Academic Publications
Growth models of major white matter tract neurite density from infancy through adolescence.
Diffusion Tensor Imaging is a technique that allows for mapping and quantification of white matter tracts. The aim of this paper is look at 10 regions of interest and quantify their timing and magnitude of development across childhood and adolescence per intracellular volume fraction (FICVF). FICVF is believed to measure axon density therefore an increase in FICVF is likely a reflection of axon diameter and/or myelination. The magnitude and timing of white matter development vary by brain region, we found cingulate gyrus develop earliest while corticospinal tract developing latest.
Novel Behavioral Paradigm for Assessing Performance in Children with Dyslexia
This paper introduces an fMRI task paradigm we created that incorporates dynamic difficulty in orthographic and phonologic word recognition. As participants select consecutive correct or incorrect responses the task gets harder or is simplified, respectively. This is meant to address a confound in many task design paradigms where motivation is not taken into consideration. For example, a dyslexic participant when faced with numerous consecutive difficult questions may become frustrated, any future errors maybe attributed to motivation rather than a lack of reading skill. We found an accuracy range similar across groups and difference in reaction time in the dyslexic group.
Characterizing Functional Reading Networks in Children with Dyslexia
With this paper we looked at the methodologies that normal vs dyslexic children use to read. We used an fMRI task where participants were asked to choose either the proper orthographic (spelling) or phonological (pronunciation ) of various words.
Across the behavioral tasks we found what is to be expected, that dyslexia children are at reading deficit (reaction time, accuracy and overall difficulty reached) compared to normal developing children. However, we are interested in the techniques used to read (orthographically vs phonemically), we found an interaction between groups and task when looking at difficulty level.
We also found that for the Dyslexic group there was no significant activation overlap compared to the Control group for mean activation. However, this maybe a result of insufficient statistical power and sample size. Alternatively, the activation threshold applied maybe too stringent to illuminate overlaps between groups.