Medicine and Health Sciences Commons^™

Characterizing Auditory Cortical Receptive Fields, Brainscan , Western University, Ingrid Johnsrude, Alex Billig, Matthew A. Howard Iii, David Steven, Jorge Burneo

Project Summaries

Through this research we have a unique opportunity to explore how auditory cortices respond to naturalistic stimuli and how that response changes with different tasks. This foundational work is critical if we are to understand abnormality in auditory cortices in disorders such as autism, specific language impairment, auditory processing disorders and prolonged auditory deprivation (due to hearing loss).

Imaging Visually-Evoked Cortical Activity, Brainscan, Western University, Blake E. Butler, Stephen Lomber, Kyle Gilbert, Mathias Dietz

Project Summaries

This work will significantly inform our understanding of 'neural plasticity', the ability of the brain to respond and reorganize to environmental changes or following an injury or disorder. It is also our hope that the results of this program will inform the design of devices to restore hearing - it might enable tuning of those devices to restore sensory representations in the brain in a patient-specific manner. We believe this will significantly reduce the impact of cognitive disorders that arise as a result of abnormal perception both in children and in older adults.

Development Of A Novel Pharmaceutical To Prevent Noise-Induced Hearing Loss, Brainscan , Western University, Brian Allman, Paul Walton

Project Summaries

To limit the damage caused by noise-induced oxidative stress, we intend to determine the most effective way to deliver a customized version of catalase to the vulnerable sensory hair cells in the cochlea. We will conduct experiments to explore how best to 'package' and deliver catalase to the subject.

System-Wide Electrophysiological Assessment Of Hearing, Brainscan , Western University, Ingrid Johnsrude, Björn Herrman, Chris Allen

Project Summaries

The current work proposes to develop and evaluate an electrophysiological recording setup capable of assessing neural function at all levels of the auditory neural pathway, including hair cells, auditory nerve fibers, brainstem and cortex. We will then test the neural responses across those levels of the auditory pathway in younger and older people.

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.

Uncovering The Neural Basis Of Cognitive Impairment Following Hearing Loss: An All-Optical Electrophysiology Approach, Brainscan, Western University, Brian Allman, Wataru Inoue

Project Summaries

We have access to state-of-the-art equipment that will enable us to visualize specific neuron types in animal models. This is a new approach that combines several recent advances in the field of 'optogenetics', a technique that uses light to control neurons. This approach will allow us to explore how hearing loss induced by loud noise exposure leads to abnormal neural activity in areas of the brain that control learning, memory and higher cognitive function.

Validating Methods For Using Noninvasive Brain Stimulation To Influence Auditory Perception, Brainscan, Western University, Jessica Grahn, Molly Henry, Blake Butler, Marc Joanisse, Stefan Everling

Project Summaries

We will be exploring the influence of a weak alternating current on neural activity at different frequencies to build a more complete picture of tACS. We will also incorporate EEG measurements to help us predict how the synchronization varies across individuals, to determine when to provide stimulation for each individual. Finally, we will vary the tACS stimulation and use participant behaviour as the measure to understand what stimulation timing produces the largest behavioural changes.

The Effect Of Musical Training On Speech And Sound Perception, Brainscan, Western University, Ingrid Johnsrude, Vanessa Irsik, Stephen Van Hedger

Project Summaries

We are going to carry out such a study, in conjunction with research labs at five other institutions. With six universities involved, we will be able to recruit a sufficiently large number of people in the study and decrease the likelihood of any regional bias influencing the outcomes. We will be trying to validate the following claims:

• that musicians have an improved ability to understand speech in noisy environments
• that the responses of a musician's brainstem to speech sounds is enhanced, and
• that older musicians have reduced symptoms from age-related hearing loss.

Preventing Noise-Induced Hearing Loss With A Novel Pharmaceutical, Brainscan, Western University, Brian Allman, Paul Walton, Shawn Whitehead, Patti Kiser, Brian Shilton, Sarah Hayes

Research Summaries

A targeted catalase, packaged and delivered via exosomes intranasally, provides protection for cochlear cells against oxidative stress, the kind of stress that results from loud noise exposure. It is able to cross the blood-brain barrier and does not result in negative outcomes elsewhere in the body.

Aging Is Associated With An Over-Sensitivity Of Brain Responses To Sounds, Brainscan, Western University, Björn Herrmann, Burkhard Maess, Ingrid S. Johnsrude

Research Summaries

Aging and hearing loss leads to increased neural responses to sounds in the auditory cortex compared to younger people. Enhanced neural activity to sound may be a physiological mechanism underlying the difficulty that older adults have with ignoring irrelevant sound information.

Familiar Voices Are More Intelligible, Even If They Are Not Recognized As Familiar, Brainscan, Western University, Emma Holmes, Ysabel Domingo, Ingrid Johnsrude

Research Summaries

This research has demonstrated that it’s easier to understand someone who is familiar to us (compared to someone unfamiliar) even if we can’t recognize them from their voice. As listeners, we focus on certain parts of speech sounds for specific purposes. For example, there may be some situations in which you can understand words spoken by your mother very well, better than you could understand a stranger in the same situation, even if you can’t tell that it’s your mother speaking.

Establishing A Translational Platform For Studying Sensory Processing In Neurodevelopmental Disorders, Brainscan , Western University, Susanne Schmid, Brian Allman, Ryan Stevenson, Janis Cardy

Project Summaries

The causes for ASD and DLD are many, complex and largely unknown. One specific cause already identified is mutation of a single gene essential for neuronal development. A useful transgenic rat model has been developed with this mutation that exhibits disabilities very reminiscient of children with ASD or DLD. We will use it to demonstrate that the same tests can show the same disruptions to the auditory system between children with ASD/DLD and this rat model. This model can then be used to undertake further exploration of the impact of ASD/DLD on the auditory system and evaluation of possible behavioural …