Electrophysiology of statistical learning: Exploring the online learning process and offline learning product

A continuous stream of syllables is segmented into discrete constituents based on the transitional probabilities (TPs) between adjacent syllables by means of statistical learning. However, we still do not know whether people attend to high TPs between frequently co‐occurring syllables and cluster them together as parts of the discrete constituents or attend to low TPs aligned with the edges between the constituents and extract them as whole units. Earlier studies on TP‐based segmentation also have not distinguished between the segmentation process (how people segment continuous speech) and the learning product (what is learnt by means of statistical learning mechanisms). In the current study, we explored the learning outcome separately from the learning process, focusing on three possible learning products: holistic constituents that are retrieved from memory during the recognition test, clusters of frequently co‐occurring syllables, or a set of statistical regularities which can be used to reconstruct legitimate candidates for discrete constituents during the recognition test. Our data suggest that people employ boundary‐finding mechanisms during online segmentation by attending to low inter‐syllabic TPs during familiarization and also identify potential candidates for discrete constituents based on their statistical congruency with rules extracted during the learning process. Memory representations of recurrent constituents embedded in the continuous speech stream during familiarization facilitate subsequent recognition of these discrete constituents.     

Working memory training and brain structure and function in extremely preterm or extremely low birth weight children

This study in children born extremely preterm (EP; <28 weeks’ gestational age) or extremely low birth weight (ELBW; <1,000 g) investigated whether adaptive working memory training using Cogmed® is associated with structural and/or functional brain changes compared with a placebo program. Ninety‐one EP/ELBW children were recruited at a mean (standard deviation) age of 7.8 (0.4) years. Children were randomly allocated to Cogmed or placebo (45‐min sessions, 5 days a week over 5–7 weeks). A subset had usable magnetic resonance imaging (MRI) data pretraining and 2 weeks posttraining (structural, n = 48; diffusion, n = 43; task‐based functional, n = 18). Statistical analyses examined whether cortical morphometry, white matter microstructure and blood oxygenation level‐dependent (BOLD) signal during an n‐back working memory task changed from pretraining to posttraining in the Cogmed and placebo groups separately. Interaction analyses between time point and group were then performed. There was a significant increase in neurite density in several white matter regions from pretraining to posttraining in both the Cogmed and placebo groups. BOLD signal in the posterior cingulate and precuneus cortices during the n‐back task increased from pretraining to posttraining in the Cogmed but not placebo group. Evidence for group‐by‐time interactions for the MRI measures was weak, suggesting that brain changes generally did not differ between Cogmed and placebo groups. Overall, while some structural and functional MRI changes between the pretraining and posttraining period in EP/ELBW children were observed, there was little evidence of training‐induced neuroplasticity, with changes generally identified in both groups. Trial registration Australian New Zealand Clinical Trials Registry, anzctr.org.au ; ACTRN12612000124831.     

Geographic disparity: the dilemma of lower socioeconomic status,multiple listing,and death on the liver transplant waiting list

Due to the current regionally based allocation system, some patients list for and are transplanted away from home in regions with shorter waits and higher transplant rates. Of 147 included patients, 120 died waiting and 27 received transplants at outside centers during the study (32.5 months). Those transplanted elsewhere had higher median incomes than patients dying on the waitlist ($84 946 vs. $55 250, p = 0.0001). Those with median incomes <$60 244 were more likely to die than those with incomes >$60 244 (94% vs. 70%, RR: 1.35, 95% CI: 1.14–1.59). Patients with Medicaid were more likely to die waiting than those with other insurance (100% vs. 77%, RR: 1.30, 95% CI: 1.18–1.44). Our analysis demonstrates that those who died waiting were more likely to have lower incomes and Medicaid compared with those transplanted elsewhere. Even when we controlled for Medicaid status, patients who died waiting had lower incomes compared with those transplanted elsewhere. Increased organ sharing over geographically broader regions, as recommended by the Institute of Medicine in 1999, may reduce incentives for patients to travel to receive a liver and reduce inequities. Current efforts to address this disparity continue to fall short of the Institute of Medicine recommendations, United States Department of Health and Human Services regulations and the Final Rule.     

Caring for Children with an Autism Spectrum Disorder: Factors Associating with Health- and Care-Related Quality of Life of the Caregivers

Journal of Autism and Developmental Disorders - This study investigated the association of child, caregiver, and caregiving measurements with the quality of life (QoL) in 81 caregivers (mostly...