Just How Smart Can We Be? Weighing The Limits Of The Human Brain

The human brain is an incredible machine, but it may have reached the limit of its abilities. Evolution could cause our brains to grow a bit more, though bigger may not necessarily be better.

Human brains are relatively big and particularly dense
Human brains are relatively big and particularly dense
Lucia Sillig

GENEVA – Human beings have bad sight, bad hearing and a bad sense of smell. We're not particularly strong either. So how did we become the planet's dominant species? "It's only because of our brain," says Heinrich Reichert from the biocenter at Basel University. "Other than that we are pretty ill-equipped animals."

Neuroscientists aren't modest. They believe our brain is the best out there. Human brains aren't all that different from the brains of other species. They're just better. "It's the same system, only much more powerful," says Reichert. "It's like comparing a super-computer to a PC."

Proportionally to the size of our bodies, our brains are big. But that in itself isn't necessarily an advantage. Elephants have huge brains. Compared to humans, their neurons are bigger as well. But so are the distances separating those neurons, meaning it takes longer for signals to transmit between them.

"What's striking in the human brain is its density," according to Micah Murray from the center of biomedical imagery at the Lausanne University teaching hospital. "Primates' neurons are more compact than those of rodents, for example. If rodents had as many nerve cells as we do, their brains would weigh about 45 kgs. And if you compare our brain with that of a chimp, it has more folds. That allows a bigger surface of grey matter and gives more possibilities for connections between neurons."

Murray believes that our unmatched ability for abstraction, thought complexity, language and learning skills as well as the capacity to project ourselves in the future -- or in fiction -- is what makes our brains exceptional.

Social creatures

So what made brought about such an evolution? To answer that question, neuroscientists are focusing on the expansion of the frontal lobe, a center of superior cognitive functions that developed among primates in general, and humans in particular.

Several studies suggest that group life played a central role in this development. From caves to social events, maneuvering the subtleties of social life well enough to understand who to stick with and who to run away from is a highly complex skill. It can also turn out to be a matter of life or death. Oxford researchers showed there was a strong link between the sizes of primate groups, the frequency of their interactions and the size of their frontal neocortex.

"This link is even more obvious in monogamous species," adds Pascal Vrticka from Geneva University. "That's probably because monogamy makes interactions even more complicated."

Mutations allowing the skull to expand may also have contributed to the development of the human brain. "One of the hypotheses is that the development of language triggered several other functions, like those linked to reasoning," says Murray.

As good as it gets?

Could the human brain become even better? "We're not sure," says Reichert. "Regarding size, its growth is limited by the size of the woman's pelvis - unless it grows after birth. That's theoretically possible… but the question is whether bigger brains would be more efficient."

Post-birth brain growth could also trigger energy problems. The brain is already the body's most energy-hungry organ. Some experts believe that if it further developed, its consumption would skyrocket, just like a sports car that burns more fuel as its speeds up.

Another possibility is that bigger brains could actually slow down thinking – like in elephants. Neurons would have to shrink in order to become even denser in the brain. But there are limits there as well. Studies by Cambridge university researchers suggest that below a certain size, transmissions are no longer reliable. There is too much "noise."

"Biology is like a do-it-yourself project," says Reichert. "In the case of the human brain, it turned out well." Throughout its evolution it overcame obstacles, took advantage of chance and adapted to certain elements in order to reach what seems to be an optimum capacity. Indeed, to go further may require that we get some outside help.

Read the original article in French

Photo – Liz Henry

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Ecological Angst In India, A Mining Dumpsite As Neighbor

Local villagers in western India have been forced to live with a mining waste site on the edge of town. What happens when you wake up one day and the giant mound of industrial waste has imploded?

The mining dumpsite is situated just outside of the Badi village in the coastal state of Gujarat

Sukanya Shantha

BADI — Last week, when the men and women from the Bharwad community in this small village in western India stepped out for their daily work to herd livestock, they were greeted with a strange sight.

The 20-meter-high small hill that had formed at the open-cast mining dumpsite had suddenly sunk. Unsure of the reason behind the sudden caving-in, they immediately informed other villagers. In no time, word had traveled far, even drawing the attention of environment specialists and activists from outside town.

This mining dumpsite situated less than 500 meters outside of the Badi village in the coastal state of Gujarat has been a matter of serious concern ever since the Gujarat Power Corporation Limited began lignite mining work here in early 2017. The power plant is run by the Power Gujarat State Electricity Corporation Limited, which was previously known as the Bhavnagar Energy Company Ltd.

Vasudev Gohil, a 43-year-old resident of Badi village says that though the dumping site is technically situated outside the village, locals must pass the area on a daily basis.

"We are constantly on tenterhooks and looking for danger signs," he says. Indeed, their state of alert is how the sudden change in the shape of the dumpsite was noticed in the first place.

Can you trust environmental officials?

For someone visiting the place for the first time, the changes may not stand out. "But we have lived all our lives here, we know every little detail of this village. And when a 150-meter-long stretch cave-in by over 25-30 feet, the change can't be overlooked," Gohil adds.

This is not the first time that the dumpsite has worried local residents. Last November, a large part of the flattened part of the dumpsite had developed deep cracks and several flat areas had suddenly got elevated. While the officials had attributed this significant elevation to the high pressure of water in the upper strata of soil in the region, environment experts had pointed to seismic activities. The change is evident even today, nearly a year since it happened.

It could have sunk because of the rain.

After the recent incident, when the villagers raised an alarm and sent a written complaint to the regional Gujarat Pollution Control Board, an official visit to the site was arranged, along with the district administration and the mining department.

The regional pollution board officer Bhavnagar, A.G. Oza, insists the changes "aren't worrisome" and attributes it to the weather.

"The area received heavy rain this time. It is possible that the soil could have sunk in because of the rain," he tells The Wire. The Board, he says, along with the mining department, is now trying to assess if the caving-in had any impact on the ground surface.

"We visited the site as soon as a complaint was made. Samples have already been sent to the laboratory and we will have a clear idea only once the reports are made available," Oza adds.

Women from the Surkha village have to travel several kilometers to find potable water

Sukanya Shantha/The Wire

A questionable claim

That the dumpsite had sunk in was noticeable for at least three days between October 1 and 3, but Rohit Prajapati of an environmental watchdog group Paryavaran Suraksha Samiti, noted that it was not the first time.

"This is the third time in four years that something so strange is happening. It is a disaster in the making and the authorities ought to examine the root cause of the problem," Prajapati says, adding that the department has repeatedly failed to properly address the issue.

He also contests the GPCB's claim that excess rain could lead to something so drastic. "Then why was similar impact not seen on other dumping sites in the region? One cannot arrive at conclusions for geological changes without a deeper study of them," he says. "It can have deadly implications."

Living in pollution

The villagers have also accused the GPCB of overlooking their complaint of water pollution which has rendered a large part of the land, most importantly, the gauchar or grazing land, useless.

"In the absence of a wall or a barrier, the pollutant has freely mixed with the water bodies here and has slowly started polluting both our soil and water," complains 23- year-old Nikul Kantharia.

He says ever since the mining project took off in the region, he, like most other villagers has been forced to take his livestock farther away to graze. "Nothing grows on the grazing land anymore and the grass closer to the dumpsite makes our cattle ill," Kantharia claims.

The mining work should have been stopped long ago

Prajapati and Bharat Jambucha, a well-known environmental activist and proponent of organic farming from the region, both point to blatant violations of environmental laws in the execution of mining work, with at least 12 violations cited by local officials. "But nothing happened after that. Mining work has continued without any hassles," Jambucha says. Among some glaring violations include the absence of a boundary wall around the dumping site and proper disposal of mining effluents.

The mining work has also continued without a most basic requirement – effluent treatment plant and sewage treatment plant at the mining site, Prajapati points out. "The mining work should have been stopped long ago. And the company should have been levied a heavy fine. But no such thing happened," he adds.

In some villages, the groundwater level has depleted over the past few years and villagers attribute it to the mining project. Women from Surkha village travel several kilometers outside for potable water. "This is new. Until five years ago, we had some water in the village and did not have to lug water every day," says Shilaben Kantharia.

The mine has affected the landscape around the villages

Sukanya Shantha/The Wire

Resisting lignite mining

The lignite mining project has a long history of resistance. Agricultural land, along with grazing land were acquired from the cluster of 12 adjoining villages in the coastal Ghogha taluka between 1994 and 1997. The locals estimate that villagers here lost anything between 40-100% of their land to the project. "We were paid a standard Rs 40,000 per bigha," Narendra, a local photographer, says.

The money, Narendra says, felt decent in 1994 but for those who had been dependent on this land, the years to come proved very challenging. "Several villagers have now taken a small patch of land in the neighboring villages on lease and are cultivating cotton and groundnut there," Narendra says.

They were dependent on others' land for work.

Bharat Jambucha says things get further complicated for the communities which were historically landless. "Most families belonging to the Dalit or other marginalized populations in the region never owned any land. They were dependent on others' land for work. Once villagers lost their land to the project, the landless were pushed out of the village," he adds. His organization, Prakrutik Kheti Juth, has been at the forefront, fighting for the rights of the villages affected in the lignite mining project.

In 2017, when the mining project finally took off, villagers from across 12 villages protested. The demonstration was disrupted after police used force and beat many protesters. More than 350 of them were booked for rioting.

The villagers, however, did not give up. Protests and hunger strikes have continued from time to time. A few villagers even sent a letter to the President of India threatening that they would commit suicide if the government did not return their land.

"We let them have our land for over 20 years," says Gohil.

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