Principle Investigator: Daniel E. Guitton, PhD
Our lab studies the brain's visuo-motor system, with an emphasis on the neural circuits that generate and coordinate saccadic eye and head movements. We analyze the neural activity that accompanies orienting eye-head movements by recording single neurons in different areas of the brain. In collaboration with laboratories in McGill’s Biomedical Engineering Department, Physiology Department, and in Neurology and Neurosurgery, we are developing a theoretical network and systems model of the eye-head motor control system. The resulting motor output model will then be compared with observed motor behaviour to develop an understanding of the system's organization. These results are interpreted with the aim of explaining normal and pathological eye-head motor behaviour.
Flow diagram of signals (GPE=Gaze Position
Error; G=Gaze) assumed to
modulate superior colliculus fixation neuron (SCFN) discharges. From Choi & Guitton,
patterns on the motor map in the intermediate layer the superior colliculus
(SC) during an orienting gaze shift
in the cat; otherwise known as the “moving hill
hypothesis” of activity that terminates in the rostral fixation zone.
From Munoz, Pelisson & Guitton, Science (1991).
Discharge locations of cellular activity at different positions on the SC motor map, organized in retinotopic coordinates as DA Robinson (1972) initially described it. The moving locus of activity would therefore move from postion 3 to postion 1 (the fixation zone of the rostral pole) over the course of an eye-head gaze shift.