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1.
Neuroimage ; 284: 120444, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37926216

RESUMEN

Previous work showed that movements are accompanied by modulation of electroencephalographic (EEG) activity in both beta (13-30 Hz) and gamma (>30 Hz) ranges. The amplitude of beta event-related synchronization (ERS) is not linked to movement characteristics, but progressively increases with motor practice, returning to baseline after a period of rest. Conversely, movement-related gamma ERS amplitude is proportional to movement distance and velocity. Here, high-density EEG was recorded in 51 healthy subjects to investigate whether i) three-hour practice in two learning tasks, one with a motor component and one without, affects gamma ERS amplitude and connectivity during a motor reaching test, and ii) 90-minutes of either sleep or quiet rest have an effect on gamma oscillatory activity. We found that, while gamma ERS was appropriately scaled to the target extent at all testing points, its amplitude decreased after practice, independently of the type of interposed learning, and after both quiet wake and nap, with partial correlations with subjective fatigue scores. During movement execution, connectivity patterns within fronto-parieto-occipital electrodes, over areas associated with attentional networks, decreased after both practice and after 90-minute rest. While confirming the prokinetic nature of movement-related gamma ERS, these findings demonstrated the preservation of gamma ERS scaling to movement velocity with practice, despite constant amplitude reduction. We thus speculate that such decreases, differently from the practice-related increases of beta ERS, are related to reduced attention or working memory mechanisms due to fatigue or a switch of strategy toward automatization of movement execution and do not specifically reflect plasticity phenomena.


Asunto(s)
Electroencefalografía , Movimiento , Humanos , Aprendizaje
2.
Eur J Neurosci ; 54(9): 7260-7273, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34618375

RESUMEN

The ability to flexibly manipulate memory representations is embedded in visual working memory (VWM) and can be tested using paradigms with retrospective cues. Although valid retrospective cues often facilitate memory recall, invalid ones may or may not result in performance costs. We investigated individual differences in utilising retrospective cues and evaluated how these individual differences are associated with brain oscillatory activity at rest. At the behavioural level, we operationalised flexibility as the ability to make effective use of retrospective cues or disregard them if required. At the neural level, we tested whether individual differences in such flexibility were associated with properties of resting-state alpha oscillatory activity (8-12 Hz). To capture distinct aspects of these brain oscillations, we evaluated their power spectral density and temporal dynamics using long-range temporal correlations (LRTCs). In addition, we performed multivariate patterns analysis (MVPA) to classify individuals' level of behavioural flexibility based on these neural measures. We observed that alpha power alone (magnitude) at rest was not associated with flexibility. However, we found that the participants' ability to manipulate VWM representations was correlated with alpha LRTC and could be decoded using MVPA on patterns of alpha power. Our findings suggest that alpha LRTC and multivariate patterns of alpha power at rest may underlie some of the individual differences in using retrospective cues in working memory tasks.


Asunto(s)
Señales (Psicología) , Memoria a Corto Plazo , Encéfalo , Humanos , Individualidad , Estudios Retrospectivos
3.
Neural Plast ; 2019: 1619290, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31223306

RESUMEN

During movement, modulation of beta power occurs over the sensorimotor areas, with a decrease just before its start (event-related desynchronization, ERD) and a rebound after its end (event-related synchronization, ERS). We have recently found that the depth of ERD-to-ERS modulation increases during practice in a reaching task and the following day decreases to baseline levels. Importantly, the magnitude of the beta modulation increase during practice is highly correlated with the retention of motor skill tested the following day. Together with other evidence, this suggests that the increase of practice-related modulation depth may be the expression of sensorimotor cortex's plasticity. Here, we determine whether the practice-related increase of beta modulation depth is equally present in a group of younger and a group of older subjects during the performance of a 30-minute block of reaching movements. We focused our analyses on two regions of interest (ROIs): the left sensorimotor and the frontal region. Performance indices were significantly different in the two groups, with the movements of older subjects being slower and less accurate. Importantly, both groups presented a similar increase of the practice-related beta modulation depth in both ROIs in the course of the task. Peak latency analysis revealed a progressive delay of the ERS peak that correlated with the total movement time. Altogether, these findings support the notion that the depth of beta modulation in a reaching movement task does not depend on age and confirm previous findings that only ERS peak latency but not ERS magnitude is related to performance indices.


Asunto(s)
Envejecimiento/fisiología , Ritmo beta/fisiología , Encéfalo/fisiología , Desempeño Psicomotor/fisiología , Adulto , Factores de Edad , Anciano , Fenómenos Biomecánicos/fisiología , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
4.
Cogn Affect Behav Neurosci ; 18(3): 495-508, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29572771

RESUMEN

Coping abilities represent the individual set of mental and behavioral strategies adopted when facing stress or traumatic experiences. Coping styles related to avoidance have been linked to a disposition to develop psychiatric disorders such as PTSD, anxiety, and major depression, whereas problem-oriented coping skills have been positively correlated with well-being and high quality of life. Even though coping styles constitute an important determinant of resilience and can impact many aspects of everyday living, no study has investigated their brain functional connectivity underpinnings in humans. Here we analyzed both psychometric scores of coping and resting-state fMRI data from 102 healthy adult participants. Controlling for personality and problem-solving abilities, we identified significant links between the propensity to adopt different coping styles and the functional connectivity profiles of regions belonging to the default mode (DMN) and anterior salience (AS) networks-namely, the anterior cingulate cortex, left frontopolar cortex, and left angular gyrus. Also, a reduced negative correlation between AS and DMN nodes explained variability in one specific coping style, related to avoiding problems while focusing on the emotional component of the stressor at hand, instead of relying on cognitive resources. These results might be integrated with current neurophysiological models of resilience and individual responses to stress, in order to understand the propensity to develop clinical conditions (e.g., PTSD) and predict the outcomes of psychotherapeutic interventions.


Asunto(s)
Adaptación Psicológica/fisiología , Mapeo Encefálico , Encéfalo/patología , Vías Nerviosas/fisiología , Adolescente , Adulto , Emociones/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos por Estrés Postraumático/fisiopatología , Adulto Joven
5.
Hum Brain Mapp ; 36(9): 3586-602, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26059228

RESUMEN

Recent evidence suggests the spontaneous BOLD signal synchronization of corresponding interhemispheric, homotopic regions as a stable trait of human brain physiology, with emerging differences in such organization being also related to some pathological conditions. To understand whether such brain functional symmetries play a role into higher-order cognitive functioning, here we correlated the functional homotopy profiles of 119 healthy subjects with their intelligence level. Counterintuitively, reduced homotopic connectivity in above average-IQ versus average-IQ subjects was observed, with significant reductions in visual and somatosensory cortices, supplementary motor area, rolandic operculum, and middle temporal gyrus, possibly suggesting that a downgrading of interhemispheric talk at rest could be associated with higher cognitive functioning. These regions also showed an increased spontaneous synchrony with medial structures located in ipsi- and contralateral hemispheres, with such pattern being mostly detectable for regions placed in the left hemisphere. The interactions with age and gender have been also tested, with different patterns for subjects above and below 25 years old and less homotopic connectivity in the prefrontal cortex and posterior midline regions in female participants with higher IQ scores. These findings support prior evidence suggesting a functional role for homotopic connectivity in human cognitive expression, promoting the reduction of synchrony between primary sensory regions as a predictor of higher intelligence levels.


Asunto(s)
Encéfalo/fisiología , Inteligencia/fisiología , Adolescente , Adulto , Envejecimiento/fisiología , Encéfalo/crecimiento & desarrollo , Mapeo Encefálico/métodos , Circulación Cerebrovascular/fisiología , Femenino , Humanos , Pruebas de Inteligencia , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/fisiología , Oxígeno/sangre , Descanso , Caracteres Sexuales , Adulto Joven
6.
Neural Plast ; 2015: 616242, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26236509

RESUMEN

In ten healthy subjects and in ten patients suffering from Multiple Sclerosis (MS), we investigated the cortical functional changes induced by a standard fatiguing repetitive tapping task. The Cortical Silent Period (CSP), an intracortical, mainly GABAB-mediated inhibitory phenomenon, was recorded by two different hand muscles, one acting as prime mover of the fatiguing index-thumb tapping task (First Dorsal Interosseous, FDI) and the other one not involved in the task but sharing largely overlapping central, spinal, and peripheral innervation (Abductor Digiti Minimi, ADM). At baseline, the CSP was shorter in patients than in controls. As fatigue developed, CSP changes involved both the "fatigued" FDI and the "unfatigued" ADM muscles, suggesting a cortical spread of central fatigue mechanisms. Chronic therapy with amantadine annulled differences in CSP duration between controls and patients, possibly through restoration of more physiological levels of intracortical inhibition in the motor cortex. These inhibitory changes correlated with the improvement of fatigue scales. The CSP may represent a suitable marker of neurophysiological mechanisms accounting for central fatigue generation either in controls or in MS patients, involving corticospinal neural pools supplying not only the fatigued muscle but also adjacent muscles sharing an overlapping cortical representation.


Asunto(s)
Amantadina/administración & dosificación , Fatiga/fisiopatología , Corteza Motora/efectos de los fármacos , Corteza Motora/fisiopatología , Esclerosis Múltiple/complicaciones , Adulto , Amantadina/uso terapéutico , Potenciales Evocados Motores/efectos de los fármacos , Fatiga/complicaciones , Fatiga/tratamiento farmacológico , Femenino , Dedos , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiopatología , Estimulación Magnética Transcraneal , Adulto Joven
7.
Brain Struct Funct ; 229(5): 1047-1072, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38683211

RESUMEN

Peripersonal space (PPS) is a construct referring to the portion of space immediately surrounding our bodies, where most of the interactions between the subject and the environment, including other individuals, take place. Decades of animal and human neuroscience research have revealed that the brain holds a separate representation of this region of space: this distinct spatial representation has evolved to ensure proper relevance to stimuli that are close to the body and prompt an appropriate behavioral response. The neural underpinnings of such construct have been thoroughly investigated by different generations of studies involving anatomical and electrophysiological investigations in animal models, and, recently, neuroimaging experiments in human subjects. Here, we provide a comprehensive anatomical overview of the anatomical circuitry underlying PPS representation in the human brain. Gathering evidence from multiple areas of research, we identified cortical and subcortical regions that are involved in specific aspects of PPS encoding.We show how these regions are part of segregated, yet integrated functional networks within the brain, which are in turn involved in higher-order integration of information. This wide-scale circuitry accounts for the relevance of PPS encoding in multiple brain functions, including not only motor planning and visuospatial attention but also emotional and social cognitive aspects. A complete characterization of these circuits may clarify the derangements of PPS representation observed in different neurological and neuropsychiatric diseases.


Asunto(s)
Encéfalo , Emociones , Espacio Personal , Cognición Social , Humanos , Encéfalo/fisiología , Encéfalo/anatomía & histología , Encéfalo/diagnóstico por imagen , Emociones/fisiología , Percepción Espacial/fisiología , Mapeo Encefálico , Animales , Vías Nerviosas/fisiología , Vías Nerviosas/anatomía & histología , Vías Nerviosas/diagnóstico por imagen
8.
Int J Clin Health Psychol ; 23(3): 100374, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36875007

RESUMEN

Violence is a major problem in our society and therefore research into the neural underpinnings of aggression has grown exponentially. Although in the past decade the biological underpinnings of aggressive behavior have been examined, research on neural oscillations in violent offenders during resting-state electroencephalography (rsEEG) remains scarce. In this study we aimed to investigate the effect of high-definition transcranial direct current stimulation (HD-tDCS) on frontal theta, alpha and beta frequency power, asymmetrical frontal activity, and frontal synchronicity in violent offenders. Fifty male violent forensic patients diagnosed with a substance dependence were included in a double-blind sham-controlled randomized study. The patients received 20 minutes of HD-tDCS two times a day on five consecutive days. Before and after the intervention, the patients underwent a rsEEG task. Results showed no effect of HD-tDCS on the power in the different frequency bands. Also, no increase in asymmetrical activity was found. However, we found increased synchronicity in frontal regions in the alpha and beta frequency bands indicating enhanced connectivity in frontal brain regions as a result of the HD-tDCS-intervention. This study has enhanced our understanding of the neural underpinnings of aggression and violence, pointing to the importance of alpha and beta frequency bands and their connectivity in frontal brain regions. Although future studies should further investigate the complex neural underpinnings of aggression in different populations and using whole-brain connectivity, it can be suggested with caution, that HD-tDCS could be an innovative method to regain frontal synchronicity in neurorehabilitation.

9.
Brain Sci ; 12(5)2022 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-35624967

RESUMEN

Emotional contexts affect memory processes. However, the impact of contextual priming as a function of the emotional valence on the recall of neutral information is not fully understood. The aim of the present study was to evaluate how a conditioning of emotional context during encoding may influence the subsequent memory of otherwise neutral materials in a well-established phenomenon as the serial position effect. Participants performed a free recall task for neutral words in three conditions: (i) word list alone; (ii) word list coupled with positive or neutral images; and (iii) word list coupled with negative or neutral images. Images were presented before each word stimulus. In three different experiments, the emotional context during the word list presentation was manipulated separately for primacy and recency clusters, and for the middle words ('middlecy'). Emotional context affects free recall of neutral stimuli, changing the serial position curve effect across conditions. Namely, emotional images presented in the primacy and recency clusters worsen accuracy, whereas their occurrence in the 'middlecy' cluster reduces the oblivion. The present findings show that the typical pattern related to the serial position curve for neutral information can be shaped by the conditioning of emotional context. Findings have implications in medical-legal contexts in the case of the recollection of events with high emotional content.

10.
Front Neurosci ; 16: 836703, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35281507

RESUMEN

Modulation of gamma oscillations recorded from the human motor cortex and basal ganglia appears to play a key role in movement execution. However, there are still major questions to be answered about the specific role of cortical gamma activity in both the planning and execution of movement features such as the scaling of peak velocity and movement time. In this study, we characterized movement-related gamma oscillatory dynamics and its relationship with kinematic parameters based on 256-channels EEG recordings in 64 healthy subjects while performing fast and uncorrected reaching movements to targets located at three distances. In keeping with previous studies, we found that movement-related gamma synchronization occurred during movement execution. As a new finding, we showed that gamma synchronization occurred also before movement onset, with planning and execution phases involving different gamma peak frequencies and topographies. Importantly, the amplitude of gamma synchronization in both planning and execution increased with target distance and predicted peak velocity and movement time. Additional analysis of phase coherence revealed a gamma-coordinated long-range network involving occipital, frontal and central regions during movement execution that was positively related to kinematic features. This is the first evidence in humans supporting the notion that gamma synchronization amplitude and phase coherence pattern can reliably predict peak velocity amplitude and movement time. Therefore, these findings suggest that cortical gamma oscillations have a crucial role for the selection, implementation and control of the appropriate kinematic parameters of goal-directed reaching movements.

11.
Neurosci Biobehav Rev ; 142: 104867, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36122739

RESUMEN

Mental health disorders and substance use disorders are a leading cause of morbidity and mortality worldwide, and one of the most important challenges for public health systems. While evidence-based psychotherapy is generally pursued to address mental health challenges, psychological change is often hampered by non-adherence to treatments, relapses, and practical barriers (e.g., time, cost). In recent decades, Non-invasive brain stimulation (NIBS) techniques have emerged as promising tools to directly target dysfunctional neural circuitry and promote long-lasting plastic changes. While the therapeutic efficacy of NIBS protocols for mental illnesses has been established, neuromodulatory interventions might also be employed to support the processes activated by psychotherapy. Indeed, combining psychotherapy with NIBS might help tailor the treatment to the patient's unique characteristics and therapeutic goal, and would allow more direct control of the neuronal changes induced by therapy. Herein, we overview emerging evidence on the use of NIBS to enhance the psychotherapeutic effect, while highlighting the next steps in advancing clinical and research methods toward personalized intervention approaches.


Asunto(s)
Trastornos Relacionados con Sustancias , Estimulación Transcraneal de Corriente Directa , Humanos , Estimulación Magnética Transcraneal/métodos , Estimulación Transcraneal de Corriente Directa/métodos , Psicoterapia/métodos , Trastornos Relacionados con Sustancias/terapia , Encéfalo/fisiología
12.
Front Neurosci ; 16: 1045715, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36507340

RESUMEN

Movement-related oscillations in the beta range (from 13 to 30 Hz) have been observed over sensorimotor areas with power decrease (i.e., event-related desynchronization, ERD) during motor planning and execution followed by an increase (i.e., event-related synchronization, ERS) after the movement's end. These phenomena occur during active, passive, imaged, and observed movements. Several electrophysiology studies have used beta ERD and ERS as functional indices of sensorimotor integrity, primarily in diseases affecting the motor system. Recent literature also highlights other characteristics of beta ERD and ERS, implying their role in processes not strictly related to motor function. Here we review studies about movement-related ERD and ERS in diseases characterized by motor dysfunction, including Parkinson's disease, dystonia, stroke, amyotrophic lateral sclerosis, cerebral palsy, and multiple sclerosis. We also review changes of beta ERD and ERS reported in physiological aging, Alzheimer's disease, and schizophrenia, three conditions without overt motor symptoms. The review of these works shows that ERD and ERS abnormalities are present across the spectrum of the examined pathologies as well as development and aging. They further suggest that cognition and movement are tightly related processes that may share common mechanisms regulated by beta modulation. Future studies with a multimodal approach are warranted to understand not only the specific topographical dynamics of movement-related beta modulation but also the general meaning of beta frequency changes occurring in relation to movement and cognitive processes at large. Such an approach will provide the foundation to devise and implement novel therapeutic approaches to neuropsychiatric disorders.

13.
Parkinsonism Relat Disord ; 88: 136-139, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34144879

RESUMEN

Extensive work on movement-related beta oscillations (~13-30 Hz) over the sensorimotor areas in both humans and animals has demonstrated that sensorimotor beta power decreases during movement and transiently increases after movement. This beta power modulation has been interpreted as reflecting interactions between sensory and motor cortical areas with attenuation of sensory afferents during movement and their subsequent re-activation for internal models updating. More recent studies in neurologically normal subjects have demonstrated that this movement-related modulation as well as mean beta power at rest increase with practice and that previous motor learning enhances such increases. Conversely, patients with Parkinson's disease (PD) do not show such practice-related increases. Interestingly, a 2-h inactivity period without sleep can restore beta power values to baseline in normal subjects. Based on these results and on those of biochemical and electrophysiological studies in animals, we expand the current interpretation of beta activity and propose that the practice-related increases of beta power over sensorimotor areas are local indices of energy used for engaging plasticity-related activity. This paper provides some preliminary evidence in this respect linking findings of biochemical and electrophysiological studies in both humans and animals. This novel interpretation may explain the high level of beta power at rest, the deficient modulation during movement as well as the decreased skill formation in PD as resulting from deficiency in energy consumption, availability and regulation that are altered in this disease.


Asunto(s)
Ritmo beta/fisiología , Hipocinesia/fisiopatología , Destreza Motora/fisiología , Plasticidad Neuronal/fisiología , Enfermedad de Parkinson/fisiopatología , Práctica Psicológica , Retención en Psicología/fisiología , Corteza Sensoriomotora/fisiopatología , Humanos
14.
Front Neurosci ; 15: 707828, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34335178

RESUMEN

We have previously demonstrated that, in rested subjects, extensive practice in a motor learning task increased both electroencephalographic (EEG) theta power in the areas involved in learning and improved the error rate in a motor test that shared similarities with the task. A nap normalized both EEG and performance changes. We now ascertain whether extensive visual declarative learning produces results similar to motor learning. Thus, during the morning, we recorded high-density EEG in well rested young healthy subjects that learned the order of different visual sequence task (VSEQ) for three one-hour blocks. Afterward, a group of subjects took a nap and another rested quietly. Between each VSEQ block, we recorded spontaneous EEG (sEEG) at rest and assessed performance in a motor test and a visual working memory test that shares similarities with VSEQ. We found that after the third block, VSEQ induced local theta power increases in the sEEG over a right temporo-parietal area that was engaged during the task. This local theta increase was preceded by increases in alpha and beta power over the same area and was paralleled by performance decline in the visual working memory test. Only after the nap, VSEQ learning rate improved and performance in the visual working memory test was restored, together with partial normalization of the local sEEG changes. These results suggest that intensive learning, like motor learning, produces local theta power increases, possibly reflecting local neuronal fatigue. Sleep may be necessary to resolve neuronal fatigue and its effects on learning and performance.

15.
J Psychiatr Res ; 136: 560-570, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33158554

RESUMEN

BACKGROUND: intrusive thoughts and compulsive behaviors that characterize obsessive compulsive disorder (OCD) are associated to aberrant resting state functional connectivity (rsFC) patterns within the cortico-striatal-thalamo-cortical (CSTC) circuits. A high percentage of OCD patients do not respond to conventional pharmacological treatments or psychotherapy. In these patients, inhibitory repetitive transcranial magnetic stimulation (rTMS) of the Supplementary Motor Area (SMA) resulted in a significant clinical benefit. METHODS: In the current study, we applied a novel protocol of 1-week MRI-guided individualized double-daily sessions of rTMS treatment (1-Hz; 110% of resting Motor Threshold/7200 pulses/day), to bilateral SMA in 9 OCD patients. We tested its (i) feasibility-safety, (ii) clinical efficacy and (iii) rsFC related changes. RESULTS: Patients reported no side effects during and after rTMS. Personalized rTMS treatment led to a significant improvement of OCD symptoms (average 25%; p = .005) and persistence of benefit up to 3-month follow-up. rsFC analysis revealed a significant reduction of connectivity patterns between bilateral SMA and subcortical regions, specifically in the basal ganglia and thalamus. Additional analysis showed that OCD symptoms severity correlates with a higher connectivity pattern between bilateral SMA and subcortical regions. CONCLUSIONS: rTMS double-daily sessions are safe, feasible and effective in OCD. The clinical outcomes, that are consistent with those found in our previous RCT, are linked to a decreased connectivity between SMA and subcortical brain areas implicated in control over obsessions and maladaptive compulsive behavior.


Asunto(s)
Corteza Motora , Trastorno Obsesivo Compulsivo , Humanos , Trastorno Obsesivo Compulsivo/terapia , Proyectos Piloto , Estimulación Magnética Transcraneal , Resultado del Tratamiento
16.
Sleep ; 44(1)2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-32745192

RESUMEN

Do brain circuits become fatigued due to intensive neural activity or plasticity? Is sleep necessary for recovery? Well-rested subjects trained extensively in a visuo-motor rotation learning task (ROT) or a visuo-motor task without rotation learning (MOT), followed by sleep or quiet wake. High-density electroencephalography showed that ROT training led to broad increases in EEG power over a frontal cluster of electrodes, with peaks in the theta (mean ± SE: 24% ± 6%, p = 0.0013) and beta ranges (10% ± 3%, p = 0.01). These traces persisted in the spontaneous EEG (sEEG) between sessions (theta: 42% ± 8%, p = 0.0001; beta: 35% ± 7%, p = 0.002) and were accompanied by increased errors in a motor test with kinematic characteristics and neural substrates similar to ROT (81.8% ± 0.8% vs. 68.2% ± 2.3%; two-tailed paired t-test: p = 0.00001; Cohen's d = 1.58), as well as by score increases of subjective task-specific fatigue (4.00 ± 0.39 vs. 5.36 ± 0.39; p = 0.0007; Cohen's d = 0.60). Intensive practice with MOT did not affect theta sEEG or the motor test. A nap, but not quiet wake, induced a local sEEG decrease of theta power by 33% (SE: 8%, p = 0.02), renormalized test performance (70.9% ± 2.9% vs 79.1% ± 2.7%, p = 0.018, Cohen's d = 0.85), and improved learning ability in ROT (adaptation rate: 71.2 ± 1.2 vs. 73.4 ± 0.9, p = 0.024; Cohen's d = 0.60). Thus, sleep is necessary to restore plasticity-induced fatigue and performance.


Asunto(s)
Electroencefalografía , Sueño , Fatiga/etiología , Humanos , Aprendizaje , Descanso
17.
Front Syst Neurosci ; 14: 61, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33013332

RESUMEN

Beta oscillations (13.5-25 Hz) over the sensorimotor areas are characterized by a power decrease during movement execution (event-related desynchronization, ERD) and a sharp rebound after the movement end (event-related synchronization, ERS). In previous studies, we demonstrated that movement-related beta modulation depth (peak ERS-ERD) during reaching increases within 1-h practice. This increase may represent plasticity processes within the sensorimotor network. If so, beta modulation during a reaching test should be affected by previous learning activity that engages the sensorimotor system but not by learning involving other systems. We thus recorded high-density EEG activity in a group of healthy subjects performing three 45-min blocks of motor adaptation task to a visually rotated display (ROT) and in another performing three blocks of visual sequence-learning (VSEQ). Each block of either ROT or VSEQ was followed by a simple reaching test (mov) without rotation. We found that beta modulation depth increased with practice across mov tests. However, such an increase was greater in the group performing ROT over both the left and frontal areas previously involved in ROT. Importantly, beta modulation values returned to baseline values after a 90-min of either nap or quiet wake. These results show that previous practice leaves a trace in movement-related beta modulation and therefore such increases are cumulative. Furthermore, as sleep is not necessary to bring beta modulation values to baseline, they could reflect local increases of neuronal activity and decrease of energy and supplies.

18.
IEEE Int Conf Rehabil Robot ; 2019: 1254-1259, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31374801

RESUMEN

Movement is associated with power changes over sensory-motor areas in different frequency ranges, including beta (15-30 Hz). In fact, beta power starts decreasing before the movement onset (event-related desynchronization, ERD) and rebounds after its end (event-related synchronization, ERS). There is increasing evidence that beta modulation depth (measured as ERD-ERS difference) increases with practice in a planar reaching task, suggesting that this measure may reflect plasticity processes. In the present work, we analyzed beta ERD, ERS and modulation depth in healthy subjects to determine their changes over three regions of interest (ROIs): right and left sensorimotor and frontal areas, during a reaching task with the right arm. We found that ERD, ERS and modulation depth increased with practice with lower values over the right sensory-motor area. Timing of peak ERD and ERS were similar across ROIs, with ERS peak occurring earlier in later sets. Finally, we found that beta ERS of the frontal ROI involved higher beta range (23-29 Hz) than the sensory-motor ROIs (15-18 Hz). Altogether these results suggest that practice in a reaching task is associated with modification of beta power and timing. Additionally, beta ERS may have different functional meaning in the three ROIs, as suggested by the involvement of upper and lower beta bands in the frontal and sensorimotor ROIs, respectively.


Asunto(s)
Corteza Motora/fisiopatología , Adulto , Electroencefalografía , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Movimiento/fisiología , Desempeño Psicomotor/fisiología , Adulto Joven
19.
Front Behav Neurosci ; 13: 49, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30923498

RESUMEN

Beta power over the sensorimotor areas starts decreasing just before movement execution (event-related desynchronization, ERD) and increases post-movement (event-related synchronization, ERS). In this study, we determined whether the magnitude of beta ERD, ERS and modulation depth are linked to movement characteristics, such as movement length and velocity. Brain activity was recorded with a 256-channels EEG system in 35 healthy subjects performing fast, uncorrected reaching movements to targets located at three distances. We found that the temporal profiles of velocity were bell-shaped and scaled to the appropriate target distance. However, the magnitude of beta ERD, ERS and modulation depth, as well as their timing, did not significantly change and were not related to movement features.

20.
IEEE Int Conf Rehabil Robot ; 2019: 1260-1265, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31374802

RESUMEN

Movement is accompanied by modulation of oscillatory activity in different ranges over the sensorimotor areas. This increase is more evident in normal subjects and less in patients with Parkinson's Disease (PD), a disorder associated with deficits in the formation of new motor skills. Here, we investigated whether such EEG changes improved in a group of PD patients, after two different treatments and whether this relates to performance. Subjects underwent either a session of 5 Hz repetitive Transcranial Magnetic Stimulation (rTMS) over the right posterior parietal cortex or a 4-week Multidisciplinary Intensive Rehabilitation Treatment (MIRT). We used a reaching task with visuo-motor adaptation to a rotated display in incremental 10° steps up to 60°. Retention of the learned rotation was tested before and after either intervention over two consecutive days. High-density EEG was recorded throughout the testing. We found that patients adapted their movements to the rotated display similarly to controls, although retention was poorer. Both rTMS and MIRT lead to improvement in retention of the learned rotation. Mean beta modulation levels changed significantly after MIRT and not after rTMS. These results suggest that rTMS produced local improvement reflected in enhanced short-term skill retention; on the other hand, MIRT determined changes across the contralateral sensorimotor area, reflected in beta EEG changes.


Asunto(s)
Aprendizaje/fisiología , Enfermedad de Parkinson/rehabilitación , Estimulación Transcraneal de Corriente Directa/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
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