Events Structure Information Accessibility Less in Children than Adults

Adults parse continuous experience into meaningful events, a process referred to as event segmentation. This segmentationin turn colors how experiences are construed content experienced within an event is held mentally in an accessible state,which is then dropped after an event boundary. However, little is known about whether children are similarly influencedby event boundaries. Here, we tested seven- to nine-year-old childrens and adults recognition of objects experienced eitherwithin or across event boundaries of two cartoons. We found that children and adults were both more accurate and fasterto correctly recognizing objects that last occurred within events than across an event boundary. We, however, additionallyobserved an interaction such that childrens access to recent experience was less influenced by event boundaries than adults.Thus, while the spontaneous segmentation of complex events emerges by middle childhood, event structure less reliablyshapes the active contents of childrens minds than adults

Comparison of Diffusion-Weighted MRI Reconstruction Methods for Visualization of Cranial Nerves in Posterior Fossa Surgery

Diffusion-weighted imaging (DWI)-based tractography has gained increasing popularity as a method for detailed visualization of white matter (WM) tracts. Different imaging techniques, and more novel, advanced imaging methods provide significant WM structural detail. While there has been greater focus on improving tract visualization for larger WM pathways, the relative value of each method for cranial nerve reconstruction and how this methodology can assist surgical decision-making is still understudied. Images from 10 patients with posterior fossa tumors (4 male, mean age: 63.5), affecting either the trigeminal nerve (CN V) or the facial/vestibular complex (CN VII/VIII), were employed. Three distinct reconstruction methods [two tensor-based methods: single diffusion tensor tractography (SDT) (3D Slicer), eXtended streamline tractography (XST), and one fiber orientation distribution (FOD)-based method: streamline tractography using constrained spherical deconvolution (CSD)-derived estimates (MRtrix3)], were compared to determine which of these was best suited for use in a neurosurgical setting in terms of processing speed, anatomical accuracy, and accurate depiction of the relationship between the tumor and affected CN. Computation of the tensor map was faster when compared to the implementation of CSD to provide estimates of FOD. Both XST and CSD-based reconstruction methods tended to give more detailed representations of the projections of CN V and CN VII/VIII compared to SDT. These reconstruction methods were able to more accurately delineate the course of CN V and CN VII/VIII, differentiate CN V from the cerebellar peduncle, and delineate compression of CN VII/VIII in situations where SDT could not. However, CSD-based reconstruction methods tended to generate more invalid streamlines. XST offers the best combination of anatomical accuracy and speed of reconstruction of cranial nerves within this patient population. Given the possible anatomical limitations of single tensor models, supplementation with more advanced tensor-based reconstruction methods might be beneficial

The Development of Learning Across Levels of Abstraction

When we learn about the world around us, we not only process what makes items unique, we also notice consistencies across items. However, it is unknown how learning at these two levels of abstraction interact. Might there be a trade-off in learning? Moreover, given children’s different cognitive abilities, do they experience a similar trade-off? Finally, are irrelevant features still processed, just in a more superficial manner? We explored these questions using a categorization task followed by a surprise recognition test in adults and children. Results suggest that adults do show a trade-off in learning. However, children’s memory scores were too low to make any definitive conclusions. Lastly, both adults and children noticed consistencies in the irrelevant features, and this knowledge also traded-off with category learning in adults and moderately in children. These data point to a fundamental cognitive process in which learning comes at a cost, at least in adults.M.A

A Trade-Off in Learning Across Levels of Abstraction in Adults and Children

Learning about novel objects not only involves noticinginformation that makes the object unique, but also what makesobjects the same. Yet, these two levels of learning involvedifferent pieces of information, meaning that learning one wellcould come at the cost of the other. Moreover, children maycategorize in a fundamentally different way, resulting in theselevels of learning interacting differently. To investigate this,we had adults and children perform a categorization taskfollowed by an item recognition test. We found that adultsshowed a trade-off, such that the ability to categorize itemscame at the cost of memory for those items. Using a subset ofmore unique lures, children’s memory trended towards a trade-off with category learning. However, this was only observedamong the older children. This suggests that adults’ efficientlearning comes at a cost, and this trade-off may start to appearin the elementary school years