Tag Archives: neuroscience

if a tree falls in the woods, and a microphone picks it up and is reviewed by an AI, who emails a human but the human doesn’t check their email, did it make a sound?

I’ve read the first couple chapters of This is Your Brain on Music: The Science of a Human Obsession. I don’t know if I’ll finish it, because I don’t seem to be in the mood for long non-fiction books at the moment. But there are some really interesting things. First, there is a definitive answer to the “if a tree falls in the woods…” question. The tree causes air and soil molecules to vibrate for sure. But for that to qualify as “sound”, it has to be detected by ears and transmitted to a brain, where it becomes sound. Squirrel ears can qualify, so the brain doesn’t happen to be human. In fact, scientists have put electrodes in animal brains and confirmed that they react to sound exactly as our brains do. So it’s interesting me to that we are born wired to understand music at a neural level – this is an instinct actually much more fundamental than language.

There’s some more interesting stuff. The reason a violin sounds different from a flute or a human voice has mostly to do with overtones – a note is not just a single pitch but many mathematically related pitches where the strength varies between pitches. (Some people say the violin is the most beautiful instrument because it is most like the human voice. I say this is an insult to violins.) There is also the “attack”, which is the percussive noise made when sound first starts on a given instrument, which is chaotic for a short period of time before stabilizing. Then there is reverberation or echo of the space the instrument happens to be in (as I was musing about pipe organs recently, you could think of the space as part of the instrument since it is so fundamental to the sound). Pipe organs are particularly interesting because they give the organist control over which overtones are sounded at various strengths. Digital synthesizers are intended to do exactly this, but I think anyone with well-functioning ears can still detect the difference between a synthetic sound and one produced by physical instruments. Then again, as most of the music we hear these days is recorded and played back, we are probably losing a lot of nuance of what the instruments sound like at the same time the synthesizing technology is continuing to improve.

human brain cells in rats

You wouldn’t necessarily get the idea from this Nature article that it is about implanting human brain cells in rats. But according to this (sensationalized?) article in Axios, that is exactly what it is about. The scientists are doing this to study diseases like autism that they can’t just study by growing human brain cells in a jar (which they have been doing for some time, apparently!).

Given all that, this is the paragraph that really caught my eye:

A current concern, though, is whether organoids might be transplanted to non-human primates. Paşca says there is no need: “It’s not something that we would do or that I would encourage doing.”

Axios

So it could be done then. And what can be done, Somebody somewhere will probably eventually do.

I have a childhood memory of seeing the Rats of Nimh on the big screen and being utterly terrified. By the Rats. Who were supposed to be the good guys in the story.

flu and Parkinson’s

This article makes a link between flu infection and increased risk of developing Parkinson’s disease later in life. It makes me wonder if a person’s history with viruses and other infections has a more significant effect on the brain than the average person things. There has been so much talk and worry about the effects of Covid-19 on the brain, but I wonder if a lot of viruses have these effects and Covid-19 is just the one we happen to have studied incredibly intensively over the past 2 years. It’s a disturbing thought, but also suggests that vaccines for certain viruses earlier in life could reduce risk of developing dementia later in life.

ultrasound treatment for dementia

This article in New Atlas (which I don’t know anything about) reports on an ultrasound-based treatment for dementia and Alzheimer’s that has been successful in mice and is moving to human trials next year.

The ultrasound treatment was first developed back in 2015 at the University of Queensland. The initial research was working to find a way to use ultrasound to temporarily open the blood-brain barrier with the goal of helping dementia-battling antibodies better reach their target in the brain. However, early experiments with mice surprisingly revealed the targeted ultrasound waves worked to clear toxic amyloid protein plaques from the brain without any additional therapeutic drugs.

“The ultrasound waves oscillate tremendously quickly, activating microglial cells that digest and remove the amyloid plaques that destroy brain synapses,” explained Jürgen Götz, one of the researchers on the project back in 2015. “The word ‘breakthrough’ is often mis-used, but in this case I think this really does fundamentally change our understanding of how to treat this disease, and I foresee a great future for this approach.”

microdosing

There are people taking small doses of LSD and other psychedelics every day for their possible/suspected health benefits, and there may actually be some science behind this.

Microdosing psychedelics – the regular consumption of small amounts of psychedelic substances such as LSD or psilocybin – is a growing trend in popular culture. Recent studies on full-dose psychedelic psychotherapy reveal promising benefits for mental well-being, especially for depression and end-of-life anxiety. While full-dose therapies include perception-distorting properties, microdosing may provide complementary clinical benefits using lower-risk, non-hallucinogenic doses. No experimental study has evaluated psychedelic microdosing, however; this pre-registered study is the first to investigate microdosing psychedelics and mental health. Recruited from online forums, current and former microdosers scored lower on measures of dysfunctional attitudes and negative emotionality and higher on wisdom, open-mindedness, and creativity when compared to non microdosing controls. These findings provide promising initial evidence that warrants controlled experimental research to directly test safety and clinical efficacy. As microdoses are easier to administer than full-doses, this new paradigm has the exciting potential to shape future psychedelic research.

scientific bathing

Apparently, you can influence your circadian rhythm by heating up or cooling down your body at certain times of day, and a well-timed and designed bath is one way to do that. You’ll need a clock, a water thermometer, an air thermometer, and an understanding of the metric system.

In the study, researchers at the University of Freiburg in Germany assigned 45 people with depression to either soak in 40C water for up to 30 minutes and then wrap themselves in blankets and hot water bottles for a further 20 minutes, or take 40 to 45 minutes of aerobic exercise twice a week. Eight weeks later, those taking regular warm baths in the afternoon scored six points lower on a commonly used depression scale, while the exercise group scored three points lower on average…

Your bathwater should be just a little hotter than body temperature, which is about 37C. Somewhere between 40C and 45C is ideal…

Consider the temperature of the room as well. A Japanese study showed that bathing in 41C water in a 25C room increased body temperature more than taking a bath in a 14C room. However, if taking a bath to promote sleep before bed, the room temperature should be cooler: 18C is ideal.

 

 

this is your brain on music, but the kind matters

Here’s an interesting article on how jazz and classical music wire your brain differently.

Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences studied the brains of thirty pianists—half jazz players, half classical. They found, the Institute reports, that “different processes occur in jazz and classical pianists’ brains, even when performing the same piece…”

While jazz improvisation may better teach creativity, classical training, as neuroscientist Ardon Shorr argues in his TEDx talk above, may better train the brain in information processing. These studies show that the effect of music on the brain cannot be studied without regard for the differing neurological demands of different kinds of music, just as the study of language processing cannot be limited to just one language.

As a classically trained musician (okay, an out of practice, amateur one at best but I did put significant time and effort into it in my youth), I can vouch for taking a jazz improv class once and being completely out of my depth. But the other students were all jazz musicians and nobody was really interested in bringing me along as a beginner. I also took a class once called “far out improv” with other classical musicians and a teacher who was specifically interested in teaching classical musicians to improvise, and I remember that being very cool. I’ve never heard or experienced anything like that since so it must have been unusual.

brain uploading

Good news – instead of killing you, slicing up your brain, freezing it and keeping it on ice so they can revive your consciousness centuries in the future, scientists might now be able to scan your brain and just store the pattern for later use. The bad news – they still have to kill you, slice up your brain, and freeze it first before they do the scanning. And of course there is still the old Star Trek transporter problem – when they save your pattern, disintegrate your matter, and recreate the pattern somewhere else using new matter, is it really still the same you, or is it a different you with the same memories as the original you? The new you won’t know the difference, and you won’t know the difference either because you won’t exist, so does it matter? Well, the technology still has a ways to go before we really have to worry about any of this. If they can ever find a way to save a detailed copy of your brain without killing you first, there would be very little downside to trying it. And before you ask, yes, I have read the book Altered Carbon, and no, I have not seen the new show Altered Carbon.

Alzheimer’s reversed in mice

An experimental genetic treatment has been able to completely remove the brain plaques that cause Alzheimers disease in mice.

BACE1 deletion in the adult mouse reverses preformed amyloid deposition and improves cognitive functions

BACE1 initiates the generation of the β-amyloid peptide, which likely causes Alzheimer’s disease (AD) when accumulated abnormally. BACE1 inhibitory drugs are currently being developed to treat AD patients. To mimic BACE1 inhibition in adults, we generated BACE1 conditional knockout (BACE1fl/fl) mice and bred BACE1fl/fl mice with ubiquitin-CreER mice to induce deletion of BACE1 after passing early developmental stages. Strikingly, sequential and increased deletion of BACE1 in an adult AD mouse model (5xFAD) was capable of completely reversing amyloid deposition. This reversal in amyloid deposition also resulted in significant improvement in gliosis and neuritic dystrophy. Moreover, synaptic functions, as determined by long-term potentiation and contextual fear conditioning experiments, were significantly improved, correlating with the reversal of amyloid plaques. Our results demonstrate that sustained and increasing BACE1 inhibition in adults can reverse amyloid deposition in an AD mouse model, and this observation will help to provide guidance for the proper use of BACE1 inhibitors in human patients.

living near a forest is good for your amygdala

The amygdala is a part of your brain, and what is good for it is good for you.

“Our results reveal a significant positive association between the coverage of forest and amygdala integrity,” the researchers report. The amygdala is the almond-shaped set of neurons that plays a key role in the processing of emotions, including fear and anxiety.

Perhaps surprisingly, Kuehn and her colleagues found no such association from living close to urban green spaces such as parks, or near bodies of water. Only proximity to forest land had this apparent positive effect…

The study complements the already-strong psychological evidence of the benefits of living close to nature. Previous research has linked access to green space to longer lives, lower levels of aggression, and kids’ cognitive development. One study suggests it even makes for nicer people.