Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 67
Filtrar
1.
Fortschr Neurol Psychiatr ; 84(2): 88-95, 2016 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-26953548

RESUMEN

Anorexia nervosa has been related to alterations in brain activity in terms of hyperactive EEG patterns. This case report illustrates the principles and results of a five-week neurofeedback treatment in a 29-year-old woman suffering from anorexia nervosa. A neurofeedback protocol to enhance alpha activity (8 - 12 Hz) was developed and conducted additionally to the standardized treatment for eating disorders in training sessions twice a week. Pre- and post-test measurements included resting state EEG measurements and a psychological test battery. The results show improvements from pre- to post-test in eating disorder psychopathology including psychological wellbeing, emotional competence, and eating behavior traits. In addition, a decrease in theta power (4 - 7 Hz), a well-known trait marker of anorexia nervosa, was measured. However, our data should be interpreted with caution because this is a single case study. Nevertheless, this report documents the practicability and method of neurofeedback as treatment adjunct in eating disorders from the clinical perspective. Although the use of neurofeedback in the treatment of anorexia nervosa is recommended in literature, empirical studies are still lacking. Randomized controlled trials to evaluate short- and long-term effects of neurofeedback are needed.


Asunto(s)
Anorexia Nerviosa/terapia , Neurorretroalimentación , Adulto , Ritmo alfa , Anorexia Nerviosa/psicología , Electroencefalografía , Emociones , Conducta Alimentaria , Femenino , Humanos , Neurorretroalimentación/métodos , Pruebas Neuropsicológicas , Ritmo Teta , Resultado del Tratamiento
2.
Biol Psychol ; 110: 126-33, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26219602

RESUMEN

Neurofeedback is a technique to learn to control brain signals by means of real time feedback. In the present study, the individual ability to learn two EEG neurofeedback protocols - sensorimotor rhythm and gamma rhythm - was related to structural properties of the brain. The volumes in the anterior insula bilaterally, left thalamus, right frontal operculum, right putamen, right middle frontal gyrus, and right lingual gyrus predicted the outcomes of sensorimotor rhythm training. Gray matter volumes in the supplementary motor area and left middle frontal gyrus predicted the outcomes of gamma rhythm training. These findings combined with further evidence from the literature are compatible with the existence of a more general self-control network, which through self-referential and self-control processes regulates neurofeedback learning.


Asunto(s)
Encéfalo/anatomía & histología , Encéfalo/fisiología , Ritmo Gamma/fisiología , Neurorretroalimentación/fisiología , Autocontrol , Adulto , Retroalimentación Sensorial , Femenino , Humanos , Aprendizaje/fisiología , Masculino , Persona de Mediana Edad , Neurorretroalimentación/métodos , Análisis de Regresión
3.
Biol Psychol ; 95: 21-30, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23714227

RESUMEN

In the present study we implemented a real-time feedback system based on multichannel near-infrared spectroscopy (NIRS). Prior studies indicated that NIRS-based neurofeedback can enhance motor imagery related cortical activation. To specify these prior results and to confirm the efficacy of NIRS-based neurofeedback, we examined changes in blood oxygenation level collected in eight training sessions. One group got real feedback about their own brain activity (N=9) and one group saw a playback of another person's feedback recording (N=8). All participants performed motor imagery of a right hand movement. Real neurofeedback induced specific and focused brain activation over left motor areas. This focal brain activation became even more specific over the eight training sessions. In contrast, sham feedback led to diffuse brain activation patterns over the whole cortex. These findings can be useful when training patients with focal brain lesions to increase activity of specific brain areas for rehabilitation purpose.


Asunto(s)
Imaginación/fisiología , Corteza Motora/fisiología , Movimiento/fisiología , Neurorretroalimentación , Espectroscopía Infrarroja Corta , Adulto , Femenino , Humanos , Masculino , Desempeño Psicomotor/fisiología , Adulto Joven
5.
Clin Neurophysiol ; 124(8): 1596-604, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23540418

RESUMEN

OBJECTIVE: We studied the activation of cortical motor and parietal areas during the observation of object related grasping movements. By manipulating the type of an object (realistic versus abstract) and the type of grasping (correct versus incorrect), we addressed the question how observing such object related movements influences cortical rhythmicity, especially the mu-rhythm, in the context of an "extended" human mirror neuron system (MNS). METHODS: Multichannel electroencephalogram (EEG) was recorded during the observation of different object-related grasping actions in twenty healthy subjects. Different movies were presented, showing sequences of correct or incorrect hand grasping actions related to an abstract or realistic (daily life) object. RESULTS: Event-related de/synchronization (ERD/ERS) analyses revealed a larger ERD in the upper alpha (10-12 Hz), beta (16-20 Hz) and gamma (36-40 Hz) frequency bands over parietal brain regions depending on the type of grasping. The type of object only influenced ERD patterns in the gamma band range (36-40 Hz) at parietal sites suggesting a strong relation of gamma band activity and cortical object representation. Abstract and realistic objects produced lower beta band synchronization at central sites only, whereas depending on the type of grasping an ERS in the upper alpha band (10-12 Hz) was observed. CONCLUSION: Depending on the type of the grasped object and the type of grasping stronger parietal cortical activation occurred during movement observation. SIGNIFICANCE: Discussing the results in terms of an "extended" human mirror neuron system (MNS), it could be concluded that beside sensorimotor areas a stronger involvement of parietal brain regions was found depending on the type of object and grasping movement observed.


Asunto(s)
Neuronas Espejo/fisiología , Percepción de Movimiento , Corteza Motora/fisiología , Lóbulo Parietal/fisiología , Adulto , Mapeo Encefálico , Electroencefalografía , Femenino , Humanos , Masculino , Adulto Joven
6.
Psychopathology ; 45(5): 310-6, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22797574

RESUMEN

BACKGROUND: Religiosity and spirituality have been found to be substantially associated with a variety of mental health and illness parameters. However, relevant empirical evidence is sparse, and more research is needed in order to further understand what role religiosity/spirituality plays in the development, progression and healing process of a psychiatric disease. Thus, the purpose of this study was to find out more information about the religious/spiritual needs of anxious/depressive inpatients. SAMPLING AND METHODS: A total sample of 200 well-characterized anxious/depressive inpatients was investigated. Results were compared to those from an adjusted group of healthy individuals (n = 200). A newly developed Multidimensional Inventory for Religious/Spiritual Well-Being was applied to both groups, together with established psychiatric measures (e.g. Beck Depression Inventory). RESULTS: Of the dimensions measured, Hope and Forgiveness turned out to be the strongest negative correlates of anxious/depressive symptoms (p < 0.001). Moreover, a lower degree of Hope (p < 0.001) and Experiences of Sense and Meaning (p < 0.01) was found in the patient group compared to healthy controls. In accordance with the literature, religiosity was confirmed to be a substantial suicidal buffer (p < 0.01). CONCLUSIONS: Our results account for a more comprehensive psychiatric evaluation, emphasizing in particular the role that religiosity/spirituality plays in overall well-being. Furthermore, religious/spiritual well-being might be considered an important resource to explore, in particular for affective mentally disordered patients.


Asunto(s)
Adaptación Psicológica , Ansiedad/psicología , Depresión/psicología , Trastornos del Humor/psicología , Religión , Adulto , Femenino , Humanos , Pacientes Internos , Masculino , Persona de Mediana Edad , Satisfacción Personal , Espiritualidad , Encuestas y Cuestionarios
7.
J Neural Eng ; 9(1): 013001, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22156029

RESUMEN

This paper summarizes two novel ways to extend brain-computer interface (BCI) systems. One way involves hybrid BCIs. A hybrid BCI is a system that combines a BCI with another device to help people send information. Different types of hybrid BCIs are discussed, along with challenges and issues. BCIs are also being extended through intelligent systems. Software that allows high-level control, incorporates context and the environment and/or uses virtual reality can substantially improve BCI systems. Throughout the paper, we critically address the real benefits of these improvements relative to existing technology and practices. We also present new challenges that are likely to emerge as these novel BCI directions become more widespread.


Asunto(s)
Inteligencia Artificial , Biorretroalimentación Psicológica/fisiología , Mapeo Encefálico/métodos , Encéfalo/fisiología , Electroencefalografía/métodos , Potenciales Evocados/fisiología , Interfaz Usuario-Computador , Biorretroalimentación Psicológica/métodos , Retroalimentación Fisiológica/fisiología , Humanos
8.
Brain Res ; 1393: 73-83, 2011 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-21513918

RESUMEN

Recognition and processing of emotional facial expression are crucial for social behavior and employ higher-order cognitive and visual working processes. In neuropsychiatric disorders, impaired emotion recognition most frequently concerned three specific emotions, i.e., anger, fear, and disgust. As incorrect processing of (neutral) facial stimuli per se might also underlie deficits in the recognition of emotional facial expressions, we aimed to assess all these aspects in one experiment. We therefore report here a functional magnetic resonance imaging (fMRI) paradigm for parallel assessment of the neural correlates of both the recognition of neutral faces and the three clinically most relevant emotions for future use in patients with neuropsychiatric disorders. FMRI analyses were expanded through comparisons of the emotional conditions with each other. The differential insights resulting from these two analyses strategies are compared and discussed. 30 healthy participants (21 F/9 M; age 36.3 ± 14.3, 17-66 years) underwent fMRI and behavioral testing for non-emotional and emotional face recognition. Recognition of neutral faces elicited activation in the fusiform gyri. Processing angry faces led to activation in left middle and superior frontal gyri and the anterior cingulate cortex. There was considerable heterogeneity regarding the fear versus neutral contrast, resulting in null effects for this contrast. Upon recognition of disgust, activation was noted in bilateral occipital, in the fronto-orbital cortex and in the insula. Analyzing contrasts between emotional conditions showed similar results (to those of contrasting with reference conditions) for separated emotional network patterns. We demonstrate here that our paradigm reproduces single aspects of separate previous studies across a cohort of healthy subjects, irrespective of age. Our approach might prove useful in future studies of patients with neurologic disorders with potential effect on emotion recognition.


Asunto(s)
Emociones/fisiología , Expresión Facial , Percepción de Forma/fisiología , Imagen por Resonancia Magnética , Reconocimiento Visual de Modelos/fisiología , Adolescente , Adulto , Factores de Edad , Anciano , Cara , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa/métodos , Adulto Joven
9.
J Neural Eng ; 8(2): 025020, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21436514

RESUMEN

The main purpose of electroencephalography (EEG)-based brain-computer interface (BCI) technology is to provide an alternative channel to support communication and control when motor pathways are interrupted. Despite the considerable amount of research focused on the improvement of EEG signal detection and translation into output commands, little is known about how learning to operate a BCI device may affect brain plasticity. This study investigated if and how sensorimotor rhythm-based BCI training would induce persistent functional changes in motor cortex, as assessed with transcranial magnetic stimulation (TMS) and high-density EEG. Motor imagery (MI)-based BCI training in naïve participants led to a significant increase in motor cortical excitability, as revealed by post-training TMS mapping of the hand muscle's cortical representation; peak amplitude and volume of the motor evoked potentials recorded from the opponens pollicis muscle were significantly higher only in those subjects who develop a MI strategy based on imagination of hand grasping to successfully control a computer cursor. Furthermore, analysis of the functional brain networks constructed using a connectivity matrix between scalp electrodes revealed a significant decrease in the global efficiency index for the higher-beta frequency range (22-29 Hz), indicating that the brain network changes its topology with practice of hand grasping MI. Our findings build the neurophysiological basis for the use of non-invasive BCI technology for monitoring and guidance of motor imagery-dependent brain plasticity and thus may render BCI a viable tool for post-stroke rehabilitation.


Asunto(s)
Algoritmos , Relojes Biológicos/fisiología , Mapeo Encefálico/métodos , Electroencefalografía/métodos , Potenciales Evocados Somatosensoriales/fisiología , Imaginación/fisiología , Corteza Motora/fisiología , Adulto , Potenciales Evocados/fisiología , Humanos , Aprendizaje/fisiología , Masculino , Interfaz Usuario-Computador
10.
J Neural Eng ; 8(2): 025010, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21436538

RESUMEN

Brain-computer interface (BCI) systems rely on the direct measurement of brain signals, such as event-related desynchronization (ERD), steady state visual evoked potentials (SSVEPs), P300s, or slow cortical potentials. Unfortunately, none of these BCI approaches work for all users. This study compares two conventional BCI approaches (ERD and SSVEP) within subjects, and also evaluates a novel hybrid BCI based on a combination of these signals. We recorded EEG data from 12 subjects across three conditions. In the first condition, subjects imagined moving both hands or both feet (ERD). In the second condition, subjects focused on one of the two oscillating visual stimuli (SSVEP). In the third condition, subjects simultaneously performed both tasks. We used logarithmic band power features at sites and frequencies consistent with ERD and SSVEP activity, and subjects received real-time feedback based on their performance. Subjects also completed brief questionnaires. All subjects could simultaneously perform the movement and visual task in the hybrid condition even though most subjects had little or no training. All subjects showed both SSVEP and ERD activity during the hybrid task, consistent with the activity in both single tasks. Subjects generally considered the hybrid condition moderately more difficult, but all of them were able to complete the hybrid task. Results support the hypothesis that subjects who do not have strong ERD activity might be more effective with an SSVEP BCI, and suggest that SSVEP BCIs work for more subjects. A simultaneous hybrid BCI is feasible, although the current hybrid approach, which involves combining ERD and SSVEP in a two-choice task to improve accuracy, is not significantly better than a comparable SSVEP BCI. Switching to an SSVEP BCI could increase reliability in subjects who have trouble producing the EEG activity necessary to use an ERD BCI. Subjects who are proficient in both BCI approaches might be able to combine these approaches in different ways and for different goals.


Asunto(s)
Algoritmos , Mapeo Encefálico/métodos , Sincronización de Fase en Electroencefalografía/fisiología , Potenciales Evocados Visuales/fisiología , Interfaz Usuario-Computador , Corteza Visual/fisiología , Adulto , Femenino , Humanos , Masculino , Sistemas Hombre-Máquina , Adulto Joven
11.
Neurology ; 76(6): 526-33, 2011 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-21300967

RESUMEN

OBJECTIVES: Cognitive dysfunction (CD) is frequent in multiple sclerosis (MS) and can occur at early stages. Whereas functional reorganization with disease progression has been described for the motor system in MS using fMRI, no such studies exist for cognition. We attempted to assess the concept of functional reorganization concerning cognition using a simple "Go/No-go" fMRI paradigm. METHODS: Patients with a clinically isolated syndrome (CIS, n = 10), relapsing-remitting MS (RRMS) (n = 10), or secondary progressive MS (SPMS) (n = 10), and 28 healthy controls (HC), underwent a comprehensive neuropsychological test battery, clinical examination, structural imaging, and an fMRI Go/No-go discrimination task at 3 T. RESULTS: Patients performed worse than HC regarding memory, sustained attention and concentration, and information processing. These differences were driven by patients with SPMS. The fMRI task elicited activation in a widespread network including bilateral mesial and dorsolateral frontal, parietal, insular, basal ganglia, and cerebellar regions. Task performance was similar between phenotypes, but deviation from the activation pattern observed in HC and patients with CIS increased with disease progression. Patients with RRMS showed increased brain activation in the precuneus, both superior parietal lobes, and the right fusiform gyrus, and recruited the hippocampus with increasing demands. Patients with SPMS demonstrated the most abnormal network function, including recruitment of pre-SMA, bilateral superior and inferior parietal, dorsolateral prefrontal, right precentral, bilateral postcentral, and right temporal brain areas. CONCLUSION: Using a cognitive fMRI paradigm, we were able to confirm adaptive changes of neuronal activation with progressing MS and to provide strong evidence for their compensatory nature, at least partially.


Asunto(s)
Encéfalo/fisiología , Trastornos del Conocimiento/fisiopatología , Progresión de la Enfermedad , Imagen por Resonancia Magnética/métodos , Esclerosis Múltiple/fisiopatología , Red Nerviosa/fisiología , Adulto , Mapeo Encefálico/métodos , Cognición/fisiología , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/psicología , Desempeño Psicomotor/fisiología , Adulto Joven
12.
Artículo en Inglés | MEDLINE | ID: mdl-20877434

RESUMEN

In recent years, new research has brought the field of electroencephalogram (EEG)-based brain-computer interfacing (BCI) out of its infancy and into a phase of relative maturity through many demonstrated prototypes such as brain-controlled wheelchairs, keyboards, and computer games. With this proof-of-concept phase in the past, the time is now ripe to focus on the development of practical BCI technologies that can be brought out of the lab and into real-world applications. In particular, we focus on the prospect of improving the lives of countless disabled individuals through a combination of BCI technology with existing assistive technologies (AT). In pursuit of more practical BCIs for use outside of the lab, in this paper, we identify four application areas where disabled individuals could greatly benefit from advancements in BCI technology, namely, "Communication and Control", "Motor Substitution", "Entertainment", and "Motor Recovery". We review the current state of the art and possible future developments, while discussing the main research issues in these four areas. In particular, we expect the most progress in the development of technologies such as hybrid BCI architectures, user-machine adaptation algorithms, the exploitation of users' mental states for BCI reliability and confidence measures, the incorporation of principles in human-computer interaction (HCI) to improve BCI usability, and the development of novel BCI technology including better EEG devices.

13.
J Neural Eng ; 7(2): 26007, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20332550

RESUMEN

Brain-computer interface (BCI) systems do not work for all users. This article introduces a novel combination of tasks that could inspire BCI systems that are more accurate than conventional BCIs, especially for users who cannot attain accuracy adequate for effective communication. Subjects performed tasks typically used in two BCI approaches, namely event-related desynchronization (ERD) and steady state visual evoked potential (SSVEP), both individually and in a 'hybrid' condition that combines both tasks. Electroencephalographic (EEG) data were recorded across three conditions. Subjects imagined moving the left or right hand (ERD), focused on one of the two oscillating visual stimuli (SSVEP), and then simultaneously performed both tasks. Accuracy and subjective measures were assessed. Offline analyses suggested that half of the subjects did not produce brain patterns that could be accurately discriminated in response to at least one of the two tasks. If these subjects produced comparable EEG patterns when trying to use a BCI, these subjects would not be able to communicate effectively because the BCI would make too many errors. Results also showed that switching to a different task used in BCIs could improve accuracy in some of these users. Switching to a hybrid approach eliminated this problem completely, and subjects generally did not consider the hybrid condition more difficult. Results validate this hybrid approach and suggest that subjects who cannot use a BCI should consider switching to a different BCI approach, especially a hybrid BCI. Subjects proficient with both approaches might combine them to increase information throughput by improving accuracy, reducing selection time, and/or increasing the number of possible commands.


Asunto(s)
Atención/fisiología , Encéfalo/fisiología , Imaginación/fisiología , Actividad Motora/fisiología , Interfaz Usuario-Computador , Percepción Visual/fisiología , Adolescente , Adulto , Electroencefalografía/métodos , Potenciales Evocados Visuales , Femenino , Lateralidad Funcional , Mano/fisiología , Humanos , Masculino , Pruebas Neuropsicológicas , Periodicidad , Estimulación Luminosa , Proyectos Piloto , Procesamiento de Señales Asistido por Computador , Adulto Joven
14.
Clin Neurophysiol ; 120(7): 1252-61, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19574091

RESUMEN

OBJECTIVE: Brain-computer interface (BCI) technology can provide severely disabled people with non-muscular communication. For those most severely disabled, limitations in eye mobility or visual acuity may necessitate auditory BCI systems. The present study investigates the efficacy of the use of six environmental sounds to operate a 6x6 P300 Speller. METHODS: A two-group design was used to ascertain whether participants benefited from visual cues early in training. Group A (N=5) received only auditory stimuli during all 11 sessions, whereas Group AV (N=5) received simultaneous auditory and visual stimuli in initial sessions after which the visual stimuli were systematically removed. Stepwise linear discriminant analysis determined the matrix item that elicited the largest P300 response and thereby identified the desired choice. RESULTS: Online results and offline analyses showed that the two groups achieved equivalent accuracy. In the last session, eight of 10 participants achieved 50% or more, and four of these achieved 75% or more, online accuracy (2.8% accuracy expected by chance). Mean bit rates averaged about 2 bits/min, and maximum bit rates reached 5.6 bits/min. CONCLUSIONS: This study indicates that an auditory P300 BCI is feasible, that reasonable classification accuracy and rate of communication are achievable, and that the paradigm should be further evaluated with a group of severely disabled participants who have limited visual mobility. SIGNIFICANCE: With further development, this auditory P300 BCI could be of substantial value to severely disabled people who cannot use a visual BCI.


Asunto(s)
Estimulación Acústica/métodos , Encéfalo/fisiología , Equipos de Comunicación para Personas con Discapacidad/tendencias , Personas con Discapacidad , Electroencefalografía , Interfaz Usuario-Computador , Adulto , Anciano , Corteza Auditiva/fisiología , Potenciales Relacionados con Evento P300/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Corteza Visual/fisiología
15.
Br J Cancer ; 100(1): 89-95, 2009 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-19088718

RESUMEN

Type II endometrial cancers (uterine serous papillary and clear cell histologies) represent rare but highly aggressive variants of endometrial cancer (EC). HER2 and EGFR may be differentially expressed in type II EC. Here, we evaluate the clinical role of HER2 and EGFR in a large cohort of surgically staged patients with type II (nonendometrioid) EC and compare the findings with those seen in a representative cohort of type I (endometrioid) EC. In this study HER2 gene amplification was studied by fluorescence in situ hybridisation (FISH) and EGFR expression by immunohistochemistry. Tissue microarrays were constructed from 279 patients with EC (145 patients with type I and 134 patients with type II EC). All patients were completely surgically staged and long-term clinical follow up was available for 258 patients. The rate of HER2 gene amplification was significantly higher in type II EC compared with type I EC (17 vs 1%, P<0.001). HER2 gene amplification was detected in 17 and 16% of the cases with uterine serous papillary and clear cell type histology, respectively. In contrast, EGFR expression was significantly lower in type II compared with type I EC (34 vs 46%, P=0.041). EGFR expression but not HER2 gene amplification was significantly associated with poor overall survival in patients with type II EC, (EGFR, median survival 20 vs 33 months, P=0.028; HER2, median survival 18 vs 29 months, P=0.113) and EGFR expression retained prognostic independence when adjusting for histology, stage, grade, and age (EGFR, P=0.0197; HER2, P=0.7855). We conclude that assessment of HER2 gene amplification and/or EGFR expression may help to select type II EC patients who could benefit from therapeutic strategies targeting both HER2 and EGFR.


Asunto(s)
Neoplasias Endometriales/genética , Receptores ErbB/análisis , Amplificación de Genes , Genes erbB-2 , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Neoplasias Endometriales/química , Neoplasias Endometriales/mortalidad , Neoplasias Endometriales/patología , Receptores ErbB/antagonistas & inhibidores , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Análisis de Matrices Tisulares
16.
Mult Scler ; 14(3): 354-63, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18208887

RESUMEN

The Faces Symbol Test (FST) has recently been proposed as a brief and patient-friendly screening instrument for the assessment of cognitive dysfunction in patients with multiple sclerosis (MS). However, in contrast to well-established MS screening tests such as the Paced Auditory Serial Addition Test, the neural correlates of the FST have not been investigated so far. In the present study, we developed a functional MRI (fMRI) version of the FST to provide first data on brain regions and networks involved in this test. A sample of 19 healthy participants completed a version of the FST adapted for fMRI, requiring matching of faces and symbols in a multiple choice test and two further experimental conditions drawing on cognitive subcomponents (face matching and symbol matching). Imaging data showed a differential involvement of a fronto-parieto-occipital network in the three conditions. The most demanding FST condition elicited brain activation patterns related with sustained attention and executive control. These results suggest that the FST recruits brain networks critical for higher-order cognitive functions often impaired in MS patients.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Imagen por Resonancia Magnética/métodos , Esclerosis Múltiple/complicaciones , Pruebas Neuropsicológicas , Adulto , Atención/fisiología , Trastornos del Conocimiento/fisiopatología , Cara , Femenino , Lóbulo Frontal/fisiología , Humanos , Masculino , Esclerosis Múltiple/fisiopatología , Lóbulo Occipital/fisiología , Lóbulo Parietal/fisiología , Reconocimiento Visual de Modelos , Estimulación Luminosa , Proyectos Piloto
17.
Int J Psychophysiol ; 67(1): 54-63, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18006099

RESUMEN

Near-infrared spectroscopy (NIRS) was used to assess human motor-cortex oxygenation changes in response to self-paced movements as well as movement imagery. We used a 24 channel NIRS-system which allows non-invasive monitoring of cerebral oxygenation changes in the human brain induced by cortical activity. From previous studies it is known that motor imagery activates sensorimotor areas similar to those activated during execution of the same movement. Sixteen healthy subjects were recruited and the changes in concentration of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) were examined during a simple right and left hand tapping task and during kinesthetic movement imagery. All subjects showed significant increases in oxy-Hb during both tasks compared to the resting period, but with different onset latencies of oxygenation. During left and right movement imagery, the oxy-Hb concentration increased about 2 s later compared to real movement execution. Furthermore, the oxygenation found was bilaterally represented for both tasks but with temporal differences. The present study reported new results concerning timing and topographical distribution of the hemodynamic response during motor imagery measured by near-infrared spectroscopy.


Asunto(s)
Mapeo Encefálico , Imaginación/fisiología , Corteza Motora/irrigación sanguínea , Destreza Motora/fisiología , Oxihemoglobinas/metabolismo , Adulto , Análisis de Varianza , Circulación Cerebrovascular/fisiología , Femenino , Hemodinámica/fisiología , Hemoglobinas/metabolismo , Humanos , Masculino , Corteza Motora/metabolismo , Movimiento/fisiología , Tiempo de Reacción/fisiología , Valores de Referencia , Flujo Sanguíneo Regional , Espectroscopía Infrarroja Corta , Factores de Tiempo
18.
IEEE Trans Neural Syst Rehabil Eng ; 14(2): 205-10, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16792295

RESUMEN

Over the last 15 years, the Graz Brain-Computer Interface (BCI) has been developed and all components such as feature extraction and classification, mode of operation, mental strategy, and type of feedback have been investigated. Recent projects deal with the development of asynchronous BCIs, the presentation of feedback and applications for communication and control.


Asunto(s)
Encéfalo/fisiopatología , Electroencefalografía/métodos , Enfermedades Neuromusculares/fisiopatología , Enfermedades Neuromusculares/rehabilitación , Proyectos de Investigación , Terapia Asistida por Computador/métodos , Interfaz Usuario-Computador , Animales , Austria , Potenciales Evocados , Humanos , Universidades
19.
Brain Res Cogn Brain Res ; 24(2): 252-9, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15993763

RESUMEN

In assuming functional differences between different EEG alpha frequency bands, recent studies emphasize the importance of using narrow (8-10 Hz or 10-12 Hz) instead of broad alpha frequency ranges (8-12 Hz). Due to individual differences in alpha activity, it has also been suggested to adjust alpha frequency bands individually for each participant. The present paper highlights the dissociating role of different task demands on the extent of event-related desynchronization (ERD) in different alpha frequency bands. In analyzing the data of four large-scale EEG studies (with sample sizes of 51, 58, 55, and 66, respectively) employing a wide range of cognitive tasks, we found evidence that the correlations between lower and upper alpha band ERD systematically decline as task demands increase.


Asunto(s)
Ritmo alfa , Sincronización Cortical , Trastornos Disociativos , Potenciales Evocados/fisiología , Procesos Mentales/fisiología , Adulto , Análisis de Varianza , Atención/fisiología , Mapeo Encefálico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Memoria/fisiología , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Valores de Referencia , Reproducibilidad de los Resultados , Conducta Verbal/fisiología
20.
Int J Psychophysiol ; 56(2): 129-41, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15804448

RESUMEN

In this study we analyzed the influence of the personality dimension extraversion-introversion (E) on the level and topographical distribution of cortical activation. In 62 participants (32 introverts and 30 extraverts), we measured the extent of Event-Related Desynchronization (ERD) in the EEG during performance of a short-term memory (i.e., temporary maintenance of information) and a more complex working memory task (i.e., temporary maintenance and active manipulation of information). The results indicate that during performance of both tasks, introverts display a larger amount of ERD than extraverted individuals. Moreover, the present E effects largely match previous studies as to the restriction of these effects to lower EEG frequency ranges (approx. 4-8 Hz). Topographical analyses show that the E effects are primarily present over (right-hemispheric) frontal and parietal regions of the cerebral cortex.


Asunto(s)
Corteza Cerebral/fisiología , Extraversión Psicológica , Memoria/fisiología , Desempeño Psicomotor/fisiología , Adulto , Femenino , Humanos , Introversión Psicológica , Masculino , Memoria a Corto Plazo/fisiología , Persona de Mediana Edad , Psicometría
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...