BrainsCAN Fellows

Research Information:
Anxiety disorders affect millions of Canadians, impairing their mental, physical, and social lives. Existing
pharmacotherapies used to treat anxiety disorders can have serious side-effects, including drug dependence and cognitive impairments. Recent research has suggested that cannabis derived compounds, particularly cannabidiol (CBD), may provide an alternative therapy for anxiety disorders. Using a model of general anxiety, this project aims to identify the neural systems associated with anxiety by employing neural recordings and advanced imaging techniques. Furthermore, we will assess the effectiveness of CBD, and other cannabis-derived substances, to treat anxiety and the associated cognitive impairment. These studies will improve our understanding of the mechanisms of anxiety disorders and the associated cognitive disorders. Additionally, this research will greatly aid in the development of safer and more effective pharmacotherapies.

Research Information:
Hearing loss affects > 40% of people aged 50 or older and increases their risk for additional health problems (e.g., depression, cognitive decline). Diagnosis of hearing impairment relies on measuring sensitivity for at‐threshold sounds, but it fails to capture problems older people experience with suprathreshold sounds. For example, many people perceive sounds at moderate intensities to be unpleasantly loud (‘hypersensitivity’), which may result in individuals being easily distractible and avoiding social situations. This project is a multi‐site collaboration involving three labs at Western University and one lab at Purdue University that will study impaired neural adaptation and its relation to hypersensitivity to sound in rats and humans. Understanding the physiological underpinnings of suprathreshold deficits is the first step to effective diagnosis and treatment.

 

Publications: 
Journal of Neuroscience: Aging Affects Adaptation to Sound-Level Statistics in Human Auditory Cortex; Media: Study: ‘Sound’ differences between age groups

Research Information:
A cornerstone of human life and culture is social interaction. Our ability to interact with others is dependent on how well we can infer another person’s internal mental states from their behavior. This proposal aims to explore how intention information embedded within action is represented in the brain, and how variations in social aptitude may impact the way we act and understand others. These findings present broad, exciting potential applications. Describing the physical and neurological mechanisms underlying intentional actions will be critical to refining theories of sociocognitive disorder (e.g. Autism) and how individuals with/without these disorders interact. Engineers could also look to this work to develop design principles that will allow smart machines to detect and respond to observable intention.

Research Information:
Dysfunctions in the frontoparietal cognitive control network is implicated in a large number of neuropsychiatric disorders. While this network likely serves as a multiple-demand system supporting diverse functions such as working memory and cognitive flexibility, it remains unclear how these processes are instantiated by the activities of distributed neuronal populations in health and how they fail in disease. To answer these questions, it is necessary to record the activities of large ensembles of individual characterized neurons in behaving subjects. 

Research Information:
The early life period sees rapid and fundamental maturational changes in the structure and function of the brain. These alterations include cortical reorganization, synaptic pruning and myelination, with varying time courses across development. This project will determine the impact of diet on functional brain network structure essential for cognition. The outcomes of this project will provide the basis for significantly reducing the impact of diet-induced cognitive decline through health recommendations in the clinic and public policy regarding diets.

 

Publications: 
Trends in Cognitive Sciences: Review suggests a reciprocal relationship between obesity and self-control

Research Information:
Oculomotor tasks have long been used as an index of cognitive control dysfunction in neuropsychiatric conditions (e.g., schizophrenia) in humans. Much of the understanding of this oculomotor circuitry has come from saccadic eye movement tasks – neuropsychiatric diseases, however, are difficult to model. With the advent of transgenic and optogenetic techniques, the use of saccadic tasks in preclinical NHP models of human brain diseases has tremendous potential for detecting the underlying disease-related pathophysiology of these debilitating brain disorders. To that end, this project involves the development of protocols for awake-behaving NHP functional magnetic resonance imaging at ultra-high field – by using saccadic tasks during fMRI acquisition, we can identify functional network topologies in NHPs that are homologous with the human brain. Understanding the functional organization of the NHP oculomotor circuitry will be important as researchers leverage the genetic similarity of NHPs to model human neuropsychiatric diseases.

Research Information:
The recognition of speech is fundamental for so many day-to-day activities that we often take this skill for granted, particularly in adverse listening conditions (e.g., maintaining a conversation in a crowded café). Reducing listening effort in these challenging environments is important for improving the quality of life for individuals across ages, and one promising means of achieving this goal is through developing perceptual expertise related to talker identity. Voices of friends or family members are substantially more intelligible than unfamiliar voices and are less susceptible to interference by competing sounds, indicating that they are less cognitively demanding and thus may reduce listening effort. Yet, a systematic understanding of how perceptual familiarity develops and leads to improved speech intelligibility is lacking. Thus, the overarching goal of this project is to determine how we develop familiarity with voices to realize maximal benefits to intelligibility. This goal will be informed by recent advances in our understanding of perceptual learning mechanisms as well as the neurobiology of sleep-dependent memory consolidation.

Research Information:
Reaching movements are critical actions for everyday life that involve processing sensory feedback from muscles, joints, and skin across muliple parts of the cerntal nervious system – initially within spinal pathways that act quickly but have limited processing capabilities, and then within cortical pathways that act slower but can produce very sophisticated motor commands. I am interested in testing whether the cortical pathways that process this type of sensory feedback “understand” the processing capabilities of spinal pathways. In the work supported by my BrainsCAN Fellowship, I will experimentally impair the spinal pathway’s ability to process sensory feedback to support reaching movements and test whether the sensory processing that occurs in cortical pathways compensates for the induced spinal dysfunction. It is my hopes that this work will provide insight into how the different areas of the central nervous system work together to processes the sensory information that is important for controlling movement, and then use these insights for improving rehab programs for various situations, including peripheral nerve injury, spinal cord injury and limb amputation.

 

Publications: 
Nature Neuroscience: Spinal stretch reflexes support efficient hand control; Media: Spinal cords contribute to complex hand function

Research Information:
One quarter of the population has such difficulty learning mathematics that it impairs their ability to use information effectively in adult life. What causes some students to struggle with math? Brain imaging research has begun to shed light on how the brain processes numerical information. However, little is known about how this information is integrated across the brain systems important for math learning, such as memory and attention. With this fellowship, I will conduct a series of studies that provide detailed information about the brain mechanisms that support math skills. First, using ultra-high field 7T magnetic resonance imaging (MRI), I will begin to answer questions about how the brain solves math problems at the individual level. This is an important advance because behavioural research shows that children with math learning difficulties are very different from one another. Second, I will investigate the possibility of subtypes of math learning disability with children who have been identified to need math remediation. To do this, I will identify subgroups of individuals with similar cognitive profiles and compare neural signatures of these cognitive profiles. Research in this area will pave the way to improved pedagogical techniques, diagnosis of learning disabilities, and remediation of deficits.