Tag: memory

Making Long-term Memories Requires DNA Damage and Brain Inflammation

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Just as you can’t make an omelette without breaking eggs, scientists at Albert Einstein College of Medicine have found that you can’t make long-term memories without DNA damage and inflammation in the brain. Their surprising findings were published online today in the journal Nature.

“Inflammation of brain neurons is usually considered to be a bad thing, since it can lead to neurological problems such as Alzheimer’s and Parkinson’s disease,” said study leader Jelena Radulovic, MD, PhD, professor of psychiatry and behavioural sciences at Einstein. “But our findings suggest that inflammation in certain neurons in the brain’s hippocampal region is essential for making long-lasting memories.”

The hippocampus has long been known as the brain’s memory centre. Dr Radulovic and her colleagues found that a stimulus sets off a cycle of DNA damage and repair within certain hippocampal neurons that leads to stable memory assemblies, ie clusters of brain cells representing past experiences.

From shocks to stable memories

The researchers discovered this memory-forming mechanism by giving mice brief, mild shocks sufficient to form an episodic memory of the shock event. Then, they analysed neurons in the hippocampal region and found that genes participating in an important inflammatory signalling pathway had been activated.

“We observed strong activation of genes involved in the Toll-Like Receptor 9 (TLR9) pathway,” said Dr Radulovic, who is also director of the Psychiatry Research Institute at Montefiore Einstein (PRIME). “This inflammatory pathway is best known for triggering immune responses by detecting small fragments of pathogen DNA. So at first we assumed the TLR9 pathway was activated because the mice had an infection. But looking more closely, we found, to our surprise, that TLR9 was activated only in clusters of hippocampal cells that showed DNA damage.”

Brain activity routinely induces small breaks in DNA that are repaired within minutes. But in this population of hippocampal neurons, the DNA damage appeared to be more substantial and sustained.

Triggering inflammation to make memories

Further analysis showed that DNA fragments, along with other molecules resulting from the DNA damage, were released from the nucleus, after which the neurons’ TLR9 inflammatory pathway was activated; this pathway in turn stimulated DNA repair complexes to form at an unusual location: the centrosomes. These organelles are present in the cytoplasm of most animal cells and are essential for coordinating cell division. But in neurons – which don’t divide – the stimulated centrosomes participated in cycles of DNA repair that appeared to organise individual neurons into memory assemblies.

“Cell division and the immune response have been highly conserved in animal life over millions of years, enabling life to continue while providing protection from foreign pathogens,” Dr. Radulovic said. “It seems likely that over the course of evolution, hippocampal neurons have adopted this immune-based memory mechanism by combining the immune response’s DNA-sensing TLR9 pathway with a DNA repair centrosome function to form memories without progressing to cell division.”

Resisting inputs of extraneous information

During the week required to complete the inflammatory process, the mouse memory-encoding neurons were found to have changed in various ways, including becoming more resistant to new or similar environmental stimuli. “This is noteworthy,” said Dr Radulovic, “because we’re constantly flooded by information, and the neurons that encode memories need to preserve the information they’ve already acquired and not be ‘distracted’ by new inputs.”

“This is noteworthy,” said Dr Radulovic, “because we’re constantly flooded by information, and the neurons that encode memories need to preserve the information they’ve already acquired and not be ‘distracted’ by new inputs.”

Importantly, the researchers found that blocking the TLR9 inflammatory pathway in hippocampal neurons not only prevented mice from forming long-term memories but also caused profound genomic instability, ie, a high frequency of DNA damage in these neurons.

“Genomic instability is considered a hallmark of accelerated aging as well as cancer and psychiatric and neurodegenerative disorders such as Alzheimer’s,” Dr Radulovic said.

“Drugs that inhibit the TLR9 pathway have been proposed for relieving the symptoms of long COVID. But caution needs to be shown because fully inhibiting the TLR9 pathway may pose significant health risks.”

PhD Student Elizabeth Wood and Ana Cicvaric, a postdoc in the Radulovic lab, were the study’s first authors at Einstein.

Source: Albert Einstein College of Medicine

New Neural Prosthetic Device Can Help Restore Memory in Humans

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Scientists have demonstrated the first successful use of a neural prosthetic device to recall specific memories. The findings appear online in Frontiers in Computational Neuroscience.

This groundbreaking research was derived from a 2018 study led by Robert Hampson, PhD, professor of regenerative medicine, translational neuroscience and neurology at Wake Forest University School of Medicine. That study demonstrated the successful implementation of a prosthetic system that uses a person’s own memory patterns to facilitate the brain’s ability to encode and recall memory, improving recall by as much as 37%.

In the previous study, the team’s electronic prosthetic system was based on a multi-input multi-output (MIMO) nonlinear mathematical model, and the researchers influenced the firing patterns of multiple neurons in the hippocampus, a part of the brain involved in making new memories.

In this study, researchers from Wake Forest and University of Southern California (USC) built a new model of processes that assists the hippocampus in helping people remember specific information.

When the brain tries to store or recall information such as, “I turned off the stove” or “Where did I put my car keys?” groups of cells work together in neural ensembles that activate so that the information is stored or recalled.

Using recordings of the activity of these brain cells, the researchers created a memory decoding model (MDM) which let them decode what neural activity is used to store different pieces of specific information.

The neural activity decoded by the MDM was then used to create a pattern, or code, which was used to apply neurostimulation to the hippocampus when the brain was trying to store that information.

“Here, we not only highlight an innovative technique for neurostimulation to enhance memory, but we also demonstrate that stimulating memory isn’t just limited to a general approach but can also be applied to specific information that is critical to a person,” said Brent Roeder, Ph.D., a research fellow in the department of translational neuroscience at Wake Forest University School of Medicine and the study’s corresponding author.

The team enrolled 14 adults with epilepsy who were participating in a diagnostic brain-mapping procedure that used surgically implanted electrodes placed in various parts of the brain to pinpoint the origin of their seizures.

Participants underwent all surgical procedures, post-operative monitoring and neurocognitive testing at one of the three sites participating in this study including Atrium Health Wake Forest Baptist Medical Center, Keck Hospital of USC in Los Angeles and Rancho Los Amigo National Rehabilitation Center in Downey, California.

The team delivered MDM electrical stimulation during visual recognition memory tasks to see if the stimulation could help people remember images better.

They found that when they used this electrical stimulation, there were significant changes in how well people remembered things. In about 22% of cases, there was a noticeable difference in performance.

When they looked specifically at participants with impaired memory function, who were given the stimulation on both sides of their brain, almost 40% of them showed significant changes in memory performance.

“Our goal is to create an intervention that can restore memory function that’s lost because of Alzheimer’s disease, stroke or head injury,” Roeder said.

“We found the most pronounced change occurred in people who had impaired memory.”

Roeder said he hopes the technology can be refined to help people live independently by helping them recall critical information such as whether medication has been taken or whether a door is locked.

“While much more research is needed, we know that MDM-based stimulation has the potential to be used to significantly modify memory,” Roeder said.

Source: Atrium Health Wake Forest Baptist

Magnetic Stimulation may Ameliorate Memory Deficits in Schizophrenia

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Schizophrenia is often accompanied by extensive impairment of memory, including prospective memory, which is the ability to remember to perform future activities. In a randomised clinical trial published in Neuropsychopharmacology Reports, researchers found that repetitive transcranial magnetic stimulation (rTMS), a non-invasive method that uses alternating magnetic fields to induce an electric current in the underlying brain tissue, may help ameliorate certain aspects of prospective memory in individuals with schizophrenia.

The trial included 50 patients with schizophrenia and 18 healthy controls. Of the 50 patients, 26 completed active rTMS and 24 completed a sham rTMS. Healthy controls received no treatment.

Investigators assessed event-based prospective memory, which is remembering to perform an action when an external event occurs, such as remembering to give a message to a friend when you next see them and also time-based prospective memory, which is remembering to perform an action at a certain time, such as remembering to attend a scheduled meeting.

Both event-based prospective memory and time-based prospective memory scores at the baseline of the trial were significantly lower in patients with schizophrenia than in controls. After rTMS treatments, the scores of event-based prospective memories in patients were significantly improved and were similar to those in controls, while patients’ scores of time-based prospective memory did not improve.

“The findings of this study may provide one therapeutic option for prospective memory in patients with schizophrenia,” said co–corresponding author Su-Xia Li, MD, PhD, of Peking University, in China.

Source: Wiley

The Vascular System also Plays a Role in Forming Memories

Diagram of a capillary. Source: Wikimedia Commons

Research on long-term memories has largely focused on the role of neurons but in recent years, research is revealing that other cell types are also vital in memory formation and storage. A new study reveals the crucial role of vascular system cells (pericytes) in the formation of long-term memories of life events – memories that are lost in diseases such as Alzheimer’s. The research, published in the journal Neuron, shows that pericytes, which wrap around the capillaries work in concert with neurons to help ensure that long-term memories are formed.

Pericytes help maintain the structural integrity of the capillaries. Specifically, they control the amount of blood flowing in the brain and play a key role in maintaining the barrier that stops pathogens and toxic substances from leaking out of the capillaries and into brain tissue.

“We now have a firmer understanding of the cellular mechanisms that allow memories to be both formed and stored,” says Cristina Alberini, a professor in New York University’s Center for Neural Science and the paper’s senior author. “It’s important because understanding the cooperation among different cell types will help us advance therapeutics aimed at addressing memory-related afflictions.”

“This work connects important dots between the newly discovered function of pericytes in memory and previous studies showing that pericytes are either lost or malfunction in several neurodegenerative diseases, including Alzheimer’s disease and other dementia,” explains author Benjamin Bessières, a postdoctoral researcher in NYU’s Center for Neural Science.

The discovery, reported in the new Neuron article, of the pericytes’ significance in long-term memory emerged because Alberini, Bessières, Kiran Pandey, and their colleagues examined the role of insulin-like growth factor 2 (IGF2) – a protein that was known to increase following learning in brain regions, such as the hippocampus, and to play a critical role in the formation and storage of memories.

They found that IGF2’s highest levels in the brain cells of the hippocampus do not come from neurons or glial cells, or other vascular cells, but, rather, from pericytes.

Source: New York University

A Curious Mindset Helps Memory More than an Urgent One

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New research from Duke University found that shifting to a curious mindset helps memory – such as video game players who imagined being a thief scouting a virtual art museum in preparation for a heist. This mindset resulted in better recalling the paintings there. Adopting a high-pressure mindset, such as players trying to execute the heist, resulted in fewer paintings being recalled.

These subtle differences in motivation – urgent, immediate goal-seeking versus curious exploration for a future goal – have big potential for framing real-world challenges such encouraging vaccination. The findings appeared in PNAS.

Alyssa Sinclair, PhD ’23, a postdoctoral researcher working in the lab of Duke Institute for Brain Sciences director Alison Adcock, PhD, MD, recruited 420 adults to pretend to be art thieves for a day. The participants were then randomly assigned to one of two groups and received different backstories.

“For the urgent group, we told them, ‘You’re a master thief, you’re doing the heist right now. Steal as much as you can!’,” Sinclair said. “Whereas for the curious group, we told them they were a thief who’s scouting the museum to plan a future heist.”

After getting these different backstories, however, participants in the two groups played the exact same computer game, scored the exact same way. They explored an art museum with four coloured doors, representing different rooms, and clicked on a door to reveal a painting from the room and its value. Some rooms held more valuable collections of art. No matter which scenario they were pretending to be in, everyone earned real bonus money by finding more valuable paintings.

The impact of this difference in mindset was most apparent the following day. When participants logged back in, they were met with a pop quiz about whether they could recognise 175 different paintings (100 from the day before, and 75 new ones). If participants flagged a painting as familiar, they also had to recall how much it was worth.

Sinclair and her co-author, fellow Duke psychology & neuroscience graduate student Candice Yuxi Wang, were gratified after they graded the tests to see their predictions had played out.

“The curious group participants who imagined planning a heist had better memory the next day,” Sinclair said. “They correctly recognized more paintings. They remembered how much each painting was worth. And reward boosted memory, so valuable paintings were more likely to be remembered. But we didn’t see that in the urgent group participants who imagined executing the heist.”

Urgent group participants, however, had a different advantage. They were better at figuring out which doors hid more expensive pieces, and as a result snagged more high value paintings. Their stash was appraised at about $230 more than the curious participants’ collection.

The difference in strategies (curious versus urgent) and their outcomes (better memory versus higher-valued paintings) doesn’t mean one is better than the other, though.

“It’s valuable to learn which mode is adaptive in a given moment and use it strategically,” Dr Adcock said.

For example, being in an urgent, high-pressure mode might be the best option for a short-term problem.

“If you’re on a hike and there’s a bear, you don’t want to be thinking about long-term planning,” Sinclair said. “You need to focus on getting out of there right now.”

Opting for an urgent mindset might also be useful in less grisly scenarios that require short-term focus, Sinclair explained, like prompting people to get a COVID vaccine.

For encouraging long-term memory or action, stressing people out is less effective.

“Sometimes you want to motivate people to seek information and remember it in the future, which might have longer term consequences for lifestyle changes,” Sinclair said. “Maybe for that, you need to put them in a curious mode so that they can actually retain that information.”

Sinclair and Wang are now following up on these findings to see how urgency and curiosity activate different parts of the brain. Early evidence suggests that, by engaging the amygdala, an almond-shaped brain region best known for its role in fear memory, “urgent mode” helps form focused, efficient memories. Curious exploration, however, seems to shuttle the learning-enhancing neurochemical dopamine to the hippocampus, a brain region crucial for forming detailed long-term memories.

With these brain results in mind, Dr Adcock is exploring how her lab’s research might also benefit the patients she sees as a psychiatrist.

“Most of adult psychotherapy is about how we encourage flexibility, like with curious mode” Dr Adcock said. “But it’s much harder for people to do since we spend a lot of our adult lives in an urgency mode.”

These thought exercises may give people the ability to manipulate their own neurochemical spigots and develop “psychological manoeuvres,” or cues that act similar to pharmaceuticals, Dr Adcock explained.

“For me, the ultimate goal would be to teach people to do this for themselves,” Dr Adcock said. “That’s empowering.”

Source: Duke University

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

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.

Recognising a Voice is Easier with a Face

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

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

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