Academic Biography

Dr. Dave Saint-Amour is a researcher at the Sainte-Justine University Hospital Centre and is affiliated with the department of ophthalmologyand the Centre de Recherche en Neuropsychologie et Cognition at the Université de Montréal.  His research focus is the visual system and the sensory integration theory of autism: the premise that many of the developmental difficulties that children with autism have are due to an inability of their brains to combine the separate senses into a coherent experience of their surroundings.

What is Autism

Autism is a severe pervasive developmental disorder characterized by impaired social interaction, problems with written and verbal communication, repetitive behaviours or restricted, obsessive interests.  These symptoms appear within the first three years of life.  The symptoms of autism may change throughout a person’s life, but autism cannot be cured.  Later in life, autism is likely to lead to problems in education, employment, and relationships.  The frequency of autism is not known, due to the difficulty of recognizing and diagnosing the disorder. 

Project Summary

Dr. Saint-Amour and his team are conducting a brain mapping study to investigate the way that children with autism age 6 to 15 combine visual and auditory information from their surroundings.

Biological Background and Rationale

Each one of our senses has a dedicated physical system to detect and process the stimuli that we receive from our surrounding environment.  Just as our eyes detect light (photons) so that we can see, and our eardrums detect sound (pressure waves in air) so that we can hear, different parts of the brain correspond to the information transmitted by light and sound.  Once this information makes its way into the brain, light and sound are translated into useful information; light becomes objects and scenery and sounds become words or music.  This information travels farther along to more complex systems in the brain where this data from the different senses combines to give us more information about our surroundings: this is known as sensory integration. 

In a healthy brain the moving lips that we see, and the words that we hear, have a meaningful link and help us to perceive speech.  However, in people with autism this deficit in sensory integration may be a contributing factor to deficits in speech perception.

To investigate the nature of this deficit in sensory integration, Dr. Saint-Amour and his team are mapping the electrical activity in the brains of children ranging in age from 6 to 15 in response to an isolated visual or sound stimulus, and to a simultaneous light and sound stimulus to test for sensory integration.  By acquiring a substantial data set from these experiments for children with and without autism they hope to form maps of each child’s brain and to locate areas in the brain where differences between the autistic and healthy group are visible in the sensory integration test. 

The process used to map the children’s brains (the electrophysiological assessment) in this experiment is called electroencephalography (EEG).  During an EEG the participant wears a net or cap embedded with precisely arrayed electrodes on their scalp.  In the brain, neurons send a chemical message to other neurons.  When a message is received from another neuron, the receiving neuron conducts an electrical current.  The EEG electrodes detect these small electrical currents and the recorded information is analyzed to find the source of the currents.  In this way the type of map that Dr. Saint-Amour needs for each participant is created.

Outcome

Dr. Saint-Amour is currently working on recruiting more participants with autism for this study.  To date, his team has collected a substantial body of data for children 6 to 15 who do not have autism.  This is a significant contribution to the scientific community because there is no published work on the brain processes underlying sensory integration in typically developing children.  Dr. Saint-Amour presented the data collected from the healthy participants at the Cognitive Neuroscience Society meeting in 2007, and plans to present more data at the International Multisensory Research Forum meeting in 2008.

Dr. Saint-Amour’s research will provide us with a better understanding of the biological processes underlying deficits in sensory integration in autism.  This could in turn lead to the development of more effective treatment and education programs for people diagnosed with autism.