Human Intelligence

Human intelligence: It’s how your brain is wired rather than size that matters

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A brain slice being scanned as part of the Human Brain Project (Credit: Mareen Fischinger/Forschungszentrum Jülich)

Human brains are bigger than those of our primate relatives, but evidence from extinct human ancestors suggests size isn’t everything. To understand human intelligence, scientists are now looking deeper

Arthur Keith was one of those misbegotten researchers who have turned out to be wrong in many of the things they said. A prominent anatomist and anthropologist in the early 20th Century, he was a proponent of scientific racism and opposed racial mixing. At least partly because of his racial views, he was convinced humans originated in Europe, not Africa as is now universally accepted. And he was a strong supporter of Piltdown Man, a notorious hoax involving fake fossils.

Keith also described a notion that became known as the cerebral Rubicon. Noting that humans have larger brains than other primates, he argued that human intelligence only became possible once our brains reached a particular threshold size. For Homo, the genus to which we belong, he thought the minimum volume was around 600-750 cubic cm (37-46 cubic inches). For our species Homo sapiens, it was 900 cubic cm (55 cubic inches). Any smaller, the argument went, and the brain wouldn’t have enough computational power to support human reasoning.

It’s certainly true that Homo sapiens, as a species, have large brains. But what this means is increasingly murky. Evidence from palaeoanthropology suggests that some species, such as the “hobbits” Homo floresiensis and Homo naledi, performed complex behaviours despite having fairly small brains. These reports are contentious. However, there is also gathering evidence from genetics and neuroscience that brain size is far from the be-all-and-end-all of intelligence.

Instead, changes to the brain’s wiring diagram, to the shapes of neurons, and even to when and where certain genes are turned on, are all equally if not more important. Size, as we might have guessed, isn’t everything.

Small-brained smarts

It’s certainly true that the human brain is unusually large.  This remains true even if you look at brain size relative to the size of our bodies. “Humans are by far the primates with the largest brain,” says neuroscientist Martijn van den Heuvel of the Free University Amsterdam in the Netherlands.

It’s also true that if you look at the last six million years of human evolution, there is a trend towards increasing brain size. Early hominins like Sahelanthropus and Australopithecus have relatively small brains, but the first Homo species have bigger ones, and Homo sapiens brains are bigger still.

However, when you look more closely at the details, the story isn’t so simple. Two species stand out for their unusually small brains: Homo floresiensis, also known as the real-life “hobbit”, and Homo naledi. Both are 21st-Century discoveries.Homo floresiensis had a skull about the size of a grapefruit and has challenged many preconceptions about how human brain size relates to intelligence (Credit: Getty Images)

Homo floresiensis had a skull about the size of a grapefruit and has challenged many preconceptions about how human brain size relates to intelligence

H. floresiensis was first described in 2004. They were just 1m (3ft) tall and lived on the island of Flores in Indonesia within the last few hundred thousand years. They died out at least 50,000 years ago. The first specimen had a brain measuring just 380 cubic cm (23 cubic inches) or perhaps 426 cubic cm (26 cubic inches), putting her on a par with chimpanzees.

There is solid evidence that H. floresiensis made and used stone tools, much as other Homo species did. Early studies also reported evidence of burning, suggesting the hobbits had control of fire. However, later re-analyses suggested the fires were all lit more recently than 41,000 years ago – suggesting they were made by modern humans, not the hobbits. Nevertheless, the stone tools alone are evidence that hobbits behaved in ways that chimpanzees cannot.

A decade later, researchers in South Africa described Homo naledi. The remains were found deep in the Rising Star cave system, which only experienced cavers can reach. Like the hobbits, H. naledi had small brains – but they also lived recently, between 200,000 and 300,000 years ago.

Lead researcher Lee Berger and his colleagues have described soot marks on the cave ceilings, which they interpret as evidence H. naledi had control of fire. It’s thought that they may have lit torches to navigate in the darkness of the deep caves.

In 2021, Berger’s team described the skull of a H. naledi child, which seemed to have been placed on a shelf-like formation in an extremely inaccessible chamber. They interpreted this as a deliberate burial. In July, they released a follow-up claiming that several skeletons had been interred in the floor of the cave, adding to the evidence for funerary behaviour.

This latest study caused a furore among palaeoanthropologists, partly because Berger announced his results before the paper had gone through the usual scientific process of peer review – including in a high-profile Netflix documentary called Unknown: Cave of Bones. When other researchers did peer review the study, some were extremely critical, saying the study “does not meet the standards of our field” and that “there is a significant amount of missing information”.

Connection patterns found in humans but not chimpanzees were often associated with a higher risk of schizophrenia

The debate over the behaviours and capabilities of H. floresiensis and H. naledi, along with their implications for the role of brain size, will likely continue for years to come. Meanwhile, another set of researchers have tackled human brain evolution in a different way: instead of examining fossilised bones, they study actual brains.

Anatomy of the mind

The first thing to note is that, although on average humans have unusually large brains, size does vary. “There are patients that have smaller brain size,” says neurobiologist Debra Silver at Duke University in Durham, North Carolina. People with microcephaly – where their head is abnormally small – often have intellectual disabilities and other symptoms. Nevertheless, says Silver, “they’re still human”. There are also cases where people are missing large chunks of their brains, and show relatively few ill effects

The human brain by numbers

At about 1.5kg, the human brain is about two to three times smaller than that of an elephant. It is up to six times smaller than the brain of some whales and dolphins.

The human brain contains 86 billion neurons and 85 billion non-neuronal cells. But despite accounting for about 2% of body mass in the average adult, the human brain burns about 20% of the calories we use.

Clearly, something else is going on. One possibility is the brain’s wiring diagram or “connectome”. The human brain contains around 86 billion specialised cells called neurons, which connect to each other and send signals back and forth. Many neuroscientists suspect that changes to the pattern of connections are more important for the development of human cognition than anything as crude as the brain’s volume.

“Even small changes in connectivity, especially in long range connectivity, it really leads to profound cognitive and behavioural changes,” says neuroscientist Nenad Sestan at Yale University in New Haven, Connecticut.

In particular, some parts of the human brain receive inputs from many other regions. This allows them to integrate multiple pieces of information, and make decisions accordingly. The prefrontal cortex, at the outermost front of the brain, is one such region. Sestan calls it “the CEO of the brain”.

“A little bit more of this integrative circuitry is really beneficial for human cognitive abilities,” agrees van den Heuvel. In a study published in May, his team showed that human and chimpanzee brains share many patterns of connectivity, but humans have stronger connectivity between regions involved in language.

These integrated areas of the brain have also been associated with psychiatric disorders. For example, in 2019 van den Heuvel’s team showed that connection patterns found in humans but not chimpanzees were often associated with a higher risk of schizophrenia. This suggests humans have made an evolutionary trade-off: greater intelligence in exchange for a higher risk of poor mental health.

Evidence like this suggests the connectome is important. But what about the neurons themselves: are human neurons different to chimpanzees’?

https://emp.bbc.com/emp/SMPj/2.51.0/iframe.html

Why you might be smarter than you think

Altered cells

“There is a long history of people searching for specific unique neurons in the human brain,” says van den Heuvel. One of the first attempts was made by Constantin von Economo, an Austrian neurologist active in the early 20th Century. He identified spindle-shaped neurons in the human cerebral cortex: these are sometimes called “von Economo neurons”. At first these were thought to be unique to humans, says van den Heuvel, “but later on they did find von Economo neurons in other brains”.

More recently, in 2022 Sestan and his colleagues studied the cells in a part of the brain known as the dorsolateral prefrontal cortex of humans, chimpanzees and monkeys. They could only find one cell type that was unique to humans. It was not a neuron, but rather a microglial cell: part of the brain’s immune system. The cells looked outwardly normal, but had activated a unique set of their genes.

Sestan is wary of hyping the findings. “I don’t think this is key,” he says. “There is no reason to think microglia would give us cognitive abilities.”

Human-specific neurons may be hard to find, but it’s clear that the proportions of different cell types have been altered during our evolution. Silver says von Economo neurons are more common in humans and great apes, compared to other primates. They “may help to take on new tasks”, she suggests.

If we have cortical neurons that make dopamine, they could be ‘a reward system for just thinking’

Understanding the modified neurons in the human brain requires understanding how the cells develop and grow. We can’t study this in living embryos for obvious reasons, but researchers can study neurons growing in the laboratory. In recent years they have also grown “organoids“: clusters of cells that mimic the structure and behaviour of part of the developing brain.

This field has produced a blizzard of findings, most of which are not fully understood, says Barbara Treutlein, a developmental neurobiologist at ETH Zürich in Switzerland. However, one pattern stands out clearly. “It takes longer in humans to make neurons and for the neurons to actually mature,” she says. “In chimpanzees neurons mature faster than in humans.”

Treutlein tentatively links this slow maturation of neurons with the relatively longer time it takes human babies to develop compared to chimpanzees. However, she also says we can’t yet draw strong links between her studies of developing neurons – which never mimic anything beyond the second trimester of pregnancy – and the behaviour of adult humans.

There is another factor to consider – the human genome and its effects on our brains.

Expressive genes

Famously, humans and chimpanzees share 99% of our DNA. “But the point is we are not 1% different from chimpanzees,” says Sestan. The difference is evidently more dramatic than that.

Geneticists have identified patches of the genome that are unique to humans, and many of them seem to have roles in the brain. For example, a 2019 study looked at human-specific stretches of DNA and found many of them had effects on cells known to be involved in brain expansion.

Similarly, a gene called SRGAP2C is unique to the Homo genus. In a 2019 study, researchers expressed this hominin gene in mice and found that it altered their connectome, creating additional connections between certain layers of the cortex. “It changes the neuronal activity and morphology of neurons at a circuit level,” says Silver.

Over the long course of human evolution, many genes have changed. In February, van den Heuvel’s team released a timeline of 13.5 million human-specific mutations spanning the last five million years – stretching back to before the origin of the Homo branch of the evolutionary tree. They found two bursts of human-specific mutations. The first occurred around 1.9 million years ago, about when the species Homo erectus evolved. The second was between 62,000 and 1,500 years ago. Mutations linked to cognition were often relatively young, says van den Heuvel.There is an ongoing debate about just how intelligent the early human ancestor Homo naledi really was with its relatively small brain size (Credit: Getty Images)

There is an ongoing debate about just how intelligent the early human ancestor Homo naledi really was with its relatively small brain size

It’s not just about the DNA sequence itself: as Sestan’s microglial study suggested, it’s also about which genes are turned on in each cell. Changes in “gene expression” can give cells fundamentally different shapes and behaviours, even though they have the same genome.

The complexity here is dizzying. A 2021 study of gene expression found that some genes that are important in the brain may make 100 proteins each, depending on how they are expressed. One gene expressed in developing humans but not chimps controls an entire network of other genes, which are thought to be involved in human brain development.

Some changes in gene expression are tantalising. In a 2017 study, Sestan’s team compared gene expression in human, chimp and monkey brains. They found that some neurons in one region of the human brain expressed genes involved in making dopamine, a brain chemical involved in feelings of reward. The equivalent cells in the chimps and monkeys didn’t express these genes. “We cultured these neurons.” says Sestan. “They can make dopamine in vitro.”

“If this holds true in a real brain, we humans could make dopamine internally in the cortex,” says Sestan. He has an intriguing speculation about what this might mean. Humans can feel pleasure just from thinking and solving problems, which may well be unique. If we have cortical neurons that make dopamine, they could be “a reward system for just thinking”. He emphasises, however, that for now this is speculation.

We have come a long way from simply comparing the sizes of different primates’ brains. Scientists are now looking at changes in genome sequences, changes in gene expression, changes in cell shape and behaviour, and changes in the brain’s wiring diagram. What we are missing is “understanding how all of these elements, as an interplay, become a system and this system shapes our behaviour”, says van den Heuvel.

Treutlein and her colleagues took a big step in this direction in 2019, publishing an “atlas” of every cell in a human brain at an early stage of development. In 2023, a team of 500 researchers from across Europe announced the completion of the Human Brain Project, a 10-year project to delve into the complex structure and function of the brain.

A huge ongoing project called the Human Cell Atlas aims to build on the insights gained so far. Its members aim to map every cell type in the human body: its position, shape, gene expression and more. “There are so many cell types in the brain,” says Treutlein. The challenge will be to make sense of the vast dataset.

While that project will take decades, it’s already possible to draw some conclusions about brain size. “I think it’s just one of many factors,” says Silver.

Yale Neuroscientists Can Now Determine Human Intelligence Through Brain Scans.

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Article Image
The human connectome. By Andreashorn – Own work, CC BY-SA 4.0.

Do you feel like you were born to do something? There is just a certain skill like playing an instrument or sport, or a certain subject, like math, which you naturally excel in? It might have to do with the way your brain is wired. Different people have different aptitudes. The repositories for these lie in different parts of the brain and, as scientists are learning more and more, in the connectome or the connections between regions.

Today, neuroscientists can determine one’s intelligence through a brain scan, as sci-fi as that sounds. Not only that, it’s only a matter of time before they are able to tell each individual’s set of aptitudes and shortcomings, simply from scanning their brain. Researchers at Yale led the study. They interpreted intelligence in this case as abstract reasoning, also known as fluid intelligence. This is the ability to recognize patterns, solve problems, and identify relationships. Fluid intelligence is known to be a consistent predictor of academic performance. Yet, abstract reasoning is difficult to teach, and standardized tests often miss it.

Researchers in this study could accurately predict how a participant would do on a certain test by scanning their brain with an fMRI. 126 participants, all a part of the Human Connectome Project, were recruited. The Human Connectome Project is the mapping of all the connections inside the brain, to get a better understanding of how the wiring works and what it means for things like intellect, the emotions, and more. For this study, researchers at Yale put participants through a series of different tests to assess memory, intelligence, motor skills, and abstract thinking.

They were able to map the connectivity in 268 individual brain regions. Investigators could tell how strong the connections were, how active, and how activity was coordinated between regions. Each person’s connectome was as unique as their fingerprint, scientists found. They could identify one participant from another with 99% accuracy, from their brain scan. Yale researchers could also tell whether the person was engaged in the assessment they were taking or if they were aloof about it.

Emily Finn was a grad student and co-author of this study. She said, “The more certain regions are talking to one another, the better you’re able to process information quickly and make inferences.” Mostly, fluid intelligence had to do with the connections between the frontal and parietal lobes. The stronger and swifter the communication between these two regions, the better one’s score in the abstract thinking test. These are some of the latest regions to have evolved in the brain. They house the higher level functions, such as memory and language, which are essentially what make us human.

Axonal nerve fibers in the real brain, by jgmarcelino from Newcastle upon Tyne, UK

Yale researchers believe that by learning more about the human connectome, they might find novel treatments for psychiatric disorders. Things like schizophrenia vary widely from one patient to the next. By finding what’s unique to a particular patient, a psychiatrist can tailor treatment to suit their needs. Understanding one’s connectome could give insight into how the disease progresses, and if and how the patient might respond to certain therapies or medications. But there are other uses which we may or may not feel comfortable with.

For instance, your child could have their brain scanned to track them at school, according to study author Todd Constable. It might be used to say whether or not a candidate is qualified for a job or should pursue a certain career. Brain scans could tell who might be prone to addiction, or what sort of learning environment a student might flourish in. School curriculum could even be changed on a day-to-day basis to fit student’s needs. And the dreaded SAT might even be shelved too, in favor of a simple brain scan.

Peter Bandettini is the chief of functional imaging methods at the National Institute of Mental Health (NIMH). He told PBS that barring ethical issues, brain scans could someday be used by employers to tell which potential candidate possesses desirable aptitudes or personality traits, be they diligent, hardworking, or what-have-you. Richard Haier, an intelligence researcher at UC Irvine, foresees prison officials using such scans on inmates to tell who might be prone to violence.

We may even someday learn how to augment human intelligence from studies such as this. It’s important to remember that intelligence research is still in its infancy. Yet, according to Yale scientists, we are moving in this direction.

Some fear a Minority Report-like misuse of said technology. Neuroethicist Laura Cabrera at Michigan State University enumerated for WIRED her concerns. What if insurance companies denied coverage based on such a scan, due to a tendency toward addiction or some other predisposition. Of course, just because someone has a higher risk of something, doesn’t mean they will develop it. Without proper guidelines in place and oversight, we could quickly see banks, schools, universities, and other institutions taking part in “neuro-discrimination.” Strong laws will have to be put in place to defend against misuse.

There are limits to what we now know about the human connectome that have yet to be overcome. For instance, we can only look at the connections as they are now. We don’t know how they form or develop over time. And fluid intelligence is merely one type out of several different kinds. We are still far from applying such technology in the real world. But the potential is there.

To learn more about the Human Connectome Project, click here:

Watch the video.URL:

Source:http://bigthink.com

 

New Study Shows How Human Intelligence May be a Product of a Basic Algorithm

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There is a theory that suggests human thoughts and functionality result from a basic algorithm N=2^i–1. Artificial neural network operate similarly to the brain, thus applying this formula might as well be the key to true intelligence, making this a huge break for Artificial Intelligence (AI).

Given that the human brain is the most sophisticated organ, the AI model is inspired by the brain. The Frontiers in Systems Neuroscience Journal recently published a study linking human intelligence as a product of a basic algorithm.

According to Joe Tsien, neuroscientist research author at Augusta University, Georgia; “relatively simple mathematical logic underlies our complex brain computations;” found in the Theory of Connectivity. Tsien first proposed the Theory of Connectivity in October 2015.

The Theory of Connectivity suggests that knowledge acquisition, ability to generalize as well as conclude from these generalizations, is a result of billions of neurons assembling and aligning. Tsien amended that there is evidence that the brain is able to operate on a pretty simple mathematical logic.

Post the Theory of Connectivity, there is the brain’s formula. Basically, clusters of similar neurons form a complexity of cliques to collectively handle information or basic ideas. These groups come together into functional connectivity motifs (FCM). FCM deals with every possible combination of ideas. With complex situations, more cliques get involved.

Tsien and team investigated and documented the algorithm functionality in 7 different brain regions. Each selected region was responsible for basic functions such as fear of mice, and liking food. The results indicated how many cliques correspond to a certain FCM, a power-or-two-based permutation logic (N=2i–1).

Four food types (rice, milk, rodent biscuits and pellets) were given to animals in the study. The scientists connected electrodes to specific brain areas and heard the neuron’s responses. As a result, all 15 individual combinations of neurons and cliques that responded to the assorted food were identified, as predicted by the Theory of Connectivity.

Since AI neural networks already match the brain’s structural wing, it is possible for the (N=2i–1) algorithm to be applied.

The Brain Tech to Merge Humans and AI Is Already Being Developed

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Are you scared of artificial intelligence (AI)?

Do you believe the warnings from folks like Prof. Stephen Hawking, Elon Musk and others?

Is AI the greatest tool humanity will ever create, or are we “summoning the demon”?

To quote the head of AI at Singularity University, Neil Jacobstein, “It’s not artificial intelligence I’m worried about, it’s human stupidity.”

In a recent Abundance 360 webinar, I interviewed Bryan Johnson, the founder of a new company called Kernel which he seeded with $100 million.

To quote Bryan, “It’s not about AI vs. humans. Rather, it’s about creating HI, or ‘Human Intelligence’: the merger of humans and AI.”

Let’s dive in.

Meet Bryan Johnson and His New Company Kernel

Bryan Johnson is an amazing entrepreneur.

In 2007, he founded Braintree, an online and mobile payments provider. In 2013, PayPal acquired Braintree for $800 million.

In 2014, Bryan launched the OS Fund with $100 million of his personal capital to support inventors and scientists who aim to benefit humanity by rewriting the operating systems of life.

His investments include endeavors to cure age-related diseases and radically extend healthy human life to 100+ (Human Longevity Inc.), replicate the human visual cortex using artificial intelligence (Vicarious), expand humanity’s access to resources (Planetary Resources, Inc.), reinvent transportation using autonomous vehicles (Matternet), educate on accelerating technological progress (Singularity University), reimagine food using biology (Hampton Creek), make biology a predictable programming language (Emulate, Gingko Bioworks, Lygos, Pivot Bio, Synthego, Synthetic Genomics), and digitize analog businesses (3Scan, Emerald Cloud Lab, Plethora, Tempo Automation, Viv), among others.

Bryan is a big thinker, and now he is devoting his time, energy and resources to building “HI” through Kernel.

The company is building on 15 years of academic research at USC, funded by the NIH, DARPA and others, and they’ll begin human trials in the coming months.

But what is HI? And neuroprosthetics? And how is AI related?

Keep reading.

BCI, Neural Lace and HI

Your brain is composed of 100 billion cells called neurons, making 100 trillion synaptic connections.

These cells and their connections make you who you are and control everything you do, think and feel.

In combination with your sensory organs (i.e., eyes, ears), these systems shape how you perceive the world.

And sometimes, they can fail.

That’s where neuroprosthetics come into the picture.

The term “neuroprosthetics” describes the use of electronic devices to replace the function of impaired nervous systems or sensory organs.

They’ve been around for a while — the first cochlear implant was implanted in 1957 to help deaf individuals hear — and since then, over 350,000 have been implanted around the world, restoring hearing and dramatically improving quality of life for those individuals.

But cochlear implants only hint at a very exciting field that researchers call the brain-computer interface, or BCI: the direct communication pathway between the brain (the central nervous system, or CNS) and an external computing device.

The vision for BCI involves interfacing the digital world with the CNS for the purpose of augmenting or repairing human cognition.

You might have heard people like Elon Musk and others talking about a “neural lace” (this was actually a concept coined by science fiction writer Iain M. Banks).

Banks described a “neural lace” as essentially a very fine mesh that grows inside your brain and acts as a wireless brain-computer interface, releasing certain chemicals on command.

Well… though the idea might have started as science fiction, companies like Kernel are making it very real.

And once they do, we’ll have robust brain-computer interfaces, and we’ll be able to fix and augment ourselves. Ultimately this will also allow us to merge with AIs and become something more than just human.

Human Intelligence (HI)

Humans have always built tools of intelligence.

We started with rocks and progressively built more intelligent tools such as thermostats, calculators, computers and now AI. These are extensions of ourselves, and so we’ve been increasing our intelligence through our tools.

But now, our tools have become sophisticated enough (thanks to exponential technologies riding atop Moore’s Law) that we are about to incorporate them into our biology and take an exponential leap forward in intelligence.

This is so significant that it will change us as a species — we’re taking evolution into our own hands.

I like to say we’re going from evolution by natural selection — Darwinism — into evolution by intelligent direction.

We can now focus on technologies to augment human intelligence (HI).

This is what Bryan Johnson and Kernel are focused on.

The first step is to answer the basic question: can we mimic the natural function of neurons firing?

If we can mimic that natural functioning, and restore circuitry, or even if we can just maintain that circuitry, it begs the question: could we improve that circuitry?

Could we make certain memories stronger? Could we make certain memories weaker? Could we work with neural code in the same way we work with biological code via synthetic biology or genetic code? How do we read and write to neurons? Could we merge with AIs?

In my friend Ray Kurzweil’s mind, the answer is most certainly yes.

A Refresher on Ray Kurzweil’s Prediction

Ray Kurzweil is a brilliant technologist, futurist, and director of engineering at Google focused on AI and language processing.

He has also made more correct (and documented) technology predictions about the future than anyone:

As reported, “of the 147 predictions that Kurzweil has made since the 1990’s, fully 115 of them have turned out to be correct, and another 12 have turned out to be “essentially correct” (off by a year or two), giving his predictions a stunning 86% accuracy rate.”

Not too long ago, I wrote a post about his wildest prediction yet:

“In the early 2030s,” Ray said, “we are going to send nanorobots into the brain (via capillaries) that will provide full immersion virtual reality from within the nervous system and will connect our neocortex to the cloud. Just like how we can wirelessly expand the power of our smartphones 10,000-fold in the cloud today, we’ll be able to expand our neocortex in the cloud.”

A few weeks ago, I asked Bryan about Ray’s prediction about whether we’d be able to begin having our neocortex in the cloud by the 2030s.

His response, “Oh, I think it will happen before that.”

Exciting times.

Yale Neuroscientists Can Now Determine Human Intelligence Through Brain Scans.

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Article Image
The human connectome. By Andreashorn

Do you feel like you were born to do something? There is just a certain skill like playing an instrument or sport, or a certain subject, like math, which you naturally excel in? It might have to do with the way your brain is wired. Different people have different aptitudes. The repositories for these lie in different parts of the brain and, as scientists are learning more and more, in the connectome or the connections between regions.

Today, neuroscientists can determine one’s intelligence through a brain scan, as sci-fi as that sounds. Not only that, it’s only a matter of time before they are able to tell each individual’s set of aptitudes and shortcomings, simply from scanning their brain. Researchers at Yale led the study. They interpreted intelligence in this case as abstract reasoning, also known as fluid intelligence. This is the ability to recognize patterns, solve problems, and identify relationships. Fluid intelligence is known to be a consistent predictor of academic performance. Yet, abstract reasoning is difficult to teach, and standardized tests often miss it.

Researchers in this study could accurately predict how a participant would do on a certain test by scanning their brain with an fMRI. 126 participants, all a part of the Human Connectome Project, were recruited. The Human Connectome Project is the mapping of all the connections inside the brain, to get a better understanding of how the wiring works and what it means for things like intellect, the emotions, and more. For this study, researchers at Yale put participants through a series of different tests to assess memory, intelligence, motor skills, and abstract thinking.

They were able to map the connectivity in 268 individual brain regions. Investigators could tell how strong the connections were, how active, and how activity was coordinated between regions. Each person’s connectome was as unique as their fingerprint, scientists found. They could identify one participant from another with 99% accuracy, from their brain scan. Yale researchers could also tell whether the person was engaged in the assessment they were taking or if they were aloof about it.

Emily Finn was a grad student and co-author of this study. She said, “The more certain regions are talking to one another, the better you’re able to process information quickly and make inferences.” Mostly, fluid intelligence had to do with the connections between the frontal and parietal lobes. The stronger and swifter the communication between these two regions, the better one’s score in the abstract thinking test. These are some of the latest regions to have evolved in the brain. They house the higher level functions, such as memory and language, which are essentially what make us human.

Axonal nerve fibers in the real brain, by jgmarcelino from Newcastle upon Tyne, UK

Yale researchers believe that by learning more about the human connectome, they might find novel treatments for psychiatric disorders. Things like schizophrenia vary widely from one patient to the next. By finding what’s unique to a particular patient, a psychiatrist can tailor treatment to suit their needs. Understanding one’s connectome could give insight into how the disease progresses, and if and how the patient might respond to certain therapies or medications. But there are other uses which we may or may not feel comfortable with.

For instance, your child could have their brain scanned to track them at school, according to study author Todd Constable. It might be used to say whether or not a candidate is qualified for a job or should pursue a certain career. Brain scans could tell who might be prone to addiction, or what sort of learning environment a student might flourish in. School curriculum could even be changed on a day-to-day basis to fit student’s needs. And the dreaded SAT might even be shelved too, in favor of a simple brain scan.

Peter Bandettini is the chief of functional imaging methods at the National Institute of Mental Health (NIMH). He told PBS that barring ethical issues, brain scans could someday be used by employers to tell which potential candidate possesses desirable aptitudes or personality traits, be they diligent, hardworking, or what-have-you. Richard Haier, an intelligence researcher at UC Irvine, foresees prison officials using such scans on inmates to tell who might be prone to violence.

We may even someday learn how to augment human intelligence from studies such as this. It’s important to remember that intelligence research is still in its infancy. Yet, according to Yale scientists, we are moving in this direction.

Some fear a Minority Report-like misuse of said technology. Neuroethicist Laura Cabrera at Michigan State University enumerated for WIRED her concerns. What if insurance companies denied coverage based on such a scan, due to a tendency toward addiction or some other predisposition. Of course, just because someone has a higher risk of something, doesn’t mean they will develop it. Without proper guidelines in place and oversight, we could quickly see banks, schools, universities, and other institutions taking part in “neuro-discrimination.” Strong laws will have to be put in place to defend against misuse.

There are limits to what we now know about the human connectome that have yet to be overcome. For instance, we can only look at the connections as they are now. We don’t know how they form or develop over time. And fluid intelligence is merely one type out of several different kinds. We are still far from applying such technology in the real world. But the potential is there.

Watch the video. URL:https://youtu.be/2nzLxAoUuts

“Big Brain Gene” Fueled Evolution of Human Intelligence

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A specific gene present in human stem cells, but not in the cells of other animals like mice (a laboratory standard) or chimps (our closest living evolutionary relative), appears to be responsible for the evolutionary increase in human brain size.

A team of scientists at the Max Planck Institute recently studied the gene, called ARHGAP11B, for clues to its purpose and origin. They hoped to explain how humans developed mental capacities suited for the expression of language and abstract thought while other species did not.

During crucial stages of human fetal brain development, scientists found the ARHGAP11B gene in high numbers. They also found the gene was very active, or “switched on,” during these stages. The gene was absent in the brains of mice, but once ARHGAP11B was inserted, the rodents’ brains grew in size and also grew what looked like larger neocortices:

“These amped-up brain regions contained loads of neurons and some even began forming the characteristic folds, or convolutions, found in the human brain, a geometry that packs a lot of dense brain tissue into a small amount of space.”

By tracing back the evolutionary history of the gene, scientists discovered ARHGAP11B not only in modern-day humans, but also in Neanderthals and another branch of extinct humans called Denisovans. Researchers did not find the gene in chimpanzees.

While the gene may explain the expansion in volume of the human brain — a necessary, but not sufficient cause of intelligence — how our intelligence evolved is another story. Both humans and Neanderthals had large brains, said Dr. Wieland Huttner, a neurobiologist also at the Max Planck Institute, but humans’ unique intelligence may have more to do with how brain cells form and prune neural networks over time.

So by now, you might think that humans were graced with the peak benefit that evolution has to offer. This isn’t exactly the case, explains theoretical physicist and popular science author Michio Kaku. Actually, so-called intelligence may yet prove an evolutionary disadvantage if we are unable to cope with the existential threats facing our species:

“Some people think that intelligence is the crowning achievement of evolution. Well if that’s true there should be more intelligent creatures on the planet Earth. But to the best of our knowledge we’re the only ones. The dinosaurs were on the Earth for roughly 200 million years and … not a single dinosaur became intelligent. We humans, modern humans, had been on the Earth for roughly a hundred thousand years. Only a tiny fraction of the 4.5 billion years that the Earth has been around. So you come to the rather astounding conclusion that intelligence is not really necessary, that Mother Nature has done perfectly well with non-intelligent creatures for millions of years and that we as intelligent creatures are the new kid on the block.”

 

Alzheimer’s Origins Tied to Rise of Human Intelligence .

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Alzheimer’s disease may have evolved alongside human intelligence, researchers report in a paper posted this month on BioRxiv.

The study finds evidence that 50,000 to 200,000 years ago, natural selection drove changes in six genes involved in brain development. This may have helped to increase the connectivity of neurons, making modern humans smarter as they evolved from their hominin ancestors. But that new intellectual capacity was not without cost: the same genes are implicated in Alzheimer’s disease.

Kun Tang, a population geneticist at the Shanghai Institutes for Biological Sciences in China who led the research, speculates that the memory disorder developed as ageing brains struggled with new metabolic demands imposed by increasing intelligence. Humans are the only species known to develop Alzheimer’s; the disease is absent even in closely related primate species such as chimpanzees.

Tang and his colleagues searched modern human DNA for evidence of this ancient evolution. They examined the genomes of 90 people with African, Asian or European ancestry, looking for patterns of variation driven by changes in population size and natural selection.

Marked by selection
The analysis was tricky, because the two effects can mimic each other. To control for the effects of population changes―thereby isolating the signatures of natural selection—the researchers estimated how population sizes changed over time. Then they identified genome segments that did not match up with the population history, revealing the DNA stretches that were most likely shaped by selection.

In this way, the researchers looked back at selection events that occurred up to 500,000 years ago, revealing the evolutionary forces that shaped the dawn of modern humans, thought to be around 200,000 years ago. Most previous methods for uncovering such changes reach back only about 30,000 years, says Stephen Schaffner, a computational biologist at the Broad Institute in Cambridge, Massachusetts.

The analytical approach that Tang’s team used is promising, he adds. “It’s treating all kinds of selection in a uniform framework, and it’s also treating different eras of selection in a more or less uniform way.” But Schaffner says that further research is needed to confirm that the method is broadly applicable.

Still, even the most powerful genomic-analysis methods can be limited by the vagaries of history. Asian and European people descended from a small number of people who left Africa around 60,000 years ago, and that population bottleneck erased earlier patterns of genetic variation in Europeans. The genomes of African people allow researchers to look much further back in time, offering more information about the evolutionary changes that shaped humanity.