Everybody has a distinct ‘memory style’ that affects how we recall things

The 1950s Japanese film Rashomon is famous for its exploration of the way people recall the same incident in different ways, but even outside of how we shape our recollections to suit our own personal narratives, it seems humans really do remember things differently.

For the first time, researchers have shown that the different ways people experience the past are associated with distinct brain connectivity patterns that may be inherent to each individual. These life-long ‘memory traits’ are the reason some people have richly detailed recollections (episodic memory) while others can recall facts but little detail (semantic memory).

“For decades, nearly all research on memory and brain function has treated people as the same, averaging across individuals,” said Signy Sheldon, a psychologist now with McGill University in Canada.

“Yet as we know from experience and from comparing our recollection to others, peoples’ memory traits vary. Our study shows that these memory traits correspond to stable differences in brain function, even when we are not asking people to perform memory tasks while in the scanner.”

To investigate how people remember things differently, the researchers had 66 healthy young adult participants complete an online questionnaire describing how well they remembered autobiographical events and facts.

They also had their brains scanned so the researchers could investigate the activity in their medial temporal lobes, which are fundamentally involved with memory functions.

The findings, published in Cortex, showed that those who had richly detailed autobiographical memories demonstrated higher medial temporal lobe connectivity to regions at the back of the brain involved in visual processing.

In contrast, participants who mostly recalled events in a factual manner without much in the way of rich detail showed higher medial temporal lobe connectivity to areas at the front of the brain, which are involved in things like organisation and reasoning.

While the results will need to be replicated in larger studies, the implications of the research suggest that certain memory traits are protective, and may even one day help us delay the manifestation of age-related cognitive decline as people get older, due to the connections between memory recall and diseases that lead to dementia.

“With ageing and early dementia, one of the first things that people notice is difficulty retrieving the details of events. ,” said one of the team, Brian Levinefrom the University of Toronto.

“People who are used to retrieving richly-detailed memories may be very sensitive to subtle memory changes as they age, whereas those who rely on a factual approach may prove to be more resistant to such changes.”

The researchers are now conducting further study to see how people’s memory styles are related to other facets of their personality, including things like depression and cognitive performance. It’s amazing to think that how we recall the past could one day help to protect our future. We can’t wait to see where this research leads.

Scientists have produced the world’s first 100% recyclable biopolymer

A type of plastic that can be reheated for an hour and converted back to its original molecular state has been developed by researchers in the US, and being completely recyclable and reusable, petroleum-free, and able to broken down by living organisms, it could change everything about how we consume and reuse plastic.

Researchers at Colorado State University developed the polymer using a monomer called Gamma-butyrolactone (GBL), which is found in superglue removers and cleaning solutions. While the scientific literature has insisted for years that its chemical structure was too stable to convert into a plastic, the team went ahead and tried it anyway.

“‘Don’t even bother with this monomer,'” Chen said, quoting the conventional wisdom. “‘You cannot make a polymer out of it because the measured reaction thermodynamics told you so.’ We suspected that some of the previous reports were probably incorrect.”

Right now, every single of one of us is consuming around 90 kilos (200 pounds) of synthetic polymers every year, most of which isn’t biodegradable or recyclable. More than 270 million tonnes of plastic is produced each year, and 18 million of that ends up in our oceans each year, adding to the 243,978 tonnes that have already accumulated.

While many of the plastic bottles and packages you use display a ‘recyclable’ symbol, they can only be reused to an extent. They can be processed and repurposed to give the plastic material a longer lifespan, but it’s not possible to convert them back to their base elements to start again.

The number of biodegradable plastics currently on the market come with the same limitations – only partially recyclable, and the process to extends their lifecycle results in unwanted byproducts. “The big drive now is to produce biorenewable and biodegradable polymers or plastics,” says Chen. “That is, however, only one part of the solution, as biodegradable polymers are not necessarily recyclable, in terms of feedstock recycling.”

That what’s so remarkable about this new type of bioplastic. Named poly(GBL), you just need heat it to between 220 and 300 degrees Celsius for an hour, and that’s all it takes to convert it back to GBL. Once back in GBL form, the polymerisation process can be begin again – under conditions of around -40 degrees Celsius, the monomer molecules react to form polymer chains or three-dimensional networks.

Chemist Eugene Chen and his team experimented with their new polymer, making different molecular shapes by changing up the catalysts – both metal-based and metal-free varieties – in the solution and elements of the production process. While scientists attempted the same thing 10 years ago, they couldn’t figure out how to convert the GBL into a polymer at anything other than crazy-high levels of pressure.

Chen and his colleagues determined that poly(GBL) is “chemically equivalent” to the commercially used biodegradable bioplastic, P4HB, but much cheaper and easier to produce because P4HB can only be derived from living bacteria. They hope poly(GBL) will end up replacing P4HB in the future, and maybe even other types of plastic, if they can figure out how to make production costs comparable.