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B.A. Psychology, Concordia University (1998)
I have ongoing research programs in three areas: (1) multisensory information in stimulus detection and identification, (2) links between cardiovascular health and cognition, and (3) action production
(1) Multisensory integration:
We interact with the world with five different senses, and the brain somehow merges information from these five senses in a coherent way. It correctly matches the face and voice of a student speaking to you as arising from the same agent. A number of rules drive how information across the sense is matched: the visual and auditory information should come from the same location, it should ‘move’ at the same time, etc… Having more than one type of information tends to facilitate the detection of specific stimuli – we are faster at detecting the presence of something if we BOTH see it and hear it. However, under certain circumstances, multisensory integration can also interfere with performance. My research in multisensory information aims to (1) investigate the behavioural locus of this integration by teasing apart sensory and motor facilitation, (2) understand the role of experience in sensory dominance and multisensory integration, and (3) investigate the relationship between visual and tactile information in visual object identification.
(2) Cardiovascular health and cognition:
This research program seeks to understand the relationship between cardiovascular health and cognitive performance in healthy undergraduate students. A number of studies have suggested that, in older individuals, cardiovascular health is closely linked to cognitive performance. Past cardiovascular health, as defined by the presence of various cardiovascular diseases like high blood pressure, is a predictor of later cognitive performance as well as a protective factor against dementias. One suggested mechanism for this relationship is that better cardiovascular health leads to better arterial function in brain areas like the frontal lobes, and therefore better exchange of oxygen and nutrients in these areas. In younger individuals, better cardiovascular health has also generally been linked with better cognitive performance. However, in many studies ‘cognition’ has been very broadly defined, and may refer to processes like attention, inhibition, speed of processing or memory. There is thus a need to better identify the cognitive processes that are affected by poor cardiovascular health; this is the first goal of this research program. Furthermore, though the relevance of cardiovascular health for older individuals is obvious – especially with the prevention of dementia – the relevance is not as self-evident for younger individuals. Therefore, the second goal of this research program is to identify whether the association between cardiovascular health and cognition reaches everyday life, specifically academic performance.
(3) Action production
This line of research focuses specifically on how we use objects. It has been shown that when people are asked to produce actions in response to objects, they tend to make visual errors. For example, when asked to make the gesture associated with a saw, people may perform a cutting action (associated with a knife) – the saw and the knife are arguably visually similar. However, people also sometimes produce semantic errors, like performing a hammering gesture in response to a saw. Though the saw and the hammer don’t look the same, they come from the same category of objects.This has lead researchers to suggest that though action production can be mediated by semantics (an indirect route to actions), the preponderance of visual errors suggests that actions are performed almost automatically in response to the visual features of objects (a direct route to actions). Some of my past research has suggested that, when learning to use NOVEL objects, semantic information may play a more important role than when using familiar objects. When participants were asked to learn to identify novel objects and perform their associated actions (e.g., a tapered object is called FINT, and it is pulled), participants tended to follow an incorrect name with its corresponding incorrect action. To explore this phenomenon more closely, I have carried out a series of experiments that investigate participants’ performance when they begin to learn about novel objects and actions, as well as how their performance changes once the objects and actions become well-known.
Desmarais, G., Meade, M., Wells, T., & Nadeau, M. (in press). Visuo-haptic integration in object identification using novel objects. Attention, Perception, and Psychophysics.
Desmarais, G., Lane, B., LeBlanc, K.A., Hiltz, J., & Richards, E.D. (in press). What's in a name? The influence of verbal labels on action production in novel object/action associations. Visual Cognition.
Macdonald, S.N., Richards, E., & Desmarais, G. (2016). Impact of semantic similarity in novel associations: Direct and indirect routes to action.Attention, Perception, and Psychophysics, 78, 37-43.
Desmarais, G., Hudson, P., & Richards, E.D. (2015). Influences of visual and action information on object identification and action production. Consciousness and Cognition, 34, 124-139.
Desmarais. G., Hudson, P., & Richards, E.D. (2013). The impact of incongruent shape and action information on object identification and action production. Journal of Vision, 13(9), 756.
Desmarais, G., Fisher, M.J., & Nicol, J. (2010). Reciprocal interference from sound and form information in stimulus identification. Journal of Vision, 10( 7), 887.
Desmarais, G., Dixon, M.J., and Myles, K. (2009). Combined effects of semantic and visual proximity on visual object identification in Alzheimer’s disease and Mild Cognitive Impairment. Journal of Vision, 9 (8), 1052.
Desmarais, G., Dixon, M.J., & Roy, E.A (2008). Task characteristics modulate the impact of action similarity on visual object identification. Journal of Vision, 8 (6), 521.
Karthaus, C., Desmarais, G., & Roy, E. (2008). Action and Semantic Attributes in Object Identification. Journal of Vision, 8(6), 1166.
Desmarais, G., Pensa, M.C., Dixon, M.J., & Roy, E.A. (2008). Adding and omitting components of actions: differences in salience between pulling, twisting, and sliding. Brain and Cognition, 67, S1, 18-19.
Painter, R., Desmarais, G., Stamenova, V., Roy, E.A., Park, N., Gold, D.A. and Lombardi, S. (2008). The impact of dementia on apraxia and function in daily living. Brain and Cognition, 67, S1, 34.
Desmarais, G., Pensa, M. C., Dixon, M. .J., Roy, E A. (2007). The effect of object similarity on action production and action identification. The Journal of the International Neuropsychological Society, 13 (6), 1021-1034.
Desmarais, G., Dixon, M. J., & Roy, E. A. (2007). A role for action knowledge in visual object identification. Memory and Cognition, 35 (7), 1712-1723.
Desmarais, G., & Dixon, M. J. (2005). Understanding structural determinants of object confusion in memory: An assessment of psychophysical approaches to estimating visual similarity. Perception and Psychophysics, 67 (6), 980-996.
Dixon, M. J., Desmarais, G., Gojmerac, C., Schweizer, T. A., & Bub, D. N. (2002). The role of premorbid expertise on object identification in category-specific visual agnosia. Cognitive Neuropsychology, 19 (5), 401-419.
Psychology 1001: Introduction to Psychology I
Psychology 2101: Biopsychology
Psychology 3101: Human Neuropsychology
Psychology 3211: Sensation and Perception
Psychology 4101: Advanced Topics in Behavioural Neuroscience
Brief Teaching Philosophy:
teaching should result in meaningful learning. As such, it is important for
students to be engaged with the material presented in class and outside
of class. In order to achieve this, I use a variety of teaching methods in the
classroom to keep students engaged, and I ensure that material presented in
class is concrete – that it becomes real for students. Furthermore, for
learning to be meaningful, it must impact behavior outside the classroom.
Teaching is more than the rote learning of information: meaningful learning
will be reflected in changes in behavior – becoming better communicators, and
better consumers of information. In order to help students become better
citizens, I focus on developing their critical thinking skills as well
as their communication skills