Current Research Projects
Post-Traumatic Stress Disorder (PTSD):
A Multidimensional Assessment of PTSD Subtypes (MAPS)
This integrative research project uses joint cognitive and neurological measures to better understand the close interplay between biological and psychological features of PTSD. Current and former Canadian Armed Forces members with PTSD undergo an fMRI scan while shown trauma words. Preliminary findings revealed that the combination of multiple biomarkers is required to refine the detection of PTSD and the prediction of key clinical features.
Neuromelanin-sensitive MRI as a marker of norepinephrine imbalance in PTSD
This naturalistic study examines neuromelanin-sensitive magnetic resonance imaging (NM-MRI) as a novel biomarker allowing treatment that is directed towards hyperarousal symptoms of PTSD. Current and former Canadian Armed Forces members with PTSD undergo an fMRI scan while performing a fear conditioning task. NM-MRI, a brief and non-invasive MRI scan, could provide a practical and reliable marker of norepinephrine excess in PTSD and thereby allow neurobiologically informed treatment decisions.
Brain activity patterns representing value and motivation in schizophrenia
This study uses a novel behavioural task to search for patterns of brain activity that track subjective pleasure and predict willingness to pay or willingness to work for rewards. In this task, participants watch movie trailers during fMRI scanning and bid money or exert effort to win a personal copy of the movies advertised. We will see if these activity patterns representing pleasure or value are disrupted in individuals with schizophrenia suffering from negative symptoms and whether this disruption occurs during the experience of pleasure and/or during the subsequent process of decision making.
Investigating the relationship between antipsychotic response and non-invasive proxies of neurochemistry in schizophrenia
The aim of this study is to better understand the neurobiology of treatment resistance in schizophrenia and pave the way for development of novel techniques to predict treatment response. This is a preliminary, proof-of-principle study to test whether schizophrenia patients who do not respond to first-line treatment will differ on NM-MRI/glutamate MRS signal compared to those who do respond. The goal is to inform the wider research and medical community of potential neuropathological differences between individuals with schizophrenia who respond and who do not respond to first-line treatment.
Neuromelanin-sensitive imaging of the substantia nigra and locus coeruleus
The neurotransmitters dopamine and norepinephrine are released from neurons located in the
substantia nigra and locus coeruleus respectively. These structures have the unique property of
containing high concentrations of neuromelanin, a dark pigment that can be visualized with
specialized MRI sequences. The neuromelanin-sensitive MRI signal has been used to visualize
degeneration of these neurons in Parkinson’s disease and Alzheimer's disease. Our recent work
has shown that this signal can also serve as a proxy measure for long-term imbalance in activity
of these neurotransmitter systems. Current projects are investigating this novel measure as a
potential biomarker in diverse populations including, PTSD, schizophrenia, Parkinson’s disease,
Alzheimer's disease, ADHD, and healthy children. The goal of this line of work is to develop and
optimize the method for expanded research and clinical applications.