Computer game for visual field loss rehabilitation: Introduction

The week before last I was in Lincoln to visit the University and give a presentation on the progress we have been making with our research at the WESC Foundation to the School of Psychology’s Perception, Action and Cognition group. I talked about some of the rehabilitation strategies used for people with low vision and about our project to develop a computer game that could be used for rehabilitating people with visual field loss.

The premise of our game is centered around the “visual search task”, which involves finding a target object in a visual display of distracting objects. In the picture on the right the distracting objects differ from the target by one feature only: colour (i.e. the target object is a green square and the distracting objects are orange squares). Simpler tasks involve finding a target that differs from the distracting objects by more than one feature (e.g. colour and shape: the target is a green square amongst orange circles). More complicated tasks involve multiple groups of distractors that share different features with the target (e.g. the target is a green square amongst orange squares and green circles).

Previous research has demonstrated that adult stroke patients with visual field loss such as hemianopia can train using visual search tasks to improve their functional vision. The mechanism for this rehabilitation is unclear and may depend on developing new eye movement strategies (compensatory visual scanning), improving visual perception and attention (perceptual training), or restoring small areas of the visual field (visual restitution therapy). However, typically visual search tasks are quite dull and unable to engage people for the long periods required for the rehabilitation to generate a significant improvement in vision. Our project aims to improve engagement and motivation by implementing the visual search task as part of an interactive computer game.

The game is still early in development and we are constantly involving potential users in the design process for input and feedback so it is all subject to change. At the moment there are three levels of gameplay: short-term, mid-term, and long-term. Short-term gameplay consists of immediate reward for finding the correct target in the visual search task such as sound and particle effects. Mid-term gameplay consists of adding some meaning to the visual search task. In the image above, the player has to find the target objects to progress passed a river of lava. Long-term gameplay consists of adding an element of progression to the game. In the current version of the game the player has to make their way through twelve different levels to reach the boat that will allow them to escape the island and complete the session for that day. As rehabilitation can take many weeks there will also be an additional extra-long-term (or replayability) element, which consists of a calendar that can visualise progress over time.

It is important to determine whether using computer game technology to make rehabilitation more engaging is a viable and effective strategy for young people with visual field loss as well as for adults. We intend to perform a pilot study next year to test the efficacy of the game as a rehabilitation tool and determine what effects the rehabilitation has on functional vision and whether these skills transfer to natural tasks and have a real impact on patients’ quality of life.

Raising awareness for nystagmus

Nystagmus is the word we use to describe an involuntary oscillation of the eyes. While it can be a normal physiological response to visual and vestibular sensations, there are unfortunate pathological variations which cause visual impairment. It is a relatively common condition affecting one in every two to three thousand people in the UK, and researchers are very interested in trying to determine the causes of pathological nystagmus and to understand how it might be effectively treated.

Nystagmus network is a charity dedicated to improving patient information, support and scientific research into nystagmus. I was recently at their 3rd international nystagmus research workshop to present some research findings from an investigation into physiological nystagmus. The workshop was particularly interesting because of the scope of different scientific disciplines represented. The programme started on the first day with presentations on mathematical and animal models of nystagmus. On the second day we discussed the results of retinal imaging studies, the genetics of nystagmus, and the impact of living with nystagmus on the quality of life of patients. Presentations on the final day were focused on tentative suggestions for both surgical and medical treatments.

Nystagmus Network are currently raising awareness of nystagmus in the run-up to their first International Nystagmus Awareness Day on November 6th. The awareness day has been labelled “Wobbly Wednesday” as nystagmus is often referred to as “wobbly eyes”. If you have been affected by nystagmus or know anyone who has you might wish to organise an event for the day, and you can register for a supporters pack by emailing info@nystagmusnet.org. Alternatively there is a Facebook group where supporters can interact with each other.

“Remember, remember, the 6th of November”.

Hubel and Wiesel’s visual feature detectors

The announcements for the 2013 Nobel Laureates are ongoing this week, with Peter Higgs and Francois Englert sharing the Nobel Prize in Physics 2013 for their theoretical discovery of the now famous Higgs boson. As a neuroscientist interested in visual impairment it seemed appropriate to consider two important contributors to the field who shared the Nobel Prize in Physiology or Medicine in 1981 for their discoveries concerning information processing in the visual system. David Hubel and Torsten Wiesel shared the Nobel Prize in Physiology and Medicine with Roger Sperry for his separate work on the functional specialisation of the two hemispheres of the brain.

Hubel and Wiesel made some of their most important discoveries during their investigations recording the responses of individual cells in the cat primary visual cortex. Unlike many of the cells in the retina, which respond to spots of light or dark, they found that cells in the visual cortex were highly selective for edges (or lines) of a specific orientation.

They proposed an organisational hierarchy within which individual cells were tuned to respond to features such as the angle of visual objects. Individual cells that shared the same tuning for features were thought to be interconnected and arranged in a regular manner. They presented these concepts in the classic “hypercolumn” model wherein vertical ocular dominance columns represent input from the left or right eye and orientation columns represent neurons that are selectively tuned to edges of a specific orientation. The exact organisation of cortical columns within the visual cortex remains an interesting topic of current research.

Later, Hubel and Wiesel performed pioneering work in the area of visual development. They found that during a sensitive period early in infancy if animals were deprived of vision from one eye the ocular dominance columns for that eye would regress while the columns representing the eye that still received vision would dominate the visual cortex. This research was critical in changing clinical practice for the childhood eye disorder amblyopia (or “lazy eye”), and highlighted the importance of early corrective treatment during the critical period of visual development for children with visual impairment.

Sadly, just two weeks ago on Sunday 22nd September we heard that David Hubel had died at the age of 87. His collaborative work with Torsten Wiesel stands as having transformed our understanding of vision and childhood visual impairment.

Introduction to the WESC Foundation

Hello, I’m Jonathan Waddington and I am a post-doc researcher currently working in the Research and Development department here at the WESC Foundation.

We are currently working on an exciting project at WESC that has been funded for two years in partnership with the University of Lincoln, with Prof. Timothy Hodgson as academic lead. One of the aims of this project is to increase expertise in neurological visual impairment at WESC using the current knowledge from neuroscience about how brain processes generate vision. A key objective of the project is to develop a fun and engaging computer game designed to improve the functional vision of children with visual field loss. The evidence that such a game will be effective is grounded in well-established theories and data from visual rehabilitation studies in adult stroke patients.

It’s a particularly enjoyable research project to be working on with the possibility of some real benefit for those children involved. It’s also good fun to be part of the development process for making the game. I recently spent a week working with Conor Linehan (a University of Lincoln lecturer of Human Computer Interaction) having a crash course in learning to use game engines and something called “juiciness”, which I am assured is a real term used in professional game design lingo.

We were lucky enough to sign up two computer science interns from the University of Lincoln for the summer holidays to develop the basic framework for the game with the provisional title: “Escape from Jonathan’s Island”, where players have to overcome obstacles such as erupting volcanos and invading aliens. One of the challenges will be to develop something that is accessible to children with a wide range of visual, physical and cognitive abilities but is still meaningful and fun to play. We are using methods of participatory user-centered design to involve the children and young adults in the development process, and to get ongoing feedback throughout the project.

We are also cultivating a number of other research proposals for future projects in collaboration with higher education and other specialist centres, and it is very exciting to be on the ground floor in setting up the Research and Development department here at WESC.