In this report, I would like to organize and reflect on the relationship between effort and reward, based on recent neuroscience research introduced on the Nature Podcast, the official program related to the international scientific journal Nature.
The source of this discussion is a study published in Nature in 2024 by a research team from Stanford University.
The podcast episode introducing this study is titled:
“How your brain chemistry rewards hard work”
This research goes beyond simple health information.
It touches on the foundations of human behavior, learning, persistence, and the sense of satisfaction we feel in daily life.
For these reasons, I believe it is a topic well suited to deeper reflection within the context of traditional Japanese body care and long-term cultivation.
The question explored in this study is surprisingly simple, yet had not been clearly explained scientifically until now.
Why do things obtained after great effort feel more valuable?
Why does the same result or reward feel completely different depending on whether it was achieved easily or through hardship?
To examine this, the research team conducted experiments using mice.
They provided rewards of the same amount and quality, while changing only one factor: the amount of effort required to obtain the reward.
The results were striking.
Even though the reward itself was identical, the amount of dopamine released in the brain increased significantly when the reward was obtained after greater effort.
In some cases, dopamine release increased more than fivefold compared to low-effort situations.
Dopamine is widely known as a neurotransmitter related to pleasure, reward, motivation, and action.
Until now, it was commonly believed that “better rewards produce more dopamine.”
However, this study clearly shows that the brain’s response changes dramatically depending on the amount of effort involved, even when the reward is the same.
An especially important part of this research is the mechanism behind this effect.
The study highlights the role of another neurotransmitter: acetylcholine.
Acetylcholine is known to be involved in attention, learning, concentration, and mind–body regulation.
In this research, it appears to function as a messenger that conveys the amount of effort to the dopamine system.
During periods of effort, acetylcholine gradually accumulates in the brain.
When a reward is finally received after sustained effort, acetylcholine is released all at once, strongly amplifying dopamine release.
What matters here is that this mechanism occurs only when effort is high.
When rewards are obtained easily, this strong cooperation between acetylcholine and dopamine does not occur.
These findings closely match what many of us have felt intuitively in daily life.
Skills acquired through hardship are not easily forgotten.
Knowledge gained without effort often fails to stay with us.
Accumulated experience later becomes a quiet form of confidence.
This study suggests that such experiences are not merely psychological or philosophical ideas, but may be explained through concrete chemical processes in the brain.
From here, we can also look at this research through the lens of traditional Japanese medicine.
In Eastern medical traditions, concepts such as accumulation, cultivation, training, and steady practice have long been emphasized.
Rather than seeking quick results, daily actions themselves are thought to nourish ki and gradually align the mind and body.
From this perspective, acetylcholine accumulating during effort could be seen as something like “stored vitality” or “inner maturation.”
Only after this accumulation does a result truly settle deeply into both body and mind.
This also helps explain why shortcuts do not always lead to real satisfaction or growth.
The research also invites us to reconsider how we view people who feel unable to make effort or continue consistently.
The researchers suggest that in conditions such as depression or addiction, the cooperation between acetylcholine and dopamine may not function properly.
In other words, difficulty in making effort may not be a matter of weak will or personality, but rather a state of the brain’s current circuitry.
So how can we use this information?
One way is in how we approach learning and training.
Rather than rushing toward short-term results, we can intentionally value processes that require a bit more time and care.
What seems like a detour may lead to deeper satisfaction and long-lasting integration.
Another application is in therapy, education, and guidance.
Instead of only offering quick relief or easy solutions, we can incorporate practices that allow individuals to accumulate effort themselves.
This approach aligns well with self-care and traditional health guidance.
A third point is how we view ourselves.
Even if past efforts did not produce dramatic results, they are still engraved in the brain and body.
Recognizing this allows us to quietly affirm our own path, rather than deny it.
This research gives new meaning to the phrase “effort is rewarded.”
It explains this idea not as moral encouragement, but at the level of brain chemistry.
At the same time, it resonates deeply with the traditional Japanese values of accumulation, cultivation, and patience.
This report is not meant to impose a single conclusion.
Instead, I hope it can be received as one context among many —
a way to reflect quietly on learning, practice, and how we choose to live.
