Author: Timothy Hodgson

“Sticky eyes”: Development of fixation control in children

Timothy Hodgson Uncategorized

The Leverhulme Trust has awarded the University of Lincoln a 3 year £230K grant to support our research into the development of children’s eye movement and fixation control. I will be leading an interdisciplinary project team including Charlotte Cartledge (Psychology), Rachel Sharpe (Education) and Frouke Hermens (Open University NL) with Julia Foecker (Psychology) and James Siddle (Lincolnshire Research School) as project advisors.

Parents know that young children are not very good at finding things (e.g. a lost toy or odd sock) often failing to spot objects that are in plain sight. Our eye tracking research studies at Lincoln Summer Scientist Week have highlighted an aspect of children’s oculomotor control that might explain why this is. We find that children are are often slow to “disengage” eye fixation from the object they are currently looking at in order to move their eyes to look at something else. In our “follow busy bee” eye tracking “game”, children have to follow a cartoon bee as it jumps around a computer screen. Normally they find this quite easy, but when another object appears at the centre of the screen and the bee is somewhere else, they often miss the bee and stay looking straight ahead. The graph below shows how these instances of the eyes getting “stuck” decrease with age. We call this “sticky fixation” and the project will investigate why it occurs and how it affects children’s visual abilities. The research will include eye tracking studies of visual search and reading, a real world study of how children use eye movements in a school classroom and laboratory based brain activity monitoring studies of fixation control.

The funding will directly support a full-time post-doctoral researcher as well as a temporary lecturer in cognitive and developmental psychology.

We are currently recruiting for the post-doctoral researcher to join the project team, so let me know if you would like to know more about this exciting project!

Guess what?! Eye gaze and conversation in Parkinsons research published

Timothy Hodgson Parkinsons, research, Uncategorized

This month we published a paper in the International Journal of Language and Communication Disorders entitled “Gaze-speech coordination during social interaction in Parkinson’s disease“. The research used mobile eye tracking to examine how people with and without Parkinsons use eye movements during spoken conversation. In order to get people talking we asked them to play a card guessing game, based on the children’s guessing game “HedBanz” in which one player has to describe an object written on a card and the other player has to guess. A link to the full open access publication is available here.

Previous research has shown that eye movements are important in signalling “turn taking” in conversation, whereby the speaker indicates to their conversation partner that the end of the speech turn is coming. Although you might not be aware that you are doing it, we often direct our eye gaze towards the other persons face to indicate it is their turn to speak next. Other work by myself and others has shown how the voluntary control of eye movements is affected in Parkinsons disease. Taking these findings together, we wondered if there were differences in how patients used their eyes during speech and conversation.

The results showed that people with Parkinsons tend to make longer duration periods of eye fixation on the other persons face and elsewhere. They did less well when describing cards to the other player, suggesting problems with speech, but guessed just as many objects when listening to someone else describing, suggesting that their condition didn’t affect their ability to understand others. We also found that the timing of speech turns was subtly different when a patient was playing the game, with a tendency towards shorter gaps and more interruptions in speech, indicating people with Parkinsons may be slightly more impulsive and sometimes “jump in” to interrupt others more.

The results confirm something I have personally noticed about people with Parkinsons over the years: That they sometimes have a subtly different pattern of gaze during conversation including extended periods of eye contact. This can be slightly disconcerting if you are not aware of it and together with phenomena like reduced facial expression might adversely affect social interaction and communication. We think that wider public knowledge and awareness of some of these more subtle features of the condition could itself improve the quality of life and social connectedness of people with Parkinsons.

The research was conducted in collaboration with Gemma Ezard (Lincolnshire NHS) and Frouke Hermans (formerly University of Lincoln now at the Open University in the Netherlands) and was funded by BA/Leverhulme small grant Ref: SG152231

Eyelander at CVRS London 2023

Timothy Hodgson Conferences, Eyelander, Impact

Last week I attended the 18th Biennial Child Vision Research Society meeting at UCL Great Ormond Street Institute of Child Health. The meeting included a symposium in honour of the late Oliver Braddick, co-founder of the UCL/Oxford Visual Development Unit together with Janette Atkinson who gave an impressive overview of the unit’s pioneering work on infant vision over the decades as part of the session.

Amongst the many other highlights of the meeting, Cathy Williams (University of Bristol), presented evidence for sub-types of Cerebral Visual Impairment (CVI) in children. It has become apparent recently that a surprisingly high proportion of children in main stream classrooms may have such brain based visual problems.

My own talk about the Eyelander game was the last presentation of the conference! But everyone stayed right to the end and seemed to really enjoy it! Eyelander is a gamified version of compensatory visual search training for children with loss of vision on one side (hemianopia) . Selective loss of vision to the left or right might occur following brain injury or neurosurgery, but may also be found in many children with CVI (see above).

I really enjoyed the CVRS meeting. It was great to meet so many new people. In fact, it was one of the friendliest and most enjoyable meetings I’ve ever been to, so I will be sure to go again in 2 years time!