Talking in your sleep

A little over a year ago, I decided to do something I've always wanted to do -- learn Japanese.

I've had a fascination with Japan since I was a kid.  My dad lived there for a while during the 1950s, and while he was there collected Japanese art and old vinyl records of Japanese folk and pop music, so I grew up surrounded by reminders of the culture.  As a result, I've always wanted to learn more about the country and its people and history, and -- one day, perhaps -- visit.

So in September of 2023 I signed up for Duolingo, and began to inch my way through learning the language.

[Image is in the Public Domain]

It's a challenge, to say the least.  Japanese usually shows up on lists of "the five most difficult languages to learn."  Not only are there the three different scripts you have to master in order to be literate, the grammatical structure is really different from English.  The trickiest part, at least thus far, is managing particles -- little words that follow nouns and indicate how they're being used in the sentence.  They're a bit like English prepositions, but there's a subtlety to them that is hard to grok.  Here's a simple example:

Watashi wa gozen juuji ni tokoshan de ane aimasu.

(I) (particle indicating the subject of the sentence) (A.M.) (ten o'clock) (particle indicating movement or time) (library) (particle indicating where something is happening) (my sister) (am meeting with) = "I am meeting my sister at ten A.M. at the library."

Get the particles wrong, and the sentence ends up somewhere between grammatically incorrect and completely incomprehensible.

So I'm coming along.  Slowly.  I have a reasonably good affinity for languages -- I grew up bilingual (English/French) and have a master's degree in linguistics -- but the hardest part for me is simply remembering the vocabulary.  The grammar patterns take some getting used to, but once I see how they work, they tend to stick.  The vocabulary, though?  Over and over again I'll run into a word, and I'm certain I've seen it before and at one point knew what it meant, and it will not come back to mind.  So I look it up...

... and then go, "Oh, of course.  Duh.  I knew that."

But according to a study this week out of the University of South Australia, apparently what I'm doing wrong is simple: I need more sleep.

Researchers in the Department of Neuroscience took 35 native English speakers and taught them "Mini-Pinyin" -- an invented pseudolanguage that has Mandarin Chinese vocabulary but English sentence structure.  (None of them had prior experience with Mandarin.)  They were sorted into two groups; the first learned the language in the morning and returned twelve hours later to be tested, and the second learned it in the evening, slept overnight in the lab, and were tested the following morning.

The second group did dramatically better than the first.  Significantly, during sleep their brains showed a higher-than-average level of brain wave patterns called slow oscillations and sleep spindles, that are thought to be connected with memory consolidation -- uploading short-term memories from the hippocampus into long-term storage in the cerebral cortex.  Your brain, in effect, talks in its sleep, routing information from one location to another.

"This coupling likely reflects the transfer of learned information from the hippocampus to the cortex, enhancing long-term memory storage," said Zachariah Cross, who co-authored the study.  "Post-sleep neural activity showed unique patterns of theta oscillations associated with cognitive control and memory consolidation, suggesting a strong link between sleep-induced brainwave co-ordination and learning outcomes."

So if you're taking a language class, or if -- like me -- you're just learning another language for your own entertainment, you're likely to have more success in retention if you study in the evening, and get a good night's sleep before you're called upon to use what you've learned.

Of course, many of us could use more sleep for a variety of other reasons.  Insomnia is a bear, and poor sleep is linked with a whole host of health-related woes.  But a nice benefit of dedicating yourself to getting better sleep duration and quality is an improvement in memory.

And hopefully for me, better scores on my Duolingo lessons.

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