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Neurology About 45 percent of all people who’ve had had a stroke in the right side of their brain, suffer from a condition called spatial neglect. Because of a ‘magnetic attraction’ towards the right side, people with this condition tend to ‘neglect’ things located on the left. Thanks to a couple of lottery tickets, researchers now have a better understanding of how this condition works. Spatial neglect can lead to bizarre behaviours. People who suffer from it might bump into objects placed on the left, or become unable to eat from the left side of a dish. Dr. Tobias Loetscher, an expert in the field of neuropsychology, examined a group of twenty patients with left spatial neglect and 17 control patients without the disorder. All of the participants had had a stroke in the right side of their brain; a so-called right hemisphere lesion. During the study, Loetscher and his colleagues used a test based on a simple lottery game. First, the patients were asked to choose six lottery numbers by marking them with a pencil on a real lottery ticket. Predictably, the patients with spatial neglect tended to pick numbers located on the righthand side of the ticket, neglecting those on the left. The second part of the experiment was more surprising. According to several studies, the disorder of spatial neglect is not restricted to physical space, but also affects the exploration of mental images on the left side of the minds eye. So when a spatial neglect patient thinks of the map of Europe for example, he will only be able to visualize the

Eastern European countries. And when they are asked to name an array of horizontally arranged objects, they begin by naming objects on the right, whereas control subjects name objects on the left. In order to test if this was also the case for the mental representation of numbers, a second test was developed. The participants were asked to pick six numbers between 1,000 and 10,000. It is commonly believed that when we think of numbers we visualize them arranged along a mental number line, with numbers increasing from left to right. According to the hypothesis, neglect patients were expected to only pick large numbers, because those are located on the right side of the mental line. However, the results showed that only four out of the twenty patients (20 %) were more likely to pick large numbers. This evidence suggests that there are different subcategories of spatial neglect: some patients only experience it while perceiving the ‘real world,’ while others also have trouble visualizing mental images. Knowing this makes it easier to find a suitable treatment for each patient. “Rehabilitation of neglect is still in its infancy,” says Loetscher. “There are many

different treatment options tested, but the shift the attention to that side.” outcomes are rather mixed. Therapy works in some, but not all patients.” Thanks to the Watch more development of simple tasks such as the one with the lottery ticket, subtypes can be distinguished and assessed. “For a patient with left-sided neglect in the real and imagined world, the left side of the world does simply not exist. However, if you have neglect for the real world, but not for your mental images you can access the left part of that mental image. This might be exploited for therapy purposes. When scanning the left part of the image the patient might become aware that he missed the left part of the real world and


Neurology Lottery