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.

Quality Adjusted Life Years and the Neuroscience of Fairness

This month we published the first ever fMRI brain imaging study of health care rationing decision making 

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decision making screens

Health care funders around the world have to make difficult moral decisions to allocate limited money to treat various medical conditions in different groups of patients. For example whether or not to support funding for expensive new drug treatments for a group of cancer patients with low chance of survival relative to a drug that will benefit a group with a higher chance of survival.  A commonly used framework on which these decisions can be based are Quality Adjusted Life Years or “QALYs”. This system is based on so-called utilitarian decision making principles, which prioritize choices that deliver the maximum benefit to the greatest number of people. The problem with QALYs  is that decisions based on this approach are often viewed negatively by members of the general public. People instead believe that everybody has a “right” to receive medical care and anything that violates this principle is unfair and immoral.

Consistent with previous work, when asked to judge the “fairness” of various scenarios depicting a split between different social groups our participants judged unequal division of funding as “unfair”, even when principles of QALY might indicate otherwise. Interestingly brain regions linked to emotion as well as cognitive processes were active during decision making. Unequal splits of resources for medical care produced activity in the anterior insula, a region often associated with social / moral disgust (see earlier posts on social norms and eating disorders). Further, under conditions where participants were prepared to judge unequal splits as fair, more activity was seen in the inferior frontal cortex, a region activated when humans inhibit a strong response impulse.

The results represent a preliminary first step for cognitive neuroscience into the field of health economics and the paper is careful to avoid over interpreting the findings and applying them to real situations outside the scanner. But the findings are consistent with a bigger idea that humans have two decision making systems, one cognitive and one more emotional / instinctive. Given enough information people may be more inclined to support healthcare decisions based on QALYs, but this requires cognitive effort to over-ride a more emotion based bias towards absolute equality and universal rights.

The paper is out  ipic2n the June edition of the Journal of Neuroscience Psychology and Economics. The research was carried out in collaboration with Prof. Paul Anand ( Open University and Health Economics Research Centre at the University of Oxford), Lisa Smith (Flinders University Austrailia) and the Exeter Magnetic Resonance Research Centre. A pre-print of the paper is available via the Lincoln Repository website.