neurobiological substrate may contribute to schizophrenia and major depression.

title: Peak alpha frequency: an electroencephalographic measure of cognitive preparedness
abstract: Electroencephalographic (EEG) peak alpha frequency (PAF) (measured in Hz) has been correlated to cognitive performance between healthy and clinical individuals, and among healthy individuals. PAF also varies within individuals across developmental stages, among different cognitive tasks, and among physiological states induced by administration of various substances. The present study suggests that, among other things, PAF reflects a trait or state of cognitive preparedness.  Experiment 1 involved 19 channel EEG recordings from 10 individuals with traumatic brain injury (TBI) and 12 healthy matched controls, before, during, and after tasks of visual and auditory attention. Experiment 2 involved EEG recordings from 19 healthy young adults before and after a working memory task (WAIS R Digit Span) repeated on 2 different days to measure within individual differences.  Experiment 1 showed significantly lower PAF in individuals with TBI, mostly during post task rest. Experiment 2 showed PAF during pre task baseline to be significantly correlated with Digit Span performance of the same day but not with Digit Span performance of another day. Moreover, PAF was significantly increased after Digit Span for those participants whose PAF was lower than the sample median before the task, but not for those who had it higher. Finally, both PAF and Digit Span performance were increased during the second day.  PAF was shown to detect both trait and state differences in cognitive preparedness, as well as to be affected by cognitive tasks. Traits are better reflected during post task rest, whereas states are better reflected during initial resting baseline recordings.

title: The validity of d prime as a working memory index: Results from the "Bergen n back task"
abstract: 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.

title: Aging and prefrontal functions: dissociating orbitofrontal and dorsolateral abilities
abstract: This study aimed to determine whether age differentially affects performance on tasks tapping orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (DLPFC) We administered prefrontal measures to healthy younger n=23; age= 28.4+ 5.9, education 15.7+ 2.6, MMSE=29.5+ 0.6 and older participants n=20; age=69.1+ 5.0, education =15.5+ 3.4, MMSE =28.9+ 1.5) Groups did not differ on education or mental status, P>0.05. Tasks thought to involve greater OFC processing included the Iowa Gambling Task and Delayed Match and Non Match to Sample Tasks. Tasks requiring greater DLPFC processing included Petrides' Self Ordered Pointing, WAIS R Digit Span Backward, Letter Fluency, and Months Backward from the Boston Revision of WMS Mental Control. Composite z scores were calculated for OFC and DLPFC tasks. A 2 x 2 ANOVA revealed a Group x Task interaction: F(1,41) =5.55, P=0.02, and a Group main effect: F(1,41) 12.16, P=0.001. Follow up analyses revealed younger adults outperformed older adults on OFC tasks only younger 0.37+ 0.46, older= 0.43+ 0.70; t(41) =4.5, P<0.001 Post hoc analyses of individual tasks confirmed that despite age differences on Petrides' Self Ordered Pointing, measures requiring relatively greater OFC involvement showed larger effect sizes for age differences. Thus, tasks emphasizing OFC functions appear more sensitive to age effects when directly compared to measures of DLPFC functioning. Reasons for this difference in magnitude may stem from differential aging of prefrontal cortex or differential recruitment of alternative brain regions for successful task completion.

title: WAIS Digit Span Based Indicators of Malingered Neurocognitive Dysfunction
abstract: The present study determined specificity and sensitivity to malingered neurocognitive dysfunction (MND) in traumatic brain injury (TBI) for several Wechsler Adult Intelligence Scale (WAIS) Digit Span scores. TBI patients (n 344) were categorized into one of five groups: no incentive, incentive only, suspect, probable MND, and definite MND. Performance of 1,063 nonincentive patients (e.g. cerebrovascular accident, memory disorder) was also examined. Digit Span scores included reliable digit span, maximum span forward both trials correct, maximum span forward, combined maximum forward and backward span, Digit Span scaled score, maximum span backward both trials correct, and maximum span backward. In TBI, sensitivity to MND ranged from 15% to greater than 30% at specificities of 92% to 98% Patient groups with documented brain pathology had higher false positive error rates. These results replicate previous known groups malingering studies and provide valuable data supporting the WAIS Digit Span scores in detection and diagnosis of malingering.

title: P300 and Neuropsychological Tests as Measures of Aging: Scalp Topography and Cognitive Changes
abstract: The rationale for the present study was to investigate several aspects of P300 topography in relation to aging and neuropsychological measures. We administered an auditory oddball ERP task to 72 participants aged 21.8 to 94.7 years, 36 males and 36 females, in addition to the Wechsler Abbreviated Scales of Intelligence (WASI) and digit span from the Wechsler Adult Intelligence Scales Revised (WAIS R) The relationship between age and P300 latency and amplitude at different electrodes was investigated, as well as the changes in the correlational pattern between P300 latency and amplitude with increasing age. A formal test of curvilinear relationships for P300 latency/amplitude and age was performed. Principal component factor analyses were performed for P300 latency and amplitude separately in order to check for possible superordinate structures in the distribution of the electrical activity measured at the scalp. In addition, each of the electrodes and each of the factors were correlated with the different neuropsychological measures, and the contribution of age to the observed relationships is discussed. The main conclusion drawn is that the activity generated from different brain areas change at different rates with age. While the posterior area shows a clear reduction of P300 amplitude and a delay of P300 latency with age, the amplitude does not decrease at the same rate in the fronto central areas, and there is at the same time a marked hemispheric asymmetry in the age dependent change of activation. Based on our data, it may be concluded that a curvilinear expression generally does not explain the aging effect on the ERP component P300. Correlations between neuropsychological measures and P300 did, as expected, vary with area of activation, and the strongest correlations were generally found between matrices, block design and digit span, and the midline and left fronto temporal electrodes. These relationships were in turn mediated by age. Implications of the findings are discussed.