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Should Biden take a cognitive test? Here's what it would — and wouldn't — tell us

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Should Biden take a cognitive test? Here's what it would — and wouldn't — tell us

It seemed like a sensible suggestion for assessing the capabilities of an 81-year-old man seeking voters’ approval to remain in the White House until January 2029.

To reassure the American people, ABC’s George Stephanopoulos asked President Biden, would he be willing to take a cognitive test and share the results with the American people?

Biden demurred. In carrying out his duties as leader of the free world, he said, “I have a cognitive test every single day.”

Though the president dismissed the suggestion, medical experts said the idea of having Biden — along with his 78-year-old challenger, former President Trump — take some kind of cognitive exam had merit.

“Let’s give it to both of them,” said Dr. Louise Aronson, a geriatrician at UC San Francisco.

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Kevin Duff, a neuropsychologist at the Oregon Health & Science University’s Alzheimer’s Disease Research Center, likened the proposal to the long-standing practice of asking presidential contenders to release their tax returns.

There would be several types of tests to choose from. A simple screening exam could involve just a handful of questions and be completed in minutes. An in-depth evaluation could take a full day.

When former White House physician Dr. Ronny Jackson evaluated Trump in 2018, he opted for the popular Montreal Cognitive Assessment, or MoCA Test. Over the course of about 15 minutes, patients are asked to recall a list of five words, draw a clock with its hands set to a particular time, do subtraction with double-digit numbers, and come up with the names of animals in a drawing, among other tasks. At the time, Trump scored a perfect 30 out of 30.

Whether long or short, a good test measures multiple “domains of cognition,” Aronson said. There’s short-term memory and long-term memory. There’s the ability to communicate through both spoken and written language. There’s attention, comprehension, judgment, reasoning, problem-solving, decision-making and more.

“If a person completely aces a test, that tells you something,” said Dr. Laura Mosqueda, a professor of family medicine and geriatrics at USC’s Keck School of Medicine. “And if they bomb a test, it tells you something.”

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A score that’s somewhere in between can be trickier, experts say.

An abnormal result on a cognitive test doesn’t necessarily mean that a patient has a true cognitive problem. In about 10% of cases, it can be chalked up to a side effect of medications, an infection, a thyroid problem, a vitamin deficiency, a mood disorder such as anxiety or depression, or something else that’s reversible.

“The thing we see constantly as geriatricians are medication reactions,” Aronson said. “I can’t tell you how often we withdraw medications and then the person goes back to normal.”

Sometimes it’s even simpler than that.

“I’ve seen people diagnosed with dementia who’ve actually had a hearing problem but didn’t want to admit it,” Mosqueda said. “They couldn’t hear the questions and so they were giving weird answers.”

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Some cognitive changes are a normal part of the aging process. Thinking speed is a prime example.

“As we age, we will do things more slowly,” Aronson said. That isn’t necessarily a sign of cognitive impairment, she said, recalling a 101-year-old patient who missed only one point on a test but needed extra time to complete it.

If a patient’s cognitive problems persist, or if caregivers want to get a better handle on the subtleties of their condition, a more in-depth assessment may be in order.

The tasks are more challenging, Duff said. For instance, instead of seeing whether a patient can remember five words after five minutes, a neuropsychologist might give a patient 15 words and see how many they recall half an hour later.

On the MoCA Test, a score of 25 or lower is considered abnormal regardless of any other factors. With a more sensitive test, the results are compared with the performance of other people of the same age, educational background, career history and other characteristics, Duff said.

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A person with Biden’s background would probably perform well on a MoCA test even if his cognition has declined, experts agreed.

“In certain patients who are particularly verbal, they won’t remember the word they want but they can work their way around it,” Aronson said. In such cases, a normal score on the test “would not necessarily rule out cognitive impairment.”

Duff said it would be like having an IndyCar driver who wants to compete in the Indianapolis 500 take the same behind-the-wheel test that the DMV uses for 16-year-olds.

“My concern is that a relatively easy test still doesn’t mean you’re up to the challenge of leading one of the most powerful countries in the world,” he said.

This isn’t an issue limited to presidential candidates. It may be appropriate to ask airline pilots, bus drivers, surgeons and other people with jobs that entail a high degree of responsibility to take cognitive tests as they get older, experts said.

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“I think you can argue this is a job where your brain should be working pretty well,” Aronson said.

There is no expert consensus on whether to screen all older adults for cognitive impairment. The U.S. Preventive Services Task Force weighed the issue in 2020 and determined there wasn’t enough evidence to make a broad recommendation one way or the other.

One of the reasons for the hesitation is that screening tests aren’t good enough, said Dr. Colleen Christmas, a geriatrician at the Johns Hopkins School of Medicine.

“You’re going to catch a lot of people who don’t have issues, and you’re going to miss a lot of people who do,” she said.

There’s also the fact that the aging process varies greatly from person to person.

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“It’s incredibly heterogeneous,” Christmas said. “There’s no way to say 80 equals old whereas 75 equals young.”

Besides, no test, no matter how sensitive, can provide a full picture of a patient’s cognitive function. Doctors also need the results of blood tests, brain scans, and information from family members, among other things. If an MRI revealed evidence of several small strokes in parts of the brain that align with the patient’s cognitive deficits, for example, it would suggest a diagnosis of vascular dementia.

“It’s like putting a puzzle together,” Mosqueda said.

Biden may be in a unique position, but his bristling reaction to the idea of taking a cognitive test was pretty typical, Christmas said.

“I think people are so afraid of the diagnosis of dementia that it’s upsetting to have your doctor or a family member suggest that you need cognitive testing,” she said. “It’s a really scary prospect.”

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Shark attacks rose in 2025. Here’s why Californians should take note

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Shark attacks rose in 2025. Here’s why Californians should take note

Shark attacks returned to near-average levels in 2025 after a dip the previous year, according to the latest report from the Florida Museum of Natural History’s International Shark Attack File, published Wednesday.

Researchers recorded 65 unprovoked shark bites worldwide last year, slightly below the 10-year average of 72, but an increase from 2024. Nine of those bites were fatal, higher than the 10-year average of six fatalities.

The United States once again had the highest number of reported incidents, accounting for 38% of global unprovoked bites when assessed on a country by country basis. That said, it’s actually a decline from recent years, including 2024, when more than half of all reported bites worldwide occurred off the U.S. coast.

In 2025, Florida led all states with 11 recorded attacks. California, Hawaii, Texas and North Carolina accounted for the remaining U.S. incidents.

But California stood out in another way: It had the nation’s only unprovoked fatal shark attack in 2025.

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A 55-year-old triathlete was attacked by a white shark after entering the water off the coast of Monterey Bay with members of the open-ocean swimming club she co-founded. It was the sole U.S. fatality among 25 reported shark bites nationwide.

It’s not surprising that the sole U.S. shark-related death occurred in California, said Steve Midway, an associate professor of fisheries at Louisiana State University. “In California, you tend to have year-to-year fewer attacks than other places in the U.S. and in the world,” Midway said. “But you tend to have more serious attacks, a higher proportion of fatal attacks.”

The difference lies in species and geography, Midway said. Along the East Coast, particularly in Florida, many bites involve smaller coastal sharks in shallow water, which are more likely to result in nonfatal injuries. California’s deeper and colder waters are home to larger species, such as the great white shark.

“Great whites just happen to be larger,” Midway said. “You’re less likely to be attacked, but if you are, the outcomes tend to be worse.”

Whether measured over 10, 20 or 30 years, average annual shark bite totals globally are actually very stable.

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“The global patterns change only slightly from one year to the other,” said Gavin Naylor, director of the Florida Program for Shark Research.

Those annual fluctuations are influenced by a combination of shark biology, ocean conditions and the number of people in the water at any given time in any given place, researchers say.

At the same time, global shark populations remain far below historical levels. Naylor categorizes about 30% of shark species as endangered, largely due to overfishing. In some countries, including the United States and Australia, stronger protections have allowed certain shark populations to recover.

Nevertheless, the risk of being bitten by a shark remains extremely low. The report notes that drowning is a far more common cause of death worldwide — and, if it helps you sleep (or swim), the data show that you are much more likely to be killed by lightning than you are by a shark.

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What a Speech Reveals About Trump’s Plans for Nuclear Weapons

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What a Speech Reveals About Trump’s Plans for Nuclear Weapons

Within hours of the expiration last week of the final arms control treaty between Moscow and Washington, the State Department sent its top arms diplomat, Thomas G. DiNanno, to Geneva to lay out Washington’s vision for the future. His public address envisioned a future filled with waves of nuclear arms buildups and test detonations.

The views of President Trump’s administration articulated in Mr. DiNanno’s speech represent a stark break with decades of federal policy. In particular, deep in the speech, he describes a U.S. rationale for going its own way on the global ban on nuclear test detonations, which had been meant to curb arms races that in the Cold War had raised the risk of miscalculation, and war.

This annotation of the text of his remarks aims to offer background information on some of the specialized language of nuclear policymaking that Mr. DiNanno used to make his points, while highlighting places where outside experts may disagree with his and the administration’s claims.

What remains unknown is the extent to which Mr. DiNanno’s presentation represents a fixed policy of unrestrained U.S. arms buildups, or more of an open threat meant to spur negotiations toward new global accords on ways to better manage the nuclear age.

Read the original speech.

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New York Times Analysis

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1

Established in 1979 as Cold War arsenals grew worldwide, the Conference on Disarmament is a United Nations arms reduction forum made up of 65 member states. It has helped the world negotiate and adopt major arms agreements.

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2

In his State Department role, working under Secretary of State Marco Rubio, Mr. DiNanno is Washington’s top diplomat for the negotiation and verification of international arms accords. Past holders of that office include John Bolton during the first term of the George W. Bush administration and Rose Gottemoeller during Barack Obama’s two terms.

3

This appears to be referring to China, which has 600 nuclear weapons today. By 2030, U.S. intelligence estimates say it will have more than 1,000.

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4

Here he means Russia, which is conducting tests to put a nuclear weapon into space as well as to develop an underwater drone meant to cross oceans.

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New York Times Analysis

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5

In this year’s federal budget, the Trump administration is to spend roughly $90 billion on nuclear arms, including basic upgrades of the nation’s arsenal and the replacement of aging missiles, bombers and submarines that can deliver warheads halfway around the globe.

6

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A chief concern of many American policymakers is that Washington will soon face not just a single peer adversary, as in the Cold War, but two superpower rivals, China and Russia.

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New York Times Analysis

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7

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The 1987 Intermediate-Range Nuclear Forces Treaty or I.N.F. banned all weapons capable of traveling between 500 and 5,500 kilometers, or 310 and 3,420 miles, whether armed with nuclear or conventional warheads. The Trump administration is now deploying a number of conventionally armed weapons in that range, including a cruise missile and a hypersonic weapon.

8

The destructive force of the relatively small Russian arms can be just fractions of the Hiroshima bomb’s power, perhaps making their use more likely. The lesser warheads are known as tactical or nonstrategic nuclear arms, and President Vladimir V. Putin of Russia has repeatedly threatened to use them in Ukraine.

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9

Negotiators of arms control treaties have mostly focused on long-range weapons because the delivery vehicles and their deadly warheads are considered planet shakers that could end civilization.

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New York Times Analysis

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10

This underwater Russian craft is meant to cross an ocean, detonate a thermonuclear warhead and raise a radioactive tsunami powerful enough to shatter a coastal city.

11

The nuclear power source of this Russian weapon can in theory keep the cruise missile airborne far longer than other nuclear-armed missiles.

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12

Russia has conducted test launches for placing a nuclear weapon into orbit, which the Biden administration quietly warned Congress about two years ago.

13

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The term refers to the five permanent members of the United Nations Security Council—China, France, Russia, the United Kingdom and the United States.

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New York Times Analysis

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14

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A top concern of American officials is that Beijing and Moscow might form an alliance to coordinate their nuclear forces. Their joint program to develop fuel for atom bombs is seen as an indication of this emerging threat.

15

This Trump administration plan is dated November but was made public in December.

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16

Released last year, this Chinese government document sought to portray Beijing as a leader in reducing the global threat of nuclear weapons.

17

Typically, arms control treaties have not required countries to destroy warheads so their keepers put them into storage for possible reuse. The United States retains something on the order of 20,000 small atom bombs meant to ignite the larger blasts of hydrogen bombs.

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18

An imminent surge centers on the nation’s Ohio-class submarines. The Trump administration has called for the reopening of submarine missile tubes that were closed to comply with the New START limits. That will add as many 56 long-range missiles to the fleet. Because each missile can hold multiple arms, the additional force adds up to hundreds more warheads.

19

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This refers to weapons meant for use on a battlefield or within a particular geographic region rather than for aiming at distant targets. It is often seen as synonymous with intermediate-range weapons.

20

Here, the talk turns to the explosive testing of nuclear weapons for safety, reliability and devising new types of arms. The United States last conducted such a test in 1992 and afterwards adopted a policy of using such nonexplosive means like supercomputer simulations to evaluate its arsenal. In 1996, the world’s nuclear powers signed a global ban on explosive testing. A number of nations, including the United States and China, never ratified the treaty, and it never officially went into force.

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21

In new detail, the talk addresses what Mr. Trump meant last fall when he declared that he had instructed the Pentagon “to start testing our Nuclear Weapons on an equal basis” in response to the technical advances of unnamed foreign states.

22

Outside experts say the central issue is not whether China and Russia are cheating on the global test ban treaty but whether they are adhering to the U.S. definition. From the treaty’s start in 1996, Washington interpreted “zero” explosive force as the compliance standard but the treaty itself gives no definition for what constitutes a nuclear explosion. Over decades, that ambiguity led to technical disputes that helped block the treaty’s ratification.

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23

By definition, all nuclear explosions are supercritical, which means they split atoms in chain reactions that become self-sustaining in sufficient amounts of nuclear fuel. The reports Mr. DiNanno refers to told of intelligence data suggesting that Russia was conducting a lesser class of supercritical tests that were too small to be detected easily. Russian scientists have openly discussed such small experiments, which are seen as useful for assessing weapon safety but not for developing new types of weapons.

24

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This sounds alarming but experts note that the text provides no evidence and goes on to speak of preparations, not detonations, except in one specific case.

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New York Times Analysis

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25

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The talk gave no clear indication of how the claims about Russian and Chinese nuclear testing might influence U.S. arms policy. But it repeated Mr. Trump’s call for testing “on an equal basis,” suggesting the United States might be headed in that direction, too.

26

The talk, however, ended on an upbeat but ambiguous note, giving no indication of what Mr. DiNanno meant by “responsible.” Even so, the remark came in the context of bilateral and multilateral actions to reduce the number of nuclear arms in the world, suggesting that perhaps the administration’s aim is to build up political leverage and spur new negotiations with Russia, China or both on testing restraints.

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Notoriously hazardous South L.A. oil wells finally plugged after decades of community pressure

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Notoriously hazardous South L.A. oil wells finally plugged after decades of community pressure

California Gov. Gavin Newsom announced this week that state oil and gas regulators have permanently closed one of the most infamous drill sites in Los Angeles, bringing an end to a decades-long community campaign to prevent dangerous gas leaks and spills from rundown extraction equipment.

A state contractor plugged all 21 oil wells at the AllenCo Energy drill site in University Park, preventing the release of noxious gases and chemical vapors into the densely populated South Los Angeles neighborhood. The two-acre site, owned by the Archdiocese of Los Angeles, is located across the street from several multifamily apartment buildings and less than 1,000 feet from St. Vincent School.

For years, residents and students had repeatedly complained about acrid odors from the site, with many suffering chronic headaches and nosebleeds. The health concerns prompted a community-driven campaign to shut down the site, with some residents even pleading (unsuccessfully) with the late Pope Francis to intervene.

AllenCo, the site’s operator since 2009, repeatedly flouted environmental regulations and defied state orders to permanently seal its wells.

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This month, the California Department of Conservation’s Geologic Energy Management Division (CalGEM) finished capping the remaining unplugged wells with help from Biden-era federal funding.

“This is a monumental achievement for the community who have endured an array of health issues and corporate stalling tactics for far too long,” Newsom said in a statement Wednesday. “I applaud the tireless work of community activists who partnered with local and state agencies to finish the job and improve the health and safety of this community. This is a win for all Californians.”

The land was donated to the Catholic Archdiocese of Los Angeles in the 1950s by descendants of one of the city’s early oil barons. Over the decades, the archdiocese leased the land to several oil companies including Standard Oil of California.

Much of the community outcry over the site’s management occurred after AllenCo took over the site in 2009. The company drastically boosted oil production, but failed to properly maintain its equipment, resulting in oil spills and gas leaks.

In 2013, U.S. Environmental Protection Agency officials became sick while inspecting the site. The federal investigators encountered puddles of crude oil on the facility grounds, as well as caustic fumes emanating from the facility, resulting in violations for air quality and other environmental infractions.

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In 2020, CalGEM ordered AllenCo to plug the wells after if determined the company had essentially deserted the site, leaving the wells unplugged and in an unsafe condition. AllenCo ignored the order.

In perhaps the most remarkable events in the site’s history, CalGEM officials in 2022 arrived on the site with a court order and used bolt cutters to enter the site to depressurize the poorly maintained oil wells.

The AllenCo wells were prioritized and plugged this week as part of a CalGEM program to identify and permanently cap high-risk oil and gas wells. Tens of thousands of unproductive and unplugged oil wells have been abandoned across California — many of which continue to leak potentially explosive methane or toxic benzene.

Environmental advocates have long fought for regulators to require oil and gas companies to plug these wells to protect nearby communities and the environment.

However, as oil production declines and fossil fuel companies increasingly become insolvent, California regulators worry taxpayers may have to assume the costs to plug these wells. Federal and state officials have put aside funding to deal with some of these so-called “orphaned” wells, but environmental advocates say it’s not enough. They say oil and gas companies still need to be held to account, so that the same communities that were subjected to decades of pollution won’t have to foot the bill for expensive cleanups.

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“This is welcome news that the surrounding community deserves, but there is much more work to be done at a much faster pace,” said Cooper Kass, attorney at the Center for Biological Diversity’s Climate Law Institute. “There are still thousands of unplugged and hazardous idle wells threatening communities across the state, and our legislators and regulators should force polluters, not taxpayers, to pay to clean up these dangerous sites.”

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