Medicine and Health Sciences Commons^™

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 …

Inference Of Language Functional Network In Healthy, Cancerous And Bilingual Brains By Fmri And Network Modeling, Qiongge Li

Dissertations, Theses, and Capstone Projects

We study the underlying mechanism by which language processing occurs in the human brain using inference methods on functional magnetic resonance imaging data. The data analyzed stems from several cohorts of subjects; a monolingual group, a bilingual group, a healthy control group and one diseased case. We applied a complex statistical inference pipeline to determine the network structure of brain components involved with language. This healthy network reveals a fully connected triangular relationship between the pre-Supplementary Motor Area (pre-SMA), the Broca's Area (BA), and the ventral Pre-Motor Area (PreMA) in the left hemisphere. This "triangle'' shows consistently in all the …

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.

Network Influence Of The Cerebellum For Predicting Dbs Response In Patients With Advanced Parkinson’S Disease, Lucy Li, Jennifer Muller, Sara Thalheimer, Mackenzie D. Silverman, Mahdi Alizadeh, Tsao-Wei Liang, Kelly Layton, Daniel Kremens, Victor Romo, Feroze Mohamed, Chengyuan Wu

Phase 1

Introduction: Deep brain stimulation (DBS) is a treatment option for reducing motor symptoms in patients with Parkinson’s Disease (PD) when first-line medication becomes ineffective. Existing literature has hypothesized that the clinical outcome of DBS may depend on brain connectivity profiles of the stimulation site to distant brain regions. However, the potential of brain connectivity profiles to predict response to DBS in PD remains unclear.

Objective: This study aimed to investigate how changes in structural and functional connectivity may relate to patient response to DBS, through the examination of brain network changes using graph theory.

Methods: Ten patients with advanced PD …

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.

Characterizing The Development Of Episodic Memory And Assessing The Reliability Of Fmri Measures, Lingfei Tang

Wayne State University Dissertations

The ability to remember past events is critical for everyday life and showed robust improvement over development from childhood to adulthood. With advances in noninvasive neuroimaging methods such as functional MRI in recent years, research efforts have been focused on identifying neural correlates underpinning developmental gains in memory performance. In my dissertation work, using a widely-validated subsequent memory paradigm, I aim to characterize functional MRI correlates of memory development. Specifically, I focused my investigation on identifying age differences in the functional patterns of two brain regions critical for memory, the prefrontal cortex and the hippocampus. Focusing on the prefrontal cortex …

Validations Of Apomorphine-Induced Bold Activation Correlations In Hemiparkinsonian Rhesus Macaques, Jorge E. Quintero, Yi Ai, Anders H. Andersen, Peter A. Hardy, Richard Grondin, Zain Guduru, Don M. Gash, Greg A. Gerhardt, Zhiming Zhang

Neuroscience Faculty Publications

Identification of Parkinson's disease at the earliest possible stage of the disease may provide the best opportunity for the use of disease modifying treatments. However, diagnosing the disease during the pre-symptomatic period remains an unmet goal. To that end, we used pharmacological MRI (phMRI) to assess the function of the cortico-basal ganglia circuit in a non-human primate model of dopamine deficiency to determine the possible relationships between phMRI signals with behavioral, neurochemical, and histological measurements. Animals with unilateral treatments with the neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), that expressed stable, long-term hemiparkinsonism were challenged with the dopaminergic receptor agonist, apomorphine, and structure-specific phMRI …