Implicación de la memoria visoespacial y fonológica en la heterogeneidad clínica del Trastorno por Déficit de Atención con Hiperactividad (TDAH) / Implication of visuospatial and phonological working memory in the clinical Heterogeneity of Attention-Deficit/Hyperactivity Disorder (ADHD)

Introducción: Recientemente se ha incrementado el interés en el estudio de los déficits neuropsicológicos que subyacen al TDAH. Entre ellos, destaca la Memoria de Trabajo (MT) en sus dimensiones visoespacial y fonológica. El objetivo del presente estudio fue explorar las diferencias de rendimiento en memoria a corto plazo y memoria de trabajo visoespacial y fonológica entre un grupo control y un grupo clínico, teniendo en cuenta la heterogeneidad clínica del trastorno. Método: Se formó un grupo clínico de 76 niños con un diagnóstico previo de TDAH, divididos según su subtipo clínico: TDAH predominantemente inatento (n = 26, edad M = 10,9, SD = 1,8; 66% varones), y TDAH combinado (n = 50, edad M = 10.8, DT = 1.9; 61.5% varones). Además, se formó un grupo control conformado por niños sin diagnóstico TDAH (n = 40, edad M = 10.2, SD = 1.9; 57.5% varones). A todo ellos se les administró un batería de pruebas para medir la memoria a corto plazo y la memoria de trabajo, tanto visoespacial como fonológica. Resultados: El grupo TDAH obtuvo un peor rendimiento en las tareas de Memoria de Trabajo visoespacial (Tarea Corsi) y fonológica ('Letras y Números'de WISC). Este peor rendimiento se mantuvo también para los subtipos clínicos. No se halló relación entre las dimensiones del TDAH y el rendimiento en las tareas neuropsicológicas empleadas. Discusión: Este estudio aporta evidencia empírica a la hipótesis que sugiere que los niños con TDAH presentan un menor rendimiento en tareas que implican la memoria de Trabajo, tanto respecto a la memoria de trabajo fonológica como visoespacial. Además, los resultados de este estudio sugieren que no existiría una relación entre las dimensiones principales del TDAH y el rendimiento en las tareas de memoria de trabajo (AU)

Introduction: The interest in studying the neuropsychological deficits that lie behind ADHD, among which the Working Memory (WM) stands out in its visuospatial and phonological dimensions, has been on increase. The aim of the current study was to explore the performance differences concerning the short-term memory and the visuospatial and phonological working memory among control and clinical groups acknowledging the clinical heterogeneity of the disorder. Method: A group of 76 children with a prior diagnosis of ADHD was divided by the clinical subtype of the disorder: ADHD predominantly inattentive (n = 26, age M = 10,9, SD = 1,8; 66% male), and combined ADHD (n = 50, age M = 10.8, DT = 1.9; 61.5% male). Additionally, a control group of typically developing children was formed (n = 40, age M = 10.2, SD = 1.9; 57.5% male). Both groups completed a task battery to aimed to measure the short-term memory, as well as the visuospatial and phonological working memory. Results: The ADHD group showed a decreased performance at visuospatial (Corsi Block Task), as well as phonological (WISC Letter-Number Sequencing) working memory tasks. The decreased performance was consistent among the clinical subtypes. The dimensions of ADHD and the performance output in the neuropsychological tasks used in the study were not related. Discussion: This study offers empirical evidence to the hypothesis that suggests that children with ADHD show a poor performance than controls at Working Memory tasks, including both visuospatial and phonological WM. In addition, the results of the study suggested that there is no correlation between the dimensions of the ADHD and the performance output in the Working Memory tasks (AU)

Late detection of hazards in traffic: A matter of response bias?

In this study, results from two different hazard perception tests are presented: the first one is a classic hazard-perception test in which participants must respond - while watching real traffic video scenes - by pressing the space bar in a keyboard when they think there is a collision risk between the camera car and the vehicle ahead. In the second task we use fragments of the same scenes but in this case they are adapted to a signal detection task - a 'yes'/'no' task. Here, participants - most of them, University students - must respond, when the fragment of the video scene ends, whether they think the collision risk had started yet or not. While in the first task we have a latency measure (the time necessary for the driver to respond to a hazard), in the second task we obtain two separate measures of sensitivity and criterion. Sensitivity is the driver's ability to discriminate in a proper way the presence vs. absence of the signal (hazard) while the criterion is the response bias a driver sets to consider that there is a hazard or not. His/her criterion could be more conservative - the participant demands many cues to respond that the signal is present, neutral or even liberal - the participant will respond that the signal is present with very few cues. The aim of the study is to find out if our latency measure is associated with a different sensitivity and/or criterion. The results of the present study show that drivers who had greater latencies and drivers who had very low latencies yield a very similar sensitivity mean value. Nevertheless, there was a significant difference between these two groups of drivers in criterion: those drivers who had greater latencies in the first task were also more conservative in the second task. That is, the latter responded less frequently that there was danger in the sequences. We interpret that greater latencies in our first hazard perception test could be due to a stricter or more conservative criterion, rather than a low sensitivity to perceptual information for collision risk. Drivers with a more conservative criterion need more evidences of danger, thus taking longer to respond.

La escala Strength and Difficulties Questionnaire (SDQ) como predictora del TDAH: comportamiento de las subescalas SDQ respecto a las dimensiones 'Hiperactividad/Impulsividad' e 'Inatención' en una muestra clínica / Strength and Difficulties Questionnaire (SDQ) as predictor of ADHD: performance between SCT rates and 'Hyperactivity/Impulsivity' and 'inattention' domains of ADHD in a clinical sample

Introducción: La escala Strength and Difficulties Questionnaire (SDQ) es una herramienta de cribado clínico para infancia y adolescencia ampliamente utilizada internacionalmente en la clínica y en la investigación. Objetivo: El objetivo de este estudio es explorar la relación entre los diferentes índices de la escala SDQ y la puntuación en las dimensiones 'Hiperactividad/Impulsividad' e 'inatención' en una escala específica de TDAH. Método: Padres y profesores/as de una muestra de 212 niños/as de entre 6 y 16 años con un diagnóstico previo de TDAH, completaron las escalas SDQ y ADHD-RS-IV. Resultados: Se confirmó la relación significativa entre la dimensión 'Hiperactividad' de la escala SDQ y ambas dimensiones del TDAH. Sin embargo, otros índices de la escala SDQ mostraron también relación con ambas dimensiones, diferenciando esta relación según el informador y la dimensión clínica. Para la familia, la 'hiperactividad/impulsividad' estaba también relacionada con puntuaciones elevadas en la subescala 'Problemas de conducta', mientras que la 'inatención' lo estaba con 'síntomas emocionales'. Conclusiones: Estos resultados sugieren la posibilidad de valorar las puntuaciones en otros índices de la escala SCT para aumentar la sensibilidad de la escala a los diferentes perfiles clínicos del TDAH

Introduction: Strength and Difficulties Questionnaire (SDQ) is an international screening tool widely used for research and clinical practice on child and adolescents. Objective: The aim of this study was to explore the relationship between SDQ indices and 'Hyperactivity/Impulsivity' and 'inattention' domains of specific ADHD scale. Method: The SDQ and ADHD-RS-IV were administered to parents and teachers of a sample of 212 children aged between 6 and 16 years old with a prior diagnosis of ADHD. Results: A significant relationship between 'Hyperactivity/inattention' Scale (SDQ) and 'hyperactivity/impulsivity' and 'inattention' ADHD dimensions was confirmed. However, other SDQ scales were also related, depending of informant and ADHD domain. For the family, 'hyperactivity/impulsivity' domain was related with high scores on 'behavior problems' scale, while the 'inattention' was related with 'emotional symptoms' scale. Conclusions: This results suggest the possibility of to take into account rating scores on SDQ scales to increase the sensitivity of the scale to discriminate ADHD clinical subtypes

Estudio comparativo de dos programas de entrenamiento de la memoria en personas mayores con quejas subjetivas de memoria: un análisis preliminar / Differential effectiveness for two memory training programs in older adults with subjective memory complaints (mnemonic training vs. everyday forgetfulness training): an exploratory analysis

Introducción: A pesar del declive cognitivo que se produce con la edad, numerosos estudios han demostrado la eficacia que tienen los programas de entrenamiento de la memoria para mejorar diversas áreas neurocognitivas en las personas mayores. Objetivo: analizar de forma preliminar el efecto diferencial de dos programas de entrenamiento de la memoria en personas mayores sobre diversas funciones cognitivas. Método: 18 sujetos entre 61 y 81 años han participado, o bien en un programa de entrenamiento en estrategias de memoria, o bien en un programa de entrenamiento en olvidos cotidianos. En todos ellos se evaluó la percepción subjetiva de la memoria, así como el desempeño cognitivo antes y después del entrena-miento. Resultados: se encontró una mejoría estadísticamente significativa en el cuestionario de quejas subjetivas de memoria en ambos grupos, y sólo se encontró cierta mejoría en memoria de trabajo visoespacial (test Corsi inverso) y en razonamiento (Analogías) en el grupo que recibió un entrena-miento en olvidos cotidianos. Conclusiones: los programas de entrenamiento de la memoria mejoran la percepción subjetiva que tienen las personas mayores del funcionamiento de la memoria, y ello es independiente de la metodología de entrenamiento utilizada

Introduction: Despite the cognitive decline that occurs with age, several studies have showed the effectiveness of memory training programs for improving some neurocognitive functions in older people. Objective: to analyze in a preliminary way the differential effect of two memory training programs on several areas of cognition in older adults. Method: 18 older adults between 61 and 81 years have participated, either in a memory strategies training program, either an everyday forgetfulness training program. All of them evaluated the subjective perception of memory and cognitive performance before and after training. Results: A statistically significant improvement in the questionnaire of subjective memory complaints was found in both groups, and only the group receiving everyday forgetfulness training improved in some cognitive performances in visuospatial working memory (Corsi test reverse) and reasoning (analogies). Conclusions: Memory training programs improve the subjective perception that older people have about its functioning, and this is independent of training methodology used

Is there a specific pattern of attention deficit in mild cognitive impairment with subcortical vascular features? Evidence from the Attention Network Test.

BACKGROUND: Mild cognitive impairment (MCI) is an intermediate state between normal aging and early dementia. Some MCI patients show white matter hyperintensities in magnetic resonance imaging, revealing subcortical vascular damage (SVD). This study aimed to evaluate potential attention deficits not previously described in these patients. Specifically, we evaluated attention network functioning in MCI on the basis of Posner's cognitive neuroscience model, which considers attention as a set of networks: alerting, orienting and executive control. METHODS: Three groups of participants were tested: 19 MCI patients with SVD (svMCI), 15 MCI patients free from SVD (nvMCI) and 19 healthy controls (HC). We used a task in which the three attention networks and their interactions can be assessed simultaneously, the Attention Network Test (ANT). RESULTS: The svMCI group showed smaller orienting effect compared with the nvMCI and HC groups. In contrast to the HC and nvMCI groups, svMCI patients did not show improvement in the executive network from the valid visual cue. CONCLUSIONS: svMCI patients show a deficit in orienting attention networks. This deficit could be related to an effect of SVD on the cholinergic system because acetylcholine is implicated in the modulation of covert orienting responses of attention.

Attention network functioning in patients with dementia with Lewy bodies and Alzheimer's disease.

BACKGROUND: Attention deficits are at the core of the defects in neuropsychological performance which define both dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Most studies have used separate tasks to test different attention abilities in patients with these diagnoses, precluding the assessment of any interaction among the different attention components. METHODS: We used a version of the Attention Network Test in which the alerting, orienting and executive attention networks, along with their interactions, could be assessed with a single task. Three groups of participants were tested: DLB patients (n = 13), AD patients (n = 18) and healthy controls (n = 18). RESULTS: The alerting signal improved orienting attention and increased the conflict effect in the healthy controls, but they had no effect on these networks in the AD patients. The DLB patients only showed preserved orienting and conflict effects when the alerting signal was present, indicating that there was regulation of the orienting and executive attention networks by the alerting signal. CONCLUSIONS: The most important differences among the 3 groups were observed in the attention network interactions, where alerting played a more relevant role in the DLB than in the AD patients. Under alerting states, the DLB patients showed evidence of certain regulation in the orienting and executive attention networks.

Posterior paralimbic and frontal metabolite impairments in asymptomatic hypertension with different treatment outcomes.

Hypertension is associated with cognitive decline in elderly persons. We studied asymptomatic hypertensive subjects using brain magnetic resonance (MR) spectroscopy to evaluate metabolite impairments before the appearance of symptoms in patients with different treatment outcomes. In all, 14 healthy controls and 37 asymptomatic hypertensive patients (17 controlled and 20 resistant) underwent brain structural MR and MR spectroscopy of the posterior paralimbic (PPL) area and left frontal white matter. Ischemic burden (IB), global cortical atrophy and microbleeds were analyzed with visual scales. Metabolite ratios involving N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho) and myoinositol (mI) were computed. Ultrasound measurements, including intima-media thickness, plaques and hemodynamic ratios, were obtained. Intergroup differences in IB, atrophy and metabolite ratios, and the atrophy and IB relationship were assessed with parametric and nonparametric statistical tests. In addition, the impacts of demographic, analytic and clinical factors, ischemia and atrophy, and ultrasound measurements on metabolite ratios were assessed. The significance level was set at P

Efectos del tiempo de exposición en una tarea de flancos en diferentes condiciones de distancia target-flanco / Effects of exposure time in a flanker task for different conditions of target-flanker distance

Este trabajo es un estudio preliminar que pretende analizar el efecto que tiene el tiempo de exposición de la información sobre la robustez del Efecto de Compatibilidad de los Flancos (ECF). Para ello, hemos llevado a cabo un experimento en el que hemos manipulado tres tiempos de exposición (14 ms, 157 ms y hasta respuesta) bajo diferentes condiciones de separación entre el target y el flanco (0,16 °, 0,47°, y 1,14° de ángulo visual de centro a centro). Los resultados indican que el tiempo de exposición no influye sobre el ECF, ni tan siquiera en diferentes condiciones de distancia espacial. Se concluye la posibilidad de que se produzca un cierto nivel de automaticidad en el procesamiento del flanco. (AU)