Neurobiology of expectancy effects and omission of reinforcement on behavior

The reinforcement omission effects have been traditionally interpreted in terms of: behavioral facilitation after reinforcement omission induced by primary frustration or behavioral suppression after reinforcement delivery induced by postconsummatory states. The studies reviewed here indicate that amygdala is involved in modulation of these effects. However, the fact that amygdala lesions, extensive or selective, can eliminate, reduce and enhance the omission effects makes it difficult to understand how it is the exact nature of their involvement. The amygdala is related to several functions that depend on its connections with other brain systems. Thus, it is necessary to consider the involvement of a more complex neural network in the modulation of the reinforcement omission effects. The connection of amygdala subareas to cortical and subcortical structures may be involved in this modulation since they also are linked to processes related to reward and expectancy.

Paroxysmal upgaze deviation: case report

The paroxysmal upgaze deviation is a syndrome that described in infants for first time in 1988; there are just about 50 case reports worldwide ever since. Its etiology is unclear and though it prognosis is variable; most case reports indicate that during growth the episodes tend to decrease in frequency and duration until they disappear. It describes a 16-months old male child who since 11-months old presented many episodes of variable conjugate upward deviation of the eyes, compensatory neck flexion and down-beat saccades in attempted downgaze. These events are predominantly diurnal, and are exacerbated by stressful situations such as fasting or insomnia, however and improve with sleep. They have normal neurologic and ophthalmologic examination, and neuroimaging and EEG findings are not relevant.

Determinación de la condición física de un grupo de montañistas de Bogotá antes y después de un programa de ejercicio físico de 7 semanas de duración

Se determino la condición física de un grupo de montañistas de Bogotá, con relación al consumo de oxígeno; fuerza muscular de cintura escapular, flexo-extensores de hombro, codo y muñeca, flexo-extensores de cadera y rodilla mediante el test de una repetición máxima (1RM) y abdominales en un minuto, así como la determinación de flexibilidad y la composición corporal que incluyó índice de masa corporal (IMC), porcentaje graso (Ross y Guimaraes) y perímetro de abdomen. También se incluyó una encuesta comportamental para determinar las líneas de acción y estrategias a seguir durante un programa de ejercicio físico que duro 7 semanas