5 Things We've Discovered About Memory In 2019 Alone
The brain is an amazing thing. It can retain facts — from the address of your preschool to the lyrics to a song you heard once in 1997 — for years in perfect clarity, sometimes without rhyme or reason. The mechanisms of memory in the human brain are fascinating, and science is still discovering many things about how they work. The first months of 2019 have been a bonanza for new research on memory, with new revelations about how it works, how everything from the language you speak to your allergy to tree pollen might affect it, and how medicine might be able to 'repair' memory damage caused by illness or aging.
There isn't one 'memory area' of the brain; different kinds of memories are stored in the hippocampus, amygdala, basal ganglia, prefrontal cortex and other places, which is why brain injuries can affect the memory in varied and sometimes bizarre ways. Science on memory is blossoming, and these discoveries might lead to some very intriguing new treatments and approaches. It's an exciting time to be interested in memory — or should we say a memorable one. Here are some of the biggest revelations from the first few weeks of 2019 alone.
1. We Might Be Able To Repair Memory Loss Caused By Depression
One of the most exciting revelations about memory in early 2019 came from a paper published in Molecular Neuropsychiatry about a particular type of memory loss: one associated with aging or serious depression. In the study, scientists discovered that some specific molecules, altered versions of the sedative drug benzodiazepine, could help memory loss by repairing damage to the brain's neurotransmitter system.
The scientists had already done studies that confirmed that memory loss in depression is often down to damage to receptors in this system, known as the GABA system. The new drug molecules they'd developed targeted those impaired receptors and reversed the symptoms of memory loss — and, interestingly, appeared to help heal the receptors themselves. Result? Better memory quality now and in the future.
It's a really interesting study; people with depression could be given this drug in the future to target memory loss, which is one of the most well-known side effects of serious depression. There's still a long way to go before it's approved as a medication, but the research is a strong start.
2. The Language We Speak Affects How We Remember
Memory, it turns out, isn't the same worldwide. That's the conclusion of a study from the Max Planck Institute for Evolutionary Anthropology, which studied a huge group of languages worldwide. And one of the biggest ways our culture affects our memory is through our language.
There are, according to the Institute, two groups of languages: 'left-branching' and 'right-branching'. "In typical right-branching (RB) languages, like Italian, the head of the sentence usually comes first, followed by a sequence of modifiers that provide additional information," they explained in a press release. "In contrast, in left-branching (LB) languages, like Japanese, modifiers generally precede heads." English is a right-branching language; we say things like 'the man who was sitting at the bus stop', while in Japanese the sentence is more like 'who was sitting at the bus stop, the man'.
This, the authors discovered in research published in Nature, affected how people remembered things. People who spoke left-branching languages could remember the information at the very start of memory tasks much better than people who spoke right-branching languages. Why? Because their languages mean they have to retain information from the beginning of a sentence to understand it at all.
3. Pro-Histamines Might Boost Long-Term Memory
Take antihistamines? They might affect your memory. Researchers at the University of Tokyo released findings in 2019 that showed that histamine-boosting treatment can temporarily boost your memory of events that took place longer than 48 hours ago.
People in the study were shown a group of images, then shown them again a few days later and asked if they remembered them. A week after that, they were given a large dose of pro-histamine and given the memory test again. The results were mixed. In people who'd done poorly at the first test, histamine appeared to boost their scores; in people who'd done well, histamine lowered their accuracy. Histamine also improved the long-term memory of mice, but only for 28 days. It's thought that histamine affects the way neural cells fire, which is why they seem to affect memory in distinct ways.
4. Remembering An Event Means Reconstructing It In Reverse
Remembering something doesn't mean going through the same process as you did when you experienced it, according to findings published in Nature Communications early in 2019. The scientists behind the study looked at the brains of people who were remembering objects, and found something interesting: the process of memory appeared to be 'backwards'.
When we first see something, we process details first and then look at the object from a wider perspective: what it's called, what it might do and so on. When people in the study remembered seeing an object, by contrast, their brains fastened onto those abstract facts first. Instead of thinking 'red, hand-shaped, leather, glove', they thought 'glove' first and then all the other attributes. This, the scientists said in a press release, is possibly why our memories can "become more abstract and gist-like with each retrieval." We're losing the details because of the backwards process of memory.
5. Being Rocked In Your Sleep Boosts Your Memory
Want better memory? Get a hammock. That's the conclusion of two different studies released in early 2019 that show both mice and humans have better memory consolidation if they're rocked while they sleep. In the study on humans, the subjects who were rocked all night showed alterations in their sleep neural patterns that improved their memories the next day. Tests on mice in the other study found that the benefits of rocking were related to the sensory system that detects bodily motion.
This may seem silly, but it could be a big deal for people who have sleep disorders, and experience memory issues as a result. As for why rocking might make us better, deeper sleepers, it's not entirely clear; for some of us, it could be related to the comforting experience of being rocked as infants, but that wouldn't explain why mice love it too. Either way, if you remember your holiday with great crispness after falling asleep in a hammock on the beach, don't be surprised; the rocking is likely responsible.
Memory is a fascinating thing, and it's going to be exciting to see the new discoveries that the rest of 2019 will undoubtedly bring. For now, however, let's appreciate just how awesome the human memory is — even if it just won't let go of that embarrassing thing you said on a date in 2012.