The exciting pace of development of cognitive neuroscience is fed by new technology for measuring the brain and behavior.
Except in rare cases when a patient is having brain surgery, we need to measure the brain in ways that are non-invasive. When a person is performing some task, in an active brain region blood vessels change in size, blood flow and oxygenation, which can be detected safely and quickly using a magnetic resonance imaging (MRI) brain scanner. As an example, here are nine slices through the brain (from low to high). The hot colors are the brain regions more activated when a people are remembering a visual pattern than when they are just resting, and the cool colors show deactivated regions.
We use MRI scanners at the adjacent Robarts Research Institute, including a Siemens Tim Trio and Canada’s only 7T MRI scanner. Scanners at nearby hospitals are also used for examining inpatients, including newborn babies, and patients with disorders of consciousness.
Another way to measure the brain is to record electrical signals on the surface of the scalp, a method known as electroencephalography (EEG). The Brain and Mind Institute has two electrically shielded recording rooms, and a number of EEG systems (ranging from 14 to 128 channels). It has a geodesic sensor net, for measuring the positions of the electrodes on the head, and an MRI-compatible EEG kit, for doing both simultaneously. It regularly acquires EEG data in patients at local hospitals.
Using MRI we can measure many different characteristics of brain anatomy, such as:
the thickness of the cortex on the surface of the brain,
the strength of “white matter” connections between brain regions,
the locations of veins and venules (the 3D volume this detail comes from was 375 megapixels in size),
the location of brain injury,
and the chemical properties of brain regions.
One of the great benefits of MRI is that by simply downloading a new “app”, the scanner can measure some new property… temperature, blood flow, microstructure… the list is enormous and growing. New imaging can also be created by adding hardware, such as smaller MRI “coils” for the newborn brain, or new inserts for measuring specific neurotransmitters in the brain.
We can also investigate which bits of the brain do what by stimulating a local region of the brain, and measuring how this interferes with a task. We can use transcranial magnetic stimulation (TMS) to stimulate a local region of the brain in a non-invasive way. The Institute has a TMS machine, and the equipment needed to target a particular brain region in an individual person.
Much can be learnt about the mind from the careful observation of behavior, both in healthy volunteers, and in patients with brain injury. The Brain and Mind Institute has special expertise in measuring movements, of the whole body, a single limb, or just the eyes. It has a number of pieces of equipment that can track movements, for example as a participant walks or grasps an object. Excitingly, it is now possible to also track movements while someone is in the brain scanner reaching for real objects.
Brain imaging methods yield many Terabytes of data each year. As time goes by, an increasing number of more complex methods are becoming available. These provide all sorts of new information about the brain, but place ever increasing demands on computing. The Institute has its own cluster, with 50 Terabytes of storage. It is also is closely involved with the Canada-wide SharcNet computing clusters, and uses commercial cloud computing from Amazon Web Services.
Effective cognitive neuroscience requires a great number of skills. Brain imaging equipment needs physicists to build it and to interpret the results. Mathematicians are needed to help create analysis methods or build models of the brain. Cognitive psychologists are needed to build models of the mind, and to design tasks that isolate particular mental processes. Physicians, from neurologists to neonatologists, are needed to help understand the problems that are most commonly encountered by patients, and how our growing knowledge of the brain can help in clinical practice. Philosophers are needed to answer new ethical questions, and help guide the development of this new science. Developmental psychologists help us understand how the brain grows, and what can go wrong during childhood. And, computer scientists are needed to run complex computer systems and engineers to build laboratory equipment to administer all manner of tasks. Only by bringing all of these people together can the brain and mind be understood. This is the purpose of the Brain and Mind Institute.
We spend nearly a third of our life asleep. But what is the function of sleep and what goes on in our brain when we are asleep? Working out the answers to these questions is crucial to understanding the impact of sleep loss, sleep disruption and of sleep disorders, which in North America, has reached epidemic proportions. About one in five Canadians suffers from sleep loss, wreaking havoc on society’s productivity, safety, physical and mental health.
Dr. Adrian Owen’s CERC award and related CFI grant have contributed significantly to renovations to the BMI which now includes a fully-equipped 3-bedroom sleep laboratory with three in-lab 32-channel EEG and polysomnographic systems for the recording and analysis of overnight sleep studies. This sleep laboratory is permitting scientists within the BMI and from elsewhere on campus to apply the latest and most advanced EEG and neuroimaging technology to some of the most important unresolved scientific questions such as “what is consciousness” and “why do we sleep” as well as characterizing the function of sleep for learning and memory, and identifying the neural substrates and activity which support sleep-dependent memory processing and synaptic plasticity.