Category: Memory

We can only recall a very small proportion of the memories we make each day.

Research finds that rewarding memories are recalled preferentially because the brain replays them automatically when we are at rest. The brain prioritises rewards as they are important cues about future behaviour. Professor Charan Ranganath, one of the study’s authors, said:

“Rewards help you remember things, because you want future rewards. The brain prioritizes memories that are going to be useful for future decisions.”

In the study people looked at various pictures of objects on different backgrounds. Some were associated with a higher reward for later recall. When given a surprise memory test afterwards, people were better at remembering the objects with higher levels of reward. Dr Matthias Gruber, one of the study’s co-authors, said:

“Also, when an object was associated with high reward, people remembered better the particular background scene that was on the screen during scanning.”

The interesting finding came from a series of brain scans conducted just after people had looked at the objects, while resting. These suggested that people were replaying the high-reward memories to help mentally fix them in place. Their brains were doing this automatically, without volition, since they didn’t know a test was coming. The people who replayed the memories the most did the best on the surprise test. Professor Ranganath said:

“It speaks to a memory process that is normally hidden from us. Are you remembering what you really need to know? It could depend on what your brain does while you are at rest.”

The study was published in the journal Neuron (Gruber et al., 2016).

The unexpected way to make memories stick—without any extra effort.

Just 10 minutes sitting quietly after learning something new is enough to boost people’s memory, research finds.

Quiet resting does not just help us remember, it also increases how much detail we subsequently recall.

Dr Michael Craig, who led the study, said:

“Recent research suggests that the memory system strengthens weak new memories by ‘reactivating’ them, where brain activity first observed during learning automatically reappears in the minutes that follow.

This appears especially true during sleep and quiet resting, when we’re not busy taking in any new sensory information.

We think that quiet resting is beneficial because it is conducive to the strengthening of new memories in the brain, possibly by supporting their automatic reactivation.

However, we don’t know exactly how this rest-related memory strengthening works.

Specifically, it remained unknown whether quiet resting only allows us to retain more information, or whether it also helps us to retain more detailed memories.”

People were shown a series of photos in the study — some were exactly the same as those they had seen before, and some were similar.

Those who rested after learning for just 10 minutes were better at spotting the subtly different photos.

Dr Craig explained:

“In this memory test, peoples’ ability to discriminate between ‘old’ and ‘similar’ photos provides a measure of how detailed stored memories are.

If detailed memories are stored, people should notice subtle differences in similar photos, and correctly respond ‘similar’.

However, if not-so detailed memories are stored, people should miss the subtle differences in similar photos, and mistake them for ‘old’ photos.

Interestingly, we found that younger adults who quietly rested in the minutes that followed the photo presentation were better at noticing subtle differences in similar photos, suggesting that these individuals stored more detailed memories, compared to those who did not rest.

This new finding provide the first evidence that a brief period of quiet rest can help us to retain more detailed memories.”

The study was published in the journal Scientific Reports (Craig et al., 2018).

Higher consumption of these foods was linked to improved memory by the study.

Eating more fruits and vegetables protects against memory loss, research finds.

Fruits and vegetables also help reduce the risk of heart disease.

Higher consumption of protein-rich foods was also linked to improved memory by the study.

A previous study, though, found that it is vegetables, more so than fruits, that really help to preserve memory.

Green leafy vegetables showed the strongest association with a better memory in that study.

More than two servings of vegetables per day was linked to the slowest rates of cognitive decline in older people.

Vegetables contain high amounts of vitamin E, which lowers the risk of cognitive decline.

Green leafy vegetables are also a key component of the MIND diet, which is frequently linked to memory improvements and reducing the risk of dementia.

Two other foods in the Mediterranean diet that have been individually linked to improved memory are nuts and mushrooms.

The Western diet

Set against these beneficial foods, one of the main enemies of healthy brain aging is sugar.

Eating too much sugar is linked to brain shrinkage.

Similarly, red meats, organ meats, butter and high-fat dairy can increase Alzheimer’s risk.

Unfortunately, these last two sentences pretty much define the so-called ‘Western diet’.

In other words, what many eat in the modern Western world is bad for the memory and bad for the brain overall.

Brain benefits of cereals

The latest study included 139,096 older Australians who were tracked over almost a decade.

Along with the finding that fruits, vegetables and protein improved memory, the researchers also found that cereals may be protective for those over 80.

Dr Luna Xu, the study’s first author, said:

“Our present study implies that the healthy eating suggestions of cereals consumption in the prevention of memory loss and comorbid heart disease for older people may differ compared to other age groups.”

Memory loss is one of the most common early symptoms of dementia.

People suffering from dementia often have other conditions, said Dr Xu:

“The dietary intervention in chronic disease prevention and management, by taking into consideration the fact that older populations often simultaneously deal with multiple chronic conditions, is a real challenge.”

Diet is key to fighting these conditions, said Dr Xu:

“To achieve the best outcome for our ageing population, strong scientific evidence that supports effective dietary intervention in preventing and managing co-occurring chronic conditions, is essential.”

The study was published in the International Journal of Public Health (Xu et al., 2020).