At busy times, I find I simply cannot read as much as I would like to. Life has a habit of filling every available hour with work, meetings, emails, chores, errands and deadlines. Standing in one of my natural habitats - a bookshop - it is frustrating to see so many things I want to read while knowing I do not have the time.
My usual consolation is to buy the book anyway and let a small, satisfying pile build up, looking ahead to the next quieter stretch when I might finally open them. It is oddly satisfying. Some might call this clutter. The Japanese have a far more elegant word for it: tsundoku .
The term describes the habit of acquiring books and allowing them to accumulate unread. It combines the idea of stacking things up (tsunde), leaving something for later (oku) and reading (doku). The result is a concept that captures the quiet optimism of a pile of books.
Far from being a sign of being time poor or lacking in discipline, tsundoku may reveal something surprisingly important about how the brain responds to anticipation.
When we encounter something that promises enjoyment or discovery, the brain's reward system becomes active. One important pathway runs from the ventral tegmental area, a dopamine-producing region in the midbrain involved in motivation, to the nucleus accumbens, a structure that helps generate feelings of reward.
Dopamine is often described as a pleasure chemical, but that is too simple. One of its key roles is helping the brain identify opportunities worth pursuing. Rather than rewarding us only after something beneficial has happened, the brain often rewards us in advance, encouraging behaviour that are likely to prove valuable.
From an evolutionary perspective, this makes sense. Our ancestors benefited from seeking out food before they were hungry, shelter before a storm arrived, and useful knowledge before they needed it. A brain that could anticipate future rewards had a clear advantage over one that responded only to immediate needs.
This means dopamine responds not only to rewards themselves, but also to the expectation of reward. The anticipation of a pleasurable experience can activate reward pathways long before the experience takes place.
An unread book is a good example. It may remain closed for weeks or months, but the brain has already recognised its potential value, enjoying the prospect before the first page has been turned.
The hippocampus, a structure deep within the brain best known for its role in memory, also plays an important part. While we often think of the hippocampus as helping us remember the past, it is equally important for imagining the future . The same neural machinery that allows us to reconstruct previous experiences helps us construct future ones.
When you picture yourself finally reading that book on a summer holiday, during a long train journey or curled up on the sofa on a rainy afternoon, the hippocampus begins to assemble that future experience. It binds together fragments of previous experiences stored across the brain - the warmth of sunshine, the smell of coffee, the sound of turning pages, the comfort of your favourite chair - into a coherent mental scene. In effect, the brain uses memories of the past to rehearse pleasures that have yet to happen.
Contributing to wellbeing
This ability may be more important than we realise. Psychologists increasingly recognise positive anticipation as a contributor to wellbeing . Looking forward to enjoyable experiences can improve mood, increase motivation and provide a buffer against everyday stress. In some circumstances, the anticipation of an event can be almost as rewarding as the event itself.
This may explain why a pile of unread books feels so different from a pile of unanswered emails. Both represent things waiting to be done, yet the difference lies in how the brain interprets them. Unanswered emails are future obligations whereas unread books are future rewards.
It is perhaps no coincidence that this behaviour feels strongest in bookshops rather than online. Physical browsing engages the brain more fully, drawing on sensory, spatial and reward systems that make discovery feel richer and more memorable. For example, the distinctive, slightly sweet scent of paper and ink is detected by the olfactory system and routed directly to regions involved in memory and emotion, including the hippocampus and amygdala.
Long before a book is read, the experience of finding it is already becoming associated with pleasure. So perhaps tsundoku may reflect one of the brain's most remarkable abilities: the capacity to derive genuine pleasure from experiences that have not yet happened.
Michelle Spear does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
