BrainsCAN Fellows

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.

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:
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 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.

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.