NeuroEngineering Research Lab

2015 Seminars

Coordinating Hand-Eye Decisions across the Parietal Cortex through Coherent Neuronal Ensembles

Date: Wednesday 4 November 2015
Speaker: Dr Yan Wong

Abstract

Foraging through the environment we gather information about our surroundings through combinations of eye and arm movements. The posterior parietal cortex (PPC) is involved in the spatial representation of movement plans for these saccades and reaches. Within the PPC, specialized neurons are involved in guiding saccadic eye movements and their activity is modulated by the value of saccade targets. However, it is unknown how these valuation signals are utilized to select, plan and coordinate movements of different effectors. Further, selecting and planning arm and eye movements recruits neurons in many different areas of the brain but how ensembles of neurons work together to make a single choice is also unknown.

This talk will explore how an effector-specific reinforcement learning model of choice behaviour can be used to accurately infer a subjects valuations of different choices, and how firing of PPC neurons are modulated by these valuations. Dr Wong will then show how these neurons can be classified based on the presence of significant spike-field coherence between different brain areas to identify neurons that have unique information about upcoming choices. Dr Wong proposes that coherent patterns of neural firing could play an important role in how we make decisions, and that temporally-coherent neural activity may provide a mechanism by which neurons coordinate their activity in order to make choices.

What can we learn from local field potentials (LFPs) recorded in the brain?

Date: Wednesday 12 August 2015
Speaker: Professor Gaute Einevoll

Abstract

While extracellular electrical recordings are the work horse in in vivo electrophysiology, the interpretation of such recordings is not trivial. The recorded extracellular potentials in general stem from a complicated sum of contributions from all transmembrane currents of the neurons in the vicinity of the electrode contact.

The high-frequency part of the recorded signal contains information about action-potential firing (spikes), and the signal can often be sorted into spiking contributions from individual neurons surrounding the electrode. The interpretation of the low-frequency part of the low-frequency part, the local field potential (LFP), is more challenging as thousands of neurons in general will contribute to the measured signal (Lindén et al., Neuron, 2011). To take full advantage of the new generation of silicon-based multielectrodes recording LFPs from tens, hundreds or even thousands of contact positions simultaneously, we thus need to develop new data analysis methods (Einevoll et al., Nat Rev Neurosci, 2013). From volume conduction theory it follows that the extracellular potentials can be calculated by adding contributions from the transmembrane currents around the electrode contact, and a forward-modeling scheme for calculating the extracellular potential generated by activity in biophysically detailed neuron models has been developed (Holt & Koch, J Comp Neurosci 1999).

Professor Gaute Einevoll will discuss results from our group where this scheme has been used to explore the neural activity underlying LFPs and to develop new analysis methods for the signal.

Biography

Gaute T. Einevoll is a professor of physics at the at the Norwegian University of Life Sciences and University of Oslo. His main research interests are on (i) biophysical modelling of electrical signals, (ii) various aspects of multiscale modeling of early sensory pathways, (iii) biophysical modeling of astrocytes and their interactions with neurons, as well as (iv) development of neuroinformatics tools for analysis of neural data. Prof. Einevoll received his master’s in physics from the Norwegian University of Science and Technology in Trondheim in 1985 and his doctoral degree in theoretical physics from the same university in 1991. He is currently serving as the vice-president of the Organization of Computational Neurosciences, and is also a co-leader of the Norwegian national node of the International Neuroinformatics Coordinating Society (INCF).

Network Inference using Data Based Modelling: Challenges and Pitfalls

Date: Wednesday 29 July 2015
Speaker: Professor Bjoern Schelter

Abstract

Complex networks are powerful representations of spatially extended systems and can advance our understanding of their dynamics. A large number of analysis techniques is available that aim at inferring the underlying network structure from data. Despite great successes in various fields, there still exist a number of problems for which there are currently no satisfactory solutions. This seminar will provide an overview of analysis techniques with particular emphasis on challenges and pitfalls when applying these techniques to data.

Biography

Bjoern Schelter assumed the position as Chair Professor in the Institute for Complex Systems and Mathematical Biology, the Institute for Pure and Applied Mathematics, and the Department of Physics at King’s College, University of Aberdeen, in 2014 after being a Senior Lecturer for 2 years. Before he was running his group “Multivariate Time Series Analysis in Neurology” at the Freiburg Centre for Data Analysis and Modelling and the Department of Physics at the University of Freiburg. His main focus of research is in data-based modelling and model-based data analysis in the Life Sciences. Prof Schelter looks back to roughly 15 years of experience in developing and applying mathematical methods for the analysis of time series with particular focus on bridging linear stochastic systems and nonlinear dynamics. Complementing his theoretical research, the spectrum of applications he has contributed to include various fields in the Neurosciences, in particular epilepsy research, tremor research with focus on Parkinson’s disease as well as dementia research. To achieve this, several theoretical developments became necessary. He has contributed to the development of mathematical methods, ranging from linear approaches to non-linear dynamics. The methods cover parametric as well as non-parametric techniques. Statistical aspects present an important part of the developments. His mathematical/ theoretical contributions are documented in roughly 30 publications. Software tools have been developed to enable a user-friendly interface to the techniques developed. Another 30 publications document Prof Schelter’s successful applications in the Life Sciences. His research has not only elicited a number of international collaborations to University partners but also several collaborations to industry partners to exploit his ideas commercially

Brain Injury

Date: Monday 27 July 2015
Speaker: Associate Professor Cameron R. ‘Dale’ Bass

Abstract

Brain injury is a conundrum. Brain injuries are common from falls, traffic crashes, military scenarios, approaching an epidemic. Mild traumatic brain injury (mTBI) or “concussive” injuries are a major societal issue and are associated with activities at all ages including sports, motor vehicle crashes, and falls. Recent emphasis on sports-related concussions (~1.6-3.8 million annually) highlights the need to understand the etiology of mTBI. Over 40 years of investigations from the early skull fracture studies to modern cellular, subcellular mechanophysiological and electrophysiological studies have left us with practical and teleological confusion. Fundamental questions such as How do we treat mild/moderate neurotrauma?, What is the human injury tolerance for repeated impact?, Is there a difference between blast and blunt neurotrauma?, Can we use animals to biofidelically model human neurotrauma? or even What causes a human to lose consciousness from impact? remain unanswered along with many others. This lack of knowledge prevents effective treatment, injury countermeasures and understanding of risks. What is the state of injury biomechanics of the brain for both blast and blunt neurotrauma? This superficial and wide-ranging discussion will touch on recent results in injury biomechanics of blunt trauma and blast trauma. This will include results and inferences on pathophysiology from the cellular to the organismal level, histopathological and biophysical results. Along the way, I will outline approaches for basic brain material characterization and modeling, including a novel fractional calculus approach to characterize viscoelasticity.

Associate Professor Cameron Bass, Duke University will discuss phenomenology and notional injury criteria for blunt and blast neurotrauma and outline approaches for mild neurotrauma biomarkers including behavioral approaches and biochemical approaches. This seminar will explore animal models and scaling to human impact conditions, physiologically, immunologically and biomechanically. Finally, the lecture will address approaches to biomechanical instrumentation for blunt impact epidemiology outlining the principal challenges in obtaining and assessing impact data in the field.

Biography

Cameron R. ‘Dale’ Bass is a Doctor of Philosophy and Associate Research Professor/Director of the Injury Biomechanics Laboratory at Duke University with many students in biomechanics, including studies in viscoelasticity imaging, blunt neurotrauma and spinal injury, and blast neurotrauma. Currently, this is 10 PhD students, all of them quite intelligent. By now, the students do all the work and Dr. Bass provides the Philosophy, often ad infinitum.

Neural mechanisms of eye-hand coordination in the posterior parietal

Date: Monday 13 July 2015
Speaker: Dr Maureen Hagan

Abstract

Everyday activities like reaching for our morning coffee depend on a well-orchestrated coupling of where we look with our eyes and where we reach with our hand. A wealth of behavioural research has contributed to our understanding of how eye movements occur in concert with arm and hand movements. However, little is known about how the brain computes the necessary transformations to link eye and hand movements.

The posterior parietal cortex (PPC) has a well-established role in visually guided behaviour and contains areas that are specialized for guiding eye movements (area LIP) as well as reaches (Parietal reach region, PRR). This research recorded spiking and local field potential activity during coordinated eye-hand tasks. The synchronization of spiking activity with the local field potential may serve as a mechanism by which the timing of neural events within and across brain areas is able to coordinate complex behaviours. This presentation is able to show that many of the behavioural features of eye-hand coordination can be directly linked to the synchronization of neural activity in the PPC.

Biography

Dr Maureen Hagan received her PhD in 2013 at the Center for Neural Science at New York University. Her thesis examined the mechanisms of eye-hand coordination by studying the interactions of spiking and LFP activity in the posterior parietal cortex. Her thesis was awarded the Dean’s dissertation award for outstanding research. She has recently joined the Physiology Department at Monash University as a postdoctoral research fellow, studying the neural basis of visual perception.

Differential changes in synaptic inputs to ON & OFF retinal ganglion cells during retinal degeneration

Date: Monday 11 May 2015
Speaker: Susmita Saha

Abstract

The results of clinical testing of the electrical retinal implants are encouragingly successful in restoring some kind of useful vision in blind patients with inherited retinal disorders like Retinitis Pigmentosa (RP). However many challenges remain for its implementation in large population. For example, to mimic the normal retinal mechanism, we need to differentially stimulate the ON and OFF ganglion cells (GCs), which is not possible with the current technology. In order to achieve that, it is utterly important to know about the functional conditions of these two types of cells at different stages of RP especially at advanced stages. The overall aim of Susmita Saha's PhD project was to demonstrate the differential effect of complete photoreceptor loss on the synapse densities, synaptic currents and spiking activities of ON and OFF retinal ganglion cells using rd1 mouse as a model of degeneration.

Biography

Susmita Saha is currently completing PhD study in the National Vision Research Institute under the department of Electrical and Electronic Engineering (EEE) and the department of Anatomy and Neuroscience in the University of Melbourne. Susmita completed my BSc in EEE from the Bangladesh University of Engineering and Technology in 2004. Then she joined the leading mobile operator company of Bangladesh as a system Engineer and worked there until Jan, 2011. During PhD study, she also did a summer internship job with Victorian Life Sciences Computation Initiative (VLSCI), Parkville in an image processing and machine learning related project.

Bilateral Cochlear Implants: Recent Advances and Future Directions

Date: Monday 27 April 2015
Speaker: Professor Ruth Litovsky

Abstract

In the field of audiology, the standard of care is to provide patients who are deaf or hard-of-hearing with cochlear implants (CIs) in both ears. The goal of bilateral implantation is to take advantage of binaural neural circuitry, which enables humans to localize sounds and to hear speech in noise at poor signal-to-noise ratios. Although bilateral CIs seem to improve performance relative to that seen with a single CI, most users show notable decrement compared to normal hearing people. The factors that are responsible for these gaps in performance will be discussed. For example, we observe limitation in the signal processing and speech coding strategies utilized by today’s clinical CIs, which do not coordinate the inputs from the two devices. Another issue to consider is the effects of auditory deprivation early in life on neural degeneration in the binaural circuitry. This talk will focus on approaches that may be needed for restoring binaural sensitivity in CI processors, the role of auditory plasticity due to congenital vs. later-onset of deafness, the potential importance of training and top-down processing such as executive function, working memory and attention).

Biography

Ruth Litovsky, PhD is Professor at the University of Wisconsin-Madison, in the Departments of Communication Sciences and Disorders, and Surgery/Division of Otolaryngology. She directs the Doctorate in Audiology Program, and the Binaural Hearing and Speech Laboratory at the Waisman Center. Professor Litovsky is actively involved in the fields of hearing research and auditory implants. She has served on numerous grant review panels and editorial boards, chaired the Conference on Implantable Auditory Prostheses at Asilomar in 2011, elected Councilor for the Association for Research in Otolaryngology and is Program Committee Chair of the Midwinter Meeting of the Association for Research in Otolaryngology, Associate Editor for Journal of the Association for Research in Otolaryngology and the Journal of the Acoustical Society of America. Litovsky received her PhD in 1991 in Developmental Psychology, with post-doctoral training in auditory neurophysiology and psychoacoustics. Her research focuses on binaural hearing, covering lifespan of humans to include infants and elderly adults, with populations of normal-hearing persons and those who are deaf and use cochlear implants. At the heart of her research questions is the issue of bilateral cochlear implants. In adults the research questions focus on the ability of people with onset of deafness in childhood vs. adulthood to integrate information from the two ears with fidelity and precision, and the extent to which functional outcomes such as sound localization and speech understanding in complex environments is similar in these individuals compared with normal hearing listeners. This research program has been funded continuously by grants from the NIH-NIDCD since 1995.

Reading with retinal prostheses: targeted stimulation strategies harnessing phosphene orientation

Date: Monday 13 April 2015
Venue: Newton Rooms, Fifth Floor, Electrical and Electronic Engineering Building 193, The University of Melbourne
Speaker: Isabell Kirak-Kornek, The University of Melbourne

Abstract

Conventional stimulation strategies for retinal implants generally assume evenly distributed, round, black-and-white phosphenes, whose intensity can be modulated to reflect different brightness levels in the image that is being presented to the implantee. However, psychophysical experiments with patients have shown that phosphenes can be very complex and can differ in size, shape, and even colour. In this talk, results are presented to demonstrate how a user could benefit from a targeted stimulation strategy that uses more than just phosphene intensity to convey information. In particular, methods to harness the phosphene shape and orientation in order to facilitate letter recognition with retinal implants and increase reading speed were investigated. The results of two psychophysical studies are presented that were conducted to assess how phosphene direction could help or hinder reading performance for simulated phosphene vision with normal-sighted subjects. This work has implications for the wider field of simulation-based psychophysical experiments to assess and improve the retinal implant user experience.

Biography

Isabell Kiral-Kornek is currently undertaking research towards a Ph.D. at The University of Melbourne. As part of Bionic Vision Australia, her research focuses on how to best convey visual information to an implant recipient to help in daily tasks, such as reading. Before she moved to Australia, she received a Diploma (Master's equivalent) in electrical engineering from the University of Hanover, Germany.

Quantitative imaging metrics for diagnosis, prediction and monitoring of arthritis in preclinical and clinical conditions

Date: Monday 30 March 2015
Venue: Newton Rooms, Fifth Floor, Electrical and Electronic Engineering Building 193, The University of Melbourne. (please turn left as you exit the lift, then left again) Speaker: Kathryn Stok, Swiss Federal Institute of Technology Zurich

Abstract

Diseased joints are often no longer capable of providing normal function; i.e. load bearing, stabilisation, painless and unrestricted activity. Today there is no truly effective procedure to regenerate articular cartilage and tissue defects induced by arthritis are often irreversible. As such research groups around the world are exploring therapeutic targets for cartilage regeneration, biomarkers for understanding joint breakdown, and reconstructive approaches for restoring joint health. Dr Kathryn Stok investigates the morphology, function, disease and repair of cartilage and joints, in order to decode the interplay between mechanical, structural and biological responses, as well as interactions with neighbouring tissues. One primary avenue for development is novel mechanical and imaging methods for preclinical animal models. The first part of this seminar will describe a study which demonstrates new metrics for sensitive discrimination of structural deterioration with traumatic osteoarthritis, and the scalability of these metrics in two different animal models and in clinical datasets. A road map to clinical use will also be described. In the second part, an overview of other methods and protocols are described, which support the ongoing effort to give new insight into the progression and monitoring of disease models.

Biography

Dr Kathryn Stok is Head of the Integrative Cartilage Research Group at the Swiss Federal Institute of Technology in Zurich (ETH Zurich) since 2009, and a Senior Scientist for Cartilage & Arthritis Imaging Development at Scanco Medical AG since January 2015. She completed her PhD in the Department of Information Technology and Electrical Engineering at ETH Zurich in 2007. Prior to that she spent a year as a research assistant at Nanyang Technological University, Singapore, and completed her undergraduate and Master degrees in Mechanical Engineering at QUT in Brisbane. Kathryn is an innovative biomedical engineer in microstructural imaging and biomechanics of cartilage and joint structures using a variety of experimental and computational approaches. Her research work merges solid engineering approaches with biological advancement, and she has worked for over twelve years in biomedical engineering research (biomechanics and bioimaging); exploring global health challenges from both a basic science and a technological perspective. Her current research interests are investigating imaging strategies for quantitative multiscale assessment of joints, cartilage tissue and tissue-engineered cartilage constructs. Additionally she is developing a technological platform for standardised production of materials for tissue engineering models; specifically for use in the cosmetic and orthopaedic industries. She has previous and ongoing collaborations within the academic, business and health sectors in order to support this vision. Kathryn currently serves on the Osteoarthritis Research Society International’s (OARSI) communications committee, and is a co-chair of the international SPECTRA collaboration (Study grouP for xtrEme-Computed Tomography in Rheumatoid Arthritis).

Neural network models of pitch perception in normal and cochlear implant (CI) hearing

Date: Monday 16 March 2015
Venue: Newton Rooms, Fifth Floor, Electrical and Electronic Engineering Building 193, The University of Melbourne. (please turn left as you exit the lift, then left again) Speaker: Nina Erfanian, The University of Melbourne

Abstract

Pitch is the perceptual correlate of sound frequency and is important for using speech prosody, understanding tonal languages, and appreciating music. The goal of this study was to develop computational models of normal and CI hearing to investigate the mechanisms of pitch perception in both cases. An artificial neural network (ANN) constituted the core of the model. Inputs to the ANN were spectral and/or temporal cues for pitch perception extracted from simulated auditory peripheral inputs. Temporal cues were extracted from the activity of the auditory nerve through a spiking neural network. Validation of the model was performed by comparing its performance with psychophysical results. The model was then applied to investigate the impact of stimulation field spread on pitch perception in CI hearing and to explore the role of and interaction between spectral and temporal cues in performing simulated pitch-related tasks. Results showed that different CI sound processing strategies were affected differently by the extent of stimulation field. It was also revealed that temporal cues for pitch perception compensated for missing spectral cues in listening conditions such as telephone conversation. Computational models of auditory perception such as this can serve as human substitutes in auditory perception studies. Since such human studies are very expensive and time consuming, these models can assist in the more rapid development of cochlear implant sound processing strategies.

Bio: Nafise (Nina) Erfanian Saeedi is a PhD student in the Electrical and Electronic Engineering department of Melbourne University. She received her Bachelor and Master of Science degree with distinction in Biomedical Engineering from Amirkabir University of Technology (Tehran Polytechnic), Iran, in 2007 and 2010, respectively. In 2011, she joined the NeuroEngineering lab in Melbourne University to undertake research towards a PhD. Her research focuses on computational models of auditory perception in normal and cochlear implant hearing.

A model of inner hair cell ion channels can explain nonrenewal properties of auditory nerve spike trains

Date: Monday 2 March 2015
Venue: Newton Rooms, Fifth Floor, Electrical and Electronic Engineering Building 193, The University of Melbourne. (please turn left as you exit the lift, then left again) Speaker: Bahar Moezzi, The University of South Australia

Abstract

We propose several modifications to an existing computational model of stochastic vesicle release in the inner hair cell ribbon synapses, with the aim of producing simulated auditory nerve fibre spiking data that more closely matches empirical data. Specifically, we studied long and short term inter-spike interval correlations in the spiking of post-synaptic auditory nerve fibres. We introduced a standard biophysical stochastic model of calcium channel opening and closing, but showed that this model is insufficient for generating a match with empirically observed spike correlations. Instead, we incorporated a stochastic fractal model of potassium channel opening and closing and produced a qualitative match with empirically observed firing correlations. By combining the fractal potassium channel model with the standard calcium channel model and changing the model’s auditory nerve refractory properties, we produced long and short term correlations in the simulated auditory nerve spike trains that matched empirical observations quantitatively.

Biography

Bahar Moezzi received her bachelor’s degree in physics from Sharif University of Technology in Iran. Later, she received two Master’s degrees in physics from Columbia University in the USA. She spent several years at the Centre for Theoretical Neuroscience at Columbia University as a research assistant before going back to Iran to work as a software developer. In 2013, she joined the Computational and Theoretical Neuroscience Laboratory of Associate Professor Mark McDonnell at the University of South Australia, as a PhD candidate.

Affordable Healthcare Technologies For South East Asia Countries

Date: Monday 23 Feb 2015
Venue: Newton Rooms, Fifth Floor, Electrical and Electronic Engineering Building 193, The University of Melbourne. (please turn left as you exit the lift, then left again) Speaker: Prof. Eko Supriyanto, Johor Bahru University, Malaysia

Abstract

Cardiovascular disease and cancer are responsible for more than 55% death in South East Asia. Unhealthy life style and environment are the most common causes of these diseases. As an effort to improve the healthy life expectancy, affordable healthcare technologies for healthcare management of more than 600 Million populations with GDP per-capita around USD 4400 are required. Low cost telehealth, diagnosis and treatment technologies have been proposed to enable the quality affordable technologies. This includes the use of low cost nanosensor and ultrasound device to detect cancer and cardiovascular diseases, application of herbal medicine for cancer and cardiovascular disease prevention and treatment and low cost biodegradable polymer stent for cardiovascular system management. Low cost nanosensor has been successfully developed and tested in our laboratory, to detect human papilloma virus (HPV) DNA in the menstrual blood. We have also successfully extracted and applied some active compounds from mistletoe to validate its anticancer activity. Prospective technologies for cardiovascular diagnosis using ultrasound and treatment using newly developed biodegradable stent have been also investigated. In this lecture, these technologies will be presented.

Biography

Eko Supriyanto is a professor in medical imaging and electronics at Universiti Teknologi Malaysia (UTM). He is also the Director of Cardiovascular Engineering Centre UTM-National Heart Institute as well as the Head of Advanced Diagnostics and E-Health Research Group. He obtained Doctor of Engineering from University of Federal Armed Forces Hamburg, Germany. His research interest encloses the application of computer, electronics and material for management of cardiovascular diseases, cancer, fetal and children development. He has published more than 140 international journal papers and 6 books in the area of biomedical engineering. He has 23 patents and 35 international awards for his research achievement.

The artificial placenta and womb: Can medical technology offer a way forward for infants born at the border of viability?

Date: Monday 9 February 2015
Speaker: Dr Stephen Bird, Department of Obstetrics and Gynaecology, Melbourne Medical School

Abstract

Preterm birth is the delivery of infants at less than 37 weeks of a full term, and is now the second major cause of death for infants under 5 years. Preterm birth can occur without warning and has many causes. Particularly concerning is the high numbers of infants born on the border of viability, between 22 and 25 week. For these infants there are few options and approximately 70% of 270,000 infants born each year do not survive to leave hospital. These babies cannot cope with life outside the womb due to the immaturity of their lungs and hearts. Those that do survive are currently at significant risk of severe, lifelong ill health. Given the technological advances in recent years, this seminar explores whether new technology approaches could overcome the current barriers to survival and give these extremely preterm infants a chance at life.

Biography

Stephen Bird has a Masters in analytical chemistry and PhD in biomedical science and more than 20 years of research experience and teaching in tertiary education. Formally, Stephen worked in New Zealand in kidney research investigating the longevity of the peritoneal membrane used in artificial renal replacement therapy. Stephen’s interest in developmental biology was inspired in the Netherlands whilst working at the Hubrecht Institute, where He helped develop a culture model of adult cardiomyocytes for regenerative heart research. These themes continued in Australia and now Stephen is focused on developing awareness of extreme prematurity and artificial placentation to help extremely preterm infants. Dr Bird holds an Honorary appointment in the Department of Obstetrics and Gynaecology, The University of Melbourne, Australia, and is a member of STC Australia. He is passionate about developing Medtech solutions for the most pressing medical problems.


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Professor David Grayden

Director, NeuroEngineering

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