Nuestros investigadores

Martín Martínez Villar

Departamento
Teoría y Métodos de Investigación Educativa y Psicológica
Facultad de Educación y Psicología. Universidad de Navarra
Líneas de investigación
Control Motor, Metodología del comportamiento, Neurociencia y cognición, Análisis estadístico, Diseño experimental, Validación de instrumentos de medidas psicológicas
Índice H
6, (Google Scholar, 09/06/2020)
6, (Scopus, 09/06/2020)

Publicaciones científicas más recientes (desde 2010)

Autores: Balaguer Estaña, Alvaro J.; Martínez Villar, Martín; Naval, Concepción
Revista: REVISTA PANAMERICANA DE PEDAGOGIA
ISSN 1665-0557  Nº 30  2020  págs. 54-72
Resumen Las vivencias de los adolescentes en los centros educativos son determinantes en su rendimiento académico y adaptación al mismo. Este artículo compara las diferencias en torno a la percepción del clima y funcionamiento del centro según curso, edad, sexo, titularidad y ámbito del centro y rendimiento académico. El estudio analiza las diferencias en una muestra de 1208 estudiantes adolescentes sobre la escala de Percepción del Clima y Funcionamiento del Centro (PCFC), y las dimensiones que la conforman. Estas dimensiones son clima, vínculo con el centro, claridad de normas y valores, y empoderamiento y oportunidades. Entre los resultados se hallaron diferencias significativas en la escala PCFC en función del curso, edad, sexo, tipo de centro y rendimiento académico. Se observa en las mujeres, una mejor percepción en las dimensiones de Vínculo y Claridad de las normas del centro educativo. La percepción global del centro disminuye con el aumento del nivel educativo y de la edad, pero aumenta con mayor rendimiento académico y en centros de titularidad privada-concertada frente a la pública. Con base en los hallazgos, proporcionamos orientaciones para centros y elaboradores de políticas educativas. A lo largo de la adolescencia, los estudiantes requieren mayor responsabilidad y participación en la toma de decisiones del centro educativo, así como que este les proporciones mayores oportunidades para su desarrollo. Abstract The experiences of adolescents in schools are decisive for their academic achievement and adaptation. This article compares the differences around the perception of the climate and school functioning according to the educational level, age, sex, ownership and school location, and academic achievement. In this article, the differences in a sample of 1208 adolescent students on the Scale of Climate Perception and School Functioning (PCFC) and their dimensions are analyzed. These dimensions are climate, school bonds, clarity of norms and values, and empowerment, and opportunities. Significant differences are found in the PCFC scale depending on the course, age, sex, type of center, and academic performance. Bonds and Clarity are better observed in women. The overall perception of the school decreases with the increase in educational level and age, but increases with greater academic achievement, as well as in schools of private ownership over the public. From the findings, we provide guidelines for schools and educational policymakers. Throughout adolescence, students claim for greater responsibility and participation in the decision making of the school, as well as providing them with greater opportunities for their development.
Autores: Zarraluqui López, Silvia; Martínez Villar, Martín; Pastor, María A.
Revista: CURRENT PSYCHOLOGY
ISSN 1046-1310  2019  págs. 1 - 9
This study presents a short and valid questionnaire for evaluating Facebook usage by the Spanish-speaking population. In order to achieve this aim, the Facebook scales developed by Ellison and collaborators (i.e., Facebook Intensity, Actual Friends, Connection Strategies, and Relationship Maintenance Behavior) were translated into Spanish and then grouped into a 31-item questionnaire: the Spanish Facebook Battery (SFB). Subsequently, the reliability and construct validity of the SFB was tested once administered to a sample of Spanish speakers (N=433) by means of an exploratory factor analysis (EFA) with iterated principal axis factoring and Promax rotation methods. The SFB showed high internal (¿=.89) and acceptable retest (¿=.65) reliability whereas the EFA indicated the retention of five dimensions that explained 89% of the total variance in this sample data. A main dimension related to Facebook Intensity was found to account for almost half of the total variance, whereas the other four dimensions were found to be associated with Online Connection Strategies, Relationship Maintenance Behaviors, Maintaining Connection Strategies, and Offline Connection Strategies. Therefore, the factor analysis returned a dimensional structure of the SFB that differed slightly from the original scales composition, stressing the difference between online and offline connection strategies in this population sample. In summary, this article proposes a short and valid tool which could be useful for assessing Facebook usage among Spanish-speakers. https://rdcu.be/bnCtQ
Autores: Bernácer María, Javier (Autor de correspondencia); Martínez Valbuena, Iván; Martínez Villar, Martín; et al.
Revista: CORTEX
ISSN 0010-9452  Vol. 113  2019  págs. 96-110
According to the theory of value-based decision making, subjects tend to choose the most valuable among a set of options. However, agents may not be consistent when facing the same decision several times. In this paper, Shannon¿s entropy (H) is employed as a measure of behavioral inconsistency: it is a central measure of information theory that, applied to decision making, allows the estimation of behavioral preferences among a set of options. We scanned (functional magnetic resonance imaging, fMRI) 24 young (18-25 year) subjects (14 female) while performing a decision-making task, where monetary rewards were devalued by physical effort (minutes running in the treadmill) and risk. Twenty different pairs of options were presented nine times each, and H was calculated for each pair and subject. Behavioral analyses showed that subjective value (SV) significantly explained agents¿ preferences only in pairs with a low inconsistent response. Averaged response time positively correlated with H, confirming entropy as an indicator of choice difficulty. Group analyses on fMRI data revealed a cluster in the paracingulate cortex as the neural correlate of H. Besides, BOLD signal in the posterior cingulate correlated with the SV of the pair only in consistent decisions, confirming that SV loses its explanatory power on highly inconsistent decisions. Finally, the anterior and central cingulate were especially recruited when predicting a secured effortless reward, compared with a secured re
Autores: Bernácer María, Javier (Autor de correspondencia); Martínez Valbuena, Iván; Martínez Villar, Martín; et al.
Revista: NEUROIMAGE
ISSN 1053-8119  Vol. 203  2019 
When humans make decisions, objective rewards are mainly discounted by delay, risk and effort. Whereas recentresearch has demonstrated that several brain areas process costs and code subjective value in effort-based decisionmaking, it remains obscure how neural activity patterns change when effort costs are reduced due to theacquisition of healthy habits, such as moving from sedentary to active lifestyles. Here, a sample of sedentaryvolunteers was behaviorally assessed and fMRI-scanned before and after completing a 3-monthfitness plan. Theimpact of effort cost on decisions, measured as the constant defining a hyperbolic decaying function, was reducedafter the plan. A logistic mixed model demonstrated that the explanatory power of effort decreased with time. At aneural level, there was a marginally significant disruption of effort-cost related functional activity in the anteriorcingulate after the plan. Functional connectivity between the amygdala and anterior cingulate cortex wasstrengthened after habit acquisition. In turn, this interaction was stronger in those participants with lower effortdiscounting. Thus, we show for thefirst time changes in value-based decision making after moving from asedentary to an active lifestyle, which points to the relevance of the amygdala-cingulate interplay when theimpact of effort on decisions fades away.
Autores: Ariz Galilea, Mikel; Abad, R. C. ; Castellanos, G. ; et al.
Revista: IEEE TRANSACTIONS ON MEDICAL IMAGING
ISSN 0278-0062  Vol. 38  Nº 3  2019  págs. 813 - 823
We present a dynamic atlas composed of neuromelanin-enhancedmagnetic resonance brain images of 40 healthy subjects. The performance of this atlas is evaluated on the fully automated segmentation of two paired neuromelanin-rich brainstem healthy structures: the substantia nigra pars compacta and the locus coeruleus. We show that our dynamic atlas requires in average 60% less images and, therefore, 60% less computation time than a static multi-image atlas while achieving a similar segmentation performance. Then, we show that by applying our dynamic atlas, composed of healthy subjects, to the segmentation and neuromelanin quantification of a set of brain images of 39 Parkinson disease patients, we are able to find significant quantitative differences in the level of neuromelanin between healthy subjects and Parkinson disease patients, thus opening the door to the use of these structures as image biomarkers in future computer aided diagnosis systems for the diagnosis of Parkinson disease.
Autores: de Andres-Nogales, F.; Casado, M. A.; Zarranz-Ventura, J.; et al.
Revista: VALUE IN HEALTH
ISSN 1098-3015  Vol. 22  Nº Supl. 3  2019  págs. S889
Autores: Martínez Villar, Martín; Villagra Poviña, Federico; Castellote, J. M.; et al.
Revista: SENSORS
ISSN 1424-8220  Vol. 18  Nº 12  2018  págs. 4224
The aim of this study is to compare the properties of free-walking at a natural pace between mild Parkinson¿s disease (PD) patients during the ON-clinical status and two control groups. In-shoe pressure-sensitive insoles were used to quantify the temporal and force characteristics of a 5-min free-walking in 11 PD patients, in 16 young healthy controls, and in 12 age-matched healthy controls. Inferential statistics analyses were performed on the kinematic and kinetic parameters to compare groups¿ performances, whereas feature selection analyses and automatic classification were used to identify the signature of parkinsonian gait and to assess the performance of group classification, respectively. Compared to healthy subjects, the PD patients¿ gait pattern presented significant differences in kinematic parameters associated with bilateral coordination but not in kinetics. Specifically, patients showed an increased variability in double support time, greater gait asymmetry and phase deviation, and also poorer phase coordination. Feature selection analyses based on the ReliefF algorithm on the differential parameters in PD patients revealed an effect of the clinical status, especially true in double support time variability and gait asymmetry. Automatic classification of PD patients, young and senior subjects confirmed that kinematic predictors produced a slightly better classification performance than kinetic predictors. Overall, classification accuracy of groups with a linear discriminant model which included the whole set of features (i.e., demographics and parameters extracted from the sensors) was 64.1%.
Autores: Eudave Ramos, Luis Humberto; Martínez Villar, Martín; Luis García, Elkin Oswaldo; et al.
Revista: HUMAN BRAIN MAPPING
ISSN 1065-9471  Vol. 39  Nº 11  2018  págs. 4196 - 4212
Numerous daily tasks, including car driving, require fine visuospatial tuning. One such visuospatial ability, speed discrimination, declines with aging but its neural underpinnings remain unknown. In this study, we use fMRI to explore the effect of aging during a high speed discrimination task and its neural underpinnings, along with a complete neuropsychological assessment and a simulated driving evaluation in order to examine how they interact with each other through a multivariate regression approach. Beyond confirming that high speed discrimination performance is diminished in the elderly, we found that this deficit might be partly due to a lack of modulation in the activity and connectivity of the default mode network (DMN) in this age group, as well as an over-recruitment of frontoparietal and cerebellar regions, possibly as a compensatory mechanism. In addition, younger adults tended to drive at faster speeds, a behavior that was associated to adequate DMN dynamics and executive functioning, an effect that seems to be lost in the elderly. In summary, these results reveal how age-related declines in fine visuospatial abilities, such as high speed discrimination, were distinctly mediated by DMN functioning, a mechanism also associated to speeding behavior in a driving simulator.
Autores: Martínez Villar, Martín; Villagra Poviña, Federico; Castellote, J. M.; et al.
Revista: SENSORS
ISSN 1424-8220  Vol. 18  Nº 12  2018  págs. 4224
The aim of this study is to compare the properties of free-walking at a natural pace between mild Parkinson's disease (PD) patients during the ON-clinical status and two control groups. In-shoe pressure-sensitive insoles were used to quantify the temporal and force characteristics of a 5-min free-walking in 11 PD patients, in 16 young healthy controls, and in 12 age-matched healthy controls. Inferential statistics analyses were performed on the kinematic and kinetic parameters to compare groups' performances, whereas feature selection analyses and automatic classification were used to identify the signature of parkinsonian gait and to assess the performance of group classification, respectively. Compared to healthy subjects, the PD patients' gait pattern presented significant differences in kinematic parameters associated with bilateral coordination but not in kinetics. Specifically, patients showed an increased variability in double support time, greater gait asymmetry and phase deviation, and also poorer phase coordination. Feature selection analyses based on the ReliefF algorithm on the differential parameters in PD patients revealed an effect of the clinical status, especially true in double support time variability and gait asymmetry. Automatic classification of PD patients, young and senior subjects confirmed that kinematic predictors produced a slightly better classification performance than kinetic predictors. Overall, classification accuracy of groups with a linear discriminant model which included the whole set of features (i.e., demographics and parameters extracted from the sensors) was 64.1%.
Autores: Eudave Ramos, Luis Humberto; Martínez Villar, Martín; Luis García, Elkin Oswaldo; et al.
Revista: HUMAN BRAIN MAPPING
ISSN 1065-9471  Vol. 39  Nº 11  2018  págs. 4196 - 4212
Numerous daily tasks, including car driving, require fine visuospatial tuning. One such visuospatial ability, speed discrimination, declines with aging but its neural underpinnings remain unknown. In this study, we use fMRI to explore the effect of aging during a high speed discrimination task and its neural underpinnings, along with a complete neuropsychological assessment and a simulated driving evaluation in order to examine how they interact with each other through a multivariate regression approach. Beyond confirming that high speed discrimination performance is diminished in the elderly, we found that this deficit might be partly due to a lack of modulation in the activity and connectivity of the default mode network (DMN) in this age group, as well as an over-recruitment of frontoparietal and cerebellar regions, possibly as a compensatory mechanism. In addition, younger adults tended to drive at faster speeds, a behavior that was associated to adequate DMN dynamics and executive functioning, an effect that seems to be lost in the elderly. In summary, these results reveal how age-related declines in fine visuospatial abilities, such as high speed discrimination, were distinctly mediated by DMN functioning, a mechanism also associated to speeding behavior in a driving simulator.
Autores: Anguiano Salcedo, María; Morales Urteaga, Xabier; Ariz Galilea, Mikel; et al.
Revista: CANCER RESEARCH
ISSN 0008-5472  Vol. 78  Nº 13 Supl.  2018  págs. 178 - 178
Autores: Eudave Ramos, Luis Humberto; Aznárez Sanado, Maite; Luis García, Elkin Oswaldo; et al.
Revista: BRAIN IMAGING AND BEHAVIOR
ISSN 1931-7557  Vol. 11  Nº 4  2017  págs. 986 - 997
Previous research on motor sequence learning (MSL) in the elderly has focused mainly on unilateral tasks, even though bilateral coordination might be impaired in this age group. In this fMRI study, 28 right-handed elderly subjects were recruited. The paradigm consisted of a Novel and a simple Control sequence executed with the right (R), left (L) and both hands (B). Behavioral performance (Accuracy[AC], Inter-tap Interval[ITI]) and associated brain activity were assessed during early learning. Behavioral performance in the Novel task was similar between unilateral conditions whereas in the bimanual condition more errors and slower motor execution were observed. Brain activity increases during learning showed differences between Conditions: R showed increased activity in pre-SMA, basal ganglia and left hippocampus while B showed activity increments mainly in posterior parietal cortex and cerebellum. L did not show any activity modulation during learning. Performance correlates for AC (related to spatial success) and ITI (related to accurate timing) shared a cortico-basal-cerebellar network. However, it was found that the ITI regressor presented additional significant correlations with activity in SMA and basal ganglia in R. The AC regressor showed additional significant correlations with activity in more extended thalamic and cerebellar areas in B. The present findings suggest that, behaviorally, the spatial and temporal components of MSL are impaired in elderly subjects when using both hands. Additionally, differential brain activity patterns were found across hand modalities. The results obtained reveal the existence of a highly specialized network in the dominant hand and identify areas specifically involved in bimanual coordination.
Autores: Martínez Villar, Martín; Valencia Ustárroz, Miguel; Vidorreta Diaz de Cerio, Marta; et al.
Revista: HUMAN BRAIN MAPPING
ISSN 1065-9471  Vol. 37  Nº 5  2016  págs. 1722 - 1737
The central nervous system has the ability to adapt our locomotor pattern to produce a wide range of gait modalities and velocities. In reacting to external pacing stimuli, deviations from an individual preferred cadence provoke a concurrent decrease in accuracy that suggests the existence of a trade-off between frequency and precision; a compromise that could result from the specialization within the control centers of locomotion to ensure a stable transition and optimal adaptation to changing environment. Here, we explore the neural correlates of such adaptive mechanisms by visually guiding a group of healthy subjects to follow three comfortable stepping frequencies while simultaneously recording their BOLD responses and lower limb kinematics with the use of a custom-built treadmill device. In following the visual stimuli, subjects adopt a common pattern of symmetric and anti-phase movements across pace conditions. However, when increasing the stimulus frequency, an improvement in motor performance (precision and stability) was found, which suggests a change in the control mode from reactive to predictive schemes. Brain activity patterns showed similar BOLD responses across pace conditions though significant differences were observed in parietal and cerebellar regions. Neural correlates of stepping precision were found in the insula, cerebellum, dorsolateral pons and inferior olivary nucleus, whereas neural correlates of stepping stability were found in a distributed network, suggesting a transition in the control strategy across the stimulated range of frequencies: from unstable/reactive at lower paces (i.e., stepping stability managed by subcortical regions) to stable/predictive at higher paces (i.e., stability managed by cortical regions).
Autores: Luis García, Elkin Oswaldo; Arrondo Ostíz, Gonzalo; Vidorreta Diaz de Cerio, Marta; et al.
Revista: PLOS ONE
ISSN 1932-6203  Vol. 10  Nº 7  2015  págs. e0131536
BACKGROUND: Imaging studies help to understand the evolution of key cognitive processes related to aging, such as working memory (WM). This study aimed to test three hypotheses in older adults. First, that the brain activation pattern associated to WM processes in elderly during successful low load tasks is located in posterior sensory and associative areas; second, that the prefrontal and parietal cortex and basal ganglia should be more active during high-demand tasks; third, that cerebellar activations are related to high-demand cognitive tasks and have a specific lateralization depending on the condition. METHODS: We used a neuropsychological assessment with functional magnetic resonance imaging and a core N-back paradigm design that was maintained across the combination of four conditions of stimuli and two memory loads in a sample of twenty elderly subjects. RESULTS: During low-loads, activations were located in the visual ventral network. In high loads, there was an involvement of the basal ganglia and cerebellum in addition to the frontal and parietal cortices. Moreover, we detected an executive control role of the cerebellum in a relatively symmetric fronto-parietal network. Nevertheless, this network showed a predominantly left lateralization in parietal regions associated presumably with an overuse of verbal storage strategies. The differential activations between conditions were stimuli-dependent and were located in sensory areas. CONCLUSION: Successful WM processes in the elderly population are accompanied by an activation pattern that involves cerebellar regions working together with a fronto-parietal network.
Autores: Martínez Villar, Martín; Villagra Poviña, Federico; Loayza Paredes, Francis Roderich; et al.
Revista: IEEE TRANSACTIONS ON MEDICAL IMAGING
ISSN 0278-0062  Vol. 33  Nº 5  2014  págs. 1044 - 1053
Repetitive and alternating lower limb movements are a specific component of human gait. Due to technical challenges, the neural mechanisms underlying such movements have not been previously studied with functional magnetic resonance imaging. In this study, we present a novel treadmill device employed to investigate the kinematics and the brain activation patterns involved in alternating and repetitive movements of the lower limbs. Once inside the scanner, 19 healthy subjects were guided by two visual cues and instructed to perform a motor task which involved repetitive and alternating movements of both lower limbs while selecting their individual comfortable amplitude on the treadmill. The device facilitated the performance of coordinated stepping while registering the concurrent lower-limb displacements, which allowed us to quantify some movement primary kinematic features such as amplitude and frequency. During stepping, significant blood oxygen level dependent signal increases were observed bilaterally in primary and secondary sensorimotor cortex, the supplementary motor area, premotor cortex, prefrontal cortex, superior and inferior parietal lobules, putamen and cerebellum, regions that are known to be involved in lower limb motor control. Brain activations related to individual adjustments during motor performance were identified in a right lateralized network including striatal, extrastriatal, and fronto-parietal areas.
Autores: Garcia Barroso, Carolina; Ugarte, A.; Martínez Villar, Martín; et al.
Revista: JOURNAL OF ALZHEIMERS DISEASE
ISSN 1387-2877  Vol. 42   Nº Suppl. 4  2014  págs. S561 - S573
Understanding the cellular and molecular processes involved in learning and memory will help in the development of safe and effective cognitive enhancers. The cAMP response element-binding (CREB) may be a universal modulator of processes required for memory formation, and increasing the levels of second messengers like cAMP and cGMP could ultimately lead to CREB activation. Phosphodiesterase (PDE) inhibitors regulate signaling pathways by elevating cAMP and/or cGMP levels, and they have been demonstrated to improve learning and memory in a number of rodent models of impaired cognition. The aim of this review is to summarize the outstanding progress that has been made in the application of PDE inhibitors for memory dysfunction. In addition, we have introduced some recent data we generated demonstrating that tadalafil could be considered as an optimal candidate for drug re-positioning and as a good candidate to enhance cognition.

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Máxima cualificación en el TFG de Ingeniería Técnica de Telecomunicaciones, en el TFG de Ingeniería de Telecomunicaciones, y en el la defensa de la Tesis Doctoral (Sobresaliente - CUM LAUDE).