Meeta Kabra

Writes content and practices yoga.
Cooks, plants, and mothers occasionally.

[Ihtesham Ali @ihtesham2005]

To get a license to drive a black cab in London, you have to memorize 25,000 streets, 20,000 landmarks, and the fastest route between any two points in a six-mile radius of Charing Cross. It takes most people three to four years.

A British neuroscientist asked the obvious question nobody had thought to ask. What does that actually do to a human brain?

Her name was Eleanor Maguire. The study changed neuroscience forever.

The exam is called The Knowledge. It was introduced in 1865, and the format has barely changed since.

Applicants ride a moped around London for years with a clipboard strapped to the handlebars, tracing every possible route between every possible pair of points in the city.

They get tested in person by an examiner who can ask them, on the spot, for the shortest legal route between any two addresses in a database of tens of thousands. Half the people who attempt it fail.

The ones who pass have spent an average of four years studying full time and have taken the test 12 times before getting through.

Maguire was watching a TV movie about it in 1995 when she had the idea. These were not ordinary people. They were people running one of the most extreme spatial memory training programs that exists anywhere on Earth.

If the human brain could be reshaped by experience, this was the cleanest natural experiment anyone was ever going to find.

She put 16 of them in an MRI machine.

Their posterior hippocampi were significantly larger than the brains of matched controls. The longer a driver had been working, the bigger the difference got.

A 40-year veteran had a measurably more developed hippocampus than a 5-year veteran, and both had more than someone who had never driven a cab.

Here is why that finding broke a century of consensus.

Until 2000, every neuroscience textbook in the world taught a version of the same idea. The adult brain is essentially fixed. You are born with a set number of neurons. Childhood is the window where the wiring gets laid down. After puberty, the structure freezes, and the rest of your life is just slow decline.

Maguire's study was one of the first pieces of human evidence that this was simply wrong. Adult brains physically remodel themselves in response to what you ask them to do. Not metaphorically. Structurally. With grey matter you can measure on a scan.

The skeptics had an obvious objection. Maybe people with bigger hippocampi were just more likely to become taxi drivers in the first place. The brains were not changing. The job was selecting for brains that already looked that way.

So Maguire ran the experiment again. Properly this time.

She recruited 79 trainees who were just starting to study for The Knowledge and 31 controls who were not. She scanned all of them at the start. Then she waited four years. Of the 79 trainees, 39 eventually passed the exam and 20 failed. She scanned them again.

The trainees who passed had grown larger posterior hippocampi over those four years. The trainees who failed had not. The controls who never studied had not. The brain change was not selection. It was construction.

The act of memorizing the city had physically rebuilt the part of the brain responsible for spatial memory, and the rebuild only happened in the people who actually did the work.

There is a quieter finding from this research that almost nobody quotes, and it is the one I cannot stop thinking about.

The drivers had a bigger posterior hippocampus, but they had a smaller anterior hippocampus. The brain had not magically expanded. It had reallocated. Tissue that was being used for one type of memory had been compressed to make room for another.

When Maguire ran follow-up cognitive tests, the cabbies were measurably worse than controls at certain visual memory tasks unrelated to navigation. They had paid for The Knowledge with something else. The trade was real.

She also ran a second control experiment that is the part of the story most people never hear. She scanned London bus drivers. Same hours behind the wheel. Same city. Same traffic. Same stress. The only difference was that bus drivers follow fixed routes. They do not have to navigate. Their hippocampi looked completely normal.

The cab drivers had not grown bigger hippocampi from driving. They had grown them from the constant, active, effortful retrieval of spatial information from memory.

That distinction is the entire study.

Then in 2020, McGill researchers ran the inverse experiment. They tracked 50 regular drivers and measured how often they used GPS. The participants who relied most heavily on turn-by-turn navigation had measurably weaker spatial memory. When the researchers retested a subset of them three years later, the heavier GPS users had declined fastest.

The hippocampus, the same region the cabbies had built up by ignoring shortcuts, was being slowly hollowed out in everyone else by accepting them.

The mechanism Maguire spent 25 years documenting works in both directions. Brains grow what you make them grow. They lose what you stop asking them to do.

The taxi drivers were running the most intense spatial memory training program on Earth. Most of the rest of us are running the opposite program without realizing it.

Maguire died in early 2025. UCL's tribute described the cabbie study as a stroke of creative genius. She had spent her entire career on a single question. What does it physically take to remember something, and what changes inside a person who remembers a lot of it.

The answer is the part that should change how you live.

[Jackson @Jacksonsrule]

A man won't treat you how he treats his mother. He will treat you how his father treated his mother. I said what I said...

[Yesterday's Print @yesterdaysprint]

The Daily Worker, New York, May 4, 1927

[goma @soigomaa]

Out of 10 men, 1 makes a sexual joke at a woman, 2 laugh, 3 fake a chuckle to fit in and 4 stay silent. None of them speak up. Later, 9 of them still believe they're the"good guys." But from the woman's perspective, the laughter, the silence, the looking away, it all creates the same environment. So when women say"most men are the same," this is what they mean: not that every man harasses women, but that most men help protect the system that does.

[Poonam Sharma 🇮🇳 @_alps]

Looking for ADHD folks to start a warm, safe ADHD support circle in South Bangalore. Monthly meetups as a friendly, judgment-free space to share peer support, practical coping ideas, gentle encouragement to help each other grow. If you’d like to build this community, DM. Pls RT!

[goma @soigomaa]

someone on tiktok said "our world is so boring we don't have mermaids, vampires, werewolves etc..." and someone replied "y'all couldn't even handle different skin colors"

[Satish Acharya @satishacharya]

Seema, Sweety etc...
#votechori

[Karthik 🇮🇳 @beastoftraal]

Bravo Godrej and Agency09! This is wonderfully done! We need a lot more stories like this.

[Pratik Sinha @free_thinker]

Very triggered are we, by this tweet of mine?

But let us examine what happens when a bomb falls on a Palestinian house and kills a child. How many gods across the world could have stopped it had they existed, and did not, because they do not.

A bomb does not appear out of thin air. It begins in a factory somewhere in the United States, produced by companies such as Lockheed Martin, Boeing, corporations who profit through perpetual conflict. How is it that these defence companies, which produce an unlimited supply of weapons to kill humans, only keep becoming richer? Could gods do something about that? Evidently not.

Once the bomb is made, it is sold under the guise of “defence cooperation”. Israel buys it, not with its own money, but with billions of dollars in annual military aid from the United States, which comes from the tax money of US voters. The lobbies spring into action at this point and ensure that politicians approve these budgets. Every American politician who votes for “aid to Israel” knows it will translate into donations for their political campaign. Each bomb carries an invisible chain of signatures from CEOs, lawmakers, investors, and voters. Could gods do something about these politicians and CEOs who sign the death warrants of innocent people? Evidently not. Because when you sign these death warrants, you get a lot of money, you can access the best healthcare, and you live very long.

Before the bomb is dropped, it travels through a propaganda system that legitimises its use. US media corporations amplify conspiracy theories, political leaders speak of Israel’s right to self-defence and give speeches that end with the phrase “God bless America”. At this point, they have convinced a large enough population that this bomb needs to be dropped. Could gods intervene at this point? Evidently not, because very often a lie is told in the name of god, and is the primary tool to influence elections around the world.

The caricature of an organisation that is the UN will at this point talk of peace, but its design ensures that the five countries which produce and sell the most weapons hold ultimate veto power. The United States has vetoed every UN resolution on Palestine, and the gods could not do a thing about it. Multiple countries whose populations follow all kinds of gods lent support to the genocide.

And when the bomb finally falls on a home, the child who dies beneath it dies because the global economy is built on profiteering from destruction. It is not a mistake, not a coincidence, but by design. The bomb exists because it is profitable. There is no god to stop this bomb that is destined to kill more and more.

Belief in god allows the rich and powerful to escape accountability. It lets people think that justice will come later, in some afterlife, while the living suffer here.

The only ones who could have saved that child were us, and we didn’t.

[karachi memon @reembeem97]

That’s actually the perfect use of generational wealth

[Miles Taylor @MilesTaylorUSA]

A few years ago, @jonstewart said:

“Comedy doesn’t change the world, but it’s a bellwether. When a society feels under threat, comedians are who gets sent away first.”

He was right.

[Karthik 🇮🇳 @beastoftraal]

"Let Umar Khalid and the likes of him not forget that they are not a Pune businessman’s son who allegedly killed two motorbike riders while driving a Porsche car in an inebriated state and was released on laughable bail conditions of writing an essay on accidents and working with the traffic police. Let them not forget that they are not Asaram Bapu or Gurmeet Ram Rahim Singh, who are in and out of jail despite being proven guilty of murder and rape".

[PenPencilDraw @penpencildraw]

Schrodinger’s case.

[Shashikant Kore @kshashi]

Idea worth stealing

[Sabahat Zakariya @sabizak]

On this 14 August I hope I live to see the day when people from all over the subcontinent can cross these borders without an issue. When we can drive to Amritsar for breakfast and be back by evening. I hope our coming generations live to see that EU-like future. It might seem like an absurdity today but it’s dreamers who change the world.

[Narendra Modi @narendramodi]

It is unfortunate that EC is not concerned about the institution's neutrality & that is why our Karyakartas have to embark on a Satyagraha.

[Rabadabadubdub @hehelarious]

First short film dropped, go watch

https://t.co/k9O5t8XgI0

[G Sampath @samzsays]

Good time to remember this academic and his paper - and how came down on him like a ton of bricks, and how much support he received, incl from the academic community.