[Treatment with bisphosphonates improves the quality of life in patients with diagnosis of osteogenesis imperfecta]. / El tratamiento con bifosfonatos mejora la calidad de vida en pacientes con diagnóstico de osteogénesis imperfecta.

INTRODUCTION: Osteogenesis imperfeta (OI) is defined as a heterogeneous group of hereditary diseases, which present with the presence of bone fragility, frequent fractures, bone deformities and short stature. Treatment with biphosfonates in patients with diagnosis of OI has shown a decrease in the frecuency of fractures, as well as an improvement in vertebral bone density. There is little evidence on quality of life in patients diagnosed with OI treated with bisphosphonates, Therefore this study evaluated the quality of life of patients diagnosed with OI after treatment with bisphosphonates. MATERIAL AND METHODS: It is a prospective, deliberate intervention, self-controlled clinical trial. Nine patients with ages between two and thirteen ages and diagnosed with OI were treated with Zolendronic, a quality of life measurement was performed in the patients before and after the application. For measuring the quality of life in the patients we used the PedsQL 4.0 quality of life survey that was applied to both children and parents. RESULTS: In the quality of life survey performed on the parents, an increase was observed in the four dimensions evaluated. In the survey made on the children two dimensions showed a significant increase. The number of fractures decreased after the treatment. CONCLUSIONS: There is a correlation between the decrease in the number of fractures and the perception that both parents and children have in the quality of life after treatment with bisphosphonates.

INTRODUCCIÓN: La osteogénesis imperfecta (OI) es un grupo heterogéneo de enfermedades hereditarias, las cuales cursan con la presencia de fragilidad ósea, fracturas frecuentes, deformidades óseas y talla baja. El tratamiento con bifosfonatos en los pacientes con diagnóstico de OI ha demostrado un decremento en la frecuencia de fracturas, así como una mejoría en la densidad ósea vertebral. Existe poca evidencia sobre la calidad de vida en pacientes con OI posterior al tratamiento con bifosfonatos. ¿Los bifosfonatos mejoran la calidad de vida de los pacientes con OI? MATERIAL Y MÉTODOS: Se trata de un ensayo prospectivo, de intervención deliberada, ensayo clínico autocontrolado. Nueve pacientes que se encontraban entre las edades de dos y 13 años con diagnóstico de OI fueron tratados con ácido zolendrónico. Se realizó una medición de la calidad de vida en los pacientes previa y posteriormente. Para la medición de la calidad de vida de los pacientes utilizamos la encuesta de calidad de vida PedsQL 4.0 que fue aplicada tanto a los niños como a los padres. RESULTADOS: En la encuesta de calidad de vida efectuada a los padres se observó un incremento en las cuatro dimensiones evaluadas. En la encuesta realizada a los niños se apreció un aumento en dos dimensiones. El número de fracturas disminuyó posterior al tratamiento. CONCLUSIONES: Existe una correlación entre la disminución del número de fracturas y la percepción que tienen tanto los padres como los niños en la calidad de vida posterior al tratamiento con bifosfonatos.

Stroop interference and negative priming (NP) suppression in normal aging.

Age-related differences in the reduction of Stroop interference were explored by comparing the performance of 18 younger (of mean age: 30.0±3.9 years) and 18 older healthy adults (of mean age: 75±7.2 years) in a color-word Stroop task. The aim of this study was to determine whether a decrease in the efficiency of inhibitory mechanisms associated with aging could account for age-related differences in the ability to suppress a pre-potent response. Participants performed a Stroop task to assess Stroop interference and NP suppression concurrently. Results showed a greater Stroop interference in older than in young adults. On the other hand, the NP effect was only reliable in the younger group, the older group not showing NP suppression. These findings suggest that the slowing hypothesis alone cannot explain this pattern of results and that the age-related differences must also involve an inhibitory breakdown during aging.

[Regional effects of age and sex in magnetic resonance spectroscopy]. / Efecto regional, de la edad y el sexo en la espectroscopia por resonancia magnética cerebral.

OBJECTIVE: To determine the regional effects of age and sex on the metabolic ratios obtained in the medial temporal lobe, the posteromedial region, and the frontal lobe at 1.5 T single-voxel magnetic resonance spectroscopy. MATERIAL AND METHODS: We used single-voxel magnetic resonance spectroscopy to study the areas of the brain most affected in neurodegenerative disease (the left frontal lobe, the left medial temporal lobe, and the posteromedial region) in 31 healthy subjects older than 55 years of age (group 1) and in 20 healthy subjects under 30 years of age (group 2). We calculated the following ratios for each voxel: N-acetyl-aspartate/creatine-phosphocreatine (NAA/Cr), N-acetyl-aspartate/choline (NAA/Cho), N-acetyl-aspartate /myoinositol (NAA/mI), choline/creatine-phosphocreatine (Cho/Cr), and myoinositol (mI/Cr). We compared the metabolic ratios in each region in each group and the correlation between age and the ratios within age ranges. Finally, we analyzed the differences in the metabolic ratios between groups and between sexes. RESULTS: In group 1, we found negative correlations between age and Cho/Cr in the frontal region and NAA/mI in the temporal region. In group 2, we found negative correlations between age and mI/Cr and NAA/Cho in the temporal region as well as a positive correlation between age and NAA/mI in the temporal region. In the frontal lobe and the posteromedial region, NAA/Cr, NAA/Cho, and NAA/mI were lower in group 1 (P≤0.003). No differences between groups were seen in Cho/Cr or mI/Cr. The values of the ratios differed regionally in all cases (P<0.001). In the temporal lobe, NAA/Cr and Cho/Cr were higher in women (P≤0.034). CONCLUSIONS: When using single-voxel magnetic resonance spectroscopy, especially in patients with neurodegenerative disease, variations due to region, age, and sex should always be taken into account.

[Cerebral mechanisms of mathematical thinking]. / Mecanismos cerebrales del pensamiento matemático.

OBJECTIVE: To suggest a cerebral map of elementary mathematical thinking, and integrate the most relevant findings from neuropsychology with those from cerebral imaging techniques and cognitive behavior experiments. DEVELOPMENT: Firstly we describe investigations into our numerical sense and the way in which numerical information is represented in the human brain. Then, using a multidisciplinary approach, we present the results of different studies of Gerstmann's syndrome, regarding the relation between numerical ability and other cognitive skills; the different participation of the cerebral hemispheres and the special implication of the parietal lobe in mathematical tasks. CONCLUSIONS: Different cerebral regions are involved in doing mental arithmetic, however simple. This makes one think more in terms of cerebral circuits than in a phrenological idea which would assign the responsibility for arithmetical calculations to a specific region. The similarity between the results analysed leads us to the conclusion that one region is particularly involved in understanding numbers, namely the inferior part of the parietal lobe. Different neuronal circuits are used depending on the type of task to be performed. Finally we describe the most relevant models for the processing of numbers which have been developed during the study.

Mecanismos cerebrales del pensamiento matemático / Cerebral mechanisms of mathematical thinking

Objetivo. Ofrecer una cartografía cerebral del pensamiento matemático elemental, e integrar los resultados más relevantes procedentes del ámbito de la neuropsicología con los de las técnicas de imagen cerebral, y con aquellos obtenidos a partir de experimentos cognitivo-conductuales. Desarrollo. En primer lugar se presentan las investigaciones sobre el origen de nuestro sentido numérico y sobre la forma en la que en nuestro cerebro se representa la información numérica. A continuación, desde un enfoque multidisciplinar, se presentan resultados de distintos estudios sobre el síndrome de Gerstmann, sobre la relación entre la habilidad numérica y otras habilidades cognitivas; la diferente participación de los hemisferios cerebrales y la especial implicación del lóbulo parietal en las tareas matemáticas. Conclusiones. Al realizar cualquier tarea aritmética mental, por muy elemental que sea, intervienen distintas regiones cerebrales, hecho que nos hace pensar más en términos de circuitos cerebrales que en una idea frenológica que asigne a una determinada región la responsabilidad del cálculo aritmético. La convergencia entre los resultados analizados nos permite afirmar que una región en particular sobresale por su implicación en la comprensión del sentido numérico: la parte inferior del lóbulo parietal. Dependiendo del tipo de tarea, del input y del output, se utilizan distintos circuitos neuronales. Finalmente, se exponen los modelos de procesamiento numérico más relevantes generados a partir de toda la investigación (AU)

Stroop interference is affected in inhibition of return.

In previous research, we have shown that the processing of targets that are presented to locations subject to inhibition of return (IOR) is affected by an inhibitory tagging mechanism. This mechanism acts by disconnecting activated representations of stimuli at inhibited locations from their associated responses. In two experiments, we assessed whether this inhibitory tagging mechanism of visual attention is also applied to task-irrelevant but prepotent dimensions of target stimuli, such as words in the Stroop task. To test this hypothesis, we examined the Stroop effect in an IOR procedure. The results showed that (1) IOR can be found in a color discrimination task, (2) the Stroop interference was reduced (Experiment 1) or eliminated (Experiment 2) when stimuli appeared at cued locations, as compared with cases in which they were presented at uncued locations, and (3) the effect of inhibitory tagging was limited to the shortest stimulus onset asynchrony value, replicating previous findings. These results agree with the idea that inhibitory tagging, occurring in IOR, affects the efficiency with which color words compete for responses in Stroop-like situations.

[Selective attention deficit in schizophrenia]. / Déficit de atención selectiva en la esquizofrenia.

OBJECTIVE: To evaluate the cognitive deficits which have been linked with schizophrenia, particularly those related to selective attention from a neurocognitive point of view. DEVELOPMENT: We present a concept of attention consistent with a system of control of information processing composed of a group of neurone networks which carry out specific functions. Some functions are related to visual orientation, while others are involved in executive functions which are at the root of many cognitive skills. The convergence of data from behaviour studies and those made available by neuroimaging techniques have facilitated the identification of neuroanatomical areas responsible for these functions. Thus, the posterior parietal lobe, superior colliculus and pulvinar nucleus of the thalamus are responsible for directing visual attention to different spatial locations. The singular cortex, parts of the medial prefrontal area and supplementary motor area will be involved in executive functions. The question arises as to whether schizophrenia is related to a general attention deficit or to specific deficits linked to the different attention neurone networks. In the studies reviewed attention tasks for the evaluation of facilitatory and inhibitory functions related to the different attention networks were used. CONCLUSIONS: The studies showed that schizophrenic patients present deficits in inhibitory mechanisms which depend on the executive attention network. These results may contribute to a better understanding of the cognitive problems which occur in schizophrenia and also to design more effective strategies for the treatment of this disorder.

Inhibition of return in aging and Alzheimer's disease: performance as a function of task demands and stimulus timing.

Inhibition of return (IOR) is a phenomenon of spatial attention that biases attention toward novel events in the environment. Recent evidence suggests that the magnitude and timing of IOR varies as a function of task conditions (e.g., detection vs. discrimination tasks, short vs. long cue-target intervals, intrinsic vs. extrinsic cues). Although IOR appears relatively preserved with both normal aging and Alzheimer's disease (AD), it has been tested under relatively simple task conditions. To test whether IOR is resistant to age and / or AD when cognitive demands are increased, we employed a double-cue IOR paradigm that required categorization as well as detection responses. The stimulus onset asynchrony (SOA) between the cue and target events was varied to determine whether group differences existed in IOR effects over time. Younger normal adults and older normal adults exhibited significant IOR effects on both the detection task and the categorization task at a short cue-target SOA (950 ms). In contrast, AD patients exhibited significant IOR effects at the short SOA on the detection task but not on the categorization task. From the short to the long SOA (3500 ms), IOR effects exhibited by younger normal adults declined significantly during both the detection and the categorization tasks, suggesting that inhibition resolved over time. In contrast, neither older normal adults nor AD patients exhibited SOA-related IOR reductions on the detection task. These results suggest that IOR may show differential age- and AD-related vulnerabilities depending on task conditions and timing characteristics.

Semantic priming in the prime task effect: evidence of automatic semantic processing of distractors.

The automaticity of the semantic processing of words has been questioned because of the reduction of semantic priming when the prime word is processed nonsemantically--for example, in letter search (the prime task effect). In two experiments, prime distractor words produced semantic priming in a subsequent lexical decision task, but with the direction of priming (positive or negative) depending on the prime task. Lexico-semantic tasks produced negative semantic priming, whereas letter search produced positive semantic priming. These results are discussed in terms of task-based inhibition. We argue that, given the results from the distractors, the absence of semantic priming does not indicate an absence of semantic activation but reflects the action of control processes on prepotent responses when less practiced responses are needed.

Word-based grouping affects the prime-task effect on semantic priming.

Semantic priming between words is reduced or eliminated if a low-level task such as letter search is performed on the prime word (the prime task effect), a finding used to question the automaticity of semantic processing of words. This idea is critically examined in 3 experiments with a new design that allows the search target to occur both inside and outside the prime word. The new design produces the prime task effect (Experiment 1) but shows semantic negative priming when the target letter occurs outside the prime word (Experiments 2 and 3). It is proposed that semantic activation and priming are dissociable and that inhibition and word-based grouping are responsible for reduction of semantic priming in the prime task effect.

Inhibitory tagging in inhibition of return is affected in schizophrenia: evidence from the stroop task.

L. J. Fuentes, A. B. Vivas, and G. W. Humphreys (1999b) showed that stimulus processing is affected when stimuli are presented to locations subject to inhibition of return. They argued that activated representations of stimuli presented at inhibited locations are disconnected from their associated responses through an "inhibitory tagging" mechanism occurring in inhibition of return. In the present research, the authors asked whether such a mechanism is affected in people with schizophrenia. Healthy adults and patients with schizophrenia performed a Stroop task in an inhibition of return paradigm. Healthy adults showed a reduction in the Stroop interference when stimuli were presented at inhibited locations, a result that agrees with the inhibitory tagging mechanism hypothesis and replicates previous findings. However, patients with schizophrenia did not show such a reduction, a result suggesting that they have a deficit in inhibitory processing occurring in inhibition of return.

Inhibitory processing in visuospatial attention in healthy adults and schizophrenic patients.

This study assessed visuospatial attention in healthy adults and medicated schizophrenic patients. Participants performed a visual orientation task in which a peripheral cue was followed. at different intervals, by a target presented either at valid or invalid locations. When the long stimulus onset asynchrony (SOA) was used, participants were presented with either a single peripheral cue (single-cue condition) or two cues, the peripheral cue followed by a central cue (the double-cue condition). Healthy adults showed marginal facilitation effects with the short SOA and similar inhibition of return effects with the long SOA in both single-cue and double-cue conditions. Schizophrenic individuals showed a big facilitation effect with the short SOA and normal inhibition of return with the long SOA in both cue conditions. Results with the short SOA replicated previous findings (Huey, E.D., Wexler, B.E., 1994. Schizophrenia Research 14, 57-63) but, in contrast, we did not observe blunted inhibition of return with the long SOA. An inspection of the differences in the procedures used in both studies may help both to account for the discrepancies and to reveal what processes involved in visuospatial attention are affected in schizophrenia.

Spatial and semantic inhibitory processing in schizophrenia.

Two experiments assessed inhibitory mechanisms associated with the posterior and anterior attention networks in schizophrenia. Experiment 1 assessed the inhibition of return effect of the posterior network. Both healthy adults and schizophrenic adults showed inhibition of return, suggesting that this inhibitory mechanism of visual orienting is preserved in schizophrenia. Experiment 2 assessed semantic inhibition, which supposedly taps the anterior network, in a lexical-decision task. Healthy adults showed semantic inhibition effects in both visual fields. Schizophrenic adults showed semantic inhibition effects when targets were presented to the left visual field, involving the right hemisphere. However, semantic facilitation rather than inhibition was observed when targets were presented to the right visual field, involving the left hemisphere. These results reflect left hemisphere dysfunction associated with deficits in attentional control in schizophrenia.

Object-based perceptual grouping affects negative priming.

In 5 experiments the authors examine the role of object-based grouping on negative priming. The experiments used a letter-matching task with multiple letters presented in temporally separated prime and probe displays. On mismatch trials, distractor letters in primes were repeated as targets in probes, or distractor and target letters were completely different. Negative priming was shown by slowed responses when distractors were repeated as targets relative to when the stimuli differed. This occurred both when only letters were presented (Experiments 1 and 4) and when letters were surrounded by boxes (Experiment 5). Experiments 2, 3, and 4 showed that negative priming was affected by the grouping of target and distractor letters in prime displays. Negative priming was reduced when 1 of the distractor letters was placed in the target box and 1 was left outside the box; facilitatory priming was observed when both distractor letters appeared in the target box. The data were accounted for in terms of there being (a) object-based competition for visual selection, (b) inhibition of distractor objects that compete for selection with target objects, and (c) activation or inhibition of the identities of all component elements within target or distractor objects.

The Role of the Anterior Attention System in Semantic Processing of both Foveal and Parafoveal Words.

Abstract This research takes advantage of combined cognitive and anatomical studies to ask whether attention is necessary for high-level word processing to occur. In Experiment 1 we used a lexical decision task in which two prime words, one in the fovea and the other in the parafovea, appeared simultaneously for 150 msec, followed by a foveal target (word/nonword). Target words were semantically related either to the foveal or to the parafoveal word, or unrelated to them. In one block of trials subjects were also required to perform an auditory shadowing task. From PET studies we know that shadowing activates the anterior cingulate cortex, involved in selective attention. If the anterior attention system is always involved in semantic processing, shadowing should reduce semantic priming obtained from both foveal and parafoveal words. In contrast, if semantic priming by parafoveal words is independent of activation in that attention area, priming will not be affected by shadowing. Our results supported the latter hypothesis. A large priming effect arose from foveal primes, which was reduced by shadowing. For parafoveal primes a smaller priming effect arose, which was not affected by shadowing. In Experiment 2 prime words were masked. Semantic priming was reliable for both foveal and parafoveal words but there were then no differences between them. Most important, the size of priming was similar to that obtained from parafoveal words in Experiment 1. We conclude that the anterior attention system increases the potency of processing of consciously perceived stimuli, but there is a component of semantic priming that occurs without both focusing of attention and awareness, involving different cerebral areas to those involved in attention to language.

Facilitation and interference effects in a Stroop-like task: evidence in favor of semantic processing of parafoveally-presented stimuli.

In this study we used a modified Stroop word-color task in which the target was a centrally fixated color frame and the distractor was an incompatible, compatible or non-color word. In Experiment 1 distractors were located either within (the inside condition) or outside the frame, at distances of 1.3 deg (near-outside condition) or 2 deg (far-outside condition). In Experiment 2 only the inside and the far conditions were used. The stimuli were on the screen for 150 msec (Experiment 1) or 50 msec (Experiment 2). A non-distractor condition was also included. In Experiment 1, incompatible distractors interfered with naming target colors, and this effect disappeared when the distractor was located far from the target. However, facilitation from compatible distractors was reliable in the farther location. These results were replicated in Experiment 2. The data suggest that (1) unattended items are processed semantically; (2) that facilitation and interference from words in color naming tasks can be caused by different mechanisms; and (3) that distractors are processed differently according to whether they are near or far from fixation.