Sapere Aude
Tag: brain
Mountain chickadees remember the location of 80K seeds
Despite weighing less than 15g, mountain chickadees are able to survive harsh winters complete with subzero temperatures, howling winds and heavy snowfall. How do they do it? By spending the fall hiding as many as 80K individual seeds, which they then retrieve — by memory — during the winter. Their astounding ability to keep track of that many locations puts their memory among the most impressive in the animal kingdom.
Based on: the characteristic distribution of neural activity, personal accounts of intense pleasure and pain, the way various pain scales have been described by their creators, and the results of a pilot study we conducted which ranks, rates, and compares the hedonic quality of extreme experiences, we suggest that the best way to interpret pleasure and pain scales is by thinking of them as logarithmic compressions of what is truly a long-tail. The most intense pains are orders of magnitude more awful than mild pains (and symmetrically for pleasure).
China, India, Iran, Russia, Japan, USA and European nations are actively working to improve existing electroencephalography, magnetic resonance, functional infrared, and the magnetic encephalography spectrums to develop future military applications. The US Air Force believes BCI interfaces could provide faster reaction times for firing missiles, drones and guns.
Translating Predictive Coding Into Perceptual Control
some people (often including me) find free energy/predictive coding very difficult to understand, but find perceptual control theory intuitive. If these are basically the same, then someone who wants to understand free energy can learn perceptual control theory and then a glossary of which concepts match to each other, and save themselves the grief of trying to learn free energy/predictive coding just by reading Friston directly.
We are generally poor at describing our mental state. Our friends generally do a better job on identifying if we are depressed. 25% of the world will develop a serious brain malfunction in their lifetime. If you spend 10-100 hours in an fMRI, we can read your thoughts. 40 Hz flickering LED light induces gamma oscillations in the brain. After 1 hour of exposure, she saw a 50% reduction in amyloid plaques in a Alzheimer’s rat model. Expansion microscopy is the opposite of normal microscopy. Instead of zooming in on the brain, you make the brain bigger with a polymer expansion similar to the gel found in super-absorbent diapers. Ed Boyden’s team can trigger brain activity at a targeted deep area with a pair of acoustic waves at close frequencies, like 2.00 and 2.01 Hz
Better tech for reading feelings and widespread hypocrisy, seem to me to be on a collision course. As a result, within a few decades, we may see something of a “hypocrisy apocalypse”, or “hypocralypse”, wherein familiar ways to manage hypocrisy become no longer feasible, and collide with common norms, rules, and laws. In this post I want to outline some of the problems we face.
Does measuring people’s spontaneous reactions to a TV ad or a stump speech tell you how they will ultimately vote, however? “On the applied side, it’s pretty unclear, the hype from the reality. It’s easy to over-believe the ability of these tools.” So far cognitive tests have had mixed results. Contrasting studies have shown that implicit attitudes both do and don’t predict how people vote. Democracy assumes the presence of rational actors, capable of digesting information from all quarters and coming to reasoned conclusions. If neuroconsultants are even 50% as good as they claim at probing people’s innermost thoughts and shifting their voting intentions, it calls that assumption into question.
Those who are trying to improve such systems have long wondered: what is the secret of human general intelligence? In this post I want to consider we can learn about this from fact that the brain evolved. How would an evolved brain be general? if we are looking to explain a surprising generality, flexibility, and rapid evolution in human brains, it makes sense to consider the possibility that human brain design took a different path, one more like that of single-celled metabolism. That is, 1 straightforward way to design a general evolvable brain is to use an extra large toolbox of mental modules that can be connected together in many different ways. While each tool might be a carefully constructed jewel, the whole set of tools would have less of an overall structure. Like a pile of logical gates that can be connected many ways, or metabolism sub-networks that can be connected together into many networks. In this case, the secret to general evolvable intelligence would be less in the particular tools and more in having an extra large set of tools, plus some simple general ways to search in the space of tool combinations. A tool set so large that the brain can do most tasks in a great many different ways.
2023-03-25: Intelligence is modular and extremely prevalent, for generous definitions of intelligence
One implication of this hierarchy of homeostatically stable, nested modules is that organisms became much more flexible while still maintaining a coherent ‘self’ in a hostile world. Evolution didn’t have to tweak everything at once in response to a new threat, because biological subunits were primed to find novel ways of compensating for changes and functioning within altered systems. For example, in planarian flatworms, which reliably regenerate every part of the body, using drugs to shift the bioelectrically stored pattern memory results in two-headed worms. Remarkably, fragments of these worms continue to regenerate two heads in perpetuity, without editing the genome. Moreover, flatworms can be induced, by brief modulation of the bioelectric circuit, to regrow heads with shape (and brain structure) appropriate to other known species of flatworms (at about 100 million years of evolutionary distance), despite their wild-type genome.
Evidence of the octopus evolution show it would have happened too quickly to have begun here on Earth. “Thus the possibility that cryopreserved Squid and/or Octopus eggs, arrived in icy bolides several 100M years ago should not be discounted as that would be a parsimonious cosmic explanation for the Octopus’ sudden emergence on Earth 270 ma BP.”
2022-01-29:
3 hearts, pumping blue-green blood because their oxygen carrying metal is copper (versus iron in the heme of our blood). They can spend 30 minutes out of the water, to scoot between tidepools.
Alien intelligence: from a distant branch in the tree of life, the octopus is the only invertebrate to have developed a complex, clever brain. Our common evolutionary ancestor is a tubule so ancient, neither brains nor eyes yet existed. They evolved independently, on land and by sea. From the Cambrian explosion of sensing, body plans, and predation, minds evolved in response to other minds. It was an information revolution. It’s where experience begins.
The octopus brain rings around its throat. 500M neurons, similar to dog (vs. human: 86B, fly: 100K).
The octopus has over 50 different functional brain lobes (versus 4 in human)
And furthermore, 60% of its neurons are out in the arms, with a high degree of autonomy. A severed arm can carry on as if nothing has changed for several hours.
It is a distributed mesh of ganglia (knots of nerves) in a ladder-like nervous system. Recurrent neural loops serve as a local short-term memory latch.
“The octopus is suffused with nervousness; the body is not a separate thing that is controlled by the brain or nervous system.” Unconstrained by bone or shell, “the body itself is protean, all possibility. The octopus lives outside the usual body/brain divide.” (PGS)
Structurally, our eyes ended up strikingly similar to the octopus (camera-like with a focusing lens, through a transparent cornea and iris aperture to a retina backing the optic nerves). But octopus eyes have a wide-angle panoramic view, and they move independently like a chameleon.
Their horizontal slit pupil stays horizontal as the body moves, like a steady cam. This is made possible by special balance receptors called statocysts (a sac with internal sensory hairs and loose mineralized balls that roll around with movement and gravity).
They can see polarized light, but not color (making their color-matching camouflage skills all the more intriguing; they also see with their skin).
Their playful interactions with humans exhibit mischief and craft, a sign of mental surplus
Humans internalized language as a tool for complex thought (we can hear what we say and use language to arrange and manipulate ideas). Octopuses are on a different path.
Their entire skin is a layered screen, with about a megapixel directly controlled by the brain.
Skin color, pattern and fleshy texture can change in 0.7 seconds.
3 layers of skin cells control elastic sacks of pigments, internal iridescent reflections, even polarization (which the octopus can see), over a white underbody. They are regulated by acetylcholine, one of the earliest neurotransmitters in evolution.
The octopus can create a voluntary light show on its skin, e.g., a dark cloud passing over the local landscape, or a dramatic display to confuse a predator while fleeing.
30 ritualized displays for mating and other signaling.
Some octopuses have regions of constant kaleidoscopic restlessness, like animated eye shadow.
1600 suckers. 16 kg of lift capacity per sucker. 10k tasting chemoreceptors per sucker. Each is controlled individually.
Octopus muscles have radial + longitudinal fibers (agile like our tongues, not our biceps).
Opposing waves of activation can create temporary elbows at the region of constructive overlap, or pass food sucker-to-sucker like a conveyor belt.
The octopus’ arm muscles can pull 100x its own weight.
It can squeeze through a hole about the size of its eyeball.
Their ink squirts contain oxytocin (perhaps to soothe prey) and dopamine, the “reward hormone” (perhaps to trick predators that they had caught the octopus in the billowy cloud).
2022-02-17:
Soft-bodied cephalopods such as the octopus are exceptionally intelligent invertebrates with a highly complex nervous system that evolved independently from vertebrates. Because of elevated RNA editing in their nervous tissues, we hypothesized that RNA regulation may play a major role in the cognitive success of this group. We thus profiled mRNAs and small RNAs in 18 tissues of the common octopus. We show that the major RNA innovation of soft-bodied cephalopods is a massive expansion of the miRNA gene repertoire. These novel miRNAs were primarily expressed in neuronal tissues, during development, and had conserved and thus likely functional target sites. The only comparable miRNA expansions happened, strikingly, in vertebrates. Thus, we propose that miRNAs are intimately linked to the evolution of complex animal brains.
1. Set an alarm for 5 hours after you go to bed.
2. When the alarm sounds, try to remember a dream from just before you woke up. If you can’t, just recall any dream you had recently.
3. Lie in a comfortable position with the lights off and repeat the phrase: ‘Next time I’m dreaming, I will remember I’m dreaming.’ Do this silently in your mind. You need to put real meaning into the words and focus on your intention to remember.
4. Every time you repeat the phrase at step 3, imagine yourself back in the dream you recalled at step 2, and visualize yourself remembering that you are dreaming.
5. Repeat steps 3 and 4 until you either fall asleep or are sure that your intention to remember is set. This should be the last thing in your mind before falling asleep. If you find yourself repeatedly coming back to your intention to remember that you’re dreaming, that’s a good sign it’s firm in your mind.
Gregor J. Rothfuss 