笑いと脳の関係
Hello everyone, SCIENSPOT is a podcast that shines a spotlight on the latest
tactical technology from Japan. Your host is REN from SCIEN-TALK.
Today, we are discussing a topic that we all love but often overlook as a health tool,
laughter. Specifically, can laughing for just a few minutes actually improve your brain function
and reduce stress? A new study published in 2025 in the journal BMC
Complementary Medicine and Therapies suggests that the answer is yes.
This research was conducted by Yamakoshi and his team at the Kirin Central Institute
of Japan. They focused on middle-aged adults aged 40 to 65, a demographic often facing high
pressure and stress in modern society. While we know laughter feels good, the researchers wanted
to scientifically measure its effect on cognitive function and the autonomic nervous system using
advanced technology. How did they test this? The team recruited 25 healthy adults and conducted
a specific type of experiment, called a single-blinded randomized crossover trial.
This means every participant experienced both the funny condition and the boring condition
on different days to compare the results fairly. For the funny condition, participants watched a
4-minute video of a famous Japanese stand-up comedy duo, Manzai, who had won the prestigious
M-1 Grand Prix. For the control, they watched a much less funny video. To see what was happening
inside the body, they used two key technologies. First is NIRS. This is Near-Infrared Spectroscopy.
漫才がもたらす脳の変化
This measures blood flow in the brain and ECG, electrocardiogram. This measures the heart rate's
variability to assess stress levels. The researchers were looking specifically at
parts of the brain called the Dorsolateral Prefrontal Cortex or DLPFC. Think of the DLPFC
as the executive control tower of your brain. It is responsible for planning, working memory,
and most importantly, focused attention. The findings were fascinating. After watching this
funny video, participants performed significantly better on cognitive tasks that required high focus.
Crucially, the NIRS data showed that during these tasks, blood flow to the DLPFC was significantly
higher after laughing compared to the boring video. Furthermore, the heart rate data showed that while
laughter initially sparked excitement, it led to a quick activation of the
parasympathetic nervous system. This is the body's rest and digest mode,
indicating rapid recovery from stress. In conclusion, this study provides scientific
evidence that viewing just a short 4-minute comedy video can do two things at once for
middle-aged adults. It activates the brain's executive center to improve focus,
and it helps the body relax and recover from stress. So taking a quick break to watch something
funny isn't a distraction. It might be the best way to boost your productivity and mental health.
文化としての漫才
I think the Japanese stand-up comedy duo called Manzai is a very famous culture in Japan,
so I love watching these Manzai Grand Prixs at the end of the year. And I think this strong
connection between brain and laughter is a very fascinating study.
That's all for today's SciencePod. This podcast is broadcast in both Japanese and English.
I'd love for you to listen to the podcast and post your thoughts with the hashtag
SciencePod. Thank you for listening and see you next time.
