Manuel Morales

Reliability and Normative Data for the Benton Visual Form Discrimination Test

Visuoperceptual disorders are a common consequence of brain disease. The Visual Form Discrimination Test is a task designed to assess the ability to make fine visual discriminations. Although its validity to assess the visuoperceptual impairments in patients with different neurological conditions has been well established, the normative data base for the test has remained small. The clinical use of the test has been limited by the scanty normative data available. Thus, with the aim of assisting the clinicians in interpreting more accurately the performances of their patients we investigated the test-retest reliability of the Benton’s VFDT and also provide normative data obtained on a sample of 397 healthy individuals.

The computerized tower of Hanoi : a new form of administration and suggestions for interpretation

A computerized version of the Tower of Hanoi with a new form of administration was administered to two different groups, 15 men and 22 women, who were university students reporting normal psychological histories, and 24 traumatically brain-injured patients (20 men and 4 women). Scores on this test for both groups can be interpreted as an index of ability to solve problems and of learning strategies. Men and women scored differently on the task, i.e., women used different strategies than men to solve problems.

Modulation of medial temporal lobe activity in epilepsy patients with hippocampal sclerosis during verbal working memory.

It has been traditionally assumed that medial temporal lobe (MTL) is not required for working memory (WM). However, animal lesion and electrophysiological studies and human neuropsychological and neuroimaging studies have provided increasing evidences of a critical involvement of MTL in WM. Based on previous findings, the central aim of this study was to investigate the contribution of the MTL to verbal WM encoding. Here, we used magnetoencephalography (MEG) to compare the patterns of MTL activation of 9 epilepsy patients suffering from left hippocampal sclerosis with those of 10 healthy matched controls while they performed a verbal WM task. MEG recordings allow detailed tracking of the time course of MTL activation. We observed impaired WM performance associated with changes in the dynamics of MTL activity in epilepsy patients. Specifically, whereas patients showed decreased activity in damaged MTL, activity in the contralateral MTL was enhanced, an effect that became significant in the 600- to 700-ms interval after stimulus presentation. These findings strongly support the crucial contribution of MTL to verbal WM encoding and provide compelling evidence for the proposal that MTL contributes to both episodic memory and WM. Whether this pattern is signaling reorganization or a normal use of a damaged structure is discussed.

Development of two spanish versions of the verbal selective reminding test.

The Selective Reminding procedure has become a widely used test for evaluating verbal learning and memory. However, since this test was mainly devised for use in English speaking individuals, disadvantages could appear when translations of the test are applied to Spanish speaking patients. To overcome these difficulties, two Spanish versions of the Verbal Selective Reminding Test were devised and administered to 48 healthy individuals, 19-31 years in age, in two separate sessions. We found that performances on the two forms were comparable, except for one measure. All the variables on both forms yielded significant positive correlations. We also examined test-retest reliability separately for both possible orders, with Order 2 (Form 2 administered first) being more reliable than Order 1 (Form 1 administered first).

Discrimination of Normal from Demented Elderly on a Spanish Version of the Verbal Selective Reminding Test

The verbal Selective Reminding Test (vSRT) is a frequently used test for evaluating verbal learning and memory. In the present study we investigated the construct validity of a Spanish version of the vSRT by determining its ability to distinguish between a group of healthy elderly subjects and a group of patients with dementia of the Alzheimer type (DAT). Further validation of the test was assessed by comparing the pattern of memory deficits found in the group of patients with DAT with findings from previous neuropsychological research concerning with memory impairments in English-speaking patients with Alzheimer’s disease. Analyses revealed that the test was able to differentiate normal individuals from patients with DAT. In addition the pattern of memory functioning found in the group of patients with DAT was consistent with findings of previous experimental and clinical reports. These results support the construct validity of the Spanish version of the vSRT.

Uses of qualitative/quantitative terms in social and educational research*

There are an increasingly greater number of authors who support the use of qualitative methodology in their research (Glaser & Strauss, 1967; Goetz & Lecompte, 1980; Bogdan & Bliken, 1982; Firestone & Herriot, 1983; Howe, 1985; Filstead, 1986, etc.). However, there are problems offering a clear conceptualization of the above mentioned notion owing to the fact that often qualitative (Q) and quantitative (C) terms are used without specifying their concrete meaning, or are even referred to polysemically. Furthermore, authors even differ in the identification of the different uses of the terms in question.With the aim of solving these problems, we thought it suitable to carry out an exploratory content analysis of the characteristics given by authors to the terms C and Q. The results illustrate that Reichardt and Cooks proposal (1986), although representing a significant advance in the field, does not go far enough, given that it does not gather all the possible uses that authors attribute to the terms C and Q. This may, in our opinion, be considered as proof of the need to search for new criteria and/or reformulate the already existing ones.

Spatial orientation deficit in children due to cerebellum astrocytoma pediatric tumor obtained by means of the Attentional Network Test

Cerebellum astrocytomas are the most typical nervous system tumors in children. Several cognitive deficits have been previously described. These deficits are probably produced by cerebellar connection and gray matter damage. The present study examines attentional deficits in children operated on for cerebellum astrocytomas, using an attentional paradigm with theoretical and clinical bases: the Attentional Network Test (ANT). This test was designed considering the attentional network theory proposed by Posner, and its usefulness has been demonstrated in clinical settings. Children operated on for cerebellar astrocytoma showed a mild attentional deficit in the orientation network.

Developmental trajectories of event related potentials related to working memory

ABSTRACT Working memory is an important cognitive function, and it is crucial to better understand its neurophysiological mechanisms. The developmental trajectories of the Event Related Potentials related to this important function have hardly been studied. However, these ERPs may provide some clues about the individual state of maturation, as has been demonstrated for anatomical brain images. The present study aims to determine the behavioral and neurophysiological development of Working Memory (WM) processes. For this purpose, 170 subjects with ages ranging from 6 to 26 years performed a visual Delayed Match‐to‐Sample task (DMTS). The RTs, total errors, and Event Related Potentials (ERPs) in the phases of encoding, retention, and matching were obtained. Results revealed a decrease in the amplitude of ERPs with age, paralleled by improved performance on the DMTS task (i.e., shorter RTs and fewer errors). None of these variables were affected by gender. To determine whether memory performance was influenced by the individual pattern of maturation beyond age, the amplitude of the different ERP components was correlated with RT and errors on the WM task after removing the effect of age. Frontal N2 and posterior P1 and the Late Positive Component were the only ERPs that presented significant correlations with behavioral errors. Behavioral performance was predicted by age and by the scores on the first component extracted from Principal Component Analysis (PCA) of the ERPs. Age (under 17 years old) explained 85.04% and the PCA component explained 14.96% of the variance explained by the bivariate model predicting behavioral errors (1/age + scores of 1st PCA component). From the age of 17 on, the principal PCA component ceases to be an independent component predicting error performance. The results suggest that the individual maturation of ERP components seems to be of particular importance in controlling behavioral errors in WM, as measured by the DMTS. HIGHLIGHTSAll the ERPs related to Working Memory during development were analyzed.All ERPs presented a reduction in amplitude with age.Frontal N2, posterior P1 and the Late Positive Component are important for controlling errors,Individual brain maturation influences cognitive performance in the 6–17 year old period.

Normative data for a six-trial administration of a spanish version of the verbal selective reminding test.

Normative data for 884 neurologically normal adults (15-93) are provided for a six-trial administration of Form 1 of the Spanish version of the Verbal Selective Reminding Test (VSRT). Form 2 was also administered to 391 adults (18-87). Age was the most important predictor of performance on all VSRT scores in Forms 1 and 2. Additionally, women and higher educated participants outperformed men and lower educated participants over the entire age range studied. Normative data are grouped by seven age cohorts: 15-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80-95.

Working Memory Development in Attention Deficit Children and Adolescents

Attentional deficit disorder (ADD, ADHD) is a complex disorder in which attention and working memory (WM) are impaired. The central hypothesis is that WM behavioral performance would be impaired in ADD and would facilitate the classification of control and ADD subjects. One hundred and eighty-one control and 41 ADD children and adolescents (6–17 years old) were behaviorally recorded using the Working Memory Test Battery for Children (WMTB-C), delayed match-to-sample test (DMTS), and oddball tasks. ADD children presented a behavioral impairment in WMTB-C, DMTS, and oddball tasks. ADD obtained lower direct scores in the three subcomponents of the Baddeley’s WM model, lower d’ values, produced more errors, and presented higher variability in RTs than controls. The discriminant analysis was able to classify correctly around 70% of controls and ADD children. The results suggest that WM is a central core dysfunction in ADD and useful as a diagnostic tool.