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In this review, we examine the structural connectivity of a recently-identified fiber pathway, the frontal aslant tract (FAT), and explore its function. We first review structural connectivity studies using tract-tracing methods in non-human primates, and diffusion-weighted imaging and electrostimulation in humans. These studies suggest a monosynaptic connection exists between the lateral inferior frontal gyrus and the pre-supplementary and supplementary motor areas of the medial superior frontal gyrus. This connection is termed the FAT. We then review research on the left FAT's putative role in supporting speech and language function, with particular focus on speech initiation, stuttering and verbal fluency. Next, we review research on the right FAT's putative role supporting executive function, namely inhibitory control and conflict monitoring for action. We summarize the extant body of empirical work by suggesting that the FAT plays a domain general role in the planning, timing, and coordination of sequential motor movements through the resolution of competition among potential motor plans. However, we also propose some domain specialization across the hemispheres. On the left hemisphere, the circuit is proposed to be specialized for speech actions. On the right hemisphere, the circuit is proposed to be specialized for general action control of the organism, especially in the visuo-spatial domain. We close the review with a discussion of the clinical significance of the FAT, and suggestions for further research on the pathway.

The structure and connectivity of the prefrontal cortex has been extensively studied for its contribution to language and executive function (EF) development, but many questions still remain whether its microstructural tissue properties can reliably predict behavioral outcomes in very young typically and atypically developing populations. In particular, the bilateral frontal aslant tract (FAT) has garnered increasing interest with respect to its potential association with both language and EF, but has yet to be examined in childhood attention disorders, such Attention Deficit Hyperactivity Disorder (ADHD). At the same time, with advances in diffusion weighted imaging (DWI), new diffusion models offer more nuanced characterizations of specific tissue properties, namely neurite (axonal and dendritic) density and organization. Restricted diffusion imaging (RDI) and neurite orientation dispersion and density diffusion imaging (NODDI) are two advanced approaches to measuring density \textit{in vivo} that have been tested in animal, infant, and adult studies, but have been sparsely examined in regards to their association with behavioral outcomes in young children. We can now apply these diffusion methods to the analysis of microstructure of the frontal lobe and its association with language and EF. Thus, across three studies, this dissertation aims to answer the following questions: Does the FAT show age-related change during the sensitive developmental period between 4- to 7-years of age, and do age-related differences differ in children diagnosed with ADHD? Can the microstructural properties of the FAT differentially predict language and EF outcomes in ADHD and control samples? Are novel DWI methods capable of reliably mapping neurite density in children and adults and expanding what we currently know about brain microstructure and maturation? And finally, can neurite density and orientation within prefrontal and subcortical brain regions predict behavioral outcomes in

In this review, we examine the structural connectivity of a recently-identified fiber pathway, the frontal aslant tract (FAT), and explore its function. We first review structural connectivity studies using tract-tracing methods in non-human primates, and diffusion-weighted imaging and electrostimulation in humans. These studies suggest a monosynaptic connection exists between the lateral inferior frontal gyrus and the pre-supplementary and supplementary motor areas of the medial superior frontal gyrus. This connection is termed the FAT. We then review research on the left FAT's putative role in supporting speech and language function, with particular focus on speech initiation, stuttering and verbal fluency. Next, we review research on the right FAT's putative role supporting executive function, namely inhibitory control and conflict monitoring for action. We summarize the extant body of empirical work by suggesting that the FAT plays a domain general role in the planning, timing, and coordination of sequential motor movements through the resolution of competition among potential motor plans. However, we also propose some domain specialization across the hemispheres. On the left hemisphere, the circuit is proposed to be specialized for speech actions. On the right hemisphere, the circuit is proposed to be specialized for general action control of the organism, especially in the visuo-spatial domain. We close the review with a discussion of the clinical significance of the FAT, and suggestions for further research on the pathway.

Summary: The current study examined the possibility of using cluster analysis to classify attachment styles in middle childhood. Attachment classifications were measured by looking at child coping strategies and perceived maternal behavior. The attachment classification was then tested for construct validity by examining whether it can predict adjustment outcomes in interpretable patterns. The adjustment outcomes examined were a self-reported global self-worth scale and peer-reported internalizing and externalizing behaviors measured using a Peer Nomination Inventory. The current study had 199 third through eight graders and provided evidence for the cluster analysis approach and also showed that the disorganized attachment was associated with the most adverse adjustment outcomes. That is, results showed that disorganized attachment was linked with the lowest levels of global self-worth and the highest rates of internalizing and externalizing behaviors and was significantly different from the securely attached cluster on each measure. The implications and possible underlying causes are discussed., 2015, Includes bibliography., Degree granted: Thesis (M.A.)--Florida Atlantic University, 2015, Collection: FAU Electronic Theses and Dissertations Collection