Orienting to social cues in Parkinsons

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

Assessing premorbid IQ with picture vocabulary tests

An important task in neuropsychology is establishing how a patient’s current state compares to how they were before they suffered  brain injury. Assessing “premorbid” IQ is also of key importance in research studies that compare cognitive abilities in patients with a group of healthy participants, as it is important that the two comparison groups are as well matched as possible.

The most common way of assessing premorbid IQ to date is the National Adult Reading Test or “NART’. This short word reading test includes words with regular and irregular spellings and is highly correlated with IQ, whilst also “holding” after brain injury (being relatively unaffected relative to other tests of cognitive function). The problem with the NART is that it requires patients to read words out loud. Brain injury can also impair speech ability meaning that the test is impossible to use in patients with conditions such as aphasia.

We have recently published a paper in the journal Applied Neuropsychology: Adult which examined the effectiveness of the British Picture Vocabulary Scale (BPVS) as an assessment of premorbid ability. In this test patients’ must point to pictures matching the words spoken by the examiner. Originally developed to assess vocabulary in young children, we found that the BPVS appears to be at least as good as the NART at “holding” after brain injury and assessing premorbid IQ.

Along with other similar picture based tests, we think the BPVS could be a useful tool to assessing premorbid IQ in research as well as clinical neuropsychology practice.

Hemi-disconnection project at Great Ormond Street Hospital

This week I have been at Great Ormond Street Hospital London setting up some tasks on an Eyelink Duo eye tracker for a project led by Dr Luis Lacerda and Prof. Chris Clark with Vision Specialist Clinical Scientist Sian Hanley.

The project will examine children’s recovery of visual function following Hemisphere disconnection surgery (which can be used to treat severe epilepsy). Luis’ team will evaluate the effectiveness of our Eyelander game for training visual search ability in these children as well as UCL’s Read Right programme, developed by my old colleague and collaborator Prof. Alex Leff.

It’s been great to visit and a privilege to be involved in such an exciting project with such an outstanding team of researchers and clinicians. Feel free to get in touch with Luis if you would like to know more about the project.

Eyelander Goes Mobile

The Eyelander game for children with visual field loss is now compatible for use on mobile devices such as phones and tablets!

The game is based on visual search training that has been shown to be effective in improving functional visual abilities in adults with homonymous hemianopia. Our recent evaluation trial showed Eyelander delivered similar magnitude of improvement in functional visual abilities in children and young adults as the more boring adult training programmes. You can play the game and sign up for research to give us feedback on the game via the Eyelander website http://www.eyelander.co.uk. It is free to play and is designed to be colourful, fun and engaging for children. Players search for shapes on the screen which help their character to escape from a mysterious island.

We have been taking a step by step approach to making the game more widely available as we build the evidence base for its effectiveness, but we decided now was the time to make it more widely available for tablets and phones. It actually makes the game more fun to play using a touch screen rather than a mouse and cursor so I am really pleased with the results.

 

 

 

 

 

The game was developed in collaboration with The WESC Foundation Exeter, the School of Computer Science University of Lincoln and Mutant Labs Ltd Plymouth. See here for previous blog posts on the game development and evaluation: Eyelander game evaluation and Parkinsons and Spatial Memory studies published “EyeLander” game for children with VI now available! “Game-ifying” visual search training for children

Eyelander game evaluation and Parkinsons and Spatial Memory studies published

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.