Impaired decision-making and time perception in individuals with stroke: Behavioral and neural correlates.

Several studies have demonstrated that stroke subjects present impairment of functions related to decision-making and timing, involving the information processing in the neural circuits of the cerebellum in association with the prefrontal cortex. This review is aimed to identify the gaps, and demonstrate a better understanding of decision-making and timing functions in the patients with stroke. Electronic literature database was searched and the findings of relevant studies were used to explore the mechanisms of decision-making and timing in patients with stroke, as well as the circuit connections in timing mediated by prefrontal cortex and cerebellum. A literature review was conducted with 65 studies that synthesized findings on decision-making and time perception in individuals with stroke. Types of neurobiological modalities in this study included: Relationships among decision-making, time perception, related cognitive aspects (such as discrimination tasks, verbal estimation, bisection tasks, time production and motor reproduction), and motor control. We demonstrate that the timing processes are important for the performance in cognitive tasks and that the cerebellum and prefrontal cortex are involved in decision-making and time perception. In the context, the decision-making is impaired in stroke patients has a great impact on executive functions, and this seems to be important in determining neurobiological aspects relevant to the time interval interpretation.

[The effects of bromazepam on the performance of a sensory-motor activity: an electroencephalographic study]. / Efectos del bromacepam en el desarrollo de una actividad sensoriomotora: un estudio electroencefalográfico.

AIMS: To investigate the effects of using bromazepam on the relative power in alpha while performing a typing task. Bearing in mind the particularities of each brain hemisphere, our hypothesis was that measuring the relative power would allow us to investigate the effects of bromazepam on specific areas of the cortex. More specifically, we expected to observe different patterns of powers in sensory-motor integration, attention and activation processes. SUBJECTS AND METHODS: The sample was made up of 39 subjects (15 males and 24 females) with a mean age of 30 +/- 10 years. The control (placebo) and experimental (3 mg and 6 mg of bromazepam) groups were trained in the typing task with a randomised double-blind model. RESULTS: A three-way ANOVA and Scheffé test were used to analyse interactions between the factors condition and moment, and between condition and sector. CONCLUSIONS: The doses used in this study facilitated motor performance of the typing task. In this study, the use of the drug did not prevent learning of the task, but it did appear to concentrate mental effort on more restricted and specific aspects of typing. It also seemed to influence the rhythm and effectiveness of the operations performed during mechanisms related to the encoding and storage of new information. Likewise, a predominance of activity was observed in the left (dominant) frontal area in the 3 mg bromazepam group, which indicates that this dose of the drug affords the subject a greater degree of directionality of cortical activity for planning and performing the task.

Efectos del bromacepam en el desarrollo de una actividad sensoriomotora: un estudio electroencefalográfico / The effects of bromazepan on the performance of a sensory-motor activity: an electroencephalographic study

Objetivos. Investigar los efectos del uso del bromacepam en la potencia relativa en alfa durante la realización de unatarea de mecanografía. Teniendo en cuenta las particularidades de cada hemisferio cerebral, nuestra hipótesis era que a travésde la medida de la potencia relativa sería posible investigar el efecto del bromacepam sobre áreas corticales específicas. Concretamente,se esperaba observar diferentes patrones de potencias en los procesos de atención, activación e integración sensoriomotora.Sujetos y métodos. La muestra estaba formada por 39 sujetos (15 hombres y 24 mujeres) con una media de edad de30 ± 10 años. Los grupos control (placebo) y experimental (bromacepam de 3 mg y 6 mg) fueron entrenados en la tarea de mecanografíacon un modelo doble ciego aleatorizado. Resultados. Mediante el ANOVA de tres vías y el test de Scheffé se comprobaroninteracciones entre los factores condición y momento y entre condición y sector. Conclusión. Las dosis empleadas en esteestudio facilitaron el desarrollo motor de la tarea de mecanografía. En este estudio, el uso del fármaco no impidió el aprendizajede la tarea, pero parece ser que concentró el esfuerzo mental sobre aspectos más restringidos y específicos de la mecanografía.Tuvo lugar una influencia sobre el ritmo y la eficacia de las operaciones ejecutadas durante mecanismos de codificacióny almacenamiento de nuevas informaciones. Asimismo, se comprobó un predominio de actividad en el área frontal izquierda(dominante) en el grupo bromacepam 3 mg, lo cual indica que esta dosis del fármaco permite al sujeto un mayor direccionamientode la actividad cortical para la planificación y la ejecución de la tarea(AU)

Aims. To investigate the effects of using bromazepam on the relative power in alpha while performing a typing task.Bearing in mind the particularities of each brain hemisphere, our hypothesis was that measuring the relative power wouldallow us to investigate the effects of bromazepam on specific areas of the cortex. More specifically, we expected to observedifferent patterns of powers in sensory-motor integration, attention and activation processes. Subjects and methods. The samplewas made up of 39 subjects (15 males and 24 females) with a mean age of 30 ± 10 years. The control (placebo) and experimental(3 mg and 6 mg of bromazepam) groups were trained in the typing task with a randomised double-blind model. Results. A threewayANOVA and Scheffé test were used to analyse interactions between the factors condition and moment, and betweencondition and sector. Conclusions. The doses used in this study facilitated motor performance of the typing task. In this study,the use of the drug did not prevent learning of the task, but it did appear to concentrate mental effort on more restricted andspecific aspects of typing. It also seemed to influence the rhythm and effectiveness of the operations performed duringmechanisms related to the encoding and storage of new information. Likewise, a predominance of activity was observed in theleft (dominant) frontal area in the 3 mg bromazepam group, which indicates that this dose of the drug affords the subject agreater degree of directionality of cortical activity for planning and performing the task(AU)

[The role played by the parietooccipital cortex in the process of sensory-motor integration: an electroencephalographic study]. / Participación de la corteza parietooccipital en el proceso de integración sensoriomotora: estudio electroencefalográfico.

INTRODUCTION: A fundamental aspect of planning future actions is the performance and control of motor tasks. This behaviour is done through sensory-motor integration. AIM: To explain the electrophysiological mechanisms in the cortex (modifications to the alpha band) that are involved in anticipatory actions when individuals have to catch a free-falling object. SUBJECTS AND METHODS: The sample was made up of 20 healthy subjects of both sexes (11 males and 9 females) with ages ranging between 25 and 40 years (32.5 +/- 7.5) who were free of mental or physical diseases (previous medical history); the subjects were right-handed (Edinburgh Inventory) and were not taking any psychoactive or psychotropic substances at the time of the study. The experiment consisted in a task in which subjects had to catch freely falling objects. The experiment was made up of six blocks of 15 tests, each of which lasted 2 minutes and 30 seconds, with a break of one minute between blocks. Data were captured by means of a quantitative electroencephalogram two seconds before and two seconds after each ball was dropped. RESULTS: An interaction of the factors moment and position was only observed for the right parietooccipital cortex, in the combination of electrodes P4-O2. CONCLUSION: These findings suggest that the right parietooccipital cortex plays an important role in increasing expectation and swiftness in the processes of preparing for a motor task.

[Learning and implicit memory: mechanisms and neuroplasticity]. / Aprendizaje y memoria implícita: mecanismos y neuroplasticidad.

INTRODUCTION: Learning and memory are complex processes that researchers have been attempting to unravel for over a century in order to gain a clear view of the underlying mechanisms. AIMS: To review the basic cellular and molecular mechanisms involved in the process of procedural retention, to offer an overall view of the fundamental mechanisms involved in storing information by means of theories and models of memory, and to discuss the different types of memory and the role played by the cerebellum as a modulator of procedural memory. DEVELOPMENT: Experimental results from recent decades have opened up new areas of study regarding the participation of the biochemical and cellular processes related to the consolidation of information in the nervous system. CONCLUSIONS: The neuronal circuits involved in acquiring and consolidating memory are still not fully understood and the exact location of memory in the nervous system remains unknown. A number of intrinsic and extrinsic factors interfere in these processes, such as molecular (long-term potentiation and depression) and cellular mechanisms, which respond to communication and transmission between nerve cells. There are also factors that have their origin in the outside environment, which use the association of events to bring about the formation of new memories or may divert the subject from his or her main focus. Memory is not a singular occurrence; it is sub-divided into declarative and non-declarative or, when talking about the time it lasts, into short and long-term memory. Moreover, given its relation with neuronal mechanisms of learning, memory cannot be said to constitute an isolated process.