Parkinsons

Posts relating to research into Parkinsons Disease

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

Orienting to social cues in Parkinsons

Timothy Hodgson General news, Impact, Parkinsons, Publications, social neuroscience

This month we published a paper in the journal Experimental Brain Research reporting how eye movements are influenced by social cues in people with Parkinsons disease.

Previous studies have suggested that Parkinsons patients have problems in directing visual attention due to loss of the chemical dopamine within the basal ganglia of the brain, but no one has specifically looked at whether they have particular problems with social cues. This question is important as problems with processing social information may lead to difficulties in everyday life for people with Parkinsons. It is also a question of scientific interest as it has been suggested that we have specialised brain pathways for processing social information (the so-called “Social Brain hypothesis”).

We used a task in which pictures of someone else’s eyes, arrows and pointing fingers are shown on a computer screen, whilst people track a spot jumping around the screen with their eyes (see picture; you can see a video of the task here). Often people make an eye movement by mistake in the direction indicted by the eyes, arrows or fingers, even when they are meant to respond directly at the target (the little black spot) and ignore the pictures. We found healthy adults made more of these errors with pointing finger cues compared to the other cue types (suggesting pointing fingers provide a particularly strong cues to eye movements) whereas people with Parkinsons made similarly high errors for all 3 cue types.

Although not specifically better or worse for socially relevant cues (eyes / fingers), Parkinsons patients clearly had difficulty in suppressing their distracting influence. This suggests the basal ganglia plays a role in controlling eye movements in response to social and non-social cues. But this doesn’t mean that people with Parkinsons don’t have particular problems with maintaining attention in social situations. On the contrary, social interaction might often take place in a busy environment, with lots of sensory information competing for attention. These deficits in the control of eye movements might therefore lead to difficulty in social interaction and might impact on patients’ quality of life.

A link to the paper can be found here

Eyelander game evaluation and Parkinsons and Spatial Memory studies published

Timothy Hodgson Eyelander, Parkinsons, Publications, research

Research in patients both young and old can be difficult, time consuming and stressful to carry out (e.g. due to the ethical approval process, patient recruitment and practical difficulties in testing patients with physical disabilities etc). Yet the importance and potential benefits to patients themselves of such research far out weighs the difficulty entailed in conducting it.

Two of my recently published papers reflect the outcome of patient based projects. Both studies use tasks which require viewers to search through items on a screen using saccadic eye movements. The first addressed the issue of working memory and oculomotor control in Parkinsons disease, a topic I have been researching since the late 1990s. Whilst the second reports the clinical trial evaluating the effectiveness of the Eyelander video game for children who have had neurological injury leading to partial visual field loss (hemianopia).

In the first study, published in the April 2019 edition of the Journal of Cognitive Neuroscience we recorded eye movements while participants performed a version of the CANTAB Spatial Working Memory task which requires patients to search through boxes on a computer screen to find hidden tokens. I first had the idea to do this study whilst watching patients performing this task on a touch screen when I was a post-doctoral research fellow at Charing Cross Hospital, London. I could see that patients were using eye movements a lot in this token “foraging” task, but at the time we didnt have the technology to track their eye movements properly. It was only later that suitable eye tracking equipment and software became available to carry out the research. Amongst other findings the paper shows that people with Parkinsons don’t use eye movements to plan ahead or look back at locations they’ve already searched as effectively as controls, most likely due to an imbalance of the neurotransmitter dopamine in the prefrontal cerebral cortex.

 

The second paper, published in the December 2018 edition of Journal of Visual Impairment and Blindness describes the evaluation of our visual search  game for children with partial visual loss following brain injury affecting the visual parts of the cerebral cortex. The results showed children were able to play the game at home unsupervised and that it had a positive effect on parallel measures of functional visual ability which was similar in magnitude to effects reported for visual search training in adult with partial visual loss following stroke. The Eyelander game is now available for anyone to play online, so please take a look. We are also starting a collaborative project with Great Ormond Street Hospital to evaluate its effectiveness for treating visual field loss following neurosurgical procedures in children.