Investigación

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http://hdl.handle.net/20.500.14454/10

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Examinando Investigación por Materia "Actividad cerebral"

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  • Miniatura
    Ítem
    Effects of non-invasive brain stimulation on foreign language learning processes
    (Universidad de Deusto, 2024-01-12) Balboa Bandeira, Yolanda; Peña Lasa, Javier; Zubiaurre Elorza, Leire; Facultad de Ciencias de la Salud
    La estimulación eléctrica transcraneal (tES) es un tipo de técnica de estimulación cerebral no invasiva (NIBS) que modula la actividad neuronal mediante la aplicación de una corriente eléctrica débil. En los últimos años, su aplicación ha aumentado significativamente, y se ha utilizado para mejorar diferentes dominios cognitivos como el lenguaje en adultos sanos. En concreto, se han realizado numerosos estudios sobre los efectos de la tES en diferentes habilidades lingüísticas (por ejemplo, fluidez verbal, denominación de imágenes, lectura de palabras) en muestras sanas. Sin embargo, hasta la fecha se han llevado a cabo pocas investigaciones sobre los efectos de la tES en los procesos implicados en el aprendizaje otros idiomas, y los resultados siguen sin estar claros. Asimismo, el uso de un único tipo de tES y un solo montaje de electrodos es habitual en los estudios sobre el lenguaje, cuando se dispone de otras técnicas y montajes de electrodos, escasamente investigados en el lenguaje. La presente tesis se compone de tres contribuciones científicas. El primer estudio cuantificó los efectos de la tES en los procesos de aprendizaje de otros idiomas (nopalabras, gramática artificial y lenguas extranjeras) mediante una revisión sistemática y un meta-análisis. El segundo estudio comparó los efectos de tres tipos diferentes de tES y analizó si la tES mejora los procesos de aprendizaje de otros idiomas. Y el tercer estudio pretendía explorar los efectos de la estimulación transcraneal de ruido aleatorio (tRNS) sobre la fluidez verbal en individuos multilingües sanos (en tres idiomas diferentes: español, euskera e inglés). Los resultados del estudio I mostraron que la tES tenía un efecto moderado de mejora inmediata en el aprendizaje general de idiomas, pero que no se mantenía a largo plazo. Además, el metaanálisis informó de que los efectos de mejora de la tES estaban moderados significativamente por los años de educación. En el estudio II se observó una precisión de aprendizaje significativamente mayor tras la aplicación de tRNS en comparación con el placebo y los otros tipos de tES, pero sólo tras dos semanas de estimulación; sin que se observaran diferencias entre las técnicas de estimulación de forma inmediata. En el estudio III los resultados revelaron un rendimiento notablemente mejor por parte de los participantes que recibieron tRNS en las tareas de fluidez verbal fonémica en español e inglés. Sin embargo, no se encontraron diferencias entre las condiciones en las tareas de fluidez verbal en euskera. En conclusión, los resultados sugieren que la tES parece potenciar los mecanismos implicados en el aprendizaje de otros idiomas y facilitar habilidades lingüísticas como la fluidez verbal en personas multilingües. También se ha descubierto que, entre los diferentes tipos de tES, la tRNS podría ser útil para potenciar los procesos implicados en el aprendizaje de vocabulario en otros idiomas y que, aplicado al córtex prefrontal izquierdo, podría ayudar a mejorar la fluidez fonémica, aunque no la semántica, en adultos multilingües sanos. En conjunto, estos resultados aportan datos basados en la evidencia sobre el potencial de la tES aplicada en procesos de aprendizaje de idiomas en poblaciones sanas, pero también indican la gran necesidad de seguir investigando para comprender el alcance y el impacto de estas técnicas en los procesos de aprendizaje de otras lenguas.
  • Miniatura
    Ítem
    Preterm birth and early life development: the influence of neuropsychology, brain and social factors
    (Universidad de Deusto, 2024-01-22) Fernández de Gamarra Oca, Lexuri; Zubiaurre Elorza, Leire; Ojeda del Pozo, Natalia; Facultad de Ciencias de la Salud
    Preterm birth (PB) alters brain development influenced by neurological damage, environmental circumstances, and the timing of their occurrence. Based on weeks of gestation, there are newborns considered moderate and late preterm (MLPT) who are born between 32 to 36 weeks of gestation. This group is of increasing interest as it comprises more than 84% of all PBs. However, there is a paucity of research converging neurodevelopmental outcomes in well-characterized samples in terms of clinical manifestations at birth, which would allow researchers to assess the effect of PB per se and brain injury on cognition and cerebral development. Especially, considering that only a small percentage of MLPT children present a profile of developmental difficulties close in phenotype to those born at a lower gestational age. Nevertheless, the existing neurodevelopmental consequences may contribute to lower education, employment status and income during adulthood in this population, leading to decreased well-being and poorer mental and physical health. Aside from the presence or absence of neonatal brain injury, some environmental factors may also place PB at even greater risk for adverse long-term development. This thesis is composed of six studies and analyzes PB taking into account different degrees of neonatal immaturity, with the first two studies focusing on childhood and the following four on adolescence and young adulthood. More specifically, it addresses the impact of PB on the neuropsychological profiles of preterm born children, adolescents and young adults according to their clinical manifestations at birth. On the other hand, it assesses the potential role of early life environmental factors on cognitive development, such as socioeconomic status, parental bonding, and adverse childhood experiences. In turn, a systematic review and meta-analysis is conducted with the aim of gaining insight into the long-term neurodevelopmental outcomes of MLPT adults in relation to cognitive functioning and psychiatric disorders. Finally, it studies the brain after PB at different developmental stages, with special emphasis on the hippocampus and amygdala taking into account the importance of both structures on cognition and social-emotional outcomes. These studies mentioned here provide different neuropsychological profiles and brain indicators in the prognosis of short- and long-term development of PB. For instance, children, adolescents, and young adults born prematurely, with or without neonatal brain injury, continued to lag behind their full-term peers in a variety of cognitive domains. However, the effects of MLPT on psychiatric illnesses are frequently small during adolescence and adulthood, even none regarding social-emotional problems at different developmental stages. At brain level, in the absence of neonatal brain injury, differences in normative structural brain development and regional white matter microstructure were found during young adulthood. Moreover, increased functional connectivity was also displayed in brain areas related to social-emotional outcomes. Although much work remains to be done regarding the inclusion of neuropsychological and brain adverse outcomes in PB care, the present thesis suggests that the use of standardized long-term follow-up may be potentially useful, even at a lower risk for developing negative developmental consequences, without ignoring the impact of different environmental factors during the first years of life.
  • Miniatura
    Ítem
    Structural and functional brain changes of cognitive and other non-motor dysfunctions in idiopathic and genetic Parkinson’s disease
    (Universidad de Deusto, 2020-01-22) Lucas Jiménez, Olaia; Ibarretxe Bilbao, Naroa; Facultad de Psicología y Educación; Programa de Doctorado en Psicología por la Universidad de Deusto
    Parkinson’s disease (PD) is the second most frequent neurodegenerative disease in our environment, affecting more than 300.000 people in Spain, more than 8.000 in the Basque Country, and 4.500 people approximately in Biscay. In addition, several studies have shown the socio-health impact of PD, both in terms of lower labor productivity and lower quality of life. PD is characterized by motor symptoms mainly, however, it also entails other alterations, such as visual hallucinations, mood disorders, sleep disturbances and cognitive dysfunction. In 30% of patients with PD, a deterioration of certain cognitive functions can be observed from the initial stages of the disease. These symptoms increase as the disease progresses, damaging many aspects of patients' daily lives and reducing their quality of life. Studies also show that 80% of PD patients with cognitive impairment develop dementia. In 2004, the team led by Dr. Zarranz and Dr. Gómez-Esteban described for the first time a mutation in the alpha-synuclein gene (E46K-SNCA) in a family from the Basque Country. This mutation induces a disease in the brain by Lewy bodies (the pathological paradigm of idiopathic PD) and also has a clinical phenotype superposable to more aggressive forms of PD, including early cognitive impairment and visuospatial disorders, therefore, is an excellent genetic model of idiopathic PD. This thesis is composed by five scientific contributions, and is an attempt to characterize the pattern of brain damage underlying cognitive impairments and other non-motor dysfunctions in PD through advanced neuroimaging techniques. Firstly, the first study aimed to investigate the neuroanatomical and neurofunctional correlates of verbal memory deficit in PD patients. The second study assessed the functional connectivity within the default mode network (DMN), and the cognitive and brain correlates of the disrupted DMN functional connectivity in PD. The third study evaluated frontal, striatal and limbic brain changes and correlates of apathy in PD patients. The fourth study investigated the classification of Lewy body diseases with a comprehensive set of non-motor features including an extensive cognitive evaluation. Finally, the fifth study assessed structural and resting-state functional connectivity brain differences in Lewy body diseases based on severity of non-motor symptoms. Results revealed verbal memory deficit in PD that was related to white matter alterations in anterior cingulate and to lower brain activation in orbitofrontal regions. Structural-functional relationship underlying verbal memory deficit was also found in PD. In addition, a disruption between posterior and temporal regions within the DMN was exhibited in PD patients, even after controlling for grey matter atrophy. The disrupted DMN functional connectivity is accompanied by lower performance in verbal and visual memory, and visual abilities. Moreover, PD patients with high apathy symptoms showed fronto-striatal and fronto-limbic disruption, while PD patients with low apathy symptoms showed fronto-limbic disruption but fronto-striatal hyperconnectivity. Finally, the clinical picture of severe Lewy body diseases and most affected idiopathic PD patients is characterized by a rapidly evolving cognitive impairment that initiates in the early phase of the development of motor symptoms, and by grey matter atrophy in temporal and parietal areas, white matter alterations in corpus callosum and anterior thalamic radiation, and functional connectivity reductions between language network and dorsal-attentional and salience networks. The characterization of the pattern of brain damage of cognitive and other nonmotor features by neuroimaging and the comparison with those observed in idiopathic forms of Lewy body diseases has an invaluable utility to improve our understanding of the pathophysiology of nervous system in PD. Moreover, it could help clinicians and researchers to identify prognostic biomarkers in this disease when tested longitudinally, which in turn may support the development of effective and more personalized treatment strategies and the accuracy of diagnosis for PD patients.