Neuroscience and Neurobiology Commons^™

Mapping The Functional Organization Of Human Frontoparietal Cortex With Fmri, Geetika Gupta

Electronic Thesis and Dissertation Repository

Higher-order cognitive functions, such as working memory, attention, and decision making, depend strongly on the functional integrity of frontal and parietal cortices. However, the internal workings of the frontoparietal network (FPN) are not well understood. A major contributor to this knowledge gap is our limited understanding of the intrinsic functional organization of the FPN. In order to address this gap, we examine task-dependent reconfigurations of functional connectivity (FC) within the FPN. We analyzed fMRI task-state data from 924 individuals from the Human Connectome Project Young Adult study. Our results show that FC within the FPN is highly stable across time …

Cognitive Resources Are Recruited Consistently Across People During Story Listening, Matthew T. Bain

Electronic Thesis and Dissertation Repository

Degraded speech encoding as a result of hearing loss increases cognitive load and makes listening effortful. Standard hearing assessment does not capture this cognitive impact of hearing impairment. Speech-in-noise testing measures intelligibility for isolated sentences that are typically not engaging and lack meaningful context. These materials may not capture the processes involved in everyday listening situations, in which people are often intrinsically motivated to comprehend the speech they are hearing. The current study explored a novel approach using natural, spoken stories. We first characterized time courses of executive load during story listening in young individuals with normal hearing using a …

Role Of Anterior Cingulate Cortex In Saccade Control, Sahand Babapoor-Farrokhran

Electronic Thesis and Dissertation Repository

Cognitive control is referred to the guidance of behavior based on internal goals rather than external stimuli. It has been postulated that prefrontal cortex is mainly involved in higher order cognitive functions. Specifically, anterior cingulate cortex (ACC), which is part of the prefrontal cortex, is suggested to be involved in performance monitoring and conflict monitoring that are considered to be cognitive control functions.

Saccades are the fast eye movements that align the fovea on the objects of interest in the environment. In this thesis, I have explored the role of ACC in control of saccadic eye movements. First, I performed …

Toward A Functional Characterization Of Cognitive Control Networks, Frederick Ezekiel

Electronic Thesis and Dissertation Repository

Cognitive control is an executive process that has been associated with a distributed set of cortical regions. These distributed regions appear to cluster into distinct networks with dissociable functions. In this study, independent component analysis was used as a tool to investigate functional connectivity in event-related fMRI data. Extracted networks of interest were functionally characterized using a hybrid task that independently probed moment-to-moment adjustments in control, and stable task-set maintenance. A cinguloinsular network was implicated in the processing of moment-to-moment adjustments in control based on its activation patterns during this task. Subsequently, functional connectivity between two networks previously implicated in …

Dissociable And Dynamic Components Of Cognitive Control: A Developmental Electrophysiological Investigation, Matthew Waxer

Electronic Thesis and Dissertation Repository

One standard task used to investigate the development of cognitive control is the Dimensional Change Card Sort (DCCS). Performance and patterns of brain activity associated with the DCCS show continued age-related advances into early adolescence. According to many theoretical accounts, the DCCS places demands on a single underlying executive control process. Three experiments examined the possibility that the DCCS places demands on multiple control processes that follow distinct developmental trajectories. In Experiment 1, rule switching and conflict processing made orthogonal contributions to DCCS performance. Rule switching was associated with a cue-locked late frontal negativity (LFN) event-related potential (ERP) and conflict …