When Half the World Goes Missing

On the 5th of November 2007, Alan Burgess suffered from a stroke, changing his relationship with the world permanently in the space of a morning. However, this didn’t happen in a way that most people would expect. He wasn’t left paralysed or with impaired vision; it was something much more bizarre. Alan’s stroke had left him with a syndrome called hemispatial neglect, where the left side of the world had completely stopped registering. People who were stood to his left, food on the left side of his plate, and even the left half of his face just ceased to exist because his brain stopped attending to it.

What is hemispatial neglect?

Hemispatial neglect has been defined as a neuropsychological condition that is characterised by reduced awareness of stimuli on one side, even though there may be no sensory loss. The patient’s visual pathways are intact, however, during information processing, one side of the world gets filtered out by the brain.

This phenomenon is most commonly seen following a stroke and occurs far more often when these affect the right hemisphere of the brain (such as Alan Burgess’s stroke that damaged the right side of his parietal lobe). This asymmetry reflects the fact that the right hemisphere is more attention-dominant than the left, as it attends to both sides of space, whereas the left hemisphere primarily concerns itself with perception of the right worldview. In theory, this means that when the left hemisphere is damaged, the right can help to compensate; however, when the right is damaged, the left side of space is left unattended with nothing to fill the gap. Therefore, hemispatial neglect following a stroke in the right hemisphere tends to be much harder to rehabilitate as the patient may not even be aware that anything is missing. 

What’s going on in the brain?

As we now know, hemispatial neglect develops most often following a right hemisphere stroke, but more specifically, after an occlusion of the right middle cerebral artery, which is the primary source of blood supply to the right cerebral cortex. The region most affected by this is the temporoparietal junction (TPJ). The TPJ plays a critical role within the process of attention, detecting unexpected stimuli in the environment and redirecting our focus towards those, which occurs automatically in everyday life. However, when the right hemisphere is damaged, the stimulus on the left no longer triggers a reorienting signal, so it goes unregistered – leaving half a world.

"The patient’s visual pathways are intact, however, during information processing, one side of the world gets filtered out by the brain"

How do neurologists test for neglect?

Since hemispatial neglect is not a visual deficit, neurologists rely on both written and behavioural assessments that reveal how a patient attends to the space around them. One of the most popular is the line bisection task, where the patient is asked to mark the midpoint on a horizontal line. Healthy individuals tend to mark quite close to the true centre, while patients suffering from neglect place the mark significantly to the right of the line. Alan Burgess’s line bisection assessment showed exactly this, with his mark sat extremely far to the right. 

The clock drawing task is another commonly used tool, where patients are asked to draw the face of a clock and fill in all twelve numbers. In theory, those suffering from hemispatial neglect would have all twelve numbers crammed into the right half of the clock face, with the left side kept completely empty. However, this method is controversial as studies have shown that verbal intelligence can sometimes compensate for hemispatial neglect, allowing patients to draw the clock faces fairly well. 

Can hemispatial neglect be treated?

Currently there is yet to be a single, established treatment for hemispatial neglect; however, several approaches to rehabilitation have shown promise. At the moment, the most well-evidenced is prism adaption therapy. This technique involves patients wearing prism goggles that shift their visual field to the right, forcing them to repeatedly try reaching slightly more to the left every time. Over time, the brain recalibrates its sense of the midpoint, with this effect seeming to persist even two hours after goggles are removed.

More recently, technological advancements have been increasing in popularity: for example, immersive virtual reality approaches – although, while studies have shown that these are generally well tolerated by patients, they are yet to produce any clinically significant improvement. Dynamic auditory stimulation, a technique which uses sound to draw attention towards the left has also been becoming particularly promising. The theory behind this is that if the brain can be prompted to redirect attention towards the left via auditory cues, it bypasses attentional deficits that can help to promote visual rehabilitation as well.

"Attention is an active, deliberately constructed process, and when one part is disrupted, entire portions of the world cease to exist"

Importantly, what these approaches share is that we need to work with the brain’s attention circuits to rehabilitate hemispatial neglect, rather than just asking the patient to pay attention to something they don’t even realise is missing.

Alan Burgess described his stroke as the beginning of a new world. His story is a reminder that some of the most unique and profound neurological conditions can also be the least visible: in this case not only to the outside observer, but potentially also to the person living with it. What makes hemispatial neglect so fascinating is what it reveals about how the brain functions. Attention is an active, deliberately constructed process, and when one part is disrupted, entire portions of the world cease to exist. As research continues, the hope is that via rehabilitation, the missing half can be somewhat reinstated.

Reference list

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Ishiai, S., Sugishita, M., Ichikawa, T., Gono, S. and Watabiki, S. (1993). Clock‐drawing test and unilateral spatial neglect. Neurology, 43(1 Part 1), pp.106–106. doi:https://doi.org/10.1212/wnl.43.1_part_1.106.

Li, K. and Malhotra, P.A. (2015). Spatial Neglect. Practical Neurology, 15(5), pp.333–339. doi:https://doi.org/10.1136/practneurol-2015-001115.

Parton, A., Malhotra, P. and Husain, M. (2004). Hemispatial neglect. Journal of Neurology, Neurosurgery, and Psychiatry, [online] 75(1), p.13. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC1757480/.

Rossetti, Y., Rode, G., Pisella, L., Farné, A., Li, L., Boisson, D. and Perenin, M.-T. (1998). Prism adaptation to a rightward optical deviation rehabilitates left hemispatial neglect. Nature, 395(6698), pp.166–169. doi:https://doi.org/10.1038/25988.

Saebo (2026). Right Hemisphere Stroke: Symptoms, Left-Side Neglect, Recovery, and Exercises. [online] Saebo. Available at: https://www.saebo.com/blogs/advice/right-hemisphere-stroke-symptoms-left-side-neglect-recovery-and-exercises [Accessed 17 May 2026].

Sarwar, A. and Emmady, P.D. (2020). Spatial Neglect. [online] PubMed. Available at: https://www.ncbi.nlm.nih.gov/books/NBK562184/.

Singh, N.R. and Leff, A. (2023). Advances in the Rehabilitation of Hemispatial Inattention. Current Neurology and Neuroscience Reports, 23(3), pp.33–48. doi:https://doi.org/10.1007/s11910-023-01252-8.

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This article was written by Gauri Nair and edited by Julia Dabrowska, with graphics produced by Lilly Green. If you enjoyed this article, be the first to be notified about new posts by signing up to become a WiNUK member (top right of this page)! Interested in writing for WiNUK yourself? Contact us through the blog page and the editors will be in touch.