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Scientists Solve Key COVID Mystery: Why Do Patients Lose Ability To Smell?

 

‘Harvard neuroscientists took a close look at a specialized type of sensory neurons in the nose that detect and transmit smells to the brain.

“Our intuition, and I think the intuition of many other people, would be that the virus would attack these sensory neurons and damage or kill these neurons, and that’s how we lose our sense of smell,” said Datta, an associate professor of neurobiology in the Blavatnik Institute at Harvard Medical School. The study Datta led was published Friday in the journal Science Advances.

“But in looking at our data, we got a big surprise,” he said. “Which is that it seems like the virus is not actually capable of attacking the neurons that live in your nose.”

Instead, the scientists discovered that two other kinds of cells that support those neurons are being attacked. Those cells can regenerate more quickly.

“And so we think, on the whole, this is good news, and suggests that people who lose their sense of smell, for the most part, are going to go on to get their sense of smell back,” Datta said.

That’s what doctors have seen as the epidemic has progressed — most patients regain their sense of smell in several weeks….’

— via WGBH

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A New Theory of Dreaming

David Eagleman and Don Vaughn’s ‘defensive activation theory’: highly original and creative, but is it convincing?

‘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….’

— Neuroskeptic, via Discover Magazine

The question for me is the basis for their assumption that visual cortical function would rapidly degrade without stimulation, as well as the notion that what happens in REM (dreaming) sleep is primarily stimulation of the visual cortex. As much as a visual experience, I have long thought of dreaming as a captivating emotional experience. I have wondered if the main purpose of dreaming might be to provide a compelling attraction to keep us asleep so that we would not miss out on the other benefits of sleep. This is experience-near — except for nightmares, which are a perversion of the process and tend to awaken us — most people when awakening from a dream try to get back to it, loathe to give it up. Given the survival value of not being caught vulnerable and asleep, we would have evolved to need less sleep if it was possible, if there were not a good reason to sleep as much as we do. And there would have to be a strong mechanism to keep us asleep and counter the attractiveness of awakening. 

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Hand to Mouth: Why?

‘If language began with gestures around a campfire and secret signals on hunts, why did speech come to dominate communication?…’

— via Aeon

Cognitive scientist Kensy Cooperrider notes the difficulty of explaining the origin of language. One particularly resilient notion has been that it began as gesture, which seems intuitive and is also borne out by examination of the communication proclivities of our primate relatives. Now to the core problem: people gesture but, outside deaf communities, speech predominates. Some factors include that speech is abstract; that it is better in the dark; that it frees up the hands to do something else; and, perhaps most important, that it takes less caloric expenditure than signing. 

So if there are good reasons to transition from gestural to verbal communication, how did it happen? There is longstanding and growing evidence of the close neurobiological coupling of hand and mouth. The mouth for example, is very active in signing, often echoing in miniaturized form. This provides a notion of a gradual route to adopt a more ‘compact’ form of communicative behavior, with gesture remaining vestigial. 

As challenging as this question is, Cooperrider ends up observing, it is only one piece of an enormously mysterious puzzle:

Even if we were able to establish some version of a gesture-first proposal as not merely plausible but likely, there would be many more layers to contend with. We would also want to understand how we came by our abilities to read other minds, to sequence and combine ideas, to conceptualise abstractions such as ‘tomorrow’ and ‘truth’. We would need to explain, not merely whether we first conveyed meaning by hand or by mouth, but why we felt an itch to mean anything at all. 

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Alexandria Ocasio-Cortez’s speech against misogyny in Congress was overdue

 

‘During a policy disagreement at the US Capitol on Tuesday, Yoho called the Congress member “crazy,” “disgusting,” and “out of [her] freaking mind.” After she left, he reportedly said she was a “fucking bitch,” according to The Hill’s Mike Lillis.

In remarks on Wednesday, Yoho glossed over most of this without taking accountability for his words. “Having been married for 45 years with two daughters, I’m very cognizant of my language,” Yoho said. “The offensive name-calling words attributed to me by the press were never spoken to my colleagues and if they were construed that way, I apologize for their misunderstanding.”

Ocasio-Cortez, however, called his deflection out for what it was: the latest example of men engaging in a culture of abuse toward women while using the women in their lives to avoid scrutiny for their actions.

“I will not stay up late at night waiting for an apology from a man who has no remorse over calling women and using abusive language towards women,” she said in a floor speech on Thursday. “But what I do have issue with is using women — wives and daughters — as shields and excuses for poor behavior.”

Her speech, which emphasized that the problem is much bigger than Yoho, was long overdue.

“Mr. Yoho was not alone. He was walking shoulder to shoulder with Representative Roger Williams,” she said. “And that’s when we start to see that this issue is not about one incident. It is cultural. It is a culture of a lack of impunity, of acceptance of violence and violent language against women, an entire structure of power that supports that.”…’

— via Vox

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Do humans have a north sense?

‘Possibly we have a sense called magnetoreception which lets us tune into the earth’s magnetic field and know where north is. Birds can do it…

There’s some scientific evidence from 2019 that humans can detect magnetic fields: when placing subjects in an isolation chamber, among many participants, changes in their brain waves correlated with changes in the magnetic field around them.

OR MAYBE:

Humans are sensitive to polarised light… Polarised light is interesting because light across the sky is polarised in a particular pattern depending on the position of the sun. See: the Raleigh sky model…

It has been suggested that Vikings were able to navigate on the open sea in a similar fashion, using the birefringent crystal Iceland spar, which they called “sunstone”, to determine the orientation of the sky’s polarization. This would allow the navigator to locate the sun, even when it was obscured by cloud cover. An actual example of such a “sunstone” was found on a sunken (Tudor) ship dated 1592, in proximity to the ship’s navigational equipment.

So maybe we unconsciously tap into a natural ability to sense polarised light, which is to say a sense of where the sun is, and so end up with a sense of north?

BONUS:

Dogs tend to poop aligned north-south. It’s probably because they’re sensitive to the earth’s magnetic field rather than polarised light. How do the scientists know? Because during magnetic storms, dogs poop any which way….’

— Matt Webb via Interconnected