Martín Martínez | Universidad de Navarra (original) (raw)
Papers by Martín Martínez
PLOS ONE, 2015
Background Imaging studies help to understand the evolution of key cognitive processes related to... more 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 highdemand 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.
Sensors, 2018
The aim of this study is to compare the properties of free-walking at a natural pace between mild... more 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 de...
Fi in ni it te e e el le em me en nt t m mo od de el li in ng g o of f t th he e m ma ag gn ne et... more Fi in ni it te e e el le em me en nt t m mo od de el li in ng g o of f t th he e m ma ag gn ne et ti ic c f fi ie el ld d o of f g gu ui it ta ar r p pi ic ck ku up ps s Martín Martínez
Frontiers in Psychology
The Teachers’ Sense of Efficacy Scale (TSES) has been the most widely used instrument to assess t... more The Teachers’ Sense of Efficacy Scale (TSES) has been the most widely used instrument to assess teacher efficacy beliefs. However, no study has been carried out concerning the TSES psychometric properties with teachers in Mexico, the country with the highest number of Spanish-speakers worldwide. The purpose of the present study is to examine the reliability, internal and external validity evidence of the TSES (short form) adapted into Spanish with a sample of 190 primary and secondary Mexican teachers from 25 private schools. Results of construct analysis confirm the three-factor-correlated structure of the original scale. Criterion validity evidence was established between self-efficacy and job satisfaction. Differences in self-efficacy were related to teachers’ gender, years of experience and grade level taught. Some limitations are discussed, and future research directions are recommended.
Personality and Individual Differences
Abstract Background The relationship between emotional intelligence (EI) and stress has been wide... more Abstract Background The relationship between emotional intelligence (EI) and stress has been widely studied, as well as the beneficial role of self-care to maintain health and wellbeing. However, the joint contribution of EI and self-care in predicting stress has not been examined during COVID-19 lockdown. This study aimed to examine the mediating role of self-care in the relationship between EI and stress and the potential moderator role of gender. Methods A sample of 1082 participants from four Hispanic countries completed measures related to socio-demographic, trait emotional intelligence (Trait Meta-Mood Scale), self-care activities (Self-care Activities Screening Scale) and stress (Perceived Stress Scale). Results Mediation analyses revealed that self-care increased the explained variance of the prediction of stress by EI dimensions after controlling gender and age. However, gender only moderated the relationship between self-care and stress in the mediation model corresponding to emotional attention. Conclusions Data supported a general model for the interaction of EI and self-care as contributing factors of stress. Further research is needed to replicate it in more culturally distant samples and to fully explore the potential role of gender differences. Future intervention programs should include a balanced combination of EI and self-care to increase their benefits on people’s health.
Health and Quality of Life Outcomes
Background In a context where there is no treatment for the current COVID-19 virus, the combinati... more Background In a context where there is no treatment for the current COVID-19 virus, the combination of self-care behaviours together with confinement, are strategies to decrease the risk of contagion and remain healthy. However, there are no self-care measures to screen self-care activities in general population and which, could be briefly in a lockdown situation. This research aims to build and validate a psychometric tool to screen self-care activities in general population. Methods Firstly, an exploratory factor analysis was performed in a sample of 226 participants to discover the underlying factorial structure and to reduce the number of items in the original tool into a significant pool of items related to self-care. Later a confirmatory factor analyses were performed in a new sample of 261 participants to test for the fit and goodness of factor solutions. Internal validity, reliability, and convergent validity between its score with perceived stress and psychological well-bei...
The aim of the present cross-sectional study was to analyze the differential impact of the first ... more The aim of the present cross-sectional study was to analyze the differential impact of the first COVID-19 lockdown (3rd April 2020) on stress, health practices, and self-care activities across different Hispanic countries, age range and gender groups. 1082 participants from Spain, Chile, Colombia, and Ecuador took part in this study. Irrespective of the country, and controlling for income level, young people, especially females, suffered a greater level of stress, perceived the situation as more severe, showed less adherence to health guidelines and reported lower levels of health consciousness, in comparison to their male peers and older groups. However, in the case of self-care, it seems that older and female groups are generally more involved in self-care activities and adopt more healthy daily routines. These results are mostly similar between Colombia, Ecuador, and Spain. However, Chile showed some different tendencies, as males reported higher levels of healthy daily routines ...
Human brain mapping, 2018
Numerous daily tasks, including car driving, require fine visuospatial tuning. One such visuospat... more 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 execut...
Brain imaging and behavior, Aug 21, 2016
Previous research on motor sequence learning (MSL) in the elderly has focused mainly on unilatera... more 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...
IEEE Transactions on Medical Imaging
Los movimientos repetitivos y alternantes de las extremidades inferiores (stepping) son un compon... more Los movimientos repetitivos y alternantes de las extremidades inferiores (stepping) son un componente específico de la marcha humana. Debido a dificultades técnicas, los mecanismos neurales responsables de tales movimientos no han sido estudiados previamente con resonancia magnética funcional (RMf). En este estudio, se presenta un nuevo dispositivo de marcha empleado para investigar la cinemática y la patrones de activación cerebral involucrados en los movimientos alternantes y repetitivos de las extremidades inferiores. Una vez dentro del escáner, diecinueve sujetos sanos fueron guiados por dos señales visuales e instruidos para realizar una tarea motora que involucró movimientos repetitivos y alternantes de ambos miembros inferiores, mientras cada sujeto seleccionaba una amplitud cómoda. El dispositivo permite un movimiento coordinado a la vez que registra los desplazamientos concurrentes, lo cual permite cuantificar algunas de las características cinemáticas primarias del movimie...
El objetivo general de éste PFC es desarrollar técnicas de análisis de polisomnogramas (PSG) para... more El objetivo general de éste PFC es desarrollar técnicas de análisis de polisomnogramas (PSG) para la extracción automática de hipnogramas con Matlab. Las medidas PSG incluyen electroencefalograma (EEG), electromiograma (EMG), electrooculograma (EOG), y otros tipos de señales. Estas medidas se han usado para dividir el sueño (estado biológico no-uniforme) en diferentes estados o etapas. La diagnosis y el tratamiento de pacientes con desordenes del sueño requiere de la clasificación de los PSGs en los diferentes estados del sueño. Normalmente, el sueño sano está organizado en secuencias de etapas en ciclos de 60-90 minutos. Dependiendo de los estándares adoptados, las diferentes etapas se derivan de cuatro estados básicos del sueño biológico: Despierto, Sueño Ligero, Sueño Profundo, y Sueño de Movimiento Rápido de Ojos (REM, del inglés Rapid Eye Movement). El hipnograma es un diagrama con la descripción evolutiva en el tiempo de las etapas de sueño. Este diagrama es usado por los médi...
Journal of Alzheimer's disease : JAD, 2014
Understanding the cellular and molecular processes involved in learning and memory will help in t... more 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.
Health and Quality of Life Outcomes, 2021
Background: In a context where there is no treatment for the current COVID-19 virus, the combinat... more Background: In a context where there is no treatment for the current COVID-19 virus, the combination of self-care behaviours together with confinement, are strategies to decrease the risk of contagion and remain healthy. However, there are no self-care measures to screen self-care activities in general population and which, could be briefly in a lockdown situation. This research aims to build and validate a psychometric tool to screen self-care activities in general population. Methods: Firstly, an exploratory factor analysis was performed in a sample of 226 participants to discover the underlying factorial structure and to reduce the number of items in the original tool into a significant pool of items related to self-care. Later a confirmatory factor analyses were performed in a new sample of 261 participants to test for the fit and goodness of factor solutions. Internal validity, reliability, and convergent validity between its score with perceived stress and psychological well-being measures were examined on this sample. Results: The exploratory analyses suggested a four-factor solution, corresponding to health consciousness, nutrition and physical activity, sleep, and intra-personal and inter-personal coping skills (14 items). Then, the four-factor structure was confirmed as the best model fit for self-care activities. The tool demonstrated good reliability, predictive validity of individuals' perception of coping with COVID-19 lockdown, and convergent validity with well-being and perceived stress. Conclusions: This screening tool could be helpful to address future evaluations and interventions to promote healthy behaviours. Likewise, this tool can be targeted to specific population self-care's needs during a scalable situation.
Sensors, 2018
The aim of this study is to compare the properties of free-walking at a natural pace between mild... more 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%.
Journal of Alzheimer's Disease, 2014
Understanding the cellular and molecular processes involved in learning and memory will help in t... more 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.
The central nervous system has the ability to adapt our locomotor pattern to produce a wide range... more 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).
Abstract-Repetitive and alternating lower limb movements are a specific component of human gait. ... more Abstract-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 (fMRI). 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, nineteen 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 (BOLD) 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.
F Fi in ni it te e e el le em me en nt t m mo od de el li in ng g o of f t th he e m ma ag gn ne ... more F Fi in ni it te e e el le em me en nt t m mo od de el li in ng g o of f t th he e m ma ag gn ne et ti ic c f fi ie el ld d o of f g gu ui it ta ar r p pi ic ck ku up ps s Opening i
PLOS ONE, 2015
Background Imaging studies help to understand the evolution of key cognitive processes related to... more 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 highdemand 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.
Sensors, 2018
The aim of this study is to compare the properties of free-walking at a natural pace between mild... more 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 de...
Fi in ni it te e e el le em me en nt t m mo od de el li in ng g o of f t th he e m ma ag gn ne et... more Fi in ni it te e e el le em me en nt t m mo od de el li in ng g o of f t th he e m ma ag gn ne et ti ic c f fi ie el ld d o of f g gu ui it ta ar r p pi ic ck ku up ps s Martín Martínez
Frontiers in Psychology
The Teachers’ Sense of Efficacy Scale (TSES) has been the most widely used instrument to assess t... more The Teachers’ Sense of Efficacy Scale (TSES) has been the most widely used instrument to assess teacher efficacy beliefs. However, no study has been carried out concerning the TSES psychometric properties with teachers in Mexico, the country with the highest number of Spanish-speakers worldwide. The purpose of the present study is to examine the reliability, internal and external validity evidence of the TSES (short form) adapted into Spanish with a sample of 190 primary and secondary Mexican teachers from 25 private schools. Results of construct analysis confirm the three-factor-correlated structure of the original scale. Criterion validity evidence was established between self-efficacy and job satisfaction. Differences in self-efficacy were related to teachers’ gender, years of experience and grade level taught. Some limitations are discussed, and future research directions are recommended.
Personality and Individual Differences
Abstract Background The relationship between emotional intelligence (EI) and stress has been wide... more Abstract Background The relationship between emotional intelligence (EI) and stress has been widely studied, as well as the beneficial role of self-care to maintain health and wellbeing. However, the joint contribution of EI and self-care in predicting stress has not been examined during COVID-19 lockdown. This study aimed to examine the mediating role of self-care in the relationship between EI and stress and the potential moderator role of gender. Methods A sample of 1082 participants from four Hispanic countries completed measures related to socio-demographic, trait emotional intelligence (Trait Meta-Mood Scale), self-care activities (Self-care Activities Screening Scale) and stress (Perceived Stress Scale). Results Mediation analyses revealed that self-care increased the explained variance of the prediction of stress by EI dimensions after controlling gender and age. However, gender only moderated the relationship between self-care and stress in the mediation model corresponding to emotional attention. Conclusions Data supported a general model for the interaction of EI and self-care as contributing factors of stress. Further research is needed to replicate it in more culturally distant samples and to fully explore the potential role of gender differences. Future intervention programs should include a balanced combination of EI and self-care to increase their benefits on people’s health.
Health and Quality of Life Outcomes
Background In a context where there is no treatment for the current COVID-19 virus, the combinati... more Background In a context where there is no treatment for the current COVID-19 virus, the combination of self-care behaviours together with confinement, are strategies to decrease the risk of contagion and remain healthy. However, there are no self-care measures to screen self-care activities in general population and which, could be briefly in a lockdown situation. This research aims to build and validate a psychometric tool to screen self-care activities in general population. Methods Firstly, an exploratory factor analysis was performed in a sample of 226 participants to discover the underlying factorial structure and to reduce the number of items in the original tool into a significant pool of items related to self-care. Later a confirmatory factor analyses were performed in a new sample of 261 participants to test for the fit and goodness of factor solutions. Internal validity, reliability, and convergent validity between its score with perceived stress and psychological well-bei...
The aim of the present cross-sectional study was to analyze the differential impact of the first ... more The aim of the present cross-sectional study was to analyze the differential impact of the first COVID-19 lockdown (3rd April 2020) on stress, health practices, and self-care activities across different Hispanic countries, age range and gender groups. 1082 participants from Spain, Chile, Colombia, and Ecuador took part in this study. Irrespective of the country, and controlling for income level, young people, especially females, suffered a greater level of stress, perceived the situation as more severe, showed less adherence to health guidelines and reported lower levels of health consciousness, in comparison to their male peers and older groups. However, in the case of self-care, it seems that older and female groups are generally more involved in self-care activities and adopt more healthy daily routines. These results are mostly similar between Colombia, Ecuador, and Spain. However, Chile showed some different tendencies, as males reported higher levels of healthy daily routines ...
Human brain mapping, 2018
Numerous daily tasks, including car driving, require fine visuospatial tuning. One such visuospat... more 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 execut...
Brain imaging and behavior, Aug 21, 2016
Previous research on motor sequence learning (MSL) in the elderly has focused mainly on unilatera... more 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...
IEEE Transactions on Medical Imaging
Los movimientos repetitivos y alternantes de las extremidades inferiores (stepping) son un compon... more Los movimientos repetitivos y alternantes de las extremidades inferiores (stepping) son un componente específico de la marcha humana. Debido a dificultades técnicas, los mecanismos neurales responsables de tales movimientos no han sido estudiados previamente con resonancia magnética funcional (RMf). En este estudio, se presenta un nuevo dispositivo de marcha empleado para investigar la cinemática y la patrones de activación cerebral involucrados en los movimientos alternantes y repetitivos de las extremidades inferiores. Una vez dentro del escáner, diecinueve sujetos sanos fueron guiados por dos señales visuales e instruidos para realizar una tarea motora que involucró movimientos repetitivos y alternantes de ambos miembros inferiores, mientras cada sujeto seleccionaba una amplitud cómoda. El dispositivo permite un movimiento coordinado a la vez que registra los desplazamientos concurrentes, lo cual permite cuantificar algunas de las características cinemáticas primarias del movimie...
El objetivo general de éste PFC es desarrollar técnicas de análisis de polisomnogramas (PSG) para... more El objetivo general de éste PFC es desarrollar técnicas de análisis de polisomnogramas (PSG) para la extracción automática de hipnogramas con Matlab. Las medidas PSG incluyen electroencefalograma (EEG), electromiograma (EMG), electrooculograma (EOG), y otros tipos de señales. Estas medidas se han usado para dividir el sueño (estado biológico no-uniforme) en diferentes estados o etapas. La diagnosis y el tratamiento de pacientes con desordenes del sueño requiere de la clasificación de los PSGs en los diferentes estados del sueño. Normalmente, el sueño sano está organizado en secuencias de etapas en ciclos de 60-90 minutos. Dependiendo de los estándares adoptados, las diferentes etapas se derivan de cuatro estados básicos del sueño biológico: Despierto, Sueño Ligero, Sueño Profundo, y Sueño de Movimiento Rápido de Ojos (REM, del inglés Rapid Eye Movement). El hipnograma es un diagrama con la descripción evolutiva en el tiempo de las etapas de sueño. Este diagrama es usado por los médi...
Journal of Alzheimer's disease : JAD, 2014
Understanding the cellular and molecular processes involved in learning and memory will help in t... more 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.
Health and Quality of Life Outcomes, 2021
Background: In a context where there is no treatment for the current COVID-19 virus, the combinat... more Background: In a context where there is no treatment for the current COVID-19 virus, the combination of self-care behaviours together with confinement, are strategies to decrease the risk of contagion and remain healthy. However, there are no self-care measures to screen self-care activities in general population and which, could be briefly in a lockdown situation. This research aims to build and validate a psychometric tool to screen self-care activities in general population. Methods: Firstly, an exploratory factor analysis was performed in a sample of 226 participants to discover the underlying factorial structure and to reduce the number of items in the original tool into a significant pool of items related to self-care. Later a confirmatory factor analyses were performed in a new sample of 261 participants to test for the fit and goodness of factor solutions. Internal validity, reliability, and convergent validity between its score with perceived stress and psychological well-being measures were examined on this sample. Results: The exploratory analyses suggested a four-factor solution, corresponding to health consciousness, nutrition and physical activity, sleep, and intra-personal and inter-personal coping skills (14 items). Then, the four-factor structure was confirmed as the best model fit for self-care activities. The tool demonstrated good reliability, predictive validity of individuals' perception of coping with COVID-19 lockdown, and convergent validity with well-being and perceived stress. Conclusions: This screening tool could be helpful to address future evaluations and interventions to promote healthy behaviours. Likewise, this tool can be targeted to specific population self-care's needs during a scalable situation.
Sensors, 2018
The aim of this study is to compare the properties of free-walking at a natural pace between mild... more 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%.
Journal of Alzheimer's Disease, 2014
Understanding the cellular and molecular processes involved in learning and memory will help in t... more 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.
The central nervous system has the ability to adapt our locomotor pattern to produce a wide range... more 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).
Abstract-Repetitive and alternating lower limb movements are a specific component of human gait. ... more Abstract-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 (fMRI). 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, nineteen 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 (BOLD) 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.
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