Dr Nicholas Price - Researcher Profile

Nicholas Price

Address

Department of Physiology
Faculty of Medicine, Nursing & Health Sciences, Clayton

Contact Details

Tel: +61 3 990 55131

Email: Nicholas.Price@monash.edu


Biography

A fundamental contribution to the bionic eye

Dr Nicholas Price says many people underestimate the role the brain plays in our eyesight. It is a common misconception that sight mainly occurs in the eye, when in fact 20 to 30 per cent of the brain is devoted to our sense of vision. Nic is interested in how we process visual information, and his research is vital to efforts by the Monash Vision Group to develop a bionic eye for human trials by 2014.

 

The Monash Vision Group is a collaboration between Monash University, Alfred Health, MiniFAB and Grey Innovation. Nic’s initial focus on fundamental brain function research has allowed him to contribute to the applied research necessary for developing a bionic eye.

“I study the neural basis of visual perception, or how our brain processes information about what’s happening in the world, and how we use that visual information to guide behaviour and inform conscious perception,” Nic explains.

“The bionic eye work takes up between 25 and 50 per cent of my time, while my other research looks at what time scales of neural activity are useful in the brain. For example, if you want to kick a football, you need things to be fast and accurate. However, there’s a trade-off in the brain between speed and accuracy, and that’s one of the things we’re looking at. I’m interested in the time scales that neurons are informative over. Does it take 50 or 500 milliseconds to get information about what colour something is, or where something is moving?” he says.

Nic says an improved knowledge of how we process images has helped the Monash Vision Group develop a visual prosthesis that works by electrically stimulating the brain.

“In normal vision, light enters the eye and a sheath of neurons at the back of the eye called the retina converts the light signal into an electrical signal. From that point, the processing in the brain is electrical, with one neuron passing information to other neurons. Because neurons communicate electrically, we can provide an electrical stimulus that mimics the normal form of inputs you receive.”

“We’re developing a method for directly electrically stimulating the visual parts of the brain and the pattern of electrical stimulation is based on how you process video images. The prosthesis will have a video camera on a pair of glasses. They’ll send a signal down to a computer the size of a mobile phone, which will send signals up to electrodes that are actually implanted into the primary visual cortex. The brain normally works with electrical signalling, so we’re delivering something the brain is used to receiving, but the information is coming from a video camera instead of the eye,” he says.

To highlight the challenge of creating an image by stimulating electrodes, Nic drew comparisons with a similar application developed more than 30 years ago.

“When we stimulate on a single electrode, we know that people perceive a fuzzy white blob called a phosphene. One phosphene is not much use to you, but three of them could be used to create a line and nine of them could create a square. We can build up an image through these building blocks, with each pixel corresponding to an electrode. The bionic ear has 22 electrodes, which means they can stimulate 22 frequencies. If you could imagine trying to recreate vision with 22 pixels on a screen, it would be pretty terrible, so we’re aiming for 500 to 1000 electrodes, or pixels.”

 

 

Keywords

Company Law, adaptation, computational modeling, motion, neuronal population, perception, prosthesis, vision

Qualifications

NEUROSCIENCE
Institution: Australian National University
Year awarded: 2006
NEUROSCIENCE (HONORS)
Institution: Australian National University
Year awarded: 2001
ELECTRIC ENGINEERING
Institution: University of Western Australia
Year awarded: 2001

Publications

Book Chapters

Price, N.S., Born, R.T., 2009, Representation of Movement, in Encyclopedia of Neuroscience, eds LR Squire, Elsevier Ltd, UK, pp. 107-114.

Journal Articles

Price, N., Born, R.T., 2013, Adaptation to speed in macaque middle temporal and medial superior temporal areas, Journal Of Neuroscience [P], vol 33, issue 10, Society for Neurosciences, USA, pp. 4359-4368.

Price, N., Edwards, G.L., 2012, Accurate reading with sequential presentation of single letters, Frontiers in Neuroscience [E], vol 6, issue 158 (Art. NO.: 158), Frontiers Research Foundation, Switzerland, pp. 1-12.

Price, N.S., Prescott, D.L., 2012, Adaptation to direction statistics modulates perceptual discrimination, Journal of Vision [P], vol 12, issue 6 (Art. ID: 32), Association for Research in Vision and Ophthalmology, USA, pp. 1-17.

Price, N., Born, R., 2010, Timescales of sensory- and decision-related activity in the middle temporal and medial superior temporal areas, Journal Of Neuroscience [P], vol 30, issue 42, Society for Neuroscience, USA, pp. 14036-14045.

Crowder, N.A., Price, N.S., Mustari, M.J., Ibbotson, M.R., 2009, Direction and contrast tuning of macaque MSTd neurons during saccades, Journal Of Neurophysiology [P], vol 101, issue 6, Americal Physiological Society, USA, pp. 3100-3107.

Crowder, N.A., Hietanen, M.A., Price, N.S., Clifford, C.W., Ibbotson, M.R., 2008, Dynamic contrast change produces rapid gain control in visual cortex, Journal Of Physiology-London [P], vol 586, issue Pt 17, Wiley-Blackwell Publishing Ltd, UK, pp. 4107-4119.

Ibbotson, M.R., Crowder, N.A., Cloherty, S.L., Price, N.S., Mustari, M.J., 2008, Saccadic modulation of neural responses: possible roles in saccadic suppression, enhancement, and time compression, Journal Of Neuroscience [P], vol 28, issue 43, Society for Neuroscience, USA, pp. 10952-10960.

Durant, S., Clifford, C.W., Crowder, N.A., Price, N.S., Ibbotson, M.R., 2007, Characterizing contrast adaptation in a population of cat primary visual cortical neurons using Fisher information, Journal Of The Optical Society Of America A-Optics Image Science And Vision [P], vol 24, issue 6, Optical Society of America, USA, pp. 1529-1537.

Ibbotson, M.R., Price, N.S., Crowder, N.A., Ono, S., Mustari, M.J., 2007, Enhanced motion sensitivity follows saccadic suppression in the superior temporal sulcus of the macaque cortex, Cerebral Cortex [P], vol 17, issue 5, Oxford University Press, UK, pp. 1129-1138.

Hietanen, M.A., Crowder, N.A., Price, N.S., Ibbotson, M.R., 2007, Influence of adapting speed on speed and contrast coding in the primary visual cortex of the cat, Journal Of Physiology-London [P], vol 584, issue Pt 2, Wiley-Blackwell Publishing Ltd, UK, pp. 451-462.

Teaching Commitment

PHY2011, PHY3111, BMS1052, RAD2092, MED1022, MED2042

Postgraduate Research Supervisions

Current Supervision

Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
A multimodal study of working memory.
Supervisors:
Rosa, M (Main), Price, N (Associate).