As dawn broke, a peaceful calm enveloped the city. The shadows along the roads gradually receded, leading us into a radiant morning. It was June, and the few early risers setting up market stalls relished the serene, gentle light, even with the enemy only 50 miles away. Many who had fled the metropolitan area clung to the hope that the defense line would hold after nearly four years. Hope remained alive.

On Houseman Street, a handful of cars headed east, but otherwise, the street was quiet as most residents lingered in wakefulness. However, the inhabitants of the second-floor apartment at No. 102 had been awake for quite some time—indeed, all night. The window shutters remained tightly drawn, as they had been for months. A green bedside lamp glowed in the otherwise darkened room, amidst furniture shrouded in shadows and filled with stramonium steam for asthma, creating a stifling atmosphere. The sounds from the street, coupled with the soundproof cork-lined walls, contributed to a sense of suffocating confinement that visitors undoubtedly felt.

Sitting on a bed in a beautifully adorned Japanese courtyard, propped up by large cushions, he usually lost himself in his manuscript. But today felt different. Overwhelming fear consumed him. One side of his face seemed to sag. When addressing Celeste, his housekeeper, he worried his words lacked clarity, turning his speech into an almost incomprehensible ramble. Convinced he was on the brink of a major stroke—the same fate that plagued both his parents—he found no alternative explanation. It was a hereditary concern. And had his beloved mother, Jeanne, escaped complete frailty? Her stroke had robbed her of language, rendering her unable to communicate with her cherished sons.

In the summer of 1918, as the Germans initiated their final offensives of World War I towards Paris, the renowned novelist Marcel Proust sat on a blue satin chair, engulfed in fear of potential brain damage. Now in his late 40s, he was all too familiar with aphasia; his mother had suffered from it, and his father, Dr. Adrian Proust, had authored an entire book on the subject prior to his own stroke.

Young Marcel had also befriended many of the city’s most distinguished neurologists. At that time, Paris stood as a prominent hub for neurology, with pioneering experts making significant advancements in understanding language disorders following strokes. Without such insights, where would Proust find himself?

On that June morning in 1918, he anticipated a meeting with Joseph Babinsky, a well-known neurologist. Babinsky, unaware of the reasons behind Proust’s visit, simply inquired, “Do you have any symptoms?”

Proust’s intention was to persuade Babinsky to perform a trepanation—drilling holes in his skull—driven by his profound belief that such a drastic step was necessary to halt the looming stroke. However, Babinsky, an expert in his field, reassured Proust that there was no evidence suggesting he was experiencing a stroke and declined to proceed with the operation. It’s difficult to imagine how the trajectory of Proust’s monumental novel would have shifted had he suffered a stroke. While Marcel Proust never experienced a stroke, the shadow of that fear haunted him throughout his life, lingering long after, even when he was near death from pneumonia, it was Babinsky he called upon.

Proust’s anxieties surrounding brain-related illnesses resonate with many. While diseases can afflict anyone in various ways, our deepest fears often lie in disorders that impact our minds. Why is that? Because neurological conditions can transform individuals dramatically. Some may struggle with communication, as Proust feared, while others could experience memory loss, distorted perceptions, or hallucinations. Some might exhibit socially inappropriate behavior, a lack of empathy, or rudeness. Others could become impulsive or withdrawn, developing new addictions or suffering from pathological indifference.

Such behavioral shifts can be distressing and terrifying for both individuals and their loved ones. Yet, they reveal profound insights into our very nature. By examining the consequences of certain brain functions being impaired, we glean understanding about our own normality, how cognitive functions shape our identities—personal and social, formed through our connections with others.

For someone like Marcel Proust, losing the ability to communicate would be devastating. Not only would he lose his gift for writing, but he would also risk dismantling his carefully crafted social presence. The social identity he had labored to cultivate would effectively disintegrate. Proust had invested years nurturing relationships with key figures in French society and possessed remarkable perceptions regarding his connections with influential individuals. As a gay man from a Jewish background, He adeptly navigated the complexities of prejudice and societal expectations in Paris.

Through keen observation and emulation, he became an integral part of the circles he thought he belonged to. Some observers suggested that Proust was a master manipulator, indicating that even while isolated in his dimly lit bedroom, he was unwilling to relinquish control over those around him. However, without language, the intricate web he had worked to weave would no longer be accessible; he would no longer “belong.”

This excerpt is from Massoud Hussain’s work Our Brains, Ourselves (Canong’s publication), recipient of The Royal Society Trivedi Science Book Prize and the latest selection from the New Scientist Book Club. Join us to read together.