Superficially, a novel about a man's decent into Alzeimers might not seem to have much in common with a graphic novel.
Though Samantha Harvey's The Wilderness and the graphic novel edition of City of Glass differ greatly (in subject, setting, genre), the two books bring the reader on the same journey from marginal certainty of the real through utter mindfuck. That journey is precisely the one Descartes evaded when questioning a reality dependent on a Christian God.
To Descartes, as an infirm man in his dressing gown, questioning the very basest measure of his centered conceptions of reality were just more than he could handle. Considering the trajectory of The Wilderness and City of Glass, Descartes might have had the right idea. At his advanced age, losing the yardstick for normalcy is much worse than losing your glasses. I doubt there's any coming back from that.
The protagonists of the two novels use the same standards for conceiving reality as Descartes: sensory information, time, sense of place. Both Jake and Quinn grapple with doubting their slipping perception of truth (knowledge) and reality.
On page 97 of my edition of City of Glass Quinn's thought bubbles struggle against the cold hard captions; "Quinn was nowhere now," reads the caption that corresponds with Quinn's thinking, "It's June 2nd". That disparity of perception and certainty escalates in the next two panels of captions with, "He had nothing, he knew nothing," and "He knew that he knew nothing". Meanwhile, the frame increases confusion by zooming closer and alternating between cantid and profile angles. The chaos of Quinn's mind increases from panel to panel; Quinn goes from progresses from a walk to a sprint, eventually sprinting through the panel frame.
The breaking of form reflects the Cartesian break down of language, sensory information, and ideas of time, ie, the indicators of the "real". As any and all information used to percieve the "real" can be faulty, doubt can seep in, and as it does for Quinn, physically breaks down what he percieves as real. sometimes pushing to Once the question has been asked, or doubt established, if not stopped by disbelief or does not lapse into post modern comfort with doubt, can spiral into the breakdown of the perceived "real".
The graphic novel form imparts hyperreality into Quinn's struggle to recognize common flagposts of reality: time, date, etc. describes changes in perception. For Jake of The Wilderness, that change in perception stems from Alzeimers. He describes his perception of the past as "the convex lens of memory", and struggles with establishing the same reality that he had constructed prior to the development of his Alzeimers.