Graduate Student Seminar Set for September 22

The first Beckman Institute Graduate Student Seminar is set for Wednesday, September 22 at Noon in Room 1005. The seminar will feature three short talks from graduate students: Laura Chaddock, Corissa Lee, and Lydia Majure. A pizza lunch is provided to those attending the seminar.

The first Beckman Institute Graduate Student Seminar is set for Wednesday, September 22 at Noon in Room 1005. The seminar will feature three short talks from graduate students: Laura Chaddock, Corissa Lee, and Lydia Majure. A pizza lunch is provided to those attending the seminar.

The titles and abstracts of the talks are:

Childhood Aerobic Fitness, Brain & Cognition
Laura Chaddock, Ph.D. student
Brain and Cognition division of the Psychology department

Children are becoming more sedentary and unfit, leading to an increase in obesity and illness throughout the lifespan. Recent reports show that an inactive lifestyle during childhood also influences brain and cognitive health. Children with low physical activity levels show diminished neuroelectric event-related potential (ERP) activation underlying attentional processes, lower academic achievement scores, and inferior cognitive performance compared to physically fit children.  Despite accumulating evidence that shows the physical and cognitive advantages of an active lifestyle during childhood, educational systems are eliminating physical education programs in favor of academic subjects.

The Kramer lab is the first to employ MRI techniques to study the fitness-cognition link in children.  Our studies extend ERP and behavioral methods by demonstrating that aerobic fitness may influence the structure and function of the developing brain.  Specifically, higher-fit children show larger hippocampal volumes which are associated with improved performance on a relational memory task.  Higher-fit children also show greater dorsal striatum volumes of the basal ganglia which relate to improved cognitive control.

Our results demonstrate a positive association between aerobic fitness, brain volume and cognition during preadolescence. We hope that our results will encourage modifications of educational and healthcare policies that will emphasize the importance of physical activity.

Mechanochemistry in Polyurethane
Corissa Lee, Graduate Research Assistant
Braun Research Group

Spiropyran (SP) mechanophores (mechanochemically reactive units) can impart the unique functionality of visual stress detection to polymers and have potential for use in smart materials with self-sensing capabilities.  These color-generating mechanophores were incorporated into polyurethane via a step growth polymerization.  Polyurethane, which is inherently a versatile engineering polymer, possesses an optimized balance of mechanical toughness and elasticity to allow for investigation of the kinetics of the SP mechanophore in the bulk polymer using fluorescence and absorbance measurements.  The stress-induced 6-π electrocyclic ring-opening to the colored merocyanine (MC) form of the mechanophore was quantified by measuring the change in absorbance of the polymer, while it was held at constant strain.  The closing kinetics of the mechanophore was also studied using fluorescence imaging. Additionally, the effects of mechanical strain on the mechanophore incorporated polymer and alterations to the equilibrium between the SP and MC forms were also studied.

Integrating Language and Motor Function on a Humanoid Robot
Lydia Majure, Graduate student
Language Acquisition and Robotics Group

Human cognition is a complex, multimodal, hierarchical system which allows flexible interaction with the outside world. The field of developmental robotics attempts to recreate such a system, allowing for robots which need no further instruction, training data, or hardcoding beyond that which is provided to human children. Until recently, such research has focused on associative memories which connect visual and auditory inputs. However, advanced humanoid robots are now allowing the study of motor learning and how to integrate it with other modes of information. Just like language is necessarily grounded in semantics built from associations between the sentences, motions need to be tied to their meaning and behavioral goals for successful learning. One of the Language Acquisition and Robotics group's current projects is implementing motor learning in an imitative framework with a human teacher, using a sensorimotor associative memory to semantically and behaviorally ground the observed actions. This approach allows for adaptive acquisition of new skills and generalization across diverse motions which share meaning.