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Visual Sciences

We take a multi-disciplinary approach to the study of vision at the neural and behavioural levels.

We use a wide range of approaches including:

molecular and cell biology
psychophysical and behavioural analysis
computational modelling
electrophysiology
brain imaging (optical and magnetic)

Our work has important applications in the development of tools and technologies for robotics and medicine.The group is part of the campus wide Centre for Visual Sciences and the ARC Centre for Excellence in Vision Science.

Current Research

Visual Processing in Mammalian Brains - Dr Michael Ibbotson (Head of Group)

My laboratory studies the neural basis of visual perception by recording single cell activity in cat and monkey cortex and by measuring human reactions to visual stimulation. Topics include the neural basis of motion processing and adaptation to contrast and motion. In behaving monkeys we record neural activity during eye movements and relate the findings to perception.

Neuroethology of Visual Information Processing and Colour Vision -

Dr Jan Hemmi

The aim of our research is to explore the relationship between an animals' information processing requirements and the design of their visual system. We are especially interested in how these factors constrain and shape their decision making, as seen in their behaviour. We work with a range of study animals such as fiddler crabs and marsupials.

Human Brain Dynamics - Dr Andrew James

We are studying interactions in the hierarchy of cortical areas using multimodal neuroimaging techniques. This includes the multifocal mapping of activity in early cortical areas combining responses recorded with electroencephalography and magnetoencephalography with spatial constraints obtained with functional magnetic resonance imaging, and the study of the effects of transcranial magnetic stimulation on perceptual processes.

Development of Visual Diagnostics for Eye Diseases - Dr Ted Maddess

We are studying how the eye processes motion, size, texture, and brightness. We are also interested in multifocal methods with applications in neurophysiology, and objective perimetry for diseases like glaucoma and multiple sclerosis.

Development of the Visual System - Dr Lauren Marotte

We are studying the development of the visual system using the marsupial mammal, the wallaby, as a model. The protracted and largely postnatal development of its visual system makes it an excellent alternative to common laboratory placental mammals for developmental studies. Molecular and anatomical methods are used to investigate mechanisms involved in establishing maps of the visual world in visual centres in the brain. A stereotaxic atlas of the wallaby brain is available here.

Retinal and Myopia Research - Dr Ian Morgan

Our current major emphasis is how retinal circuits control eye growth, and hence regulate the development of short-sightedness. In human epidemiological studies, we explore environmental (education and life-style) factors that promote short-sightedness. In parallel laboratory experimentation, we explore the optical and cellular/molecular pathways that control eye growth, in an attempt to develop preventive regimes.

Foveal Development and Macular Degeneration - Prof Jan Provis

Signals from cone photoreceptors provide the basis of almost all of our useful vision. Pathways originating from cones mediate high acuity, colour vision via so-called 'Midget' pathways, which dominate the central few millimeters of primate retina, including the fovea centralis ('fovea'). During early development foveal cones are amongst the first cells to differentiate, appearing as cuboidal, epithelial-like cells. Over the first few years of life they become slender, elongated cells with an elaborate axon, and highly elongated inner and outer segments. A slender shape facilitates close-packing of cones at the fovea, and is the anatomical stubstrate of high resolution vision. In the central fovea, the photoreceptor mosaic comprises cones exclusively, at their highest spatial density; these cones are narrower and more elongated than elsewhere in the retina.

Attainment of adult-like acuity functions in childhood is associated with a slender, elongated cone morphology at the fovea; loss of this morphology is a critical feature of both age-related macular degeneration (AMD) and retinal detachment. Despite the critical relationship between cone shape and visual function, the mechanisms that mediate morphological differentiation during development, and the maintenance of cones through adulthood and old-age, have not been identified. Work in this lab is directed at understanding the mechanisms underlying morphological differentiation of cone photoreceptors, development of the fovea and surrounding macula, and ageing and degeneration of the macula, as occurs in Age-related Macula Degneration.

Retinitis Pigmentosa - Prof Jonathan Stone

We are exploring the mechanisms which control the stability of nerve cells of the central nervous system, and whose breakdown results in neuronal death, causing the degenerative disease of the CNS. Many of our projects concern the retina of the eye, and especially the neurones specialised to detect light, the photoreceptors. These highly active and specialised neurones are amongst the most fragile of CNS cells; they degenerate in response to both genetic and environmental stresses. Retinitis pigmentosa (RP) is a diagnosis given to a group of diseases where the insidious death of retinal photoreceptor occurs causes blindness. RP affects 1 person in 4,000, thus about 5,000 Australians and 1-2 million people world-wide. Patients are usually in their late teens or early 20's when diagnosed and they face a life of gathering blindness with no effective treatment. Our laboratory is part of a world-wide effort to find effective treatment.

Effects of environmental factors on the rodent retina

Extensive work has been done on the causes of retinal degenerations. About 50% are clearly genetic, the other 50% occur without family history. Several features of retinitis pigmentosa also remain unexplained, particularly the relentless progression of the disease. Many forms of RP are caused by genetic mutation of rod-specific genes, yet the degeneration spreads from the rods to the cones, causing the loss of the entire photoreceptor population and blindness. Recent work in our laboratory led us to formulate an "oxygen toxicity" hypothesis, to explain the progressive nature of the disease. In this series of studies we are looking at the effects of different oxygen levels or light intensity levels on photoreceptor survival in normogenetic and degenerative retinae. By understanding the mechanisms underlying retinal degenerations, we will be able to model retinal degenerations and to study the effects of therapeutical interventions on these theoretical models, and to use our knowledge in clinical trials.

Protective mechanisms in the rodent retina

Examining the effects of changing environmental factors on the progress of retinal degneration, genetic or environmental, we are learning the process of the disease and the protective mechanisms by which the retina fights to survive. It has become clear in recent years that the degeneration takes place against a background of active resistance by the retina. The mechanisms by which the retina protects itself are also becoming clear. The retina is able to secrete proteins - sometimes called factors - which somehow protect retinal cells against damage. The mechanisms of secretion and action of these factors remain largely unknown. In this series of experiments we assess the role of protective (neurotrophic) factors in the normal retina's resistance to stress, such as light damage, identify the high-affinity receptors involved and trace their regulation by genetic and environmental stress. By using electroretinography we also assess the direct effects of these factors on photoreceptor function.

Roles of Mitochondria in Retinal Degenerations

Mitochondria serve (at least) 3 functions in every cell. They are the site of oxidative metabolism, and the source of signals which induce or suppress apoptotic (programmed) cell death. Mitochondria are abundant in photoreceptors, and we have begun testing whether mitochondrial damage is a factor in photoreceptor degeneration. We have shown for the first time that deletions in mtDNA (mitochondrial DNA) are abnormally frequent in degenerating retina. Recent studies have shown that somatically aquired mutations such as deletion of mtDNA are caused by oxygen damage or UV irradiation during the life of the individual. Accumulation of these somatic mutations in postmitotic cells (such as neurones) causes bioenergetic deficiency leading to age-associated dysfunction of cells and organs. An accelerated accumulation of mtDNA fragmentation leads to premature ageing and/or degenerative diseases. In this study we are screening photoreceptors of normal ageing and degenerative retinae . We are also looking at the role of mtDNA deletions in light induced retinal degenerations.

Retinal cell damage and repair: development of cellular biology based therapies - Dr Krisztina Valter

Photoreceptors are the light sensitive cells in the retina, and the sites where light is captured and transformed from electromagnetic waves to neural signals. Thus, photoreceptors are making the first steps in the process of vision. Damage to the photoreceptors leads to severe visual disturbances or blindness. Understanding the mechanisms that lead to photoreceptor damage and the processes by which the retinal tissue is trying to heal damaged cells are important. To find out more about the repair systems of the retina, we are using rodent models of retinal degenerations to follow the progression of cell damage and repair. Using genetic and environmentally-induced retinal dystrophy models, we are looking at signs of reversible and irreversible damage in photoreceptors, and the long-term consequences of cell loss on the function and structure of the retina. Changes in retinal metabolism, mitochondrial status and protective factor expressions are the focus of our investigations. Using our understanding of the cell biology of these cells and the protective mechanisms, we are developing non-invasive therapeutical approaches to prevent or slow photoreceptor degenerations.

Visual Ecology - Dr Jochen Zeil

We aim to understand the evolution and adaptive significance of eye specialisations in animals. One of our major projects at the moment is to establish an inventory of visual tasks in fiddler crabs. We also use a mobile robotic gantry to reconstruct the views seen by flying insects. For further details see Visual Ecology webpage.

Insect Vision, Perception and Navigation - Dr Shao Wu Zhang

Insects such as honeybees are impressive navigators despite their relatively small brains and simple nervous systems. We aim to elucidate principles of vision, flight control and navigation in honeybees through behavioural experiments.

People and Contacts

Name Role Phone Email

Alkaladi, Ali PhD Student
+61 2 6125 1529

Berry, Richard
+61 2 6125 5089

Blest, David Visiting Fellow

Bumsted O'Brien, Keely
+61 2 6125 2389

Byrne, Kirsten

Caetano, Tiberio Visiting Fellow

Carle, Corinne PhD Student
+61 2 6125 6799

Carr, Owen PhD Student
+61 2 6125 9069

Chrysostomou, Vicki PhD Student
+61 2 6125 4489

Chung, Shin-Ho Professor
+61 2 6125 2024

Cloherty, Shaun
+61 2 6125 2749

Culek, Eva
+61 2 6125 5094

Goh, Xin-Lin PhD Student
+61 2 6125 1659

Gordon, Daniel Postdoctoral Fellow
+61 2 6125 4743

Guez, David Fellow
+61 2 6125 1529

Harley, Nerida

Hietanen, Markus PhD Student
+61 2 6125 8562

Horridge, Adrian Emeritus Professor
+61 2 6125 4532

How, Martin PhD Student
+61 2 6125 4486

Hung, Yu-Shan PhD Student
+61 2 6125 6799

Karunaratne, Nilushi Visiting Scholar
+61 2 6125 9069

Kirk, Diana PhD Student
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Kolic, Maria Masters Student
02 6285 5814

Kozulin, Peter PhD Student
+61 2 6125 1378

Kucharski, Robert Postdoctoral Fellow
+61 2 6125 8592

Kuran, Kathryn
+61 2 6125 5051

Li, Jasmine

Lockett, Gabrielle PhD Student
+61 2 6125 5080

Maleszka, Joanna Senior Technical Officer
+61 2 6125 0451

McCarthy, Siobhan
+61 2 6125 4747

Mohammadi, Amir PhD Student
+61 2 6125 2371

Narendra, Ajay Postdoctoral Fellow
+61 2 6125 4799

Natoli, Riccardo PhD Student
+61 2 6125 8559

Ngo, Silvie Research Assistant
+61 2 6125 2024

Nguyen, Thanh
+61 2 6125 2024

O'Brien, Brendan
I don

Pix, Waltraud Fellow
+61 2 6125 2040

Querubin, Angeliza PhD Student
+61 2 6125 1378

Reid, Samuel PhD Student
+61 (2) 6125 9701

Salmon, Tina
+61 2 6125 7544

Salmon, Tina Technical Assistant
+61 2 6125 7544

Shiels, Lynette

Si, Aung
+61 2 6125 2040

Stange, Gert Visiting Fellow

Stone, Jonathan Visiting Fellow
+61 2 6125 5878

Valter-Kocsi, Krisztina Research Fellow
+61 2 6125 1095

Vlahos, Lisa PhD Student
+61 2 6125 4486

Voicu, Cristian
+61 2 6125 4099

Vora, Taira Research Assistant
+61 2 6125 4034

Walker, Michael

Zhu, Hong Member
+61 2 6125 5145

Zhu, Yuan PhD Student
+61 2 6125 4489

Zsögön, Agustin PhD Student
+61 2 6125 2406