Category: Memory

Exercise does more than just boost mood.

Long-term memory is boosted by exercise four hours after learning, a new study finds.

Exercising directly after learning, though, provides no boost to memory whatsoever.

The study split people into three groups, all of whom learnt a series of picture-location associations.

One carried out exercise just after learning, another four hours later and the final group did no exercise.

The exercise involved 35 minutes of interval training on an exercise bike.

Two days after learning they returned to the lab to see how much they could remember — and to have their brains scanned.

It was those who had exercised four hours after learning who displayed the best recall.

In addition, brain scans revealed that exercise lead to more precise representations of memories in the hippocampus.

The authors write:

“Our results suggest that appropriately timed physical exercise can improve long-term memory and highlight the potential of exercise as an intervention in educational and clinical settings.”

The scientists are not sure yet why exercise after learning boosts memory.

However, they write:

“Considering that the exercise intervention took place after learning, delayed exercise most likely affected memory retention through an impact on memory consolidation.

[…]

…previous research suggests that exercise triggers the release of BDNF, plasticity-related products (PRPs), noradrenaline, and dopamine, among other substances that promote neural plasticity.

Such factors are critical for the consolidation of synaptic potentiation, as proposed in the synaptic tagging and capture (STC) hypothesis, and are also important for later stages of memory consolidation.

The study was published in the journal Current Biology (van Dongen et al., 2016).

Spice already linked to a variety of health benefits.

Turmeric — which is used in curries — can block fear memories after a traumatic experience, recent research finds.

Turmeric has already been linked to a variety of medicinal properties, including helping to treat stomach problems, arthritis and diabetes.

The study on rats has shown that the yellow-coloured, ginger root could have psychological benefits as well.

Professor Glenne Schafe, who led the research, said:

“We showed that rats freely fed a diet enriched with curcumin [found in turmeric] have impaired encoding of fear memories.

We also showed that rats with a pre-existing fear memory can lose that memory when it is recalled while they are eating a curcumin-enriched diet.”

Rats in the study who were fed the curcumin had their bad memories repressed for a long time.

Curcumin seemed to prevent the fearful memories being reconsolidated.

In other words: it was very hard for the fearful memories to return.

The authors write:

“Curcumin, a yellow-pigment compound found in the popular Indian spice turmeric (Curcuma longa), has been extensively investigated for its anti-inflammatory, chemopreventative and antidepressant properties.

Here, we examined the efficacy of dietary curcumin at impairing the consolidation and reconsolidation of a Pavlovian fear memory, a widely studied animal model of traumatic memory formation in post-traumatic stress disorder (PTSD).”

Rats in the study, though, were given about 1 gram of curcumin per kilogram of their body weight.

This would mean giving 68 grams to an average human — an amount that is way to high.

Unfortunately the compound is very poorly absorbed by the body and turmeric only contains about 3% curcumin.

Future research will look at ways of increasing the concentration  and absorption of the compound.

The study’s authors conclude:

“…our findings indicate that a diet enriched with curcumin is capable of impairing fear memory consolidation and reconsolidation processes, findings that may have important clinical implications for the treatment of disorders such as PTSD that are characterized by unusually strong and persistently reactivated fear memories.”

The study was published in the journal Neuropsychopharmacology (Monsey et al., 2015).

Men with schizophrenia or bipolar disorder were more likely to have a history of this infection.

Candida yeast infections are linked to serious mental health problems, new research finds.

Men with schizophrenia or bipolar disorder were more likely to have a history of infection.

Women with schizophrenia or bipolar disorder who also had a Candida infection were more likely to have poorer memory.

Dr Emily Severance, the study’s first author, said:

“It’s far too early to single out Candida infection as a cause of mental illness or vice versa.

However, most Candida infections can be treated in their early stages, and clinicians should make it a point to look out for these infections in their patients with mental illness.”

Nevertheless, the study suggests there are critical links between psychiatric disorders, memory problems and yeast infections.

Candida infections can be tackled by washing properly, lowering sugar intake and avoiding unnecessary antibiotics.

Candida albicans is a fungus which naturally occurs in the human digestive tract.

It can cause rashes as well as sexually transmittable yeast infections.

Dr Severance said:

“Although we cannot demonstrate a direct link between Candida infection and physiological brain processes, our data show that some factor associated with Candida infection, and possibly the organism itself, plays a role in affecting the memory of women with schizophrenia and bipolar disorder, and this is an avenue that needs to be further explored.

Because Candida is a natural component of the human body microbiome, yeast overgrowth or infection in the digestive tract, for example, may disrupt the gut-brain axis.

This disruption in conjunction with an abnormally functioning immune system could collectively disturb those brain processes that are important for memory.”

The study was published in the journal npj Schizophrenia (Severance et al., 2016).

Research finds the herbs that can improve mood, memory and induce calmness.

Chamomile, peppermint, rosemary and lavender can all affect mood and memory, new research finds.

Peppermint tea can improve alertness while chamomile does indeed provide a calming effect.

Smelling rosemary, meanwhile, improved the memories of people over 65 by an average of 15%.

Lavender, though, impaired their memory.

The conclusions come from a series of studies which compared memory and thinking skills before and after exposure to various  herbs.

Dr Mark Moss, one of the study’s authors, said:

“Peppermint has a reputation for being psychologically or mentally alerting.

It picks you up and makes you feel a little bit brighter, so we endeavoured to test this out by giving people peppermint tea, or chamomile tea, which is a more calming drink and then put them through some computerised tests.

We found that those people who had drunk the peppermint tea had better long-term memory.

They were able to remember more words and pictures that they had seen.

Dr Moss continued:

“In contrast, the people who had the chamomile were slower in responding to tasks.

Rosemary meanwhile has a reputation about being associated with memory – even Shakespeare said ‘rosemary is for remembrance’ – and it’s also associated with being invigorating.

We have found that people are more alert after being in a room that has rosemary aroma in it.

We tested prospective memory – our ability to remember to remember to do something – on people over 65 years of age, to see if we could improve their ability and we found that rosemary could do that.

This is potentially very important because prospective memory, for example, enables you to remember to take your medication at certain times of the day.

Dr Moss said the varied results for different herbs were interesting:

“It is interesting to see the contrasting effects that different herbs can have on both mood and memory, and our research suggests that that they could have beneficial effects, particularly in older age groups.

If you were otherwise healthy then this research suggests that there is an opportunity to have an improved memory.”

The findings were presented at the annual British Psychological Society Conference in Nottingham (26-28 April 2016).

Study tests effects of mental imagery on memory.

Mental imagery is an effective way to improve memory and reduce some false memories, new research finds.

People in the study who were told to create images for words were better able to remember them.

Images also helped people avoid false memories.

Ms Merrin Oliver, the study’s first author, said:

“Creating images improved participants’ memories and helped them commit fewer errors, regardless of what kind of list we gave them.”

False memories can be related to misremembering the source, Ms Oliver explained:

“We aren’t good at judging the source of our memories.

These lists usually remind people of a word that they didn’t actually study, so they mistakenly recollect studying words similar to those on the list.”

For the research, one group were told to use imagery to remember a list of words while the other were just told to remember the words.

Ms Oliver said:

“Our study suggests more detailed imagery instructions are necessary to help filter out false memories during a recognition test, where false memories are typically very high.

People should create detailed images with unique characteristics to help avoid the endorsement of false memories on recognition-based tests like true/false or multiple-choice assessments, where you are tempted by lures and possible false memories.”

The study was published in The Journal of General Psychology (Oliver et al., 2016).

How Memory Works: 21 Psychological Insights

Brain image from Shutterstock

Study compares writing by hand with real and virtual keyboards.

Writing by hand strengthens memory in comparison to writing on a real or virtual keyboard, new research finds.

The motor feedback from the process of writing along with the sense of touching paper and pen helps people learn.

Areas of the brain vital to language are more strongly activated by the physical activity.

The study compared 36 people writing in three different ways:

• on a conventional keyboard,
• on a virtual keyboard (like an iPad),
• or handwriting.

They were read a list of words which they wrote down.

Their memory for the words was then tested for both free recall and recognition.

The results showed that the method of writing down the words did not effect recognition, but free recall was better for handwriting.

Since it is much harder to recall a word than to recognise it, memory was stronger for handwritten words.

The authors explain the study’s results:

“…keyboard writing per se (whether on a virtual or a conventional keyboard) attenuates or disrupts memory for what is written.

However, with respect to aspects of word recall, our findings indicate that there may be certain cognitive benefits to handwriting which may not be fully retained in keyboard writing.”

The advantage of handwriting is that the attention is all on the same thing at the same time.

The study’s authors think the problem with keyboard writing could be partly down to a split in attention:

“The visual attention of keyboard writers is split between looking at the emerging text and looking at the keyboard on which they write.

From a visual-spatial perspective, a keyboard separates the “motor area” (or input area) where the letters are being produced (the keyboard) from the visual presentation area of the letters (the screen; or output area).

A keyboard thereby provides less real-time sensory and visual information about the writer’s own writing process, a fact which may result in less robust mental representations of the words.

One consequence of such a separation may be that the writer engages less with the written text and consequently is provided with an attenuated visual memory of the word, than in the handwriting condition, where the subject may fixate near the point where the physical writing takes place.”

The study was published in the Journal of Writing Research (Mangen et al., 2016).

Handwriting image from Shutterstock

The experience of distressing, intrusive memories was reduced by over a half.

Inhaling laughing gas after a traumatic event reduces the later intrusion of distressing memories, new research finds.

People who inhaled nitrous oxide experienced fewer intrusive thoughts a day later, the study found.

Dr Ravi Das, the study’s first author, explained:

“The day after they saw the film, the number of intrusions experienced by the group who received nitrous oxide fell by over a half.

By contrast, the decline in intrusions was much slower in the group who received air, where there was not a significant drop in intrusions until the fourth day.

We think that this is because nitrous oxide disrupts a process that helps permanent memories to form.”

The study involved participants watching a distressing video clip.

Afterwards, half were given air, the other half a mixture containing the laughing gas.

Dr Das said:

“On any given day your brain will be exposed to a huge amount of information, some important, but most trivial.

If information is ‘important’ enough to remember, for instance because it produces a strong emotional response, it is ‘tagged’ for storage.

The brain requires N-Methyl D-Aspartate (NMDA) receptors to tag information during the day, which is then filed for long-term storage while we sleep.

We know that nitrous oxide blocks NMDA receptors, so could interfere with tagging.

This might explain why the nitrous oxide group seemed to have weaker memories of the film the day after they watched it.”

Dr Sunjeev Kamboj, one of the study’s co-authors, said:

“Nitrous oxide is routinely used as a painkiller by paramedics and in A&E departments because it is safe and easy to administer.

Many people who end up in an ambulance will have undergone some form of psychological trauma, and our study suggests that the nitrous oxide is likely to be having some effect on how their brain processes it.

However, whether it helps to prevent symptoms of PTSD or makes them more likely may depend on how dissociated patients feel before they receive it.

Further research is now needed to determine whether dissociation similarly affects the response of trauma victims who receive nitrous oxide or other painkillers such as ketamine.

It is worth noting that our volunteers were given nitrous oxide continuously for half an hour, whereas the amount that hospital patients receive will vary significantly.

Some may only receive small doses in the ambulance whereas others could be breathing it on-and-off for hours in a hospital bed.

Any effects, positive or negative, are also likely to vary depending on the dose.

The amount of nitrous oxide used recreationally in a balloon, for example, would likely be too small to have a noticeable effect on memory formation.”

The study was published in the journal Psychological Medicine (Das et al., 2016).

Sad man image from Shutterstock