Three years ago I volunteered to be a ‘subject’ in a study of neuropsychological testing in people with Anorexia Nervosa (AN). As a Biomedical Scientist and Geek myself, I absolutely ADORE data and I was interested to know how my brain processes information relative to other people with or without a history of AN.
At the time of testing, my weight was higher than it has ever been (above the ‘anorexic range’ – for what that range is worth….) and I felt well physically. My weight had been at this higher level for two years, which meant that I fitted to the ‘recovered’ category. Although I had done IQ tests before, I had never done any of these particular tests before and didn’t know what they would entail.
The tests focused on executive functioning; particularly attention to detail, central coherence (i.e. an ability to ‘see the bigger picture’) and cognitive flexibility. There were also tests examining the processing of emotional cues, and I filled in a lot of questionnaires. I found the tests quite fun and they involved playing card games on a computer, searching for hidden objects in complex diagrams and looking at faces, or parts of people’s faces. None of the tests examined anything to do with food, weight, body image, or ‘typical’ anorexic cognitions.
I do not have access to all my test results, but I have displayed some of the findings below. Please note that although I am a scientist, I am not a Neuroscientist or Neuropsychologist and can profess no expertise on this branch of psychology. I have done my best to explain the data in terms of my understanding of this field. (So if there are any Neuropsychologists reading this, do feel free to comment and correct any errors I have made in terms of data interpretation).
The data are displayed as mean (i.e. average) values for two groups: (1) People with a diagnosis of AN – and (2) Healthy Controls – where the latter are age-matched individuals who have never had an eating disorder. No standard error bars are displayed on the graphs, but I was told that the effect sizes (variation around mean values) were quite small. My results are marked in the graphs as ‘Cathy’.
The first set of test results look at Attention to Detail. The first graph below shows data from a test called the Rey Osterreith Complex Figure test (copy condition) and examines visuospatial processing. The ED group as a whole seem to focus more on details than controls, and it seemed that I did in particular.
I cannot remember the name of this test, but it involved spotting a small geometric shaped object in a large, complex design. The time taken to spot the object is noted. As you can see, the ED group has a higher attention to detail and is faster at ‘picking out the tree in the forest’.
The third test looked at Central Coherence. On average, people with AN have poorer Central Coherence than healthy controls, but my own result was similar to that of healthy controls, possibly because I was a near healthy weight at the time.
The next set of tests looked at cognitive flexibility. The data show that the ED group is less flexible (more rigid) than the Control group, and it seemed that I was/am particularly rigid… See, I don’t do change. I find change really difficult. No surprise there then…….
The next test was really interesting to do. It is a Stroop test, but I cannot remember what it is called. It involved the observer timing how long it took me to name the colour in the background of a picture of a face. Some of the faces had neutral expressions, while others looked angry and threatening. Intermittently, a neutral object (chair) flashed up on the screen.
I found the angry/threatening faces quite upsetting. They made me jump and feel nervous…
The data show that the AN group do seem to get caught up with threat and find faces difficult to ignore: especially angry faces. But even the chair seems more difficult for anorexic people to ignore, perhaps because of the high attention to detail.
The final test looks at emotion recognition from region around the eyes only. It’s a test devised by Professor Simon Baron Cohen, an autism expert. People with autism do seem to struggle with this test, as do people with AN. It certainly seems I wasn’t very good at it, but I think I know why. From being a small child I have found faces both threatening and too detailed. There’s too much information there. I have never found eye contact easy (except with cats ). I find it threatening. And so I have tended to avoid eye contact most of my life (or try not to avoid it…), which some people find weird. I do not have a diagnosis of autism, but some professionals have suggested I have many autistic traits. Indeed, attention to detail and cognitive rigidity, along with a difficulty in interpreting people’s emotions from just the eye region are symptomatic of people with autistic spectrum conditions.
So there we are…. The data are interesting because they do suggest that people with AN have a different style of information processing than people who have never had an ED. But to what extent this different pattern of information processing is a feature of malnutrition and to what extent it is neuro-developmental and possibly genetic, is still under investigation.
An important point, however…. This type of cognitive profile is not ‘bad’ in itself. Attention to detail and ability to focus on one specific task for a long time are qualities that make a good scientist, mathematician or artist, for example. But it may be that these characteristics are what maintain the behaviours of AN.