A New Theory of Dreaming - Latest Govt Exam
Connect with us

Environment

A New Theory of Dreaming

Published

on

Why do we dream? Psychologists and neuroscientists have been debating the function of dreams for centuries, but there is still no accepted answer.

Now, David M. Eagleman​​ and Don A. Vaughn​ have proposed a new theory. Their preprint article, which has not yet been peer reviewed, is called The Defensive Activation theory: Dreaming as a mechanism to prevent takeover of the visual cortex.

To my mind, it’s a highly original and creative theory, but I’m not convinced by it.

Here’s Eagleman​​ and Vaughn​’s theory in nutshell: The role of dreams is to ensure that the brain’s visual cortex is stimulated during sleep. Otherwise, if the visual system were deprived of input all night long, the visual cortex’s function might degrade.

We know that the visual cortex, in the brain’s occipital lobe, can start to respond to non-visual signals if it is deprived of visual input. In blind people, for instance, the occipital lobe strongly responds to touch. This rewiring or repurposing of under-utilized brain areas is a form of neuroplasticity.

Neuroplasticity is generally considered a good thing. But Eagleman​​ and Vaughn point out that for the visual system, neuroplasticity could actually pose a threat, because vision — unlike our other senses — isn’t active all the time.

If we are in a dark place, or it’s night, we get little or no visual input. So — in theory — our visual cortex would be vulnerable to ‘takeover’ by other senses, every single night. Dreams, on this view, are our brain’s way of defending the integrity of our visual system by keeping it active.

*

As I said, I love the ingenuity of this theory, but I don’t really buy it. We know that dreams are associated with stimulation of the occipital cortex during a sleep stage called REM sleep. So it’s true that dreams stimulate the visual system. But I’m not convinced that this is the main purpose of dreams.

For one thing, Eagleman​​ and Vaughn’s theory only makes sense if neuroplastic repurposing of the cortex happens very quickly. For the visual cortex to need defending, harmful neuroplasticity would need to occur in the space of a few hours. The authors do discuss evidence that rapid neuroplasticity can occur, but they don’t show any evidence that these rapid changes are strong enough to be harmful.

In fact, Eagleman​​ and Vaughn don’t really discuss any direct evidence for the dreams-as-defense.

They show a correlation between amount of REM sleep and the pace of development among primate species. Primates whose babies learn to walk faster and reach maturity faster, tend to have less REM. (Humans, the slowest maturing primates, have the most REM.)

Primate development and REM sleep

Primate development and REM sleep, from Eagleman and Vaughn (2020)

The idea is that faster development means slower neuroplasticity, and slower neuroplasticity means less need to protect the visual cortex from encroachment. This is very much circumstantial. The authors do cite some other indirect evidence, but admit that: “The present hypothesis could be tested more thoroughly with direct measures of cortical plasticity.”

I think this hypothesis could be tested quite easily. You’d take a group of human volunteers and give them an fMRI scan, at baseline, to establish the extent of their visual cortex and how visually selective it is (i.e. how well it responds only to visual input, not touch or other senses.)

Then, for 24 hours, half of the volunteers would wear a blindfold to produce visual deprivation. Half would have REM sleep disrupted that night (selective REM disruption is possible). At the 24 hour point, they get a second fMRI scan.

Eagleman​​ and Vaughn’s theory would predict that the vision-deprived people would have less visually selective visual cortex, and, crucially, that REM disruption would enhance this effect. The authors suggest a similar experiment.

Source link

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Environment

Women in the newsroom: Why South Africa leads the way

Published

on

Mahlatse Mahlase is group editor-in-chief of Eyewitness News, a major broadcaster in South Africa. It’s a role she would have been unlikely to fill 30 years ago, under the apartheid regime, whose hierarchy put Black women on a bottom tier.

But no matter where you look in the world, women’s leadership in the news media has lagged – and still does. South Africa, in fact, is a relative success story. Today, women lead nearly half of the country’s major publications and broadcasters, according to a recent analysis by Oxford University. That puts it ahead of the United States, the United Kingdom, and even countries held up as models of gender parity, like Finland.

Yet South African women’s gains have been especially hard-won, and incomplete. Women hold few of journalism’s purse strings, for instance. 

Ms. Mahlase says she has reflected on representation through a new prism since she gave birth seven months ago to her first child, a boy. 

“I want my son to grow up in a world where he has female bosses,” she says. “I want him to grow up listening to women experts on the radio, hearing them as contributors to changing the world and not just as victims of an unfair system.”

Johannesburg

Nwabisa Makunga can point to the exact moment she knew she would become a journalist.

It was April 1993 and she was 11 years old, watching the TV broadcast of the funeral of assassinated anti-apartheid leader Chris Hani with her family in their living room. The presenter was a Black reporter named Noxolo Grootboom, and her powerful tribute to Mr. Hani brought Ms. Makunga’s parents to tears.

“She was a woman who looked like me, who spoke like me, telling the story of a man who had been so important to people from my community,” she recalls. “I said to myself – this is what I’m going to do. I’m going to be like Noxolo, and I’m going to tell stories.”

Three decades later, Ms. Makunga is the editor-in-chief of the Sowetan, one of South Africa’s most-circulated daily newspapers. She is part of a generation of women who have risen through the ranks to take leadership of many of the country’s most important news outlets. Today, these women – most of them Black, Asian, and multiracial – lead nearly half the country’s major publications and broadcasters, according to a recent analysis by Oxford University. That makes the country a global leader for women’s leadership in the media, putting it ahead of the United States, the United Kingdom, and even countries held up as models of gender parity, like Finland.

And the achievement is doubly remarkable in South Africa, where only a generation ago the entire country was run largely by white men. Editors like Ms. Makunga grew up not only with few role models who looked like them, but also in a world where the media was used as a weapon of the apartheid regime, premised on white supremacy – enforcing a hierarchy in which they were the bottom tier.

Alexander Joe/AFP/Getty Images/File

A vendor sells a Daily Sun edition honoring former South African President Nelson Mandela’s birthday on July 18, 2013. The country’s transition to democracy opened up opportunities for many of today’s journalists.

Hard-won gains

Even after apartheid formally ended, these editors came up in newsrooms where its effects lingered. They were told their accents were “too African,” or their looks “too tempting.” Even as the newsrooms around them began to change from mostly white to mostly not, they still found themselves edged out of the pub trips and golf games where their male colleagues networked their way to the top.

“Make no mistake: Those statistics changing are the result of a fight,” says Mahlatse Mahlase, group editor-in-chief of Eyewitness News, a major breaking-news broadcaster. Women in South Africa’s newsrooms “have fought racism and they’ve also fought the patriarchy. The discrimination came from every side.”

Although they’ve now arrived, many of these same leaders note that South Africa’s media transformation remains incomplete. Women hold few of journalism’s purse strings, for instance. Just 19% of the board members at media companies here are female, according to a 2018 academic study of women in the media called “Glass Ceilings.” The vast majority of the country’s major media houses have a male CEO.

And while the proportion of Black, Asian, and multiracial women in the top echelons of South African media companies has grown from 6% in 2006 to 30% in 2018, that number still lags, in a country where they represent 46% of the population, according to the Glass Ceilings survey. Once they get there, meanwhile, they’re often placed under intense scrutiny and pressure.

“When men get to the top of their profession, they’re celebrated. When women get there, particularly Black women, there’s backlash, there’s trolling, there’s bullying,” says Glenda Daniels, an associate professor of media studies at the University of the Witwatersrand in Johannesburg and the co-author of the Glass Ceilings study. She uses the term “Black” as it is frequently applied in South Africa, to describe anyone who is not white. “Women at the top find they’re often exhausted just proving over and over that they deserve to be in the room.”

“Newsrooms figured out they needed to mimic what was happening in society so they wouldn’t end up on the wrong side of history.” – Mapula Nkosi, editor of the Daily Sun

Coming up the ladder

In 1994, the same year Nelson Mandela took the oath as South Africa’s first Black president, an ambitious young reporter named Mapula Nkosi walked into the Johannesburg newsroom of the Weekly Mail, which made its name opposing apartheid, to begin her career as a cadet reporter.

When she looked up the ranks, she says, she saw only men. But all around her, the country had a new buzzword: transformation. The process was often fuzzy, but the objective was clear: The structures that ruled the country should look more like the people who lived in it.

“Those newsrooms figured out they needed to mimic what was happening in society so they wouldn’t end up on the wrong side of history,” says Ms. Nkosi, now the editor of the Daily Sun, the country’s most-circulated daily newspaper. “The whole time I was coming up I had people on one side of me saying, ‘We don’t understand why you’re in this position,’ and people on the other side saying, ‘We are so excited to see where you go.’”

Those competing forces followed many of South Africa’s women journalists through their rise. Each time they pulled themselves up another rung on the ladder, they heard whispers – that they only got this job because leadership wanted a woman, that they’d never make it.

But when they did, the conversation changed.

“When you do well, you become almost genderless,” says Paula Fray, a media consultant and the first woman to edit the Saturday Star, a major South African newspaper. “But if you don’t do well, then your failings represent your whole gender.”

Meanwhile, women leaders in the newsroom “carry the added responsibility of making these environments more welcoming for women,” says Mary Papayya, a veteran journalist and editor who now sits on the board of the South African Broadcasting Corp. That, she notes, is a particularly difficult task at a time when many outlets have seen their budgets slashed and are now contending with a pandemic that has made news reporting both more dangerous and less lucrative.

And the fight for change goes beyond who sits in the corner office. In South Africa, like many countries, men are disproportionately both the experts and subjects of news stories. A recent analysis of the South African media’s coverage of the COVID-19 pandemic by the organization Media Monitoring Africa, for instance, found that 80% of those quoted in stories about the virus were men.

Ms. Mahlase, the radio news editor, says she sees these kinds of statistics through a new prism since she gave birth seven months ago to her first child, a boy. 

“I want my son to grow up in a world where he has female bosses,” she says. “I want him to grow up listening to women experts on the radio, hearing them as contributors to changing the world and not just as victims of an unfair system.”

Source link

Continue Reading

Environment

Women in the newsroom: Why South Africa leads the way

Published

on

Mahlatse Mahlase is group editor-in-chief of Eyewitness News, a major broadcaster in South Africa. It’s a role she would have been unlikely to fill 30 years ago, under the apartheid regime, whose hierarchy put Black women on a bottom tier.

But no matter where you look in the world, women’s leadership in the news media has lagged – and still does. South Africa, in fact, is a relative success story. Today, women lead nearly half of the country’s major publications and broadcasters, according to a recent analysis by Oxford University. That puts it ahead of the United States, the United Kingdom, and even countries held up as models of gender parity, like Finland.

Yet South African women’s gains have been especially hard-won, and incomplete. Women hold few of journalism’s purse strings, for instance. 

Ms. Mahlase says she has reflected on representation through a new prism since she gave birth seven months ago to her first child, a boy. 

“I want my son to grow up in a world where he has female bosses,” she says. “I want him to grow up listening to women experts on the radio, hearing them as contributors to changing the world and not just as victims of an unfair system.”

Johannesburg

Nwabisa Makunga can point to the exact moment she knew she would become a journalist.

It was April 1993 and she was 11 years old, watching the TV broadcast of the funeral of assassinated anti-apartheid leader Chris Hani with her family in their living room. The presenter was a Black reporter named Noxolo Grootboom, and her powerful tribute to Mr. Hani brought Ms. Makunga’s parents to tears.

“She was a woman who looked like me, who spoke like me, telling the story of a man who had been so important to people from my community,” she recalls. “I said to myself – this is what I’m going to do. I’m going to be like Noxolo, and I’m going to tell stories.”

Three decades later, Ms. Makunga is the editor-in-chief of the Sowetan, one of South Africa’s most-circulated daily newspapers. She is part of a generation of women who have risen through the ranks to take leadership of many of the country’s most important news outlets. Today, these women – most of them Black, Asian, and multiracial – lead nearly half the country’s major publications and broadcasters, according to a recent analysis by Oxford University. That makes the country a global leader for women’s leadership in the media, putting it ahead of the United States, the United Kingdom, and even countries held up as models of gender parity, like Finland.

And the achievement is doubly remarkable in South Africa, where only a generation ago the entire country was run largely by white men. Editors like Ms. Makunga grew up not only with few role models who looked like them, but also in a world where the media was used as a weapon of the apartheid regime, premised on white supremacy – enforcing a hierarchy in which they were the bottom tier.

Alexander Joe/AFP/Getty Images/File

A vendor sells a Daily Sun edition honoring former South African President Nelson Mandela’s birthday on July 18, 2013. The country’s transition to democracy opened up opportunities for many of today’s journalists.

Hard-won gains

Even after apartheid formally ended, these editors came up in newsrooms where its effects lingered. They were told their accents were “too African,” or their looks “too tempting.” Even as the newsrooms around them began to change from mostly white to mostly not, they still found themselves edged out of the pub trips and golf games where their male colleagues networked their way to the top.

“Make no mistake: Those statistics changing are the result of a fight,” says Mahlatse Mahlase, group editor-in-chief of Eyewitness News, a major breaking-news broadcaster. Women in South Africa’s newsrooms “have fought racism and they’ve also fought the patriarchy. The discrimination came from every side.”

Although they’ve now arrived, many of these same leaders note that South Africa’s media transformation remains incomplete. Women hold few of journalism’s purse strings, for instance. Just 19% of the board members at media companies here are female, according to a 2018 academic study of women in the media called “Glass Ceilings.” The vast majority of the country’s major media houses have a male CEO.

And while the proportion of Black, Asian, and multiracial women in the top echelons of South African media companies has grown from 6% in 2006 to 30% in 2018, that number still lags, in a country where they represent 46% of the population, according to the Glass Ceilings survey. Once they get there, meanwhile, they’re often placed under intense scrutiny and pressure.

“When men get to the top of their profession, they’re celebrated. When women get there, particularly Black women, there’s backlash, there’s trolling, there’s bullying,” says Glenda Daniels, an associate professor of media studies at the University of the Witwatersrand in Johannesburg and the co-author of the Glass Ceilings study. She uses the term “Black” as it is frequently applied in South Africa, to describe anyone who is not white. “Women at the top find they’re often exhausted just proving over and over that they deserve to be in the room.”

“Newsrooms figured out they needed to mimic what was happening in society so they wouldn’t end up on the wrong side of history.” – Mapula Nkosi, editor of the Daily Sun

Coming up the ladder

In 1994, the same year Nelson Mandela took the oath as South Africa’s first Black president, an ambitious young reporter named Mapula Nkosi walked into the Johannesburg newsroom of the Weekly Mail, which made its name opposing apartheid, to begin her career as a cadet reporter.

When she looked up the ranks, she says, she saw only men. But all around her, the country had a new buzzword: transformation. The process was often fuzzy, but the objective was clear: The structures that ruled the country should look more like the people who lived in it.

“Those newsrooms figured out they needed to mimic what was happening in society so they wouldn’t end up on the wrong side of history,” says Ms. Nkosi, now the editor of the Daily Sun, the country’s most-circulated daily newspaper. “The whole time I was coming up I had people on one side of me saying, ‘We don’t understand why you’re in this position,’ and people on the other side saying, ‘We are so excited to see where you go.’”

Those competing forces followed many of South Africa’s women journalists through their rise. Each time they pulled themselves up another rung on the ladder, they heard whispers – that they only got this job because leadership wanted a woman, that they’d never make it.

But when they did, the conversation changed.

“When you do well, you become almost genderless,” says Paula Fray, a media consultant and the first woman to edit the Saturday Star, a major South African newspaper. “But if you don’t do well, then your failings represent your whole gender.”

Meanwhile, women leaders in the newsroom “carry the added responsibility of making these environments more welcoming for women,” says Mary Papayya, a veteran journalist and editor who now sits on the board of the South African Broadcasting Corp. That, she notes, is a particularly difficult task at a time when many outlets have seen their budgets slashed and are now contending with a pandemic that has made news reporting both more dangerous and less lucrative.

And the fight for change goes beyond who sits in the corner office. In South Africa, like many countries, men are disproportionately both the experts and subjects of news stories. A recent analysis of the South African media’s coverage of the COVID-19 pandemic by the organization Media Monitoring Africa, for instance, found that 80% of those quoted in stories about the virus were men.

Ms. Mahlase, the radio news editor, says she sees these kinds of statistics through a new prism since she gave birth seven months ago to her first child, a boy. 

“I want my son to grow up in a world where he has female bosses,” she says. “I want him to grow up listening to women experts on the radio, hearing them as contributors to changing the world and not just as victims of an unfair system.”

Source link

Continue Reading

Environment

Trump Administration Penalizes Chinese Officials for Hong Kong Crackdown

Published

on

WASHINGTON — The Trump administration on Friday imposed sanctions on 11 senior Chinese Communist Party officials and their Hong Kong allies, including chief executive Carrie Lam, over their role in cracking down on political dissent in the southern Chinese territory.

These are the first sanctions against officials from China and Hong Kong over suppression of pro-democracy protests and dissent in the territory. They are being imposed as actions following an executive order President Trump signed last month seeking to punish China for its repression in Hong Kong.

“The United States stands with the people of Hong Kong and we will use our tools and authorities to target those undermining their autonomy,” Steven T. Mnuchin, the Treasury secretary, said in a statement.

The action is another in a series of measures the Trump administration has taken in recent months to ratchet up pressure on Beijing. Last month, the administration imposed sanctions on the Chinese government, including a senior member of the Communist Party, over human rights abuses against the largely Muslim Uighur minority.

Beijing announced in June that it was imposing a new national security law in Hong Kong to grant security agencies expansive powers to crack down on dissent.

Since then, American officials have debated how to get Beijing to roll back the law or how to penalize the action.

Last month, Mr. Trump signed an executive order ending the special status that the United States grants Hong Kong in diplomatic and trade relations, saying Hong Kong was no longer an autonomous entity, and officials are now beginning to treat the territory like mainland China.

Some administration officials had wanted Mr. Trump to announce during the signing that his government was imposing sanctions on Ms. Lam and other officials in China and Hong Kong. The president declined to do so then.

The current flurry of actions against China dovetails with a core part of Mr. Trump’s campaign strategy. His campaign aides are trying to show Mr. Trump is hitting China hard in order to shift the national conversation from his failures on managing the coronavirus pandemic and the economy.

The initial virus outbreak began in central China, and Mr. Trump has blamed Chinese officials for failing to contain it, though he also praised China’s leader, Xi Jinping, for efforts this winter.

Some of the administration’s China hawks are trying to set the two nations on a course for long-term confrontation and ensure that relations remain in a state of open rivalry even if Democratic candidate Joseph R. Biden Jr. wins the November election.

Source link

Continue Reading

Trending