Wednesday, April 26, 2017

How the brain predicts speech: Key region found that could help create accurate mind-reading devices

  • Researchers found a brain region involved in identifying sounds
  • It is used to predict upcoming words during conversation
  • The region is blocked in people with disorders such as dyslexia and ADHD
  • Study authors say that companies like Google and Facebook could one day use the region to  predict user behaviour
Scientists have discovered how the brain helps us to predict what is coming next in speech. The researchers say they have found a key part of the brain involved in identifying sounds that is used to predict upcoming words during conversation 

Scientists have discovered how the brain helps us to predict what is coming next in speech.

The researchers say they have found a key part of the brain involved in identifying sounds that is used to predict upcoming words during conversation.

And companies like Google and Facebook could one day use the technology to create devices that read users' minds, one researcher suggests.

'Google and Facebook are really interested in how your brain makes predictions and learns because they want to use brain signals to control phones or to improve predictions in their software,' study lead author Professor Chris Petkov, a neuropsychologist at Newcastle University, told MailOnline.

'They want to know how they can predict what people do, and how they can then change devices to reflect this. 'Our work shows how this happens in the brain: Neurons make predictions at specific points in time and adjust those predictions when a prediction mistake happens.'

The researchers say that the area they have identified is found within the brain's 'auditory cortex', a region unchanged by evolution for millions of years.

It is inhibited in people with disorders such as dyslexia, schizophrenia and Attention Deficit Hyperactivity Disorder (ADHD). The finding could one day lead to a better understanding and treatment of these conditions, the researchers claim. 'There are groups around the world who could use these findings to see how the brain makes predictions and also how it responds when it is wrong,' Professor Petkov told MailOnline.

'Ultimately we do want to help people who struggle to make predictions, such as those with dyslexia or ADHD, to better make those predictions.

'In some cases we will be at the stage where we can help the brain to recover from these conditions.'

Using an approach developed for studying language learning in children, Professor Petkov and his team had humans and monkeys decode a made-up language.

The groups were played a sequence of sounds or short sentences of words spoken in the language, which has properties and rules that subjects could follow.

The team made their finding by having humans and monkeys decode a made-up language. This image shows the artificial grammar rules of the fake language and the phase-amplitude coupling seen by the team in the human 'auditory cortex' - a key region used to decode sound

Both species were able to learn the predictive relationships between the spoken sounds in the sequences.

Activity in the auditory cortex of the two species revealed how groups of neurons responded to the speech sounds and to the learned predictive relationships between those sounds.

'Even direct recordings from the brain do not give us access to what the neurons are doing, which is why the link to monkeys was so important to establish,' Professor Petkov told MailOnline.

'We see that certain types of neurons are constantly and actively making predictions.

'This occurs shortly before the neurons notice when a prediction mistake has occurred.

'The reason this is important relates to how it could ultimately help people with problems predicting what will happen next. 'For example, scientists can next ask whether one or both types of neuronal predictive responses rely on each other and which might be malfunctioning in people that suffer from different types of disorders.'

The brain responses in monkeys and humans were found to be remarkably similar in both species.

This suggests that the way the human auditory cortex responds to speech has been passed down through a common ancestor, rather than being uniquely specialised in humans for speech or language.

'A number of things were very similar between the monkeys and humans, suggesting a fundamental element to prediction in the brain,' Professor Petkov told MailOnline.

'Being able to predict events is vital for so much of what we do every day.'

Study coauthor Dr Yuki Kikuchi added: 'In effect we have discovered the mechanisms for speech in your brain that work like predictive text on your mobile phone, anticipating what you are going to hear next.

'This could help us better understand what is happening when the brain fails to make fundamental predictions, such as in people with dementia or after a stroke.'

Building on these results, the team are working to understand how predictive brain signals go wrong in patients with stroke or dementia.

The long-term goal is to identify strategies that yield more accurate prognoses and treatments for these patients.
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UA researchers hope to cure diseases with a common brain parasite


A mouse brain genetically engineered to show green where Toxoplasma Gondii has infected the brain.

There might be a parasite in your brain.

It’s estimated that up to one-third of the world’s population is infected with the brain parasite Toxoplasma gondii.

The U.S. has a relatively low rate of infected people, estimated to be between 10 and 25 percent. Countries such as France have an infection rate of 60 to 80 percent.

As far as parasites go, Toxoplasma gondii isn’t’ that bad, unless you’ve had a transplant and are left immunocompromised. Folks who have a weakened immune response can suffer brain damage and even death if infected with toxoplasmosis.

University of Arizona researchers are studying whether the unique relationship between the parasite and the brain could lead to breakthroughs in understanding Alzheimer’s and other brain-related illnesses..

“There are very few microbes that can persist in the brain without causing symptoms,” said Dr. Anita Koshy, a research physician at the University of Arizona who studies Toxoplasma gondii..

How it responds in the body Toxoplasma gondii can exist within the brain for the lifespan of its host because of how it interacts with the body’s immune response. Healthy adults will show no symptoms because their immune systems keep the parasite from damaging the brain..

Infected neurons glow green, and the parasite living in the cell glows red.

“Toxo knows how to change the brain in a positive way that allows the parasite to persist, which we presume means it tunes down the immune response to toxo in the brain,” said Koshy.

“There is a lot of literature that suggest the immune response, in things from stroke to Alzheimer’s to MS to Parkinson’s disease is actually what causes the problems in those diseases and disorders," she added. "If we can learn how the parasite manipulates the brain immune response, maybe we can do it for the same reason.”

Koshy wants to understand how Toxoplasma gondii avoids being attacked by the body’s immune response. Infected brain cells are changed by the parasite so that it can survive.

They think toxo might completely block out the immune response. Another theory is that the parasite silences the cell it’s infecting, not allowing it to call out for help to nearby cells.

What’s certain is that toxo keeps itself alive by keeping the immune response in check and vice-versa. This is how it’s able to persist throughout the lifespan of its human hosts. When a person’s immune system is no longer able to keep a front with toxo, the host becomes ill and can die.

“A lot of people are infected with toxo. We think it doesn’t have any problems except in those who end up being immunocompromised,” said Koshy.

“So, if they end up getting AIDS, or get a bone marrow transplant, or if they’re infected when they’re a fetus," she continued, "then it can have huge problems in the brain. There’s no known way to cure toxo.”

Genetically engineered mice and parasite allow Koshy’s research lab to see how the parasite effects the brain.

What the studies show
Koshy and her lab use mice to study how Toxoplasma gondii interacts with the brain’s immune response. The infected mice are engineered to express a green-colored protein within their brain cells when infected with parasite proteins.

“Using mice allows us to track the cells and figure out which cells interact with the parasite. We can pull those green cells out and molecularly dissect how the parasite has modified that specific cell, compared to the cell that’s next to it,” Koshy said.

There are three studies on mice that showed being chronically infected with Toxoplasma gondii made the mice more resistant to central nervous system inflammation, the same type of inflammation that occurs in stroke and Alzheimer’s patients.

“Toxo is one of those parasites that can infect the brain and effectively hide from the immune response,” said Oscar Mendez, a graduate student in Koshy’s lab.

Toxoplasma gondii’s primary hosts are cats — the only known mammals that allow the parasite to reproduce. The parasite offspring are found with cat feces. After a gestation period, they release a spore that will infect a new host.

Mendez studies the behaviors of mice infected with toxo. His theory: The parasite might change the brain chemistry in mice, luring them to cat urine. This would make them an easier target for cats. He believes the parasite does this to infect its primary host.

Tuesday, April 25, 2017

Exercise boosts brain power in over 50s, concludes latest meta-analysis

The latest review concludes that exercise can, in fact, benefit the brains of older adults.

Over the years, there has been much research on the potential cognitive benefits of exercise on mental performance in older adults. Overall, results have been inconclusive, but a new review takes a fresh look at the data.

As we age, our cognitive prowess tends to take a hit. Finding a way to halt or reduce this decline would make a huge difference to billions of lives.

One potential intervention is exercise, and many researchers have attempted to prove whether or not it can stave off age-related mental decline and neurodegenerative conditions.

Early research and meta-analyses demonstrated strong, positive results. Over recent years, however, published reviews on the topic have not reported such strong effects.

A fresh look at aging and the brain
According to the authors of the current paper, recently published reviews and meta-analyses have been inconclusive due to their restrictive inclusion criteria. For instance, some focused on just one type of exercise, while others limited their literature search to a narrow date range. The latest review is published this week in the British Journal of Sports Medicine.

The new analysis casts its net wide, looking at aerobic exercise, resistance training (such as weights), multicomponent exercise (including both resistance and aerobic training), tai chi, and yoga.

To fully assess the impact of these interventions, they looked at a raft of cognitive parameters. These include:
1. Brain capacity - global cognition
2. Attention - sustained alertness, including speed of information processing
3. Executive function - including goal-oriented behaviors
4. Memory - storage and retrieval
5.Working memory - the part of short-term memory that deals with immediate conscious perceptual and language processing

The team's analysis showed that exercise improved the brain power of people aged 50 and older, regardless of their current brain health.

Prescribing exercise
The results suggested that aerobic exercise enhanced cognitive abilities, while resistance training had a positive influence on executive function, memory, and working memory. According to the researchers, the results were strong enough to recommend prescribing both exercise types to bolster brain health in over 50s.

The next question asks how much exercise is needed. According to the analysis, a session of moderate to vigorous intensity lasting between 45 and 60 minutes was beneficial to brain health. In fact, any frequency had positive effects. The authors conclude that:

"The findings suggest that an exercise program with components of both aerobic and resistance type training, of at least moderate intensity and at least 45 minutes per session, on as many days of the week as possible, is beneficial to cognitive function in adults aged over 50 years."

Interestingly, tai chi was also found to improve cognitive capabilities. This is important because, as a low-impact exercise, it can be carried out by people who could not physically cope with more intense regimes. However, the authors point out that this conclusion was based on only a small number of studies, making the finding less robust.

How exercise might reduce cognitive decline
Although there is a great deal of debate on this topic, scientists believe that there are a number of ways that exercise could help to stave off dementia and other degenerative neurological conditions.

According to the authors of the study, these include the promotion of neurogenesis (growth of new nervous tissue), angiogenesis (growth of new blood vessels), synaptic plasticity (the ability of synapses to strengthen or weaken over time), decreased pro-inflammatory processes, and reduced cellular damage due to oxidative stress.

Although the results will be widely heralded as positive, the authors note certain limitations to the study. For example, the analysis was limited to studies that looked at supervised exercise, and only those that were published in the English language.

If physical exercise really can stave off cognitive decline, it will benefit the population at large. This type of intervention can, of course, be cost effective or even free. If it has large-scale benefits, it could be a simple way of improving the lives of millions of older adults.

Even though the cognitive benefits may be small, the physical benefits of exercise are well established - so it is a win-win situation either way.

Working memory training combined with brain stimulation can improve performance, research shows

Your Saturday Salsa club or Introductory Italian class might be even better for you than you thought.

According to Sandia National Laboratories cognitive scientist Mike Trumbo, learning a language or an instrument or going dancing is the best way to keep your brain keen despite the ravages of time. Not only do you enhance your cognition but you also learn a skill and have fun..

Several commercial enterprises have claimed you can get cognitive benefits from brain training games intended to enhance working memory. Working memory is the amount of information you can hold and manipulate in your mind at one time, said cognitive scientist Laura Matzen. However, a burgeoning body of research shows working memory training games don't provide the benefits claimed. A study by Trumbo, Matzen and six colleagues published in Memory and Cognition shows evidence that working memory training actually impairs other kinds of memory..

On the other hand, studies have shown that learning another language can help school-age children do better in math and can delay the onset of dementia in older adults. Also going dancing regularly is the best protection against dementia compared to 16 different leisure activities, such as doing crossword puzzles and bicycling. Playing board games and practicing a musical instrument are the next best activities for keeping the mind sharp. Dancing is probably so effective because it combines cognitive exertion, physical exercise and social interaction, said Trumbo..

New research from Sandia published in Neuropsychologia shows that working memory training combined with a kind of noninvasive brain stimulation can lead to cognitive improvement under certain conditions. Improving working memory or cognitive strategies could be very valuable for training people faster and more efficiently..

"The idea for why brain stimulation might work when training falls short is because you're directly influencing brain plasticity in the regions that are relevant to working memory task performance. If you're improving connectivity in a brain region involved in working memory, then you should get transfer to other tasks to the extent that they rely on that same brain region," said Trumbo. "Whereas when you're having people do tasks in the absence of brain stimulation, it's not clear if you're getting this general improvement in working memory brain areas. You might be getting very selective, task kind of improvements.".

Matzen cautioned that research using transcranial direct current stimulation (tDCS) to improve cognitive performance is relatively new, and the field has produced mixed results. More research is needed to understand how best to use this technology..

Neurons that fire together wire together
Using more than 70 volunteers divided into six groups, the researchers used different combinations of working memory training with transcranial direct current stimulation. Then they assessed the volunteers' performance on working memory tests and a test of problem-solving ability..

Using electrodes placed on the scalp and powered by a 9-volt battery, a tDCS unit delivers weak constant current through the skull to the brain tissue below. According to Trumbo, most people feel some mild tingling, itching or heat under the electrode for the first few minutes. There are well-established safety guidelines for tDCS research, ensuring that the procedure is safe and comfortable for participants and this research was approved by Sandia's Human Studies Board and the University of New Mexico's Institutional Review Board. There are commercial tDCS devices already on the market..

Researchers think tDCS makes neurons a little bit more likely to fire, which can help speed up the formation of neuronal connections and thus learning, said Matzen. Though the exact mechanisms aren't well understood, its potential is. According to studies, tDCS can help volunteers remember people's names, is better than caffeine at keeping Air Force personnel awake and may even help fight depression. Brain stimulation and brain training: better together? In the Sandia-led study, the volunteers played verbal or spatial memory training games for 30 minutes while receiving stimulation to the left or right forehead. That part of the brain is called the dorsolateral prefrontal cortex and is involved in working memory and reasoning. Since the right hemisphere is involved in spatial tasks and the left hemisphere is involved in verbal tasks, the researchers thought volunteers who received stimulation on the right side while training on spatial tasks would improve on spatial tests and those who received stimulation on the left side while training on verbal tasks would improve on verbal tests...

The verbal task involved remembering if a letter had appeared three letters back in a string of letters, for instance A-C-B-A-D. The spatial task was similar but involved remembering the sequence that blocks appear in a grid...

As expected, the spatial/right group got better at the spatial test but not verbal or reasoning tests. The spatial/left group performed about the same as the volunteers that received mock stimulation. The verbal/left group got better at the verbal test but not spatial or reasoning tests...

However, the results from the verbal/right group were surprising, said Trumbo. This group got better at the trained task -- remembering strings of letters -- as well as the closely related task -- remembering the sequence of boxes in a grid. They also improved on a reasoning test. The sample size was small, with only 12 volunteers, but the improvements were statistically significant, said Matzen...

One explanation Trumbo offered is that the right dorsolateral prefrontal cortex is particularly involved in strategy use during tasks. By stimulating the right side during the verbal task, the volunteers might get better at using a strategy. The tDCS improves the connections of these neurons, which leads to enhanced ability to use this strategy, even on other tasks...

He added, "We did not explicitly collect data related to strategy use, so it is kind of an open question. I'd really like to do some follow-up work."..

If tDCS can reliably enhance working memory or cognitive strategies, it could be very useful for training people faster and more efficiently. Matzen said, "This could benefit many mission areas at Sandia where people must learn complex tools and systems. ..

Reducing training time and improving cognitive performance would have substantial benefits to overall system performance."

Health benefits of Salmon


Salmon is both a freshwater and a saltwater fish. It is anadromous, meaning that it is born in freshwater, travels and lives in salt water and returns to freshwater to spawn. It is a fish that can be called the holy grail of healthy diet due to the multiple benefits it offers. It is great for hair, skin, joints and brain. Enriched with vitamins, minerals and, most importantly, omega-3, salmon is known to have uncountable benefits for the body. Due to these, salmon is also taken by many in the form of tablets, syrups and as frozen.

There are various varieties of salmon available in the market, such as sockeye, Atlantic and coho. In India, salmon is mostly imported from many parts of the world. Since salmon farming is significant to places like Canada, Norway and Scotland, it is used all over the world, especially in countries like United States of America. Indian subcontinent mostly gets imported frozen salmon, which is then later developed into various other forms.


How to consume salmon? 

 Salmon is a high-oil fish and can be consumed grilled, braised or baked along with steamed or blanched vegetables. Since salmon is available in many forms like tablets and oils, it can be consumed as instructed by your family physician.

How to store salmon?
Ensure that the freezer is set at a temperature of less than 4 degree Celsius. Keep the salmon either in a vacuum pack or plastic wrapping, as this pink-coloured fish gets affected by the smells of other foods.

Due to the rich nutrients it offers, salmon is a favourite amongst health experts, doctors and fitness enthusiasts. Following are the natural contents that it contains and things that make it a healthy fish:


Omega 3: 

Omega-3 are fatty acids which are essential for our body. Omega-3 is important as it promotes healthy joints and skin, reduces the risk of heart diseases and aids in brain development. According to many studies, it has been proved that consumption of omega-3 is good for cardiovascular health.

Omega-3 fatty acids also help in preventing high blood pressure, high cholesterol, diabetes, arthritis, depression, brain disorders, skin disorders and some types of cancers.

Omega-3 is specified and termed as an essential fatty acid because the body cannot synthesise it on its own and it must be obtained from what we eat. Since salmon is an oily fish, omega-3 occurs naturally in it. Omega-3, according to many scientists, may also lower the risk of many chronic diseases such as diabetes and depression.

Although there is no recommended daily intake of omega-3 fatty acids, many health experts and doctors recommend that adults should intake a minimum of 250-500 mg of omega-3 per day. The American Heart Association (AHA) recommends that adults should include at least 2 servings of omega-3 per week to get maximum benefits out of this fresh water fish.

Proteins: 
Salmon contains essential amino acids that promote growth and help maintain muscle tissue mass. The protein found in salmon helps the body maintain a healthy metabolism which promotes weight loss. A 100 gm fillet or serving of salmon contains 22-23 grams of protein. Since proteins are the building blocks of our body, it is essential to get it from the most natural sources possible. Several studies have shown that salmon contains small bio-active protein molecules that provide special support for joint cartilage, insulin effectiveness and control of inflammation in the digestive tract.

Vitamins:
To maintain a healthy active lifestyle, it is essential to include salmon in your diet because it contains vitamins like B1, B2, B3 and B5 in optimum quantities. These vitamins are involved in several important processes in our body. These processes include turning the food we consume into energy, creating and repairing DNA genes and reducing inflammation that can trigger possible heart diseases. According to recent research, Vitamin B of all kinds help to maintain optimal functioning of our brain and nervous system. Salmon is also rich in vitamin D. Vitamin D promotes healthy bones and teeth and may help decrease the risk of developing multiple sclerosis and some types of cancer.

Minerals: 
Salmon is a source of minerals like phosphorous, potassium and selenium.

Wild salmon is quite high in potassium. In the fruit world, banana is considered to have high potassium levels. Salmon, on the other hand, contains 10% more potassium than a banana. Potassium needs to be consumed to help control your blood pressure level, especially in a country like India, where sodium levels in food is very high. This is because potassium helps prevent excess water retention in the body.

Phosphorous plays numerous roles in the body. These include building strong bones and teeth, maintaining a healthy heart and promoting good kidney health.

Another type of mineral found in salmon is selenium. Selenium helps fight heart diseases, some cancers and thyroid disease. A low intake of minerals contributes to reduced immune function, increased risk of developing some cancers and easily catching viral diseases.

Monday, April 24, 2017

Dementia news: New method can PREDICT brain condition (even before it happens)

DEMENTIA can affect men and women of all ages, but researchers say they’ve found a way to identify those at higher risk of the brain condition.




Dementia used: method could predict who will suffer
Dementia is a set of symptoms - including memory loss and difficulties with thinking, problem-solving or language - which are caused when the brain is damaged by diseases.

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It affects 850,000 people in the UK, according to the Alzheimer’s Society, and while the condition is predominantly in those who are older, there are 42,000 sufferers below the age of 65.
Now a study by Lund University in Sweden has discovered a method for predicting who might develop it.
They found people with microvascular endothelial dysfunction - a hormonal imbalance in the inner lining of the blood vessels - were more likely to then get dementia.


Dementia breakthrough: endothelial dysfunction could indicate it
The researchers examined the association of the condition with three potential indicators. Of the 5,347 people they studied - none of whom had the condition at the start - 373 were diagnosed with dementia.
"Elevated plasma concentration of MR-proANP is an independent predictor of all-cause and vascular dementia," wrote study author Hilma Holm. "Pronounced increase in CT-proET-1 indicates higher risk of vascular dementia."
While all types of dementia may be predicted this way, vascular dementia was highlighted in the study.
It’s the second most common type after Alzheimer’s disease, and occurs when the brain is damaged due to problems with the blood supply to the brain. 
The study provides the possibility dementia can be systematically predicted before the onset of symptoms, and therefore treatment could happen sooner.

Person with dementia is anxiousGETTY
Brain health: it could open up more possibilities to treat the condition
Up until now, it’s been difficult to predict the condition, and Alzheimer Europe say people shouldn’t spend time or money on the tests currently available as even if someone has a particular gene - ApoE4 gene in Alzheimer’s disease, for example, they might not necessarily develop it.
Mostly people will have to wait until they develop symptoms to be diagnosed. These include difficulty recalling events, problems making decisions, trouble following conversation, losing track of the date and becoming confused about where they are.
However, people at higher risk include those who are over 65 years - one in 14 of this age group has the condition - and those with a family history who have inherited the gene, meaning they will probably suffer before the age of 65.
Vascular dementia, on the other hand, can be triggered by a stroke, blood clots, or most commonly when small blood vessels become diseased, known as subcortical vascular dementia. All three happen when blood flow to the brain is temporarily stopped or reduced.
Man with dementia is looked after by nurseGETTY
Vascular dementia: type highlighted in the study


How to spot if someone is suffering from dementia



Early signs for this type include problems perceiving objects in three dimensions and a slower speed of thought.
Because vascular dementia sufferers are often aware of the problems their condition is causing, they can often become depressed and more emotional.
While you can’t fully protect yourself against developing dementia, there are certain ways you can reduce your risk.
A study by the University of Chicago found those who ate leafy green vegetables twice a day suffered less cognitive decline, while the Central Institute of Mental Health in Mannheim, Germany discovered a daily glass of wine or pint of beer can also cut risk.

Mystery human species Homo naledi had tiny but advanced brain


It’s not the size of your brain, it’s how you organise it. The most recently discovered species of early human had a skull only slightly larger than a chimpanzee’s, but its brain looked surprisingly like our own – particularly in an area of the frontal lobe with links to language.
This could back suggestions that these mysterious early humans showed advanced behaviours, such as teamwork and burial, even though we still don’t know exactly when they lived.
In 2013, news broke of an extraordinary discovery in a chamber deep inside a South African cave. Researchers led by Lee Berger at the University of the Witwatersrand in Johannesburg had discovered thousands of ancient human fossils – comfortably the largest cache of its kind ever found in Africa.
The first official scientific reports were published in 2015, and they painted a confusing picture. The bones belonged to a never-before-seen early human, which was named Homo naledi.

Burial rites

It had a peculiar mix of anatomical features, which is part of what makes it hard to tell when the species lived. But what really set tongues wagging was the suggestion by Berger and his colleagues that H. naledi had deliberately disposed of its dead in this deep, dark, difficult-to-reach cave chamber full of remains.
Such an endeavour probably required emotional sophistication, not to mention teamwork, to carry out the task, but H. naledi’s skull was less than half the size of our own. Could its tiny brain have powered such advanced behaviour?
Berger and the other members of the H. naledi research team think it could. Using pieces of fossil skull, the group has now produced casts of parts of H. naledi’s small brain. The pattern of ridges and troughs (called gyri and sulci) on the surface of the casts offers hints about the way the brain was organised.
“Some of the casts we are working on are the most extraordinarily preserved I’ve ever seen,” says John Hawks at the University of Wisconsin-Madison. “The detail is just pristine.”

Tiny human

What excites the team most is a region on the side of H. naledi’s frontal lobe called Brodmann area 45, part of Broca’s area, which in modern humans has links to speech production. In this part of our brains, the pattern of gyri and sulci is very different from that seen in chimpanzees. H. naledi seems to have had our pattern, even though as an adult its BA45 was not much larger than that of a chimpanzee.
“You look at the naledi cast and you think – holy crap this is just a tiny human,” says Hawks.
Team member Shawn Hurst of Indiana University in Bloomington discussed the findings at a meeting of the American Association of Physical Anthropologists in New Orleans last week. “I would think the implication is that [H. naledi] was moving strongly towards enhanced communication,” he says.
Hurst adds that there is also evidence for a general expansion of the bottom surface of the frontal lobes – a region associated with higher emotions like empathy. Together, these observations might help to explain why groups of the small-brained hominin could have become interested in careful disposal of their dead, and how they could work together to transport bodies through the narrow and pitch-black cave system that led to the burial chamber.
Dean Falk at Florida State University in Tallahassee was also at last week’s meeting, and had an opportunity to look at the H. naledi brain casts and discuss them with Hurst. “We agreed on most of the interpretations,” she says – but not on the presence of a modern BA45. “This is just my initial reaction, but I’m not seeing BA45,” says Falk. “To me the general shape of the region looks ape-like.”
Hurst isn’t surprised by Falk’s conclusion. “My first reaction was the same,” he says. It was only after hours spent carefully comparing the H. naledi brain cast with the casts of other hominin and ape brains that he and his colleagues became convinced that it had a modern configuration. When the research is officially published, Falk and other researchers will have a better opportunity – and more time – to properly assess the claim.

Socially sophisticated

Other regions of the H. naledi brain tell a similar story. Ralph Holloway at Columbia University in New York also gave a talk at the New Orleans meeting, focusing on casts of the rear part of the H. naledi brain.
Holloway looked at a sulcus here that he says separates the visual cortex at the very rear of the brain from the parietal and temporal lobes that lie slightly further forward. In humans, the sulcus is smaller than in chimpanzees, reducing the size of the visual cortex and increasing the size of the parietal and temporal lobes. In H. naledi, the sulcus seems to have begun shifting into a modern-human-like configuration along some of its length,.
“The significance is that the visual cortex is purely sensory,” says Holloway. “But the parietal and temporal lobes right adjacent to it are very important for complex social behaviour.”
Again, it seems that H. naledi was more socially sophisticated than the small size of its brain might suggest.
“In our field, there is this dispute about whether the important thing in human brains is their size or the way they are organised,” says Hawks. H. naledi seems to suggest organisation is more critical.
Simon Neubauer at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, says the work supports the idea that parts of the brain became modern in their configuration before they grew large.
But he adds that we won’t know how significant the new findings are until we have some idea of how old the H. naledifossils are.