Assessment of preschooler’s scientific reasoning in adult–child interactions: What is the optimal context?

In educational settings, continuous assessment of the child's level of understanding is necessary to effectively utilize the principles of scaffolding and to create contexts that can advance the scientific reasoning of the child. In this article, we argue that a child's performance is a dynamic notion that is created by all elements in an interaction, including the task. Therefore, we studied preschoolers' levels of scientific reasoning varying different properties of the assessment context. Young children were interviewed about four scientific tasks using one out of four different protocols (varying in the degree of flexibility and adaptiveness) by an adult. In the first study, different task contents resulted in different performance levels. The second study indicated that the most structured protocol elicited the highest maximum level of reasoning in children and the highest percentage of correct predictions. The third study showed differences between the protocols in the adult's verbal behavior. Adaptation in verbal behavior to different children by the adult did not result in higher scientific understanding by the children, whereas a higher degree of task structure did. Combined, the studies emphasize the importance of context, which has implications for assessment and teaching situations

'Grassland Compass': a practical tool to improve grass production and grass utilization at Dutch dairy farms

Dutch dairy farms feel an increasing need to improve grassland production and grassutilization while at the same time reducing the environmental impact because of sustainability goals, legislation on manure management and recent intended policies

'Grassland Compass': a practical tool to improve grass production and grass utilization at Dutch dairy farms

Dutch dairy farms feel an increasing need to improve grassland production and grassutilization while at the same time reducing the environmental impact because of sustainability goals, legislation on manure management and recent intended policies

Top-down modulation in human visual cortex predicts the stability of a perceptual illusion

Conscious perception sometimes fluctuates strongly, even when the sensory input is constant. For example, in motion-induced blindness (MIB), a salient visual target surrounded by a moving pattern suddenly disappears from perception, only to reappear after some variable time. Whereas such changes of perception result from fluctuations of neural activity, mounting evidence suggests that the perceptual changes, in turn, may also cause modulations of activity in several brain areas, including visual cortex. In this study, we asked whether these latter modulations might affect the subsequent dynamics of perception. We used magnetoencephalography (MEG) to measure modulations in cortical population activity during MIB. We observed a transient, retinotopically widespread modulation of beta (12-30 Hz)-frequency power over visual cortex that was closely linked to the time of subjects' behavioral report of the target disappearance. This beta modulation was a top-down signal, decoupled from both the physical stimulus properties and the motor response but contingent on the behavioral relevance of the perceptual change. Critically, the modulation amplitude predicted the duration of the subsequent target disappearance. We propose that the transformation of the perceptual change into a report triggers a top-down mechanism that stabilizes the newly selected perceptual interpretation