July 2020

Experiment tests human vs. parrot memory in a complex shell game

What happens when an African grey parrot goes head-to-head with 21 Harvard students in a test measuring a type of visual memory? Put simply: The parrot moves to the head of the class.

Harvard researchers compared how 21 human adults and 21 6- to 8-year-old children stacked up against an African grey parrot named Griffin in a complex version of the classic shell game.

It worked like this: Tiny colored pom-poms were covered with cups and then shuffled, so participants had to track which object was under which cup. The experimenter then showed them a pom-pom that matched one of the same color hidden under one of the cups and asked them to point at the cup. (Griffin, of course, used his beak to point.) The participants were tested on tracking two, three, and four different-colored pom-poms. The position of the cups were swapped zero to four times for each of those combinations. Griffin and the students did 120 trials; the children did 36.

The game tests the brain’s ability to retain memory of items that are no longer in view, and then updating when faced with new information, like a change in location. This cognitive system is known as visual working memory and is the one of the foundations for intelligent behavior.

So how did the parrot fare? Griffin outperformed the 6- to 8-year-olds across all levels on average, and he performed either as well as or slightly better than the 21 Harvard undergraduates on 12 of the 14 of trial types.

That’s not bad at all for a so-called bird brain.

Three graphs indicting the parrot’s success against the human participants

“Think about it: Grey parrot outperforms Harvard undergrads. That’s pretty freaking awesome,” said Hrag Pailian, the postdoctoral fellow at the Graduate School of Arts and Sciences who led the experiment. “We had students concentrating in engineering, pre-meds, this, that, seniors, and he just kicked their butts.”

Full disclosure: Griffin has been the star of past cognitive studies, like showing he’s smarter than the typical 4-year-old and as intelligent as a 6- to 8-year-old child. But making Harvard students do a double take on their own intelligence is quite the step up.

To be fair, the Harvard students did manage to keep (some) of their Crimson pride intact. On the final two tests, which involved the most items and the most movement, the adults had the clear edge. Griffin’s average dipped toward the children’s performance — though never below it. The researchers were unable to determine the precise reason for this drop, but they believe it has something to do with the way human intelligence works (arguably making the Harvard students’ victory a matter of performance enhancement of the genetic variety).

The experiment was part of a study published in Scientific Reports in May. Pailian was the lead author and he collaborated with comparative psychologist Irene Pepperberg, Henry A. Morss Jr. and Elisabeth W. Morss Professor of Psychology Susan Carey, and Justin Halberda at John Hopkins University.

The researchers were investigating the limits of the brain’s ability to process and update mental representations. In other words, they were looking at the “working” portion of the visual working memory system. The ability is referred to as manipulation. And ultimately, they were hoping to gain insights into the development and origin of the visual working memory system and the nature of human intelligence.

“Any operation that you perform in your mind, it takes place in visual working memory,” Pailian said. “You store information from the outside world; you play around with it; and then you shuttle it up for higher cognition. It helps fuel STEM aptitude, mental wellness, and all these different types of important cognitive attributes …. We think that one of the main components of human intelligence, the key characteristic is that we’re able to think about all these things in our minds and do these mental manipulations, but if we find that other animals, other species can perform those manipulation operations [and also see how ancient this ability is], maybe that can help us inform what delineates human intelligence from other animal intelligence, as well.”

At a broad level, the paper’s findings hint at the possible evolutionary origins of the ability to manipulate visual memory. Griffin’s success suggests it is not limited to humans and might be shared across species derived from a common ancestor. In this case, the ancestor would be the dinosaurs, since humans and parrots are separated by more than 300 million years of evolution.

“We’re suggesting that it’s possible — we can’t prove this — that dinosaurs, our common ancestor, may have had some basic capacity,” said Pepperberg, a research associate in Harvard’s Psychology Department. “Then this [advanced manipulation] ability could have evolved in parallel [in primates and birds]. The other possibility is that our common ancestor lacked this ability, and it somehow arose independently in these two lines. But we’re arguing that because manipulation is built on storage capacity, and so many different species have similar storage capacities, that some simple form of manipulation likely existed in a common ancestor.”

In the paper, the researchers note that future work is needed to confirm manipulation ability across a wider variety of species and identify its origins.

“It’s not that we proved everything provable,” Pepperberg added. “It’s that we’ve demonstrated a behavior that leads to a lot of different questions.”

Griffin was a prime candidate for this experiment because the researchers needed an animal whose brain was functionally similar to humans but evolutionarily distant for comparison. It was also likely that parrots possessed the manipulation ability because of environmental pressures in the wild, like tracking their hungry fledglings or threats like predators. Plus, Griffin is always ready to show off his brain power and earn a few cashews as a reward.

“He’s the kind of student who asks you, ‘What do I have to do to get the A?’” and then goes and does it, Pepperberg said.

References:

When a bird brain tops Harvard students on a test.

Experiment tests human vs. parrot memory in a complex shell game.

PUBLISHED By: The Harvard Gazette SCIENCE & TECHNOLOGY.

In a disturbing parallel to H.I.V., the coronavirus can cause a depletion of important immune cells, recent studies found.

An alarming new study may explain why immunity after coronavirus infection might be fleeting, and suggests that the virus may need a cocktail of drugs to be brought under control.Credit…Niaid

At the beginning of the pandemic, the coronavirus looked to be another respiratory illness. But the virus has turned out to affect not just the lungs, but the kidneys, the heart and the circulatory system — even, somehow, our senses of smell and taste.

Now researchers have discovered yet another unpleasant surprise. In many patients hospitalized with the coronavirus, the immune system is threatened by a depletion of certain essential cells, suggesting eerie parallels with H.I.V.

The findings suggest that a popular treatment to tamp down the immune system in severely ill patients may help a few, but could harm many others. The research offers clues about why very few children get sick when they are infected, and hints that a cocktail of drugs may be needed to bring the coronavirus under control, as is the case with H.I.V.

Growing research points to “very complex immunological signatures of the virus,” said Dr. John Wherry, an immunologist at the University of Pennsylvania whose lab is taking a detailed look at the immune systems of Covid-19 patients.

In May, Dr. Wherry and his colleagues posted online a paper showing a range of immune system defects in severely ill patients, including a loss of virus-fighting T cells in parts of the body.

In a separate study, the investigators identified three patterns of immune defects, and concluded that T cells and B cells, which help orchestrate the immune response, were inactive in roughly 30 percent of the 71 Covid-19 patients they examined. None of the papers have yet been published or peer reviewed.

Researchers in China have reported a similar depletion of T cells in critically ill patients, Dr. Wherry noted. But the emerging data could be difficult to interpret, he said — “like a Rorschach test.”

Research with severely ill Covid-19 patients is fraught with difficulties, noted Dr. Carl June, an immunologist at the University of Pennsylvania who was not involved with the work.

“It is hard to separate the effects of simply being critically ill and in an I.C.U., which can cause havoc on your immune system,” he said. “What is missing is a control population infected with another severe virus, like influenza.”

One of the more detailed studies, published as a preprint and under review at Nature Medicine, was conducted by Dr. Adrian Hayday, an immunologist at King’s College London.

He and his colleagues compared 63 Covid-19 patients at St. Thomas’s Hospital in London to 55 healthy people, some of whom had recovered from coronavirus infections.

St. Thomas’s Hospital in London, where 63 patients involved in one of the studies were treated Credit…Andy Rain/EPA, via Shutterstock

Dr. Hayday and his colleagues began with the assumption that the patients would generate a profound immune response to the coronavirus. That is why most people recover from infections with few, if any, symptoms.

But those who get very sick from the virus could have immune systems that become impaired because they overreact, as happens in sepsis patients. Alternately, the scientists hypothesized, these patients could have immune systems that struggle mightily, but fail to respond adequately to the virus.

One of the most striking aberrations in Covid-19 patients, the investigators found, was a marked increase in levels of a molecule called IP10, which sends T cells to areas of the body where they are needed.

Ordinarily, IP10 levels are only briefly elevated while T cells are dispatched. But in Covid-19 patients — as was the case in patients with SARS and MERS, also caused by coronaviruses — IP10 levels go up and stay up.

That may create chaotic signaling in the body: “It’s like Usain Bolt hearing the starting gun and starting to run,” Dr. Hayday said, referring to the Olympic sprinter. “Then someone keeps firing the starting gun over and over. What would he do? He’d stop, confused and disoriented.”

The result is that the body may be signaling T cells almost at random, confusing the immune response. Some T cells are prepared to destroy the viruses but seem undermined, behaving aberrantly. Many T cells apparently die, and so the body’s reserves are depleted — particularly in those over age 40, in whom the thymus gland, the organ that generates new T cells, has become less efficient.

The research also suggests that a popular idea for treatment may not help most people.

Some patients are severely affected by coronavirus infections because their immune systems respond too vigorously to the virus. The result, a so-called cytokine storm, also has been seen in cancer patients treated with drugs that supercharge T cells to attack tumors.

These overreactions can be quelled with medications that block a molecule called IL-6, another organizer of immune cells. But these drugs have not been markedly effective in most Covid-19 patients, and for good reason, Dr. Hayday said.

“There clearly are some patients where IL-6 is elevated, and so suppressing it may help,” he explained. But “the core goal should be to restore and resurrect the immune system, not suppress it.”

The new research may help answer another pressing question: Why is it so rare for a child to get sick from the coronavirus?

Children have highly active thymus glands, the source of new T cells. That may allow them to stay ahead of the virus, making new T cells faster than the virus can destroy them. In older adults, the thymus does not function as well.

The emerging picture indicates that the model for H.I.V. treatment, a cocktail of antiviral drugs, may be a good bet both for those with mild illnesses and those who are severely ill.

Some experts have wondered if antiviral treatment makes sense for severely ill Covid-19 patients, if their main affliction is an immune system overreaction.

But if the virus directly causes the immune system to malfunction, Dr. Hayday said, then an antiviral makes sense — and perhaps even more than one, since it’s important to stop the infection before it depletes T cells and harms other parts of the immune system.

“I have not lost one ounce of my optimism,” Dr. Hayday said. Even without a vaccine, he foresees Covid-19 becoming a manageable disease, controlled by drugs that act directly against the virus.

“A vaccine would be great,” he said. “But with the logistics of its global rollout being so challenging, it’s comforting to think we may not depend on one.”

Referrences

Published: June 26, 2020, New York Times.

By: Gina Kolata

Monthly Archives: July 2020

When a bird brain tops Harvard students on a test

How the Coronavirus Short-Circuits the Immune System