The human brain is an ongoing dynamic system not activated by experience but nudged from intrinsic activity into new network configurations during perception and learning. Ongoing neural activity during rest is assumed to reflect these intrinsic dynamics in a relatively closed system state. Traditionally, inter-regional connectivity in this system is measured by obtaining time-locked correlations in BOLD activity using fMRI. It is well documented, however, that neural activity unfolds across time and is not isolatent to some reference point.  

                This exploratory study is a theoretical analysis of how a lagged analysis of resting state dynamics in fMRI could represent persistent representations of knowledge in the neocortex. A novel procedure using both surface based maps and independent component analysis (ICA) is applied to a small group of 54 adolescents. The ICA methods appear to reveal lagged structures with different information than traditional resting state analysis. The group level results are symmetrical between hemispheres and may represent high level perceptual systems. 

                The components obtained from this exploration are then used to attempt understand how these knowledge systems in neocortex frame mind-wandering frequency when reading aloud in a subset of 38 individuals. The results did not correlate with any known neural systems related to mind wandering, but the methods here are unique. One of the identified components shows significant difference in the lag structure of the occipital cortex as a function of mind wandering frequency during oral reading. This demonstrates that it may be worth exploring the timing in visual system to understand why individuals mind wander when reading aloud. Reverse inference is used to interpret results and suggest future approaches.

This study examines how gains in mathematics achievement are related to executive processing functions and student sociodemographic characteristics across schools’ national representative longitudinal sample of children in kindergarten (K) followed through grade four in the Early Childhood Longitudinal Study of 2010.

Mathematics trajectories were nonlinear, with greater gains in early versus later grades and small drops each summer. Children entering K with lower math demonstrated steeper gains over time. Relative to Caucasian children, Hispanic and African American children entered K with lower math. Hispanic children had higher growth rates whereas African American children had lower growth rates. Girls entered K with higher math, but boys gained more over time. Lower SES was associated with lower math but also steeper increases. Demographic factors explained a larger proportion of between-school differences in mathematics achievement than within-school differences in initial levels and long-term gains but not summer drops (66.23% versus 8.11% of variance at K; 17.02% versus 4.55% of variance in gains; 20% versus 0% of variance in summer drops). Similarly, shaped trajectories and demographic effects were found for working memory, while the cognitive flexibility trajectory (measured only from 2nd grade) was a more linear. Critically, just as lower math scores in K were associated with steeper growth, lower working memory in K was also associated with steeper trajectories. In addition, positive associations were observed between working memory and math in K, trajectories of working memory and cognitive flexibility were strongly associated with trajectories of mathematics achievement. A similar pattern was observed for cognitive flexibility. These inclusions of demographic covariates did not alter these associations. Overall, these findings bolster the independent importance of executive function and sociodemographic factors, with the latter explaining a large amount of between-school variability. Education stakeholders such as teachers, school administrations, and school district can rely on the research findings in designing practical models of teaching mathematics that will take into consideration the role of sociodemographic factors as well as executive functioning among students, thereby improving their overall performance.

As an asphalt concrete demonstration project implemented under the California Department of Transportation's Long-Life Pavement Rehabilitation Strategies program, a 4.4 km stretch of Interstate-710 (1-710) in Long Beach was successfully rehabilitated during eight repeated 55-h extended weekend closures using around-the-c lock construction operations and counterflow traffic. This case study documented the accelerated rehabilitation process, assessed traffic impacts, and compared collected productivity data. Compared to the productivity rates of traditional nighttime closures. the 55-h weekend closures effectively reduced the construction duration and the overall traffic inconvenience. Noticeable improvement ("learning-curve effect") in the contractor's production rates was observed as the weekend Closures were repeated. As a result of a significant (38%) traffic demand reduction through the work zone, the traffic impact of construction closures was tolerable to the extent that traffic was in free-flow condition throughout the highway network. This case study will be useful for transportation agencies and contractors in developing integrated construction and traffic management plans for urban freeway rehabilitation projects to maximize pavement life expectancy and construction productivity while minimizing agency and road user costs.

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