Some building blocks for motion vision

On Wednesday 13 July 2011, Dr Samuel Solomon, Senior Lecturer in Physiology at The University of Sydney's School of Medical Sciences Bosch Institute, will speak on the subject of building blocks for motion vision.
 
In primates, including humans, the analysis of visual motion requires at least two stages. In primary visual cortex neurons signal motion energy over local regions of space; neurons at later stages, including the middle-temporal area (MT / V5), can integrate these signals to compute the true velocity of a moving pattern. The robustness of this pattern-motion computation is not clear, and it remains a puzzling fact that only a small proportion of neurons in area MT seem capable of performing it. We addressed this through single- and multi-electrode recordings from area MT in the marmoset, a New World primate. We first show that the signals of pattern-motion neurons, but not other neurons, are stable across large changes in spatial form, and are capable of representing the motion of transparent surfaces. Thus motion vision should rely on the signals of pattern-motion neurons and not others. We then show that pattern-motion neurons are found clustered together within area MT, particularly at regions where the preferred direction of neurons is changing rapidly, but are not confined to particular layers. This suggests that the pattern-motion computation reflects local circuits but is not easily linked to a hierarchal staging of motion analysis. Our observations show that pattern-motion neurons can provide a robust signal for motion vision; how their signals are drawn selectively remains a mystery.
 
DETAILS
Date: 13 July 2011
Time: 12:00 - 1:00PM
Location: Level 7 Auditorium, QBI Building (#79), St.Lucia Campus
For a list of upcoming seminars at QBI, go to http://www.qbi.uq.edu.au/neuroscience-seminars

On this site

Go to top