Overview
- In late June researchers led by Ryuta Kawashima at Tohoku University reported that driving a car with a manual transmission produces stronger activation in the prefrontal cortex than driving an automatic.
- The team reached this conclusion using functional near‑infrared spectroscopy, a brain imaging method that tracks changes in blood flow linked to mental effort during demanding driving tasks.
- Kawashima and coverage in major outlets noted a practical recommendation to drive manual cars when possible to keep the brain engaged, but the authors and reporters stress that this is a hypothesis not backed by clinical trials.
- The idea faces a real‑world limit because manual transmissions are shrinking worldwide as automatics and electric vehicles spread, which reduces how many people could use this form of daily mental activity.
- Experts and the reporting say the next step is long‑term, peer‑reviewed clinical studies to test whether the repeated mental effort of shifting gears yields lasting benefits for aging brains, a question with particular relevance for countries with older populations like Japan.