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The decline in semantic verbal fluency as we age may originate from both semantic memory degradation and executive function deficits. We investigated to what extent semantic memory is organized into categories in older adults with mild cognitive impairment (n=81) and healthy controls (n=83). We obtained the semantic networks automatically from the probability of co-occurrence of words in a verbal fluency test and characterized them with graph-theory tools. We found that the degree of categorical organization was similar for both diagnostic groups, but there was a higher tendency to transition to other categories during word production in the patient group. These results suggest that the semantic network is preserved in mild cognitive impairment, but also that the existing associations are exploited less efficiently during long-term memory search, possibly because of deficits in executive function., Ministerio de Economía y Competitividad, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Subjective cognitive decline (SCD) might represent the preclinical phase of Alzheimer’s disease. Given the interest to characterize it, the present study explores (1) if there are differences in lexical retrieval (LexR) and sentence comprehension (SComp) between SCD and matched controls, and (2) the predictive value of demographic variables and executive functions in relation to LexR and SComp in each group. A sample of 135 participants voluntarily took part in this study (66 with SCD). They all completed the Trail Making, the Stroop, the Boston Naming, and the ECCO-Senior tests, as well as verbal fluency tasks (VF). Results show that (1) groups differ in LexR and in inhibition efficiency, and (2) VF is explained by years of formal education, particularly in the control group; SComp in the most complex items seems to rely in different strategies, related to flexibility in controls and to inhibition efficiency in SCD patients., Ministerio de Economía y Competitividad, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Interindividual variability in vocabulary, sentence comprehension and working memory is studied in older people with mild cognitive impairment, very low cognitive impairment and normal state, according to the Mini Examen Cognoscitivo (MEC). In the study participated 71 seniors, aged between 62 to 90 years of age, with low instructional level (from one to five years of regular education). Variability measures were calculated in a test of lexical knowledge, another of working memory, and also in one of sentence comprehension. The results obtained using a polynomial regression analysis of the absolute residual scores on the MEC, showed that: (a) variability increases in a linear fashion as the MEC score decreases in the case of nouns, and sentences with one proposition that do not follow the canonical order of constituents in Spanish; (b) Performance on the simpler sentences (one proposition and canonical order) and in the most complex ones (two propositions and non-canonical order) variability showed a change in its trend from MEC scores that indicate cognitive deterioration; (c) In relation to performance on the verbs, variability’s change of trend is not linked to cognitive deterioration. We discuss the results in terms of the utility of these measures as potential indicators of cognitive impairment., Se estudia la variabilidad interindividual en el vocabulario, la comprensión de oraciones y la memoria operativa en personas mayores con deterioro cognitivo leve, deterioro cognitivo muy leve y normales, de acuerdo con el Mini-Examen Cognoscitivo (MEC). Participaron 71 personas mayores, de edades comprendidas entre los 62 y los 90 años de edad, con un nivel de estudios bajo (de uno a cinco años de escolaridad). Se calcularon las medidas de variabilidad interindividual en una prueba de conocimiento del léxico, otra de memoria operativa, y en una de comprensión de oraciones. Los resultados obtenidos empleando un análisis de regresión polinómica de los residuos absolutos sobre las puntuaciones del MEC, muestran: (a) que la variabilidad aumenta de forma lineal a medida que disminuye la puntuación del MEC en el caso de los sustantivos y de las oraciones de una proposición que no siguen el orden sintáctico canónico; (b) que en las oraciones más fáciles (una proposición y orden canónico) y en las más difíciles (dos proposiciones y orden no-canónico) la variabilidad muestra un cambio de tendencia a partir de puntuaciones del MEC que indican deterioro cognitivo; (c) en relación con el rendimiento ante los verbos, el cambio de tendencia que se observa en la variabilidad no está vinculado a la constatación de deterioro cognitivo. Se discuten los resultados en relación con la utilidad de estas medidas como posibles indicadores del deterioro cognitivo, Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Evidence has shown that negative distracting stimuli are most difficult to control when we are focused in a relevant task, while positive and neutral distractors might be equally overcome. Still, recent meta-analytic evidence has pointed out that differences in the ability to cope with positive or neutral distractors may be difficult to detect in healthy people and in laboratory sets. Here we re-analyse memory performance in four already published working memory experiments in which affective and non-affective distractors were used. We focused on the positive versus neutral contrast, which did not reveal differences in the original analysis, with the aim of quantifying evidence for the null hypothesis using a Bayesian approach. Bayes factor (BF) estimates show substantial evidence in favour to the absence of differences in three out of four datasets. Further, BF aggregated from the four studies shows stronger evidence for the null hypothesis. Results from this analysis show that WM performance after positive and neutral interference can be considered equivalent, suggesting that positive distractors can be overcome to the same extent as neutral ones., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Background music is a part of our everyday activities. Considerable evidence suggests that listening to music while performing cognitive tasks may negatively influence performance. However, other studies have shown that it can benefit memory when the music played during the encoding of information is also provided during the retrieval of that information, in the so called context dependent memory effect. Since controversial results may be attributed to the nature of the material to be memorized, the aim of the present study is to compare the potential effect of consistent background music on the immediate and long-term recall of verbal and visuospatial information. Experiment 1 showed that instrumental background music does not benefit nor decrease recall of a list of unrelated words, both at the immediate and the 48-hours-delayed tests. By contrast, Experiment 2 revealed that the same background music can impair immediate, and therefore long-term memory for visuospatial information. Results are interpreted in terms of competition for neurocognitive resources, with tasks mostly relying on the same brain hemisphere competing for a limited set of resources. Hence, background music might impair visuospatial memory to a greater extent than verbal memory, in the context of limited capacity cognitive system. In conclusion, the nature of the material to be learnt must be considered to fully understand the effect of background music on memory., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Introducción y objetivo. El análisis cuantitativo y cualitativo de la tarea de fluidez verbal semántica ha permitido observar que las personas con demencia producen menos palabras y en grupos más pequeños que las personas sin demencia. Sin embargo, en personas con deterioro cognitivo leve de tipo amnésico (DCLa) la investigación ha mostrado resultados contradictorios respecto a la cantidad y el número de los agrupamientos semánticos que se realizan. El objetivo de este estudio consistió en aportar nuevos datos para intentar solventar dicha controversia. Sujetos y métodos. Participaron en el estudio 22 personas mayores con diagnóstico de DCLa (8 varones y 14 mujeres) y 43 adultos mayores (7 varones y 36 mujeres) con funcionamiento cognitivo normal que sirvieron de grupo control. Todos fueron evaluados en el Centro de Prevención del Deterioro Cognitivo del Ayuntamiento de Madrid, tras completar la prueba de fluidez verbal de animales además de otras pruebas neuropsicólogicas. Resultados. Como se esperaba, la producción de animales fue menor en el grupo DCLa que en el grupo control, pero no se observaron diferencias ni en el tamaño medio de las agrupaciones semánticas ni en el número de cambios entre dichas agrupaciones. Conclusiones. Los resultados son coherentes con investigaciones previas que sugieren que en el DCLa no sólo concurren déficits en la memoria episódica y la memoria operativa, sino también en la memoria semántica. Sin embargo, los datos no aclaran el papel de los procesos ejecutivos estratégicos, como parece suceder en la enfermedad de Alzheimer., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

During sentence processing there is a preference to treat the first noun phrase found as the subject and agent, unless marked the other way. This preference would lead to a conflict in thematic role assignment when the syntactic structure conforms to a non-canonical object-before-subject pattern. Left perisylvian and fronto-parietal brain networks have been found to be engaged by increased computational demands during sentence comprehension, while event-reated brain potentials have been used to study the on-line manifestation of these demands. However, evidence regarding the spatiotemporal organization of brain networks in this domain is scarce. In the current study we used Magnetoencephalography to track spatiotemporally brain activity while Spanish speakers were reading subject- and object-first cleft sentences. Both kinds of sentences remained ambiguous between a subject-first or an object-first interpretation up to the appearance of the second argument. Results show the time-modulation of a frontal network at the disambiguation point of object-first sentences. Moreover, the time windows where these effects took place have been previously related to thematic role integration (300–500 ms) and to sentence reanalysis and resolution of conflicts during processing (beyond 500mspost-stimulus). These results point to frontal cognitive control as a putative key mechanism which may operate when a revision of the sentence structure and meaning is necessary., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub

Neuropsychological tests have commonly been used to determine the organization of cognitive functions by identifying latent variables. In contrast, an approach which has seldom been employed is network analysis. We characterize the network structure of a set of representative neuropsychological test scores in cognitively healthy older adults and MCI and dementia patients using network analysis. We employed the neuropsychological battery from the National Alzheimer’s Coordinating Center which included healthy controls (n=7623), mild cognitive impairment patients (n=5981) and dementia patients (n=2040), defined according to the Clinical Dementia Rating. The results showed that, according to several network analysis measures, the most central cognitive function is executive function followed by language, attention, and memory. At the test level, the most central test was the Trail Making Test B, which measures cognitive flexibility. Importantly, these results and most other network measures, such as the community organization and graph representation, were similar across the three diagnostic groups. Therefore, network analysis can help to establish a ranking of cognitive functions and tests based on network centrality and suggests that this organization is preserved in dementia. Central nodes might be particularly relevant both from a theoretical and clinical point of view, as they are more associated with other nodes, and their disruption is likely to have a larger effect on the overall network than peripheral nodes. The present analysis may provide a proof of principle for the application of network analysis to cognitive data., Depto. de Psicología Experimental, Procesos Cognitivos y Logopedia, Fac. de Psicología, TRUE, pub