151 research outputs found
The Role of Neurosciences in Education... and Vice Versa
One of the key questions in education is how the learning process in the classroom takes place and how different environmental and individual circumstances (attention, motivation, nutrition, stimulus presentation, etc.) can enhance the child’s capabilities to learn and to remember. These and other cognitive skills are shaped as a consequence of the infant brain activity. Therefore, the provision of any information (included that obtained using animal models) relating to how the brain builds up learning and memory should be of high adaptive value. It is considered that an effort is needed to establish both a common language between education and neuroscience and a clear framework for exchanging questions and data
Interval Timing and Time-Based Decision Making
International audienceThe importance of time perception and timed performance is revealed in everyday activities from the sleep–wake cycle to verbal communication, playing, and appreciating music, the exquisite temporal control of both voluntary and involuntary behavior, and choice. With regard to the last point, making decisions is heavily influenced by the duration of the various options, the duration of the expected delays for receiving the options, and the time constraints for making a choice. Recent advances suggest that the brain represents time in a distributed manner and reflects time as a result of temporal changes in network states and/or by the coincidence detection of the phase of different neural populations. Moreover, the oscillatory properties of neural circuits can be shown to influence the acquisition of conditioned responding and the timing of motor responses. This Research Topic on “Interval Timing and Time-Based Decision Making” emerged from a symposium sponsored by the European COST-Action on Time In MEntaL activity: theoretical, behavioral, bioimaging, and clinical perspectives (TIMELY) that was a satellite of the European Brain and Behaviour Society meeting held in Seville, Spain (September 9, 2011). The focus of that TIMELY symposium was on “Neurobiology of Time Perception: From Normality to Dysfunction” and was organized by Valérie Doyère, Argiro Vatakis, and Elzbieta Szelag
El cerebro como máquina para aprender, recordar y olvidar
The brain is the organ responsible for two noticeable abilities, to think and to behave, the two of which are dependent on the capability to learn and to store the acquired information. The evident advances of the Neurosciences in the past few years has allowed the discovery of the mechanism underlying those processes, but many other aspects still wait for a discovery. Reasonable information is available on neuronal architecture and neuronal connecting processes, as well as on cerebral structures related with the generation and storage of the different types of memory. These findings have opened a path for the developing of drugs related to those neural processes. On the other hand, science fiction and media influences have potentiated the survival of several legends regarding the nervous system extraordinary capabilities: from considering the brain as a computer to accepting that it is a plastic structure with unlimited capabilities.El cerebro es el órgano responsable de dos grandes habilidades, pensar y actuar, las cuales requieren de la capacidad de aprender y de recordar la información adquirida. El gran avance de las Neurociencias en los últimos años ha permitido conocer algunos de los mecanismos que subyacen a estos procesos, pero quedan aún muchos aspectos por descubrir. Se conoce la estructura neuronal y muchos de los mecanismos de comunicación entre neuronas y se han identificado algunas estructuras relacionadas con la elaboración y almacenamiento de los diferentes tipos de memoria. Esto ha animado al desarrollo de fármacos que puedan incidir positivamente sobre estos procesos. La ciencia ficción por un lado, y la presión mediática por el otro, han hecho que perduren algunas leyendas acerca de las extraordinarias capacidades del sistema nervioso: desde aceptar que el cerebro es como un ordenador a pensar que es de una estructura plástica con capacidades prácticamente ilimitadas
Differing Presynaptic Contributions to LTP and Associative Learning in Behaving Mice
The hippocampal CA3-CA1 synapse is an excellent experimental model for studying the interactions between short- and long-term plastic changes taking place following high-frequency stimulation (HFS) of Schaffer collaterals and during the acquisition and extinction of a classical eyeblink conditioning in behaving mice. Input/output curves and a full-range paired-pulse study enabled determining the optimal intensities and inter-stimulus intervals for evoking paired-pulse facilitation (PPF) or depression (PPD) at the CA3-CA1 synapse. Long-term potentiation (LTP) induced by HFS lasted ≈10 days. HFS-induced LTP evoked an initial depression of basal PPF. Recovery of PPF baseline values was a steady and progressive process lasting ≈20 days, i.e., longer than the total duration of the LTP. In a subsequent series of experiments, we checked whether PPF was affected similarly during activity-dependent synaptic changes. Animals were conditioned using a trace paradigm, with a tone as a conditioned stimulus (CS) and an electrical shock to the trigeminal nerve as an unconditioned stimulus (US). A pair of pulses (40 ms interval) was presented to the Schaffer collateral-commissural pathway to evoke field EPSPs (fEPSPs) during the CS-US interval. Basal PPF decreased steadily across conditioning sessions (i.e., in the opposite direction to that during LTP), reaching a minimum value during the 10th conditioning session. Thus, LTP and classical eyeblink conditioning share some presynaptic mechanisms, but with an opposite evolution. Furthermore, PPF and PPD might play a homeostatic role during long-term plastic changes at the CA3-CA1 synapse
BASES FISIOLÓGICAS DEL APRENDIZAJE ASOCIATIVO
El condicionamiento clásico del reflejo corneal es un modelo muy utilizado en el estudio de los procesos de aprendizaje y memoria. Nuestro grupo de investigación ha estudiado las características cinéticas de las respuestas palpebrales reflejas, voluntarias, emocionales y aprendidas, así como la
fisiología de las motoneuronas que inervan el músculo orbicularis oculi, encargado de realizar dichos movimientos. Las motoneuronas faciales codifican la velocidad de cierre de los párpados durante respuestas reflejas y su posición durante respuestas aprendidas. Esta diferencia indica un diferente procesamiento (y/u origen) de ambas órdenes motoras. Tanto la corteza paravermal como el núcleo interpósito posterior del cerebelo están relacionados con los movimientos palpebrales reflejos y aprendidos, contribuyendo a su correcta realización, pero no a su aprendizaje. A su vez, el hipocampo interviene en la determinación del valor predictivo del estímulo condicionado, durante condicionamientos de tipo pavloviano
Timing and Causality in the Generation of Learned Eyelid Responses
The cerebellum-red nucleus-facial motoneuron (Mn) pathway has been reported as being involved in the proper timing of classically conditioned eyelid responses. This special type of associative learning serves as a model of event timing for studying the role of the cerebellum in dynamic motor control. Here, we have re-analyzed the firing activities of cerebellar posterior interpositus (IP) neurons and orbicularis oculi (OO) Mns in alert behaving cats during classical eyeblink conditioning, using a delay paradigm. The aim was to revisit the hypothesis that the IP neurons (IPns) can be considered a neuronal phase-modulating device supporting OO Mns firing with an emergent timing mechanism and an explicit correlation code during learned eyelid movements. Optimized experimental and computational tools allowed us to determine the different causal relationships (temporal order and correlation code) during and between trials. These intra- and inter-trial timing strategies expanding from sub-second range (millisecond timing) to longer-lasting ranges (interval timing) expanded the functional domain of cerebellar timing beyond motor control. Interestingly, the results supported the above-mentioned hypothesis. The causal inferences were influenced by the precise motor and pre-motor spike timing in the cause-effect interval, and, in addition, the timing of the learned responses depended on cerebellar–Mn network causality. Furthermore, the timing of CRs depended upon the probability of simulated causal conditions in the cause-effect interval and not the mere duration of the inter-stimulus interval. In this work, the close relation between timing and causality was verified. It could thus be concluded that the firing activities of IPns may be related more to the proper performance of ongoing CRs (i.e., the proper timing as a consequence of the pertinent causality) than to their generation and/or initiation
Neural bases of freedom and responsibility
This review presents a broad perspective of the Neuroscience of our days with special attention to how the brain generates our behaviors, emotions, and mental states. It describes in detail how unconscious and conscious processing of sensorimotor and mental information takes place in our brains. Likewise, classic and recent experiments illustrating the neuroscientific foundations regarding the behavioral and cognitive abilities of animals and, in particular, of human beings are described. Special attention is applied to the description of the different neural regulatory systems dealing with behavioral, cognitive, and emotional functions. Finally, the brain process for decision-making, and its relationship with individual free will and responsibility, are also described
An agonist–antagonist cerebellar nuclear system controlling eyelid kinematics during motor learning
The presence of two antagonistic groups of deep cerebellar nuclei neurons has been reported as necessary for a proper dynamic control of learned motor responses. Most models of cerebellar function seem to ignore the biomechanical need for a double activation–deactivation system controlling eyelid kinematics, since most of them accept that, for closing the eyelid, only the activation of the orbicularis oculi (OO) muscle (via the red nucleus to the facial motor nucleus) is necessary, without a simultaneous deactivation of levator palpebrae motoneurons (via unknown pathways projecting to the perioculomotor area). We have analyzed the kinetic neural commands of two antagonistic types of cerebellar posterior interpositus neuron (IPn) (types A and B), the electromyographic (EMG) activity of the OO muscle, and eyelid kinematic variables in alert behaving cats during classical eyeblink conditioning, using a delay paradigm. We addressed the hypothesis that the interpositus nucleus can be considered an agonist–antagonist system controlling eyelid kinematics during motor learning. To carry out a comparative study of the kinetic–kinematic relationships, we applied timing and dispersion pattern analyses. We concluded that, in accordance with a dominant role of cerebellar circuits for the facilitation of flexor responses, type A neurons fire during active eyelid downward displacements—i.e., during the active contraction of the OO muscle. In contrast, type B neurons present a high tonic rate when the eyelids are wide open, and stop firing during any active downward displacement of the upper eyelid. From a functional point of view, it could be suggested that type B neurons play a facilitative role for the antagonistic action of the levator palpebrae muscle. From an anatomical point of view, the possibility that cerebellar nuclear type B neurons project to the perioculomotor area—i.e., more or less directly onto levator palpebrae motoneurons—is highly appealing
El procesamiento temporal en el Trastorno por Déficit de Atención e Hiperactividad
El procesamiento temporal es una actividad cerebral primordial para el adecuado funcionamiento de las personas en las actividades de la vida diaria
y su afectación constituye uno de los signos de disfunción más importantes en el Trastorno por Déficit de Atención e Hiperactividad (TDAH). El
objetivo de este trabajo es revisar los antecedentes y estudios científicos realizados sobre el procesamiento del tiempo en personas con TDAH, así
como realizar una propuesta de valoración de esta función en poblaciones con este trastorno del neurodesarrollo. El procesamiento del tiempo ha
sido poco estudiado clínicamente, aunque sí en el ámbito neurocientífico y experimental. La mayoría de los estudios se han basado en mecanismos
relacionados con la percepción temporal y la reproducción de intervalos de tiempo a nivel motor, en los cuales se han descrito distorsiones en personas
con TDAH. Se han propuesto diversas teorías basadas en una afectación primaria de la percepción del tiempo, aunque en otras ocasiones
esta afectación se ha considerado secundaria a las alteraciones nucleares del trastorno. Entre las conclusiones del estudio destacamos que los
procesos cognitivos relacionados con el procesamiento temporal son diversos y requieren del funcionamiento de distintos dominios cognitivos. Si
bien se han desarrollado algunas pruebas para la evaluación de esta función, precisamos de nuevas herramientas para la adecuada valoración del
procesamiento del tiempo en personas con TDAH.
Palabras clave: Inatención; Hiperactividad; Impulsividad;Time Processing in Attention Deficit Hyperactivity Disorder. Time processing is a primary brain activity for the proper functioning of people in their
daily activities. Its affectation is one of the most important signs of dysfunction in Attention Deficit Hyperactivity Disorder (ADHD). The aim was to
review the background and scientific studies carried out on time processing in patients with ADHD, as well as top put forward a proposal for evaluating
this function in populations with this neurodevelopmental disorder. Although time processing has not been studied clinically in detail, it has been
approached experimentally in the neuroscientific field. Most studies of time processing have been based on functional phenomena related to time
perception and timed motor reproductions; distortions of these two functions have been described in people with ADHD. Several theories based on
a primary affectation of time processing have been proposed; however, on some occasions this affectation has been considered secondary to the
nuclear alterations of the disorder. The cognitive processes related to temporal processing are rather diverse and require the functioning of different
cognitive domains. Although some tests have been developed for the evaluation of this function, new tools are needed for the proper assessment
of time processing in people with ADH
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