// Reader Q&A

“If rest helps my brain learn, does a nap count too?”

It counts, and it may count more than you think.

A team in Singapore had 84 young adults learn facts about ants and crabs. Midway through, one group took a one-hour nap. A second group spent that hour on cramming. The third sat and watched a movie.

Half an hour after the last lesson, the nap and cram groups both beat the movie group. A week later, the team tested them again.

Only the nappers still held a clear edge. The cram gains had faded out.

One catch: these were college kids, not folks in their fifties. Still, the logic is sound. I take a short nap after a big read, and the facts stick.

People: 84 · Nap: 1 hour · Edge at 1 week: nap group only

// What you picked

“Is a fish oil pill worth it for my memory?”

It may help, with one big catch.

The best-known trial is called MIDAS. It gave 485 adults aged 55 and up a daily pill. Half got 900 mg of DHA, the rest a dummy. DHA is the main omega-3 fat in your brain.

Each person had mild memory gripes at the start. After six months, both groups made fewer errors on a learning test. But the DHA group cut its errors by close to twice as much.

Here’s the catch. The firm that made the pill paid for the trial. It had a dummy pill and passed peer review. So I don’t toss it out. Still, I want a second team to match it.

So I go food first. Two plates of oily fish a week, like salmon or sardines, is my plan.

Adults: 485 · Dose: 900 mg DHA/day · Length: 24 weeks

// Reader Spotlight

“I’m 63. What hobby does the most for my brain?”

Pick the one that makes you sweat a bit.

A UT Dallas team put 221 adults aged 60 to 90 in groups for three months. Some learned digital photo work or quilting. They put in about 15 hours a week. Others joined a social club, or did easy tasks at home.

Only the groups that took on a new, hard skill gained on memory tests. The photo group did best.

Asked why, lead scientist Denise Park said it was the hardest. In other words, the stretch is the point.

So skip the hobby you could do in your sleep. Choose one that makes you think, like a camera or a new language. I took up the guitar for this reason. It keeps my mind on its toes.

Adults: 221 · Ages: 60 to 90 · Length: 3 months