Neural Systems and Circuits for Binocular Vision

Lead Research Organisation: University of Oxford
Department Name: Physiology Anatomy and Genetics

Abstract

When we see a child of 18 months reach out and pick up a toy, we are witnessing in this everyday event a most remarkable skill. The child's brain uses vision to direct a movement to the position and depth of the toy that the child desires. The child's grasp needs to be correct for the object: small toys need fingers; large ones may need two hands.

Our laboratories study one important component of this skill, namely judging the depth of objects. In looking towards an object, we use our left and right eyes in co-ordination. The centre of each eye points accurately towards the object. In this way, the most sensitive part of each eye points directly at the object. If the object is close to us, then each eye rotates a little bit inwards, towards the nose, to achieve this.

As well as controlling the movement of the eyes very accurately, the brain also puts together the visual images from the left and right eyes and uses these in co-ordination as well. The separation of the two eyes means that each eye gets a slightly different picture of the visual scene: the bigger the difference between the images, the bigger the change in depth out in the visual world. These differences in the images are called "binocular disparity" and the entire process is called "binocular vision".

Binocular vision gives us a sense of depth; it can tell the brain how far away objects are, what size they are and where one object sits in relation to another. We are now improving our understanding of what actually happens in the brain when we see things in depth. Whilst solving this puzzle is an interesting problem in itself, it turns out that binocular vision often goes wrong during development. About 1 in 50 people have a problem with their binocular vision and the problem is often apparent as a squint or "lazy eye".

Large numbers of children have surgical operations on their eyes to get them straight again: there is about one operation every 25 minutes of each working day in the UK alone. At present, most of this surgery is cosmetic: the eyes end up without a squint but they do not work properly in co-ordination. Even after the corrective surgery, the nerves leaving one eye may never make their proper connections with the rest of brain and the person may become blind in that eye for the rest of their life. Sometimes later in life, people suffer an injury or disease in the other, "good" eye and become totally blind. All of this implies a large health care cost and a significant burden of disease, partly because these problems are so common.

Nobody really knows whereabouts in the brain the necessary connections are disrupted. For a while, many scientists thought that this disruption happens exactly at the point where the nerves from the eyes first reach the cerebral cortex. It is now clear that this is only a partial explanation. Our aim is to find out exactly where and how binocular vision happens in the brain.

Part of our strategy uses brain imaging with humans. We will be able to use a new and more powerful brain scanner provided by the MRC to Oxford. We will use this to find out how the human brain responds to binocular depth by studying normal individuals and comparing them with people who have problems with their binocular vision. Although we work with human brain imaging, investigations with animals are also part of our research strategy. Here we can examine directly the neural signals and circuitry that are responsible for binocular depth.
Once we have this new knowledge we will be able to understand how problems with binocular vision begin in early life, what parts of the brain are affected and whether we can propose some specific eye training that could help to prevent or even alleviate the problems.

Technical Summary

Design of Studies
1) Parametric assessment of brain's response to binocular depth: this involves collection of brain signals (BOLD fMRI in the case of human studies; electrical activities of nerve cells in the case of animal studies) with simultaneous performance of a behaviourally relevant task. Change of behavioural state will be a parameter in the studies. The human studies will include the investigation of former patient groups. Conservative estimates of required statistical power can be gained from large number of studies conducted with these techniques before.
2) Identification of brain regions processing depth. High-field MRI at 7-Tesla will be used to measure the response of cortical areas and sub-compartments within those areas. Structural and functional measures will be used to gain converging evidence.

Technical Measurements
1) High-field MRI at 7-Tesla: BOLD & fMRI, diffusion tensor imaging, multi-voxel pattern analysis, objective identification of cortical areas, visual behaviour within the scanner
2) Multi-electrode neurophysiology in identified locations in experimental animals: statistics of neural firing, correlated firing within populations, identification of "brain signatures" of perceptual events, linking neuronal signals to functional MRI.

Planned Impact

This research has the capacity to benefit three areas of activity, outside of the immediate network of systems neuroscientists, who study the encoding of information by neuronal cells and circuits within the brain.

First, understanding the brain is important for translational neuroscience: the application of scientific studies of the brain to clinical problems. In our own case, elements of the proposed work will build on our current collaboration with John Elston (Hospital Consultant: Oxford Eye Hospital) to examine vision in individuals who have been treated for disorders of binocular stereoscopic vision. This is a common childhood disorder: correction of squint is the second-most common reason for elective surgery in childhood in the UK. This project will provide basic knowledge about how the brain processes visual depth and 3-D shape, which can be applied in the context of the ongoing translational studies.

Second, there is a wide community of scientists and technologists who are interested in the encoding of information, particularly the question of whether studies of the nervous system can provide any novel insights that they could exploit in their own work. These scientists and technologists are in the fields of computer science, intelligent devices and the knowledge-based economy. They will be the driving-force behind new technological developments, which are acknowledged as an important factor in creating new economic growth in established Western economies, like the UK. The studies proposed will be significant for this group.

Third, the wider public continues to have a fascination with understanding the workings of the brain, as evidenced by the large number of popular science books and media presentations. This research will ultimately feed into this activity, thereby enhancing public understanding of science and contributing to the social and cultural life of the UK.

Transfer of the benefits of this research will be facilitated in a number of ways: publication of papers, interdisciplinary communication of results and sharing of data will be the main route for the clinicians, scientists and technologists in related fields; wider discussion of neuroscience and appropriate use of public media will be the route for the general public; and pursuit of applied and translational research will be main route for involving more health practitioners.

The time scale on which these benefits will begin to be felt is likely to be 3 years in respect of the health practitioners, scientists and technologists in related fields and perhaps 4-5 years in respect of the other groups. However, this project is addressing a major scientific issue about the functioning of the brain and it is reasonable to argue that the impact of this project is likely to be prolonged, lasting hopefully some 10-15 years after the initial benefits have been felt.

Publications

10 25 50
 
Description Strategic Award: ????Integrated neural networks in the primate brain
Amount £4,850,000 (GBP)
Funding ID 101092 
Organisation Wellcome Trust 
Department Wellcome Trust Strategic Award
Sector Charity/Non Profit
Country United Kingdom
Start 01/2014 
End 04/2020
 
Description Studentship for DPhil
Amount £60,000 (GBP)
Organisation University of Oxford 
Sector Academic/University
Country United Kingdom
Start 10/2019 
End 09/2022
 
Title Combined fMRI/MRS imaging 
Description In collaboration with Dr Uzay Emir when he worked in Oxford, we developed the application of a combined fMRI/MR spectroscopy scan protocol and analysis for use with the visual system and other brain systems. Dr Betina Ip has trained others in our centre on how to use it. 
Type Of Material Physiological assessment or outcome measure 
Year Produced 2017 
Provided To Others? Yes  
Impact Use of the technique has resulted in 2 papers for our group, and we are aware of several other groups within the WIN Centre using this protocol. 10.1109/IC3D48390.2019.8976001 10.1016/j.neuroimage.2017.04.030 
 
Description Spectroscopy 
Organisation Purdue University
Country United States 
Sector Academic/University 
PI Contribution The partnership has been with MR Spectroscopist Dr Uzay Emir, and we have provided visual experiments to test the utility of new methods of spectroscopic imaging.
Collaborator Contribution Dr Emir is an expert on MR spectroscopy, and has provided us with sequences for optimal imaging, and provided training on analysis of the data.
Impact 10.1109/IC3D48390.2019.8976001 10.1523/JNEUROSCI.3021-18.2019 10.1016/j.neuroimage.2017.04.030
Start Year 2014
 
Description University of Pisa 
Organisation University of Pisa
Country Italy 
Sector Academic/University 
PI Contribution I hosted a postdoctoral research fellow to acquire data on our 7T scanner. We designed protocols and taught data acquisition and analysis.
Collaborator Contribution The postdoctoral fellow is funded by the collaborator
Impact 10.1109/IC3D48390.2019.8976001 10.1016/j.cub.2015.04.021
Start Year 2012
 
Title MRI-compatible stereoscope 
Description The device is a stereoscope that can be used inside the 3T scanner to present image separately to the two eyes. This is far superior to other methods such as using red-green glasses. 
Type Of Technology Systems, Materials & Instrumental Engineering 
Year Produced 2018 
Impact The stereoscope has been used in 3 studies, the manuscripts for which are in preparation. 
 
Description A-level days 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Related to the Brain Diaries exhibition run at the Natural History Museum, we put together a day for A-level students about the brain, MRI and vision. The day had interactive talks in the morning and then activities in the afternoon. It was so successful that we ran it a second time.
Year(s) Of Engagement Activity 2017
 
Description Big Brain Roadshow 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact The activity is a play about the brain that last around 25 minutes and explores the history of brain imaging. Then there are 4-8 interactive activities that people can participate in, including vision-related activities based on the research in this award.
Year(s) Of Engagement Activity 2018,2019,2020
 
Description Brain Diaries 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact I contributed to a Neuroscience Exhibition at the Natural History museum in Oxford that ran from April 2017 until December 2017. As part of this we ran a competition that attracted over 750 entries. Thousands of people saw the exhibition and I also took a group of visually impaired people through the exhibition.
Year(s) Of Engagement Activity 2017
URL http://www.oum.ox.ac.uk/braindiaries/
 
Description Christmas Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Around 300 pupils attended a Christmas lecture demonstrating how the visual system system works and how we use MRI to understand it. Excellent feedback from pupils was received.
Year(s) Of Engagement Activity 2017,2018
 
Description Consciousness 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact BBC world service 'The Why Factor'. Did interview about vision and consciousness that appears in the first of two programmes.
Year(s) Of Engagement Activity 2019
URL https://www.bbc.co.uk/sounds/play/w3csyv0d
 
Description Contributor to Lab Animal Tour 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact A virtual visit to the Oxford lab animal facilityWelcome to Oxford University's primate research facility.

This facility has been specially designed to accommodate behavioural neuroscience research involving Rhesus Macaque (Macaca mulatta) monkeys.

Macaques are socially and cognitively complex animals, characteristics that make them ideal subjects for our behavioural neuroscience studies. Because of these characteristics it is really important that we provide high standards of care.

Our species-specific environmental enrichment program and reward-based training strategies are key to ensuring the animals are appropriately acclimatised to the staff, the laboratory environment and the research procedures.

During this virtual tour you will have an opportunity to meet the staff and animals, to see the facilities and to learn about some of the studies that we carry out.
Year(s) Of Engagement Activity 2017,2018
URL http://www.labanimaltour.org
 
Description Curiosity Carnival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact We scripted and acted in a lighthearted play about the brain and how we understand its function. It has been performed 3 times, first at the European Researchers Night in September and then twice at a public event at the Natural History Museum in Oxford.
Year(s) Of Engagement Activity 2017
 
Description Hay Festival 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I participated in a debate and a discussion workshop at Hay Literary Festival.
Year(s) Of Engagement Activity 2015
 
Description In2Science coordination 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact In2Science is an organisation that recruits 6th form students from deprived regions without a family history of attending University. The WIN centre hosted 4 students for a 2-week period in 2017 and 2018.
The students who attend this programme have a greatly increased likelihood of attending a top University.
Year(s) Of Engagement Activity 2017,2018
URL http://in2scienceuk.org
 
Description Neuroscience experience 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Each year 12 Year 12 pupil spend 1 week in our Brain Imaging Centre undertaking mini project to learn about the brain, including vision research. The week gets consistently good feedback and has included the quote 'Probably the best thing I've ever done'.
Year(s) Of Engagement Activity 2015,2016,2017,2018,2019,2020
URL https://www.ndcn.ox.ac.uk/public-engagement/work-experience-placements
 
Description Primary school visits to MRI scanner 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Each year, around 120-150 primary school pupils visit the Wellcome Centre for Integrative Neuroimaging to experience a brain scan and interactive presentations from researchers.
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015,2016,2017,2018,2019,2020
 
Description Talk about imaging and visual perception 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact In each case, around 30 pupils attended an interactive talk. The talk has been delivered in many schools:

Aureus School
Matthew Arnold School
Headington School
Charterhouse School
Cheney School
Year(s) Of Engagement Activity 2015,2016,2017,2018,2019,2020
 
Description Teachers evening 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact A teachers evening to educate both primary and secondary school teachers about the brain and particularly how it underlies reward and language, and how exercise and mindfulness can influence learning.
Year(s) Of Engagement Activity 2019
 
Description Vision in the Real World 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact The York University
Centre for Vision Research
and the
Vision: Science to Applications Program


International Conference
on Vision in the Real World

Recital Hall, Accolade East Building
June 13-16, 2017
Year(s) Of Engagement Activity 2017