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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 …

Sign And Speech Share Partially Overlapping Conceptual Representations, Samuel Evans, Cathy J. Price, Jörn Diedrichsen, Eva Gutierrez-Sigut, Mairéad Macsweeney

Brain and Mind Institute Researchers' Publications

© 2019 The Author(s) Conceptual knowledge is fundamental to human cognition. Yet, the extent to which it is influenced by language is unclear. Studies of semantic processing show that similar neural patterns are evoked by the same concepts presented in different modalities (e.g., spoken words and pictures or text) [1–3]. This suggests that conceptual representations are “modality independent.” However, an alternative possibility is that the similarity reflects retrieval of common spoken language representations. Indeed, in hearing spoken language users, text and spoken language are co-dependent [4, 5], and pictures are encoded via visual and verbal routes [6]. A parallel approach …

Binding During Sequence Learning Does Not Alter Cortical Representations Of Individual Actions, Patrick Beukema, Jörn Diedrichsen, Timothy D. Verstynen

Brain and Mind Institute Researchers' Publications

Copyright © 2019 the authors. As a sequence of movements is learned, serially ordered actions get bound together into sets to reduce computational complexity during planning and execution. Here, we investigated how actions become naturally bound over the course of learning and how this learning affects cortical representations of individual actions. Across 5 weeks of practice, neurologically healthy human subjects learned either a complex 32-item sequence of finger movements (trained group, n = 9; 3 female) or randomly ordered actions (control group, n = 9; 3 female). Over the course of practice, responses during sequence production in the trained group …

Understanding The Neural Bases Of Implicit And Statistical Learning, Laura J. Batterink, Ken A. Paller, Paul J. Reber

Brain and Mind Institute Researchers' Publications

© 2019 Cognitive Science Society, Inc. Both implicit learning and statistical learning focus on the ability of learners to pick up on patterns in the environment. It has been suggested that these two lines of research may be combined into a single construct of “implicit statistical learning.” However, by comparing the neural processes that give rise to implicit versus statistical learning, we may determine the extent to which these two learning paradigms do indeed describe the same core mechanisms. In this review, we describe current knowledge about neural mechanisms underlying both implicit learning and statistical learning, highlighting converging findings between …

The Neural Association Between Arithmetic And Basic Numerical Processing Depends On Arithmetic Problem Size And Not Chronological Age, Anna A. Matejko, Daniel Ansari

Brain and Mind Institute Researchers' Publications

© 2019 The Authors The intraparietal sulcus (IPS) is thought to be an important region for basic number processing (e.g. symbol-quantity associations) and arithmetic (e.g. addition). Evidence for shared circuitry within the IPS is largely based on comparisons across studies, and little research has investigated number processing and arithmetic in the same individuals. It is also unclear how the neural overlap between number processing and arithmetic is influenced by age and arithmetic problem difficulty. This study investigated these unresolved questions by examining basic number processing (symbol-quantity matching) and arithmetic (addition) networks in 26 adults and 42 children. Number processing and …

The Search For Consciousness, Adrian Owen

BrainsCAN Publications

In recent years, rapid technological developments in the field of neuroimaging have provided new methods for assessing residual cognition, detecting consciousness, and even communicating with patients who clinically appear to be in a vegetative state. Here, I highlight some of the major implications of these developments, discuss their scientific, clinical, legal, and ethical relevance, and make my own recommendations for future directions in this field.

Developing A Mechanistic Understanding Of Crossmodal Reorganization Following Sensory Loss, Brainscan, Western University, Blake E. Butler, Brian Allman, Ravi Menon

Project Summaries

Our long-term goal is to understand how plasticity reshapes circuits in the brain in response to atypical early experiences. This will allow us to better understand how the Deaf brain processes the world around us, and will make clear the challenges that must be overcome to optimize the function of cochlear implants and prostheses designed to restore sensory functions more broadly.

Can Self-Efficacy Training Improve Memory And Functional Activation In Older Adults With Mild Cognitive Impairment? A Proof-Of-Concept Intervention Study, Brainscan, Western University, Lindsay Nagamatsu, Derek Mitchell, Paul Minda, Amer Burhan, Becky Horst

Project Summaries

The goal of this study is to examine the changes in brain activity after a memory self-efficacy training program to better understand the mechanisms of memory self-efficacy. We will conduct a proof-of-concept six-week memory self-efficacy intervention in older adults with MCI, in order to demonstrate that self-efficacy impacts brain function. This will allow us to determine whether self-efficacy interventions may be a potential strategy for combating AD in the future.

Detecting Fine-Grained Population Codes In Human Prefrontal Cortex, Brainscan, Western University, Marieke Mur, Julio Martinez-Trujillo, Ravi Menon, Joe Gati

Project Summaries

In this project, we will develop techniques for improving our measurement resolution so that we can gain access to prefrontal population codes. We will combine high-field fMRI with pattern analysis techniques to unlock population coding in the prefrontal cortex. This is essential for understanding how the brain supports higher-order cognition, and ultimately, for treating dysfunctions of cognitive flexibility in the clinic.

Evaluating Cognitive Impairment, Imaging And Blood Biomarkers In A Pre-Clinical Model Of Concussion, Brainscan, Western University, Arthur Brown, Marco Prado, Rob Bartha, Ravi Menon, Mark Daley

Project Summaries

The foundational milestone for the research, that we are addressing in this project, is to demonstrate that cognitive impairments in mouse models and humans are similar by using touchscreen technology. We will also be applying fMRI and MRS analyses to mouse models since they are analogous to that used in human studies - it will help us establish relevant endpoints for the studies as part of understanding the underlying characteristics, pathways and effects of concussion.

Imaging Fetal Brain Connectivity In High Risk Pregnancy, Brainscan, Western University, Sandrine De Ribaupierre, Barbara De Vrijer, Charles Mckenzie, Roy Eagleson, Simon Levin, Jacqueline Olgivie

Project Summaries

Our hypothesis is that differences in the regional connectivity within the fetal brain (the structural and functional connections between regions of the brain) can be observed with fetal fMRI as early as in the second trimester of pregnancy.

If we can detect differences in an at-risk fetal brain and associate that with plancental and maternal data, we could recommend interventions, such as diet or medication changes, and then monitor the impact of treatment on the fetal brain.

Development Of Fmri Compatible Reversible Deactivation To Examine Cerebral Networks, Brainscan , Western University, Stephen Lomber, Blake Butler, Stefan Everling, Blaine Chronik

Project Summaries

This study will permit us, for the first time, to examine the effects of deactivation of one cortical site on large-scale neural networks. It will permit neural networks to be functionally disassembled and the consequences of 'reversible' lesions, strokes or tumors to be assessed and modeled before they occur.

Relating Functional And Structural Signatures Of Parkinson’S Disease To Changes In Dopamine Signalling: A Pet/Fmri Study, Brainscan . Western University, Penny Macdonald, Udunna Anazodo, Justin Hicks, Frank Prato, Alain Dagher

Project Summaries

Cognitive impairments in early Parkinson's disease are known to be linked to complex changes in the dopamine system within the brain. For example, dopamine-producing neurons in one key region of the brain are significantly degenerated, but those in another are spared. Dopamine-replacement therapy (DRT) has been pursued and it has produced significant improvements in certain cognitive functions - unfortunately it also produced significant impairments in others.

The Impact Of Violent Gaming On The Brain As A Function Of Individual Differences In Trait Empathy, Brainscan , Western University, Derek Mitchell, Elizabeth Finger, Richard Neufeld

Project Summaries

In this project, we will uncover any existing interaction between violent media and the capacity for empathic reactions (known as trait empathy) at a neural level, as the foundational milestone for the kind of large-scale study discussed above.

The level of trait empathy varies by individual - we will explore whether exposure to violent media exacerbates the difficulties that those with low trait empathy already show in relating to the emotions of others

Assessing Listening With Engaging, Real-World Auditory Signals, Brainscan , Western University, Björn Herrmann, Ingrid Johnsrude 6612111

Project Summaries

Our project will develop and evaluate a novel way (using functional imaging, fMRI, and electrophysiology, EEG) to assess this cognitive impact of hearing loss with engaging, real‐world auditory stimuli. We will try to assess listening effort in more realistic listening situations among healthy listeners, comparing detected effort in degraded and clear acoustic conditions.

Using EEG, we will then develop measures that are sensitive to the cognitive demands imposed by degraded speech, using these features to assess hearing function with engaging narratives in natural listening conditions.

Ommaba: The Open Multimodal Music And Auditory Brain Archive, Brainscan , Western University, Jessica Grahn, Jorn Diedrichsen, Joe Gati, Molly Henry, Robert Zatorre, Jean-Baptiste Poline, Bratislav Misic, Estrid Jakobsen, Mor Regev, Marcel Farrés Franch, Virginia Penhune, Emily Coffey

Project Summaries

We will create a specific neuroimaging database focused on the auditory domain. It will allow researchers to ask questions about the neural circuitry underlying auditory behaviour in the healthy brain and to understand the sources of individual variability. We will include detailed information about experiential factors, such as musicianship and bilingualism that are not documented in any existing databases, so that it will be possible to investigate plasticity-related effects. It will also provide baseline data for clinical studies.

Development Of Virtual Gaming Environments For Functional Magnetic Resonance Imaging, Brainscan, Western University, Jody Culham, Ingrid Johnsrude, Julio Martinez-Trujillo

Project Summaries

The goal of this project is to develop, validate and test three aspects of a 3D video game environment for neuroscience.

Developing Behavioural Testing And Mr Imaging To Evaluate Cognitive Impairment In Models Of Cns Autoimmunity, Brainscan, Western University, Steven Kerfoot, Sarah Morrow, Ravi Menon, Flavio Beraldo

Project Summaries

This project will investigate cognition and cognitive fatigue in models of CNS autoimmunity. We will use automated touchscreens and fMRI to measure deficits in higher order brain functions.

We have two critical milestones in this project:

• to use touchscreen testing protocols to determine if mouse models demonstrate the same kinds of attention, working memory and cognitive fatigue deficits observed in MS, and
• to use fMRI to measure higher-order defects in the autoimmune models and identify any changes present that might be associated with cognitive dysfunction and the findings from human studies.

Persistent Post-Concussion Brain Changes In Adolescent Hockey Players, Brainscan, Western University, Kathryn Y. Manning, Amy Schranz, Robert Bartha, Gregory A. Dekaban, Christy Barreira, Arthur Brown, Lisa Fischer, Kevin Asem, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Ravi S. Menon

Research Summaries

Changes continue to occur in a concussed brain even after standard clinical tests have returned to normal. Damage in the very long fibre tracks in the brain of concussed players can be detected up to three months after the concussion and after the individuals have been approved for return to athletics. It is also possible to detect ‘hyper-connectivity’ in the brain, suggesting the brain is still trying to compensate for the concussion.

Multiparametric Mri Changes Persist Beyond Recovery In Concussed Adolescent Hockey Players, Kathryn Y. Manning, Amy Schranz, Robert Bartha, Gregory A. Dekaban, Christy Barreira, Arthur Brown, Lisa Fischer, Kevin Asem, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Ravi S. Menon

BrainsCAN Publications

Objective: To determine whether multiparametric MRI data can provide insight into the acute and long-lasting neuronal sequelae after a concussion in adolescent athletes.

Methods: Players were recruited from Bantam hockey leagues in which body checking is first introduced (male, age 11–14 years). Clinical measures, diffusion metrics, resting-state network and region-to-region functional connectivity patterns, and magnetic resonance spectroscopy absolute metabolite concentrations were analyzed from an independent, age-matched control group of hockey players (n 5 26) and longitudinally in concussed athletes within 24 to 72 hours (n 5 17) and 3 months (n 5 14) after a diagnosed concussion.

Results: There were …

Shared Neural Substrates Of Emotionally Enhanced Perceptual And Mnemonic Vividness, Rebecca M. Todd, Taylor W. Schmitz, Josh Susskind, Adam K. Anderson

Brain and Mind Institute Researchers' Publications

It is well known that emotionally salient events are remembered more vividly than mundane ones. Our recent research has demonstrated that such memory vividness is due in part to the subjective experience of emotional events as more perceptually vivid, an effect we call emotion-enhanced vividness, or EEV. The present study built on previously reported research in which fMRI data were collected while participants rated relative levels of visual noise overlaid on emotionally salient and neutral images. Ratings of greater EEV were associated with greater activation in the amygdala, visual cortex, and posterior insula. In the present study, we measured BOLD …

Decoding Motor Intentions From Human Brain Activity, Jason P. Gallivan

Electronic Thesis and Dissertation Repository

“You read my mind.” Although this simple everyday expression implies ‘knowledge or understanding’ of another’s thinking, true ‘mind-reading’ capabilities implicitly seem constrained to the domains of Hollywood and science-fiction. In the field of sensorimotor neuroscience, however, significant progress in this area has come from mapping characteristic changes in brain activity that occur prior to an action being initiated. For instance, invasive neural recordings in non-human primates have significantly increased our understanding of how highly cognitive and abstract processes like intentions and decisions are represented in the brain by showing that it is possible to decode or ‘predict’ upcoming sensorimotor …

Activation Of Brain Regions Vulnerable To Alzheimer's Disease: The Effect Of Mild Cognitive Impairment, S. C. Johnson, T. W. Schmitz, C. H. Moritz, M. E. Meyerand, H. A. Rowley, A. L. Alexander, K. W. Hansen, C. E. Gleason, C. M. Carlsson, M. L. Ries, S. Asthana, K. Chen, E. M. Reiman, G. E. Alexander

Brain and Mind Institute Researchers' Publications

This study examined the functionality of the medial temporal lobe (MTL) and posterior cingulate (PC) in mild cognitive impairment amnestic type (MCI), a syndrome that puts patients at greater risk for developing Alzheimer disease (AD). Functional MRI (fMRI) was used to identify regions normally active during encoding of novel items and recognition of previously learned items in a reference group of 77 healthy young and middle-aged adults. The pattern of activation in this group guided further comparisons between 14 MCI subjects and 14 age-matched controls. The MCI patients exhibited less activity in the PC during recognition of previously learned items, …