Honours Research Projects Available:

1. Neurophysiology of feature discriminating neurons

Supervisor: Dr Steven Wiederman

Have you ever thought about how challenging it is to visualize objects that move relative to the surround - such as when you are chasing a ball across a footy oval? Detection of features that move within visual clutter is a common task for many animals searching for prey or conspecifics. This is even more visually challenging if the pursuer itself is in motion, so that the feature needs to be analysed against the motion of background texture. Despite the limited optical acuity of compound eyes this challenging task seems to have been solved by the tiny visual system of insects.

We have described both 'target' and 'bar' specific neurons within the insect brain. These visual neurons respond selectively to either small moving targets or large moving contrast boundaries. We would like to discover to what features in natural scenes these neurons are most responsive. Interestingly, some of these neurons show characteristics similar to cells found in the vertebrate V1 cortex! We are currently investigating more about the underlying neurophysiology making feature detection in clutter possible.

This project would include intracellular electrophysiology of optic lobe neurons, potentially combined with in silico modelling. The project will allow the student to gain experience in electrophysiological techniques widely used in neuroscience research. The student will also gain a broad understanding of visual motion processing which is analogous in both insects and vertebrates.

2. Visual processing of natural scenes

Supervisor: Dr Russell Brinkworth

For many years, visual neuroscience has relied on simple stimuli like pulses of light or grating patterns to characterise neurons involved in the visual system. Yet the real world contains much richer and more complex scenery. With recent technological advances in computer graphics and displays, we are now able to replicate some of this visual complexity in the lab. As such many vision scientists are now turning their attention to studying visual neurons with natural stimuli. So far the results have been fascinating - visual neurons respond very differently to natural scenes than we could have predicted based on their responses to more simple stimuli.

This project would apply state-of-the-art stimulus and intracellular recording techniques to study second order visual interneurons in flies under realistic conditions. These recordings will then be ‘resynthesised’ to produce a view of the world as seen from inside the brain of a fly.

3. The neurophysiology of motion processing

Supervisor: Assoc. Prof David O'Carroll

Flies process motion vision in much the same way as humans do and can therefore be used as a model to understand processing that takes place in our brains. We have recently used images taken from natural environments to show that the motion detecting neurons in the brain adapt to prolonged motion in very specific ways that lead to a highly robust and consistent response to enormously different natural scenes. How this adaptation matches the response to the particular scene is still largely a mystery. This project would involve intracellular electrophysiology of optic lobe neurons to investigate some of the parameters that drive motion adaptation in different scenes and at different speeds. The project will allow the student to gain experience in electrophysiological techniques widely used in neuroscience research. The student will also gain a broad understanding of visual motion processing which is analogous in both insects and vertebrates. If students have an interest in computational approaches to studying biological information processing, they could also learn to use computer simulation of this system to compare with the physiologically recorded response and test experimental approaches in silico.