Category: Memory

One key to learning is the exact opposite of what you’d expect.

Forgetting is a normal and necessary part of learning, a new study finds.

The instability of memory is the key to how we transfer skills and experiences to new situations, researchers have found.

Professor Edwin Robertson, from the Centre for Cognitive Neuroimaging, said:

“Our work shows that an unstable memory is a key component of the mechanism for learning transfer.

An unstable memory prevents learning from being rigidly linked to one task; instead, it allows learning to be applied flexibly.

In this study we tested the link between a memory being unstable and the transfer of learning to a different type of memory task.

We measured how learning in one task transferred to and thus improved learning in a subsequent task.

There was transfer from a motor skill to a word list task and, vice versa, from a word list to a motor skill task.

What was transferred was a high-level relationship between elements, rather than knowledge of the individual elements themselves.”

For the research, people were given the two tests 12 hours apart.

The results showed that learning between the two different tasks was only transferred when memory was unstable.

Professor Robertson said:

“Stabilised memories consistently prevented transfer to the subsequent memory task.

This suggests that the transfer of learning across diverse tasks is due to a ‘high-level representation’ that can only be formed when a memory is unstable.

Our work has identified an important function of memory instability.

An unstable memory provides a window of opportunity for communication between memories, leading to the construction of a high-level or abstract memory representation, which allows the transfer of knowledge between memory tasks.

An unstable memory is in a privileged state: only when unstable can a memory communicate with and transfer knowledge to affect the acquisition of a subsequent memory.”

The study was published in the journal Current Biology (Mosha & Robertson, 2015).

A fascinating new explanation of why our brains forget some things we’ve learned.

The brain may forget in order to save energy, a new study suggests.

So, our brains contain mechanisms that help us erase unnecessary learning.

Now scientists have uncovered how this may happen at the cellular level.

The results come from a strange finding about how we learn.

You may know the story of Pavlov’s dogs, who were taught to salivate at the ringing of a bell because they associated it with being fed.

Similarly, both humans and animals can learn to link a certain tone with a puff of air to the eyes.

This, of course, causes people to blink — it’s an automatic response.

However, you can remove the actual puff of air to the eyes and people will blink at just the sound of the tone.

They have learned to link the tone to the puff of air so they blink — even when there’s no puff.

Here’s the kink in the story, though.

When you add the puff of air back in, paradoxically people’s learning gets worse.

It’s like the extra stimulus is actually causing forgetting.

Professor Germund Hesslow, who led the new research said:

“Two stimuli therfore achieve worse results than just one.

It seems contrary to common sense, but we believe that the reason for it is that the brain wants to save energy.”

What seems to be happening is that when we’ve successfully learned a link, a neuronal braking mechanism activates.

Professor Hesslow continued:

“You could say that the part of the brain that learned the association (a part of the brain called the cerebellum) is telling its ‘teacher’: ‘I know this now, please be quiet’.

When the brain has learnt two associations, the brake becomes much more powerful.

That is why it results in forgetting, usually only temporarily, however.”

The new research describes how the nerve cells learn and forget.

Professor Hesslow said:

“Obviously, it should be important for teachers to know the mechanisms by which the brain erases the things it considers unnecessary.

You do not want to accidentally activate these mechanisms.”

The study was published in the journal PNAS (Rasmussen et al., 2015).

Confused image from Shutterstock

Even three months later those who combined both techniques had the best recall, study finds.

Rewards combined with naps can help you learn, a new study finds.

When memories are linked to rewards, researchers found they stick better in the brain.

Adding a short nap afterwards can provide an extra boost.

Dr Kinga Igloi, who led the research, said:

“Rewards may act as a kind of tag, sealing information in the brain during learning.

During sleep, that information is favourably consolidated over information associated with a low reward and is transferred to areas of the brain associated with long-term memory.

Our findings are relevant for understanding the devastating effects that lack of sleep can have on achievement.”

In the study people were given pairs of pictures to try and remember.

Some took naps after learning, while others did not.

Sometimes participants were given small rewards after learning as well.

The study revealed that people remembered the pairs of pictures better when they received a reward.

But it was the group that slept after learning that performed the best overall.

Brain scans also showed that those who slept had higher activity in the hippocampus, an area vital to forming new memories.

People were asked back into the lab three months later for a surprise test.

Even three months later the group who were rewarded and slept after learning had the best recall.

Dr Igloi said:

“We already knew that sleep helps strengthens memories, but we now also know that it helps us select and retain those that have a rewarding value.

It makes adaptive sense that the consolidation of memory should work to prioritise information that is critical to our success and survival.”

The study was published in the journal eLife (Igloi et al., 2015).

Brain image from Shutterstock

The mental health problem that affects at least one in six people in their lifetime.

People with recurrent depression have a smaller hippocampus, a new study finds.

The hippocampus is part of the brain most strongly linked to forming new memories.

The study may help to explain some of the typical, but lesser known symptoms of depression.

People experiencing depression have particular problems with declarative memory, which is the memory for specific facts like names or places.

Depression blurs other types of memory as well, including the ability to recall meanings and to navigate through space.

Precisely because of memory difficulties and depressed mood, it can be difficult for depressed people to remember the good times.

The findings about the hippocampus come from a study which looked at the brain scans of almost 9,000 people around the world.

Neuroscientists compared the brains of healthy individuals with those who have major depression.

Major depression will affect at least one in six people in their lifetime.

The condition typically returns for weeks, months or even years at a time.

A handful of the emotional symptoms include sadness, anger, frustration and loss.

There are many other less-known symptoms like sleeping problems and changes to appetite (see: 5 Classic Signs of Depression Most People Don’t Recognise).

Dr Jim Lagopoulos, one of the study’s authors, said:

“These findings shed new light on brain structures and possible mechanisms responsible for depression.

Despite intensive research aimed at identifying brain structures linked to depression in recent decades, our understanding of what causes depression is still rudimentary.

One reason for this has been the lack of sufficiently large studies, variability in the disease and treatments provided, and the complex interactions between clinical characteristics and brain structure.”

Dr Lagopoulos continued:

“This new finding of smaller hippocampal volume in people with major depression may offer some support to the neurotrophic hypothesis of depression.

This hypothesis argues that a range of neurobiological processes such as elevated glucocorticoid levels in those with chronic depression may induce brain shrinkage.

Clearly, there’s a need for longitudinal studies that can track changes in hippocampal volume among people with depression over time, to better clarify whether hippocampal abnormalities result from prolonged duration of chronic stress, or represent a vulnerability factor for depression, or both.”

• Depression: 10 Fascinating Insights into a Misunderstood Condition

The study was published in the journal Molecular Psychiatry (Schmaal et al., 2015).

Brain image from Shutterstock

These four straightforward activities have surprising mental benefits.

1. Stare at a grassy rooftop to reduce errors

Taking a 40 second break to glance at a grassy rooftop boosts concentration and reduces mental errors.

It doesn’t even need to be an actual grassy rooftop, only a picture of one.

Dr Kate Lee, of the University of Melbourne Faculty of Science, who led the study, said:

“We know that green roofs are great for the environment, but now we can say that they boost attention too.

Imagine the impact that has for thousands of employees working in nearby offices.

This study showed us that looking at an image of nature for less than a minute was all it took to help people perform better on our task.”

This study is a neat twist on the well-known benefits of a micro-break.

It nicely illustrates the fact that a little break from work shouldn’t just be checking your email or looking at your screensaver…

…unless the screensaver is a grassy rooftop of course.

2. Chew gum to get rid of an earworm

Got a song stuck in your head that just won’t go away?

No problem, chew some gum.

Amazingly earworms can be countered by chewing gum, a recent study has found.

This is because, the study’s authors write:

“…an articulatory motor activity—in this case, chewing gum—interferes with the experience of “hearing” musical recollections both voluntarily, or at any rate without any specific instruction to suppression the recollection…”

In other words: chewing is like talking, which is like singing, so somehow messes up the recall of the song.

3. Eat chocolate to boost attention

I could remind you that going for a run boosts attention, but lets forget about that for a moment…

…because eating chocolate can do the job.

Actually it does need to be dark chocolate and it will increase your blood pressure, so the news isn’t all good.

Professor Larry Stevens, who conducted the study, said:

“A lot of us in the afternoon get a little fuzzy and can’t pay attention, particularly students, so we could have a higher cacao content chocolate bar and it would increase attention.”

Well, alright, if you absolutely insist Professor.

4. Climb a tree for better memory

It may feel like your brain is slowing down with age, but that’s not it.

In fact, psychologists have discovered, adults don’t climb enough trees.

Climbing a tree can actually improve working memory by 50%, a new study has found.

The same is true of other dynamic activities like balancing on a beam, carrying awkward weights and navigating around obstacles.

It seems to be because it forces working memory to work harder.

(Perhaps it’s trying to remember not to fall out of the tree.)

Dr Ross Alloway, the study’s first author, said:

“This research suggests that by doing activities that make us think, we can exercise our brains as well as our bodies.

This research has wide-ranging implications for everyone from kids to adults.

By taking a break to do activities that are unpredictable and require us to consciously adapt our movements, we can boost our working memory to perform better in the classroom and the boardroom.”

Mind hack image from Shutterstock

How fear-related memories can be buried in the unconscious — and then retrieved.

Hidden memories could be accessed if the brain is returned to the same state, a new study finds.

Scientists have found that mice can ‘forget’ a traumatic experience under certain circumstances.

But, when their brains are returned to the original state, they remember the traumatic experience.

The research could have implications for the treatment of people who may have repressed traumatic memories.

Professor Jelena Radulovic, one of the study’s authors, said:

“The findings show there are multiple pathways to storage of fear-inducing memories, and we identified an important one for fear-related memories.

This could eventually lead to new treatments for patients with psychiatric disorders for whom conscious access to their traumatic memories is needed if they are to recover.”

The scientists put the mice into a different state by giving them a drug which affects neurotransmitters.

Professor Radulovic explained:

“The brain functions in different states, much like a radio operates at AM and FM frequency bands.

It’s as if the brain is normally tuned to FM stations to access memories, but needs to be tuned to AM stations to access subconscious memories.

If a traumatic event occurs when these extra-synaptic GABA receptors are activated, the memory of this event cannot be accessed unless these receptors are activated once again, essentially tuning the brain into the AM stations.”

The mice were given electric shocks in a box while in this altered state.

After their neurotransmitters returned to normal, though, they showed no memory of this fearful experience.

However, when given the drug again, the mice froze in the box.

Professor Radulovic said:

“This establishes when the mice were returned to the same brain state created by the drug, they remembered the stressful experience of the shock.”

Some memories may be hidden due to the way they are stored.

Normally, memories are stored across the brain in a distributed network.

The drug, though, causes the memories to be stored mainly in subcortical regions.

The study was published in the journal Nature Neuroscience (Jovasevic et al., 2015).

Brain illustration image from Shutterstock