The story begins with her friends and family recounting the event, then moves on to Sodderland’s first attempts to film herself. Her struggle with speech and obvious confusion and frustration are shocking and moving. Sodderland’s initial recordings express her delight and relief that she is alive at all, and given that stroke is the UK’s third biggest killer, and affects around 150,000 people each year, such feelings seem well founded. It is not unmixed delight however: although the blood clot was successfully removed, Sodderland’s neurologist explains that the damage to the brain was already done and is likely to be irreversible. Having to move back in with her mother, losing her independence and becoming “disabled”, is a struggle; at one point Sodderland says that she feels like a baby.

Sodderland eventually spends three months as an inpatient in Homerton’s neurological rehabilitation unit, working to improve her speech and deal with the demands of everyday life. Good humour and determination keep her going, even though we see her distress at getting her words wrong: the stroke has left her with aphasia, making it impossible for her to read and, at first, write. Part of her rehabilitation is to try and help her re-calibrate her brain hemispheres. Her neuro-psychologist explains that the pathways for reading and writing are slightly different: you don’t have to see to write, but you need the visual connections to read.

Sodderland’s desire to create her own narrative, to fix memories and move on with her life, leads her to join a research study into transcranial stimulation at University College London. This non-invasive brain stimulation technique aims to speed up language recovery. Sodderland dutifully goes to daily sessions and practices at home; she has her brain stimulated whilst hearing and seeing words on a screen, trying to help her make new neural pathways.

One of the most arresting features of the film is its visual style. The stroke caused an impairment in Sodderland’s right eye, something her ophthalmologist says probably cannot be repaired. Robinson says that when Sodderland first started speaking to her about the “trippy” other-dimensional views she had from her right side “it became very important to use that and make the film feel a bit different so we can feel what it’s like in Lotje’s head”.

Indeed, the experience is very dreamlike, sometimes terrifying. Sodderland initially describes it as being like another dimension, which can make her feel euphoric and give her a new experience of colours and sounds. As the story continues, however, it is clear that the impairments haven’t remained quite so awe-inspiring, becoming instead “an exquisite painful nightmare” taking place in her head.

This is an absorbing study of how our sense of self is defined by our personal narrative and the memories we write each moment, and what it means to lose the ability to make those memories. It is also a reminder of the nature of personal independence. As Sodderland points out: when you are unable to communicate and tell your story you can’t live your life in an independent way, you’ll always need someone to help. With her sense of time removed, and unable to remember things, the sense of the significance for Sodderland of making the film and preserving her story was palpable, despite her admisson after the screening that she no longer watches it. The audience is implicated in Sodderland’s story: we will remember even if she can’t.

MBBB is a moving film which deals with the philosophy of who we are and what makes us a person, alongside showing us just how fragile our understanding of the brain is. It’s significant how often the physicians involved in Sodderland’s care use the phrase “I don’t know”: the brain remains a mysterious place.

Sodderland and Robinson have made a beautiful film which at turns is frightening, as it reveals how close we all are to losing our essential selves, and hopeful. Studies and research are constantly striving to find out just what makes the brain tick and how we can help those who have had a severe brain injury come back to us; perhaps not as we knew them before but, as Sodderland puts it, with a new life, full of endless possibility.

My Beautiful Broken Brain was shown as part of the Ideas & Science strand at Sheffield Doc/Fest 2015, for future screenings please visitmybeautifulbrokenbrain.com.

This article first appeared on The Guardian website here