Tag: memory

Categories : Neurology PaediatricsTags :

Children with Autism Have Memory Impairments, Study Finds

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Children with autism have memory challenges that hinder not only their memory for faces but also their ability to remember other kinds of information, according to new research. These impairments are reflected in distinct connection patterns children’s brains, the study found.

Published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, the study findings clarify a debate about memory function in children with autism, showing that their memory struggles surpass their ability to form social memories. The finding should prompt broader thinking about autism in children and about treatment of the developmental disorder, according to the scientists who conducted the study.

“Many high-functioning kids with autism go to mainstream schools and receive the same instruction as other kids,” said lead author Jin Liu, PhD at Stanford University. Memory is a key predictor of academic success, said Liu, adding that memory challenges may academically disadvantage children with autism.

The study’s findings also raise a philosophical debate about the neural origins of autism, the researchers said. Social challenges are recognised as a core feature of autism, but it’s possible that memory impairments might significantly contribute to the ability to engage socially.

“Social cognition can not occur without reliable memory,” said senior author Vinod Menon, PhD.

“Social behaviours are complex, and they involve multiple brain processes, including associating faces and voices to particular contexts, which require robust episodic memory,” Menon said. “Impairments in forming these associative memory traces could form one of the foundational elements in autism.”

Comprehensive memory tests

Affecting about one in every 36 children, autism is characterised by social impairments and restricted, repetitive behaviours. The condition exists on a wide spectrum, with those on one end having severe intellectual disability and about a third of people with autism have intellectual impairments. On the other end of the spectrum, many people with high-functioning autism have normal or high IQ, complete higher education and work in a variety of fields.

Children with autism are known to have difficulty remembering faces. Some small studies have also suggested that children with autism have broader memory difficulties. They included children with wide ranges of age and IQ, both of which influence memory.

To clarify the impact of autism on memory, the new study included 25 children with high-functioning autism and normal IQ who were 8 to 12 years old, and a control group of 29 typically developing children with similar ages and IQs.

All participants completed a comprehensive evaluation of their memory skills, including their ability to remember faces; written material; and non-social photographs, or photos without any people. The scientists tested participants’ ability to accurately recognise information (identifying whether they had seen an image or heard a word before) and recall it (describing or reproducing details of information they had seen or heard before). The researchers tested participants’ memory after delays of varying lengths. All participants also received fMRI scans of their brains to evaluate how memory-associated regions are connected to each other.

Distinct brain networks drive memory challenges

In line with prior research, children with autism had more difficulty remembering faces than typically developing children, the study found.

The research showed they also struggled to recall non-social information. On tests about sentences they read and non-social photos they viewed, their scores for immediate and delayed verbal recall, immediate visual recall and delayed verbal recognition were lower.

“We thought that behavioural differences might be weak because the study participants with autism had fairly high IQ, comparable to typically developing participants, but we still observed very obvious general memory impairments in this group,” Liu said.

Among typically developing children, memory skills were consistent: If a child had good memory for faces, he or she was also good at remembering non-social information.

This wasn’t the case in autism. “Among children with autism, some kids seem to have both impairments and some have more severe impairment in one area of memory or the other,” Liu said.  

“It was a surprising finding that these two dimensions of memory are both dysfunctional, in ways that seem to be unrelated – and that maps onto our analysis of the brain circuitry,” Menon said.

The brain scans showed that, among the children with autism, distinct brain networks drive different types of memory difficulty.

For children with autism, the ability to retain non-social memories was predicted by connections in a network centred on the hippocampus. But face memory was predicted by a separate set of connections centred on the posterior cingulate cortex, a key region of the brain’s default mode network, which has roles in social cognition and distinguishing oneself from other people.

“The findings suggest that general and face-memory challenges have two underlying sources in the brain which contribute to a broader profile of memory impairments in autism,” Menon said.

In both networks, the brains of children with autism showed over-connected circuits relative to typically developing children. Over-connectivity, likely from insufficient selective pruning of neural circuits, has been found in other studies of brain networks in children with autism.

New autism therapies should account for the breadth of memory difficulties the research uncovered, as well as how these challenges affect social skills, Menon said. “This is important for functioning in the real world and for academic settings.”

Source: Stanford University Medical Center

Categories : Mental Health NeurologyTags :

Why do People Remember Emotional Events Better?

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Most people remember emotional events, like their wedding day, very clearly, but researchers are not sure how the human brain prioritises emotional events in memory. In a study published in Nature Human Behaviour, Joshua Jacobs, associate professor of biomedical engineering at Columbia Engineering, and his team identified a specific neural mechanism in the human brain that tags information with emotional associations for enhanced memory.

The team demonstrated that high-frequency brain waves in the amygdala, a hub for emotional processes, and the hippocampus, a hub for memory processes, are critical to enhancing memory for emotional stimuli. Disruptions to this neural mechanism, brought on either by electrical brain stimulation or depression, impair memory specifically for emotional stimuli.

Rising prevalence of memory disorders

The rising prevalence of memory disorders such as dementia has highlighted the damaging effects that memory loss has on individuals and society. Disorders such as depression, anxiety, and post-traumatic stress disorder (PTSD) can also feature imbalanced memory processes, especially with the COVID pandemic. Understanding how the brain naturally regulates what information gets prioritised for storage and what fades away could provide critical insight for developing new therapeutic approaches to strengthening memory for those at risk of memory loss, or for normalising memory processes in those at risk of dysregulation.

“It’s easier to remember emotional events, like the birth of your child, than other events from around the same time,” says Salman E. Qasim, lead author of the study, who started this project during his PhD in Jacobs’ lab at Columbia Engineering. “The brain clearly has a natural mechanism for strengthening certain memories, and we wanted to identify it.”

The difficulty of studying neural mechanisms in humans

Most investigations into neural mechanisms take place in animals such as rats, because such studies require direct access to the brain to record brain activity and perform experiments that demonstrate causality, such as careful disruption of neural circuits. But it is difficult to observe or characterise a complex cognitive phenomenon like emotional memory enhancement in animal studies.

To study this process directly in humans. Qasim and Jacobs analysed data from memory experiments conducted with epilepsy patients undergoing direct, intracranial brain recording for seizure localisation and treatment. During these recordings, epilepsy patients memorised lists of words while the electrodes placed in their hippocampus and amygdala recorded the brain’s electrical activity.

Studying brain-wave patterns of emotional words

Qasim found that participants remembered more emotionally rated words, such as “dog” or “knife,” better than more neutral words, such as “chair.” Whenever participants successfully remembered emotional words, high-frequency neural activity (30-128 Hz) would become more prevalent in the amygdala-hippocampal circuit, a pattern which was absent when participants remembered more neutral words, or failed to remember a word altogether. Analysing 147 participant, they found a clear link between participants’ enhanced memory for emotional words and the prevalence in their brains of high-frequency brain waves across the amygdala-hippocampal circuit.

“Finding this pattern of brain activity linking emotions and memory was very exciting to us, because prior research has shown how important high-frequency activity in the hippocampus is to non-emotional memory,” said Jacobs. “It immediately cued us to think about the more general, causal implications – if we elicit high-frequency activity in this circuit, using therapeutic interventions, will we be able to strengthen memories at will?”

Electrical stimulation disrupts memory for emotional words

In order to establish whether this high-frequency activity actually reflected a causal mechanism, Jacobs and his team formulated a unique approach to replicate the kind of experimental disruptions typically reserved for animal research. First, they analysed a subset of these patients who had performed the memory task while direct electrical stimulation was applied to the hippocampus for half of the words that participants had to memorise. They found that electrical stimulation, which has a mixed history of either benefiting or diminishing memory depending on its usage, clearly and consistently impaired memory specifically for emotional words.

Uma Mohan, another PhD student in Jacobs’ lab at the time and co-author on the paper, noted that this stimulation also diminished high-frequency activity in the hippocampus. This provided causal evidence that, by knocking out the brain activity pattern correlating with emotional memory, stimulation was also selectively diminishing emotional memory.

Depression acts similarly to brain stimulation

Qasim further hypothesized that depression, which can involve dysregulated emotional memory, might act similarly to brain stimulation. He analyzed patients’ emotional memory in parallel with mood assessments the patients took to characterize their psychiatric state. And, in fact, in the subset of patients with depression, the team observed a concurrent decrease in emotion-mediated memory and high-frequency activity in the hippocampus and amygdala.

“By combining stimulation, recording, and psychometric assessment, they were able to demonstrate causality to a degree that you don’t always see in studies with human brain recordings,” said Bradley Lega, a neurosurgeon and scientist at the University of Texas Southwestern Medical Center and not an author on the paper. “We know high-frequency activity is associated with neuronal firing, so these findings open new avenues of research in humans and animals about how certain stimuli engage neurons in memory circuits.”

Next steps

Qasim is now investigating how individual neurons in the human brain fire during emotional memory processes. Qasim and Jacobs hope that their work might also inspire animal research exploring how this high-frequency activity is linked to norepinephrine, a neurotransmitter linked to attentional processes that they theorise might be behind the enhanced memory for emotional stimuli. They also hope that future research will target high-frequency activity in the amygdala-hippocampal circuit to protect memory.

“Our emotional memories are one of the most critical aspects of the human experience, informing everything from our decisions to our entire personality,” Qasim added. “Any steps we can take to mitigate their loss in memory disorders or prevent their hijacking in psychiatric disorders is hugely exciting.”

Source: Columbia University School of Engineering and Applied Science.

Categories : NeurologyTags :

Recognising a Voice is Easier with a Face

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To recognise a famous voice, human brains use the same centre that is activated when the speaker’s face is presented, according to the results of an innovative neuroscience study which asked participants to identify US presidents.

The new study, published in the Journal of Neurophysiology, suggests that voice and face recognition are linked even more intimately than previously thought. It offers an intriguing possibility that visual and auditory information relevant to identifying someone feeds into a common brain centre, allowing for more robust, well-rounded recognition by integrating separate modes of sensation.

“From behavioural research, we know that people can identify a familiar voice faster and more accurately when they can associate it with the speaker’s face, but we never had a good explanation of why that happens,” said senior author Taylor Abel, MD, associate professor of neurological surgery at the University of Pittsburgh School of Medicine. “In the visual cortex, specifically in the part that typically processes faces, we also see electrical activity in response to famous people’s voices, highlighting how deeply the two systems are interlinked.”

Even though the interplay between the auditory and the visual brain processing systems has been widely acknowledged and investigated by various teams of neuroscientists all over the world, those systems were traditionally thought to be structurally and spatially distinct.

Few studies have attempted to directly measure activity from the brain centre – which primarily consolidates and processes visual information – to determine whether this centre is also engaged when participants are exposed to famous voice stimuli.

Researchers recruited epilepsy patients who had been implanted with electrodes measuring brain activity to determine the source of their seizures.

Abel and his team showed five participants photographs of three US presidents – Bill Clinton, George W. Bush and Barack Obama – or played short recordings of their voices, and asked participants to identify them.

Recordings of the electrical activity from the region of the brain responsible for processing visual cues (the fusiform gyri) showed that the same region became active when participants heard familiar voices, though that response was lower in magnitude and slightly delayed.

“This is important because it shows that auditory and visual areas interact very early when we identify people, and that they don’t work in isolation,” said Abel. “In addition to enriching our understanding of the basic functioning of the brain, our study explains the mechanisms behind disorders where voice or face recognition is compromised, such as in some dementias or related disorders.”

Source: University of Pittsburgh

Categories : NeurologyTags :

Improving Short Term Memory Problems – with Laser Light

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UK and Chinese scientists have demonstrated that laser light therapy is effective in improving short term memory in a study published in Science Advances. The innovative, non-invasive therapy could improve short term, or working memory in people by up to 25%.

The treatment, termed transcranial photobiomodulation (tPBM), is applied to the right prefrontal cortex, an area important for working memory. In their experiment, the team showed how working memory improved among research participants after several minutes of treatment. They were also able to track the changes in brain activity using electroencephalogram (EEG) monitoring during treatment and testing.

Previous studies have shown that laser light treatment will improve working memory in mice, and human studies have shown tPBM treatment can improve accuracy, speed up reaction time and improve high-order functions such as attention and emotion. This is the first study, however, to confirm a link between tPBM and working memory in humans.

Co-author Dongwei Li, a visiting PhD student, said, “People with conditions like ADHD (attention deficit hyperactivity disorder) or other attention-related conditions could benefit from this type of treatment, which is safe, simple and non-invasive, with no side-effects.”

In the study researchers at Beijing Normal University carried out experiments with 90 male and female participants aged between 18 and 25. Participants were treated with laser light to the right prefrontal cortex at wavelengths of 1064 nm, while others were treated at a shorter wavelength, or treatment was delivered to the left prefrontal cortex. Each participant was also treated with a sham, or inactive, tPBM to rule out the placebo effect.

After tPBM treatment over 12 minutes, the participants were asked to remember the orientations or colour of a set of items displayed on a screen. The participants treated with laser light to the right prefrontal cortex at 1064 nm showed clear improvements in memory over those who had received the other treatments. While participants receiving other treatment variations were about to remember between three and four of the test objects, those with the targeted treatment were able to recall between four and five objects.

Data, including from electroencephalogram (EEG) monitoring during the experiment was analysed at the University of Birmingham and showed changes in brain activity that also predicted the improvements in memory performance.

The researchers do not yet know precisely why the treatment results in positive effects on working memory, nor how long the effects will last. Further research is planned to investigate these aspects.

Professor Ole Jensen, also at the Center for Human Brain Health, said, “We need further research to understand exactly why the tPBM is having this positive effect, but it’s possible that the light is stimulating the astrocytes –the powerplants – in the nerve cells within the prefrontal cortex, and this has a positive effect on the cells’ efficiency. We will also be investigating how long the effects might last. Clearly if these experiments are to lead to a clinical intervention, we will need to see long-lasting benefits.”

Source: University of Birmingham

Categories : NeurologyTags :

Smartphone Use may Help with Memory Skills

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Instead of causing people to become lazy or forgetful, the use of smartphones and other digital devices could help improve memory skills, report the authors of a new study published in Journal of Experimental Psychology: General.

The research, showed that digital devices serve to aid people storing and recalling crucial information. This, in turn, frees up their memory to remember additional, less important, things.

Neuroscientists have previously expressed concerns that the overuse of technology could result in the breakdown of cognitive abilities and cause ‘digital dementia’.

The findings show that, on the contrary, using a digital device as external memory not only helps people to remember the information saved into the device, but it also helps them to remember unsaved information too.

To demonstrate this, researchers developed a memory task to be played on a touchscreen digital tablet or computer. The test was undertaken by 158 volunteers aged between 18 and 71.

Participants were shown up to 12 numbered circles on the screen, and had to remember to drag some of these to the left and some to the right. The number of circles that they remembered to drag to the correct side determined their pay at the end of the experiment. One side was designated “high value,” meaning that remembering to drag a circle to this side was worth 10 times as much money as remembering to drag a circle to the other “low value” side.

Participants performed this task 16 times. They had to use their own memory to remember on half of the trials and they were allowed to set reminders on the digital device for the other half.

The results found that participants tended to use the digital devices to store the details of the high-value circles. And, when they did so, their memory for those circles was improved by 18%. Their memory for low-value circles was also improved by 27%, even in people who had never set any reminders for low-value circles.

However, results also showed a potential cost to using reminders. When they were taken away, the participants remembered the low-value circles better than the high-value ones, showing that they had entrusted the high-value circles to their devices and then forgotten about them.

Senior author Dr Sam Gilbert said, “We wanted to explore how storing information in a digital device could influence memory abilities.

“We found that when people were allowed to use an external memory, the device helped them to remember the information they had saved into it. This was hardly surprising, but we also found that the device improved people’s memory for unsaved information as well.

“This was because using the device shifted the way that people used their memory to store high-importance versus low-importance information. When people had to remember by themselves, they used their memory capacity to remember the most important information. But when they could use the device, they saved high-importance information into the device and used their own memory for less important information instead.

“The results show that external memory tools work. Far from causing ‘digital dementia,’ using an external memory device can even improve our memory for information that we never saved. But we need to be careful that we back up the most important information. Otherwise, if a memory tool fails, we could be left with nothing but lower-importance information in our own memory.”

Source: University College London

Categories : NeurologyTags :

Newly Discovered Neuron Type may Help Explain Memory Formation

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A healthy neuron.
A healthy neuron. Credit: NIH

Scientists publishing in Neuron have described how a newly discovered neuron type may be involved with the formation of memory in the hippocampus, which is marked by high-frequency electrical events.

It is known that memory is represented by changes in the hippocampus. One of the well-established changes in the hippocampus that has been associated with memory is the presence of so-called sharp wave ripples (SWR). These are brief, high-frequency electrical events generated in the hippocampus, and they are believed to represent a major event occurring in the brain in the so-called episodic memory, such as recalling a life event or a friend’s phone number.

However, what happens in the hippocampus when SRWs are generated has not been well understood.

Now a new study sheds light on the existence of a neuron type in the mouse hippocampus that might be a key to better understanding of episodic memory.

Professor Marco Capogna and Assistant professor Wen-Hsien Hou have contributed to the discovery of the novel neuron that is associated with sharp wave ripples and memory.

Possible disruption in dementia and Alzheimer’s

The study describes the novel neuron type in the hippocampus.

“We have found that this new type of neuron is maximally active during SWRs when the animal is awake – but quiet – or deeply asleep. In contrast, the neuron is not active at all when there is a slow, synchronized neuronal population activity called “theta” that can occur when an animal is awake and moves or in a particular type of sleep when we usually dream,” Prof Capogna said.

Because of this dichotomic activity, this novel type of neuron is named theta off-ripples on (TORO).

“How come, TORO-neurons are so sensitive to SWRs? The paper tries to answer this question by describing the functional connectivity of TORO-neurons with other neurons and brain areas, an approach called circuit mapping. We find that TOROs are activated by other types of neurons in the hippocampus, namely CA3 pyramidal-neurons and are inhibited by inputs coming from other brain areas, such as the septum,” Prof Capogna explained.

“Furthermore, the study finds that TOROs are inhibitory neurons that release the neurotransmitter GABA. They send their output locally – as most GABAergic neurons do – within the hippocampus, but also project and inhibit other brain areas outside the hippocampus, such as the septum and the cortex. In this way, TORO-neurons propagate the SWR information broadly in the brain and signal that a memory event occurred,” he concluded.

The team has monitored the activity of the neuron by using electrophysiology – a technique that detects activity of the neurons by measuring voltage versus time, and by using imaging that detects activity by measuring changes in calcium signalling inside the neurons.

Demonstrating a causal link between the activity of TORO-nerve cells and memory will be the next step, and exploring whether inhibition of TORO-neurons and sharp wave ripples occurs in dementia and Alzheimer’s diseases. 

Source: Aarhus University

Categories : NeurologyTags :

An Anti-HIV Drug for Memory Recall in Older Adults?

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Old man
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The human brain usually stores memories in groups so that the recollection of one significant memory triggers the recall of others connected by time. With ageing, the brain gradually loses this ability to link related memories.

Now, researchers have discovered a key molecular mechanism behind this memory linking, and also identified a way to restore this brain function in middle-aged mice. They also found an anti-HIV drug that can do this.

Published in Nature, the findings suggest a new method for strengthening human memory in middle age and a possible early intervention for dementia.

“Our memories are a huge part of who we are,” explained Professor Alcino Silva. “The ability to link related experiences teaches how to stay safe and operate successfully in the world.”

The team from UCLA focused on a gene called CCR5 that encodes the CCR5 receptor – the same one that HIV hitches a ride on to infect brain cells, resulting in memory loss in AIDS patients.

In previous work, Prof Silva’s lab showed that CCR5 expression reduced memory recall.

In the current study, Prof Silva and his colleagues discovered a central mechanism underlying mice’s ability to link their memories of two different cages. Using a tiny microscope, the researchers observed neurons firing and creating new memories in the brains of the mice.

They found that boosting CCR5 gene expression in the brains of middle-aged mice interfered with memory linking, with animals forgetting the connection between the two cages.

Mice with the CCR5 gene knocked out were able to link memories that normal mice could not.

Proof Silva had previously studied the anti-HIV drug maraviroc, which inhibits the entry of HIV into human cells. His lab discovered that maraviroc also suppressed CCR5 in the brains of mice.

“When we gave maraviroc to older mice, the drug duplicated the effect of genetically deleting CCR5 from their DNA,” said Prof Silva. “The older animals were able to link memories again.”

The finding suggests that maraviroc could be used off-label to help restore middle-aged memory loss, as well as reverse the cognitive deficits caused by HIV infection.

“Our next step will be to organise a clinical trial to test maraviroc’s influence on early memory loss with the goal of early intervention,” said Prof Silva. “Once we fully understand how memory declines, we possess the potential to slow down the process.”

All of this raises a question: what’s the purpose of a gene that interferes with the brain’s ability to link memories?

“Life would be impossible if we remembered everything,” said Prof Silva. “We suspect that CCR5 enables the brain to connect meaningful experiences by filtering out less significant details.”

Source: University of California – Los Angeles Health Sciences

Categories : Neurodegenerative DiseasesTags :

An AI ‘Storytelling’ Companion to Assist Dementia Patients

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Researchers at the National Robotarium in the UK, are developing an artificial intelligence (AI) ‘storytelling’ companion that will aid memory recollection, boost confidence and combat depression in patients suffering from Alzheimer’s disease and other types of dementia.

The idea for the ground-breaking ‘Agent-based Memory Prosthesis to Encourage Reminiscing’ (AMPER) project came from Dr Mei Yii Lim, a co-investigator of the project and an experienced memory modelling researcher.

In Alzheimer’s patients, memory loss occurs in reverse chronological order, with pockets of long-term memory remaining accessible even as the disease progresses. Rehabilitative care methods currently focus on physical aids and repetitive reminding techniques, but AMPER’s AI-driven user-centred approach will instead focus on personalised storytelling to help bring a patient’s memories back to the surface.

Dr Lim explained the project: “AMPER will explore the potential for AI to help access an individual’s personal memories residing in the still viable regions of the brain by creating natural, relatable stories. These will be tailored to their unique life experiences, age, social context and changing needs to encourage reminiscing.”

Having communication difficulties and decreased confidence are commonly experienced by people living with dementia and can often lead to individuals becoming withdrawn or depressed. By using AI to aid memory recollection, researchers at the National Robotarium hope that an individual’s sense of value, importance and belonging can be restored and quality of life improved.

The project’s long-term vision is to show that AI companions can become more widely used and integrated into domestic, educational, health and assistive-needs settings.

Professor Ruth Aylett from the National Robotarium is leading the research. She said: “One of the most difficult aspects of living with dementia can be changes in behavior caused by confusion or distress. We know that people can experience very different symptoms that require a range of support responses. Current intervention platforms used to aid memory recollection often take a one-size-fits-all approach that isn’t always suitable to an individual’s unique needs.”

“AI technology has the potential to play a pivotal role in improving the lives of people living with cognitive diseases. Our ambition is to develop an AI-driven companion that offers patients and their caregivers a flexible solution to help give an individual a sustained sense of self-worth, social acceptance and independence.

“Through projects like AMPER, we’re able to highlight the many ways AI and robotics can both help and improve life for people now and in the future. At the National Robotarium, we’re working on research that will benefit people in adult care settings as well as across a wide range of other sectors that will make life easier, safer and more supported for people.”

Once developed, the AI technology will be accessed through a tablet-based interface to make it more widely accessible and low-cost. The National Robotarium team will also investigate a using the AI in a desktop robot to see if a physical presence has any benefit.

Source: Heriot Watt University

Categories : NeurologyTags :

Prompts During Sleep Boosts Recall of Names and Faces

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Hearing names repeated during deep sleep may help bolster recall of names and faces, according to new research from Northwestern University.

The researchers found that people’s name recall improved significantly when memories of newly learned face-name associations were reactivated while they were napping. Uninterrupted deep sleep was key in this improvement.

“It’s a new and exciting finding about sleep, because it tells us that the way information is reactivated during sleep to improve memory storage is linked with high-quality sleep,” said lead author Nathan Whitmore, a PhD candidate in the Interdepartmental Neuroscience Program at Northwestern University.

The research is reported in the Nature partner journal npj Science of Learning.

The three main stages of the experiment of Whitmore et al. (2022). First, participants learned 80 face-name associations. Next, they slept while EEG was monitored to determine sleep stage, and 20 of the spoken names were presented softly over background music during slow-wave sleep. Finally, memory testing showed superior memory due to memory reactivation during sleep, but only when sleep was undisturbed by sound presentations. Credit: Nathan Whitmore, a Ph.D. candidate in the Interdepartmental Neuroscience Program at Northwestern University.

The results also highlighted the importance of adequate sleep: for study participants with EEG measurements that indicated disrupted sleep, the memory reactivation had no effect and may even be detrimental. But in those with uninterrupted sleep during the specific times of sound presentations, the reactivation helped participants recall just over 1.5 more names.

The study recruited 24 participants, aged 18-31 years old, who were asked to memorise the faces and names of 40 pupils from a hypothetical Latin American history class and another 40 from a Japanese history class. When each face was presented again, they were asked to recall the associated name. After the learning exercise, participants took a nap while the researchers carefully monitored brain activity using EEG measurements. When participants reached the N3 “deep sleep” state, some of the names were softly played on a speaker with music that was associated with one of the classes.

When participants awoke, they were again tested on recognising faces and recalling their names.

According to the researchers, the finding on the relationship between sleep disruption and memory accuracy is noteworthy for several reasons.

“We already know that some sleep disorders like apnoea can impair memory,” said Whitmore. “Our research suggests a potential explanation for this—frequent sleep interruptions at night might be degrading memory.”

The lab is currently exploring the reactivation of memories and deliberately disrupting sleep in order to learn more about the relevant brain mechanisms.

Source: EurekAlert!

Categories : PaediatricsTags :

Earliest Childhood Memories Date Back to Two and a Half

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People’s earliest childhood memories they can recall are on average from just two-and-a-half years old, according to a new study published in the journal Memory.

It was previously held that the earliest memories are from three-and-a-half years old. Research on earliest memories dates back to the late 1800s, when it was first noted that most adults lack memories from the first 3 to 4 years of their lives, a phenomenon later termed infantile or childhood amnesia.

The evidence for the lower age of earliest memories is presented in a new 21-year study, which followed on from a review of already-existing data.

“When one’s earliest memory occurs, it is a moving target rather than being a single static memory,” explained lead author Dr Carole Peterson, a childhood amnesia expert from Memorial University of Newfoundland.

“Thus, what many people provide when asked for their earliest memory is not a boundary or watershed beginning, before which there are no memories. Rather, there seems to be a pool of potential memories from which both adults and children sample.

“And, we believe people remember a lot from age two that they don’t realise they do.

“That’s for two reasons. First, it’s very easy to get people to remember earlier memories simply by asking them what their earliest memory is, and then asking them for a few more. Then they start recalling even earlier memories – sometimes up to a full year earlier. It’s like priming a pump; once you get them started its self-prompting.

“Secondly, we’ve documented those early memories are systematically misdated. Over and over again we find people think they were older than they actually were in their early memories.”

Dr Peterson has conducted studies on memory for over two decades, focusing on the ability of children and adults to recall their earliest years.

This latest study reviewed 10 of her research articles on childhood amnesia followed by analyses of both published and unpublished data collected in Dr Peterson’s laboratory since 1999. This comprised 992 participants, and memories of 697 participants were then compared to the recollections of their parents.

The finding shows that children’s earliest memories date from before when they think it happened, backed up by their parents.

‘Telescoping’ memories

The evidence from this research to move our potential memory clock is “compelling”. For example, when reviewing a study which interviewed children after two and eight years had passed since their earliest memory they were able to recall the same memory, however in the subsequent interviews reported a later age as to when they occurred.

“Eight years later many believed they were a full year older. So, the children, as they age, keep moving how old they thought they were at the time of those early memories,” explained Dr Peterson, from the Department of Psychology at Memorial University.

The finding is due to something in memory dating called ‘telescoping’, she believes.

“When you look at things that happened long ago, it’s like looking through a lens.

“The more remote a memory is, the telescoping effect makes you see it as closer. It turns out they move their earliest memory forward a year to about three and a half years of age. But we found that when the child or adult is remembering events from age four and up, this doesn’t happen.”

She says, after combing through all of the data, it clearly shows that people recall much more of their early childhood, a lot farther back, than they think they do, and helping to access those memories is fairly simple.

“When you look at one study, sometimes things don’t become clear, but when you start putting together study after study and they all come up with the same conclusions, it becomes pretty convincing.”

This lack of clarity is a limitation of her research, she acknowledges, one which is also common to all research done to-date in the subject area.

“What is needed now in childhood amnesia research are independently confirmed or documented external dates against which personally derived dates can be compared, as this would prevent telescoping errors and potential dating errors by parents,” Dr Peterson said.

She is currently doing research on this with verified dating, both in her laboratory and elsewhere to further confirm the answer to this long-debated question.

Source: Taylor & Francis Group

Journal information: Peterson, C., (2021) What is your earliest memory? It depends. Memory. doi.org/10.1080/09658211.2021.1918174.