News & Media
The NEURO Science Letter is an electronic newsletter highlighting activities at the Montreal Neurological Institute and Hospital. It is published three times a year in February, June and October. If you have any comments, please send them to Communications. To subscribe and receive e-mail notification when a new issue becomes available, click here.
Neuroscience 101 When will we have thinking machines?
"Why are there so many robots in fiction, but none in real life?" asked
Stephan Pinker in How the Mind Works. Pinker wasn't talking about the
robots that fasten rivets in automobile assembly lines. He was referring to
robots like C3PO in Star Wars and Data in Star Trek: The Next
Generation - sentient beings with thoughts, feelings and
personalities. Pinker's answer to his rhetorical question was, essentially,
that there are real no robots because no machine could - at least in 1998,
when the book was published - come close to achieving the remarkable
capabilities of human perception, cognition and action. But computer
hardware and software have come a long way since then. My $500 digital
video camera recognizes faces, and my home computer can translate my spoken
words into written text. The gap between what humans can do and what
machines can do is narrowing. So, how long before there really are machines
with minds as good as or better than those of human beings? This is really
two separate questions: How do we build a thinking machine, and how will we
know when we've succeeded?
Life and Death Decisions
The Barker lab studies biochemical signals, which determine whether neurons
survive and grow or, instead commit suicide through a process called
apoptosis. Neurons make these life-and-death decisions in response
to a family of molecules called neurotrophins, which are secreted
into the environment surrounding the cells. Neurotrophins bind to and
activate specialized proteins called receptors, which are located
on the surface of the cells (Fig. 1). The interaction between a
neurotrophin and its receptor is like a key fitting into a lock: the
receptor contains a binding site which specifically accommodates the
neurotrophin. Once activated by the binding of a neurotrophin molecule, the
receptor initiates a cascade of biochemical events inside the cell.
Depending on the specific circumstances - e.g. the type of neurotrophin,
the type of receptor or the specific properties of the cell - these
biochemical signals may cause the nerve cell to thrive or to kill itself by
apoptosis. We are especially interested in a type of neurotrophin receptor
called p75 NTR, which is important for normal apoptosis and which has also
been implicated in Alzheimer's disease, amyotropic lateral sclerosis (ALS)
and the irreversible damage that occurs after nerve injury.
Language and the Mind
I came to the Montreal Neurological Institute from South Africa in 1992 to
work with the renowned neuropsychologist, Brenda Milner. My work with Dr.
Milner, and subsequently in my own independent laboratory at the MNI, has
focused on understanding how speech and language are represented and
processed in the brain. My arrival at the MNI coincided with the emerging
availability of brain imaging technologies, such as PET and functional MRI,
which have enabled cognitive neuroscientists to view the brain in action.
My research approach combines these powerful neuroimaging techniques with
behavioural measures to investigate how the brain enables us to speak and
to understand language.