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Large-Scale Functional Hyperconnectivity Patterns In Trauma-Related Dissociation: An Rs-Fmri Study Of Ptsd And Its Dissociative Subtype, Saurabh B. Shaw, Braeden A. Terpou, Maria Densmore, Jean Theberge, Pau Frewen, Margaret C. Mckinnon, Ruth A. Lanius

Department of Medicine Publications

The dissociative subtype of post-traumatic stress disorder (PTSD) is a distinct PTSD phenotype characterized by trauma-related dissociation, alongside unique patterns of functional connectivity. However, disparate findings across multiple scales of investigation have highlighted the need for a cohesive understanding of dissociative neurobiology. We took a step towards this goal by conducting one of the broadest region of interest (ROI)-to-ROI analyses performed on a PTSD population to date. In this retrospective study, we investigated resting-state functional MRI data collected from a total of 192 participants, 134 of whom were diagnosed with PTSD. Small functional connectivity differences (maximum effect size 0.27) were …

White Matter Connectome Associations With Reading Functions In Children, Chenglin Lou

Electronic Thesis and Dissertation Repository

This thesis investigated associations between the white matter connectome and reading in children with a wide range of reading abilities. It is well established that the connectome supports the interplay among brain regions and connections within an integrated system. In this dissertation, I examine the hypothesis that it could therefore represent multiple mapping processes among reading components and further explain variations in reading performance. Such associations between the organization of the connectome and reading skills have not been well explored. This thesis aimed to address this issue by considering both the relationship between connectome measures and standardized reading performance out …

Fraction Magnitude Understanding Across Learning Formats: An Fmri Study, Chloe A. Henry

Electronic Thesis and Dissertation Repository

Knowledge of fraction magnitudes are an important, but notoriously difficult mathematical concept to master. Behavioural work has begun to explore and compare the instructional tools used for fraction learning. However, how fraction instructional tools are processed in the brain remains an underexplored question. Therefore, in the present thesis, we used functional brain MRI methodology to examine the neural activity of adult participants while completing a fraction verification task using the number line and area model, two common methods of fraction learning. We found that both models commonly recruited fronto-parietal activity, the neural regions typically implicated in number processing. However, we …

Investigating The Roles Of The Dorsal And Ventral Striatum In Humor Comprehension And Appreciation Throughout Health, Aging, And Parkinson’S Disease, Maggie Prenger

Electronic Thesis and Dissertation Repository

Humor processing is thought to involve two distinct components. The first, humor comprehension, involves detecting and resolving incongruities that are present within a humorous stimulus. This is related to cognitive processes such as ambiguity resolution, response inhibition, working memory, and cognitive flexibility, functions that are mediated in part by the dorsal portion of the striatum (DS). Humor appreciation, on the other hand, refers to the subjective amusement and mirth that one experiences in response to a joke. This is related to reward processing, which implicates the ventral portion of the striatum (VS). Across three separate studies, we investigated the involvement …

Neural Correlates Of Online Movement Preparation, Mahdiyar Shahbazi

Electronic Thesis and Dissertation Repository

The ability to prepare future action while controlling the ongoing execution is a fundamental characteristic of complex sequential behavior. Recent evidence suggests that when movement preparation and execution are separated in time, brain activity patterns for preparation are highly correlated with those underlying execution. But what happens when the brain needs to prepare and execute movements at the same time, as in the context of rapid movement sequences? We designed a 7T functional magnetic resonance imaging experiment with conditions where the next response preparation either overlapped with the current response execution or did not. Although overlap and non-overlap conditions were …

Examining The Relationships Between Socio-Cognitive Factors And Neural Synchrony During Movie Watching Across Development, Kathleen M. Lyons

Electronic Thesis and Dissertation Repository

While different cognitive abilities mature, the conscious experiences of children likely become richer and more elaborate. A challenge in investigating relationships between cognitive development and real-world experiences is having measures that assess naturalistic processing. Movie watching offers a solution, since following the plot of a film requires cognitive processes that are similar to real-world experiences. When different adults watch the same film, their brain activity begins to align (known as neural synchrony). The strength of this alignment has been shown to reflect the degree to which different individuals are having a similar experience of the movie. While this phenomenon has …

Role Of The Default-Mode Network During Narrative Integration In Major Depressive Disorder, Darren Ri-Sheng Liang

Electronic Thesis and Dissertation Repository

How brain activity is synchronized across individuals during narrative comprehension has previously been characterized by functional magnetic resonance imaging (fMRI) in healthy and patient populations. To our knowledge, there has been limited investigation as to how it is affected by major depressive disorder (MDD). We addressed this issue with fMRI through examination of inter-subject synchronization in the default mode network (DMN), brain structures which have previously been implicated in MDD pathology. Twenty-two patients with MDD and 20 matched control participants listened to Intact versus Scrambled versions of an auditory narrative; these experimental conditions differed in the degree of temporal integration …

Human Claustrum Activation During Pain, Zoravar S. Sidhu, David A. Seminowicz, Brent W. Stewart

Undergraduate Student Research Internships Conference

Chronic pain is one of the principal causes of disability in the world. Many if not all of us deal with or know of someone who deals with chronic pain. Interestingly, it appears that a mysterious part of the brain known as the claustrum has a hand in chronic pain. Although little is known about the actual function of the claustrum, it is hypothesized to synchronize cortical networks during tasks which have a cognitive load.

Recent literature has indicated that during chronic pain conditions, neural network recruitment is modified. In addition, an analysis of an existing fMRI data set determined …

Three Dimensions Of Association Link Migraine Symptoms And Functional Connectivity, Samuel R. Krimmel, Danielle D. Desouza, Michael L. Keaser, Bharati M. Sanjanwala, Robert P. Cowan, Martin A. Lindquist, Jennifer A. Haythornthwaite, David A. Seminowicz

Neuroscience Institute Publications

Migraine is a heterogeneous disorder with variable symptoms and responsiveness to therapy. Because of previous analytic shortcomings, variance in migraine symptoms has been inconsistently related to brain function. In the current analysis, we used data from two sites (n = 143, male and female humans), and performed canonical correlation analysis, relating restingstate functional connectivity (RSFC) with a broad range of migraine symptoms, ranging from headache characteristics to sleep abnormalities. This identified three dimensions of covariance between symptoms and RSFC. The first dimension related to headache intensity, headache frequency, pain catastrophizing, affect, sleep disturbances, and somatic abnormalities, and was associated with …

Mapping The Integration Of Sensory Information Across Fingers In Human Sensorimotor Cortex, Spencer A. Arbuckle, J. Andrew Pruszynski, Jörn Diedrichsen

Neuroscience Institute Publications

The integration of somatosensory signals across fingers is essential for dexterous object manipulation. Previous experiments suggest that this integration occurs in neural populations in the primary somatosensory cortex (S1). However, the integration process has not been fully characterized, as previous studies have mainly used 2-finger stimulation paradigms. Here, we addressed this gap by stimulating all 31 single- and multifinger combinations. We measured population-wide activity patterns evoked during finger stimulation in human S1 and primary motor cortex (M1) using 7T fMRI in female and male participants. Using multivariate fMRI analyses, we found clear evidence of unique nonlinear interactions between fingers. In …

Neural Correlates Of Familiarity Across Time Scales And Their Involvement In Explicit Memory Decisions, Haopei Yang

Electronic Thesis and Dissertation Repository

Familiarity is a type of memory signal that can support recognition of prior occurrences without retrieval of associated contextual information. It is typically probed with respect to recent laboratory exposure in recognition-memory studies involving human participants. This line of work has revealed several neural correlates including event-related potentials (ERPs) and blood-oxygenation-level-dependent (BOLD) activity in several regions. However, few studies have examined familiarity accumulated outside of laboratory settings through lifetime experience. Hence, it is currently unclear whether similar neural correlates are involved. The fluency-attribution framework decomposes familiarity judgement into automatic and decision-related processes. Since recent and lifetime familiarity are phenomenologically and …

Mapping Of Structure-Function Age-Related Connectivity Changes On Cognition Using Multimodal Mri, Daiana Roxana Pur, Maria Giulia Preti, Anik De Ribaupierre, Dimitri Van De Ville, Roy Eagleson, Nathalie Mella, Sandrine De Ribaupierre

Neuroscience Institute Publications

The relationship between age-related changes in brain structural connectivity (SC) and functional connectivity (FC) with cognition is not well understood. Furthermore, it is not clear whether cognition is represented via a similar spatial pattern of FC and SC or instead is mapped by distinct sets of distributed connectivity patterns. To this end, we used a longitudinal, within-subject, multimodal approach aiming to combine brain data from diffusion-weighted MRI (DW-MRI), and functional MRI (fMRI) with behavioral evaluation, to better understand how changes in FC and SC correlate with changes in cognition in a sample of older adults. FC and SC measures were …

Can Novel Findings From Emerging Neuroscientific Technologies Be Incorporated Into Trademark Law In Canada?, Pankhuri Malik

Electronic Thesis and Dissertation Repository

American scholar, Mark Bartholomew, predicted in 2018 that a new kind of neuroscientific evidence would help businesses involved in lawsuits connect their trademarks with the public’s perception of their trademarks. Bartholomew coined the term "neuromarks’ for this evidence. Bartholomew focused on U.S. trademark law. This research demonstrates, looking at both Canada’s domestic law and Canada’s relevant international treaties and trade agreements, that such evidence has not yet been used (in 2022) in trademark litigation in Canadian courts or tribunals but that there appears to be no legal barrier to its use in future in Canada. This research notes that neuroscience …

While You Were Sleeping: Evidence For High-Level Executive Processing Of An Auditory Narrative During Sleep, Stuart Fogel, Laura Ray, Zhuo Fang, Max Silverbrook, Lorina Naci, Adrian M. Owen

Neuroscience Institute Publications

During sleep we lack conscious awareness of the external environment. Yet, our internal mental state suggests that high-level cognitive processes persist. The nature and extent to which the external environment is processed during sleep remain largely unexplored. Here, we used an fMRI synchronization-based approach to examine responses to a narrative during wakefulness and sleep. The stimulus elicited the auditory network and a frontoparietal pattern of activity, consistent with high-level narrative plot-following. During REM sleep, the same frontoparietal pattern was observed in one of three participants, and partially in one other, confirming that it is possible to track and follow the …

Neuroimaging Depression Risk In A Sample Of Never-Depressed Children, Matthew R. J. Vandermeer

Electronic Thesis and Dissertation Repository

Children of mothers with a history of depression are at significantly higher risk for developing depression themselves. Although numerous mechanisms explaining this relationship have been proposed (Goodman & Gotlib, 1999), relatively little is known about the neural substrates of never-depressed children’s depression risk. Of the few studies that have used neuroimaging techniques to characterize risk-based differences in children’s neural structure, function, and functional connectivity, most have used samples that include participants with a personal history of depression or older samples (i.e., past the typical age of onset for depressive disorders). These approaches limit what can be determined regarding whether findings …

Investigating Bone Cement Susceptibility Related Artifacts And Adhesion, Eric Kuindersma

Electronic Thesis and Dissertation Repository

Blood Oxygen Level Dependent (BOLD) functional Magnetic Resonance Imaging (fMRI) utilizes pulse sequences sensitive to changes in concentration of deoxyhemoglobin to indirectly measure neural activity. Sequences used for BOLD are sensitive to magnetic susceptibility differences that may cause signal voids. Our lab has designed an awake marmoset head coil that eliminates confounds associated with imaging an animal under anesthesia. This design requires a head chamber attached to an animal’s skull with a cement that may cause a susceptibility artifact. Motivation behind this project was to find an MRI compatible cement that remains secure to the skull with minimal artifacts. Four …

Neural Markers Of Musical Memory In Young And Older Adults, Avital Sternin

Electronic Thesis and Dissertation Repository

Memory for music can be preserved in the presence of neurodegenerative disorders even when other memories are forgotten. However, understanding how the brain remembers music has proven difficult despite decades of research. The central goal of this thesis was to elucidate the neural correlates of musical memory by exploring how the presence of language and music information affect the way young and older adults remember music. To that end, I 1) used a controlled training paradigm to familiarize participants with novel stimuli that manipulated the presence of language and music, and 2) collected functional magnetic resonance imaging data to compare …

Inter-Subject Correlation Using Movie-Driven Fmri In Drug-Resistant Epilepsy, Hana H. Abbas

Electronic Thesis and Dissertation Repository

Treating drug-resistant epilepsy with surgery requires the localization of the epileptic focus. We explored the potential for movie-driven functional magnetic resonance imaging (fMRI) to act as a sensitive, non-invasive, and cost-effective tool to identify functionally disturbed networks. We assessed neural synchronization (inter-subject correlation; ISC) between presurgical epilepsy patients (n = 18) and healthy controls (n = 24) as they watched a suspenseful movie clip in the scanner. To optimize denoising, we compared ISC values with and without an automated Independent Components Analysis-based denoising step (ICA-AROMA). We found that denoising with ICA-AROMA elicited augmented correlation values, supporting its use …

Discovering The Brain Activation Patterns Associated With Somatosensory Stimulation In The Lower Extremity In Healthy Adults At Rest: Preliminary Results For A Systematic Review, Siying Luan

Undergraduate Student Research Internships Conference

Stroke, which is the leading cause of disability and the third leading cause of death in adults in North America, burdens millions of people as they age. When people experience the long-lasting consequences of stroke, such as limited mobility, the rehabilitation process becomes critical. The mechanism behind walking is supported by a complex system, the somatosensory nervous system. This system transmits information that is essential for one to complete daily tasks, which means the relationship between the somatosensory system and walking is critical to understand for future innovative rehabilitation interventions. Thus, we are investigating the brain activation patterns associated with …

Speech-Evoked Brain Activity Is More Robust To Competing Speech When It Is Spoken By Someone Familiar, Emma Holmes, Ingrid S. Johnsrude

Communication Sciences and Disorders Publications

When speech is masked by competing sound, people are better at understanding what is said if the talker is familiar compared to unfamiliar. The benefit is robust, but how does processing of familiar voices facilitate intelligibility? We combined high-resolution fMRI with representational similarity analysis to quantify the difference in distributed activity between clear and masked speech. We demonstrate that brain representations of spoken sentences are less affected by a competing sentence when they are spoken by a friend or partner than by someone unfamiliar—effectively, showing a cortical signal-to-noise ratio (SNR) enhancement for familiar voices. This effect correlated with the familiar-voice …

Brain Representations Of Dexterous Hand Control: Investigating The Functional Organization Of Individuated Finger Movements And Somatosensory Integration, Spencer Arbuckle

Electronic Thesis and Dissertation Repository

Using our hands to manipulate objects in our daily life requires both dexterous movements and the integration of somatosensory information across fingers. Although the primary motor (M1) and somatosensory cortices (S1) are critical for these two complementary roles, it is unclear how neural populations in these regions functionally represent these processes. This thesis examined the functional organization of brain representations (the representational geometry) in M1 and S1 for dexterous hand control and somatosensory processing. To that end, representational geometries were estimated from fine-grained brain activity patterns measured with functional MRI (fMRI). Since fMRI measures a blood-based proxy of neural activity, …

Reciprocal Relations Between Reading Skill And The Neural Basis Of Phonological Awareness In 7- To 9-Year-Old Children, Jin Wang, Julia Pines, Marc Joanisse, James R. Booth

Linguistics Publications

By using a longitudinal design and functional magnetic resonance imaging (fMRI), our previous study (Wang et al., 2020) found a scaffolding effect of early phonological processing in the superior temporal gyrus (STG) in 6-year-old children on later behavioral reading skill in 7.5-year-old children. Other than this previous study, nothing is known about longitudinal change in the bidirectional relation between reading skill and phonological processing in the brain. To fill this gap, in the current study, we used the same experimental paradigm as in Wang et al. (2020) to measure children's reading skill and brain activity during an auditory phonological awareness …

The Hijacked Self: Midbrain And Default Mode Network Functional Patterns In Ptsd, Braeden A. Terpou

Electronic Thesis and Dissertation Repository

In post-traumatic stress disorder (PTSD), self-related processing disturbances are demonstrated commonly and have been linked to the default mode network (DMN), a large-scale, neural network altered significantly after trauma. However, emerging evidence suggests the midbrain may be underlying self-related processing disturbances as well, yet midbrain systems remain poorly characterized in PTSD. Here, we evaluated midbrain activity and functional connectivity during subliminal, trauma-related stimulus processing (Chapters 2–4), as well as during moral injury-related (MI) memory recall (Chapter 5) in participants with PTSD as compared to healthy controls. Initially, during subliminal, trauma-related stimulus processing, we revealed stronger midbrain periaqueductal gray (PAG) activity …

Brain Signatures Of Human Skill Learning: From Single Movements To Movement Sequences, Eva Berlot

Electronic Thesis and Dissertation Repository

Sequences of finger movements, such as making a cup of coffee or playing the piano, have a key role in our lives. An important neuroscientific question is how such movement sequences are represented in the brain. The central goal of this thesis was to investigate how different brain regions represent individual movements, and how these representations change when learning sequences of movements. To that end, we used 1) high-field functional magnetic resonance imaging (fMRI) to measure brain activation in humans while they produced finger movements on a keyboard-like device, and 2) advanced multivariate analyses to characterize the brain representations underlying …

Shame On The Brain: Neural Correlates Of Moral Injury Event Recall In Posttraumatic Stress Disorder, Chantelle S. Lloyd, Andrew A. Nicholson, Maria Densmore, Jean Théberge, Richard W. J. Neufeld, Rakesh Jetly, Margaret C. Mckinnon, Ruth A. Lanius

Department of Medicine Publications

Background: Moral injury (MI) is consistently associated with adverse mental healthoutcomes, including the development of posttraumatic stress disorder (PTSD) andsuicidality. Methods: We investigated neural activation patterns associated with MI eventrecall using functional magnetic resonance imaging in participants with military andpublic safety‐related PTSD, relative to civilian MI‐exposed controls. Results: MI recall in the PTSD as compared to control group was associatedwith increased neural activation among salience network nodes involved inviscerosensory processing and hyperarousal (right posterior insula, dorsalanterior cingulate cortex; dACC), regions involved in defensive responding(left postcentral gyrus), and areas responsible for top‐down cognitive controlof emotions (left dorsolateral prefrontal cortex; dlPFC). Within …

Evaluating Anesthetic Protocols For Non-Human Primate Functional Neuroimaging, Megha Verma

Electronic Thesis and Dissertation Repository

Functional magnetic resonance imaging (fMRI) is a non-invasive technique that can be used to measure a proxy of neural activity in vivo with high spatial specificity. One subject can be followed for a long period of time to assess changes in functional brain organization. However, fMRI is extremely sensitive to motion. The challenges of training non-human primates to reduce motion in an MRI scanner motivate the study of anesthesia which is commonly used to substitute for this training. In this thesis, I compare three different commonly used anesthetic protocols: isoflurane, propofol-fentanyl in combination, and fentanyl alone, to test which of …

Sharing Voxelwise Neuroimaging Results From Rhesus Monkeys And Other Species With Neurovault, Andrew S. Fox, Daniel Holley, Peter Christiaan Klink, Spencer A. Arbuckle, Carol A. Barnes, Jörn Diedrichsen, Sze Chai Kwok, Colin Kyle, J. Andrew Pruszynski, Jakob Seidlitz, Xu Feng Zhou, Russell A. Poldrack, Krzysztof J. Gorgolewski

Brain and Mind Institute Researchers' Publications

© 2020 The Authors Animal neuroimaging studies can provide unique insights into brain structure and function, and can be leveraged to bridge the gap between animal and human neuroscience. In part, this power comes from the ability to combine mechanistic interventions with brain-wide neuroimaging. Due to their phylogenetic proximity to humans, nonhuman primate neuroimaging holds particular promise. Because nonhuman primate neuroimaging studies are often underpowered, there is a great need to share data amongst translational researchers. Data sharing efforts have been limited, however, by the lack of standardized tools and repositories through which nonhuman neuroimaging data can easily be archived …

Symbols Are Special: An Fmri Adaptation Study Of Symbolic, Nonsymbolic, And Non-Numerical Magnitude Processing In The Human Brain, H Moriah Sokolowski, Zachary Hawes, Lien Peters, Daniel Ansari

Brain and Mind Institute Researchers' Publications

How are different formats of magnitudes represented in the human brain? We used functional magnetic resonance imaging adaptation to isolate representations of symbols, quantities, and physical size in 45 adults. Results indicate that the neural correlates supporting the passive processing of number symbols are largely dissociable from those supporting quantities and physical size, anatomically and representationally. Anatomically, passive processing of quantities and size correlate with activation in the right intraparietal sulcus, whereas symbolic number processing, compared with quantity processing, correlates with activation in the left inferior parietal lobule. Representationally, neural patterns of activation supporting symbols are dissimilar from neural activation …

Structure Of Population Activity In Primary Motor Cortex For Single Finger Flexion And Extension, Spencer A. Arbuckle, Jeff Weiler, Eric A. Kirk, Charles L. Rice, Marc Schieber, J. Andrew Pruszynski, Naveed Ejaz, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Copyright © 2020 the authors How is the primary motor cortex (M1) organized to control fine finger movements? We investigated the population activity in M1 for single finger flexion and extension, using 7T functional magnetic resonance imaging (fMRI) in female and male human participants and compared these results to the neural spiking patterns recorded in two male monkeys performing the identical task. fMRI activity patterns were distinct for movements of different fingers, but were quite similar for flexion and extension of the same finger. In contrast, spiking patterns in monkeys were quite distinct for both fingers and directions, which is …

The Neural Basis Of Metacognitive Monitoring During Arithmetic In The Developing Brain, Elien Bellon, Wim Fias, Daniel Ansari, Bert De Smedt

Brain and Mind Institute Researchers' Publications

In contrast to a substantial body of research on the neural basis of cognitive performance in several academic domains, less is known about how the brain generates metacognitive (MC) awareness of such performance. The existing work on the neurobiological underpinnings of metacognition has almost exclusively been done in adults and has largely focused on lower level cognitive processing domains, such as perceptual decision-making. Extending this body of evidence, we investigated MC monitoring by asking children to solve arithmetic problems, an educationally relevant higher-order process, while providing concurrent MC reports during fMRI acquisition. Results are reported on 50 primary school children …