The homunculus is a traditional neuroscience diagram that depicts the mind areas that understand and management the totally different physique components. It illustrates the truth that we now have bigger mind areas dedicated to physique components which have extra differentiation in notion and management, such because the arms and face.
These areas has been well-mapped for many years, however a brand new examine made some updates to the motor homunculus as proven beneath.
The up to date map contains three new areas, depicted in crimson. These separate the first motor cortex into three sections: decrease physique, higher physique/torso, and head. The crimson areas are labelled intereffector areas, and doubtless operate to coordinate actions between the totally different sections. These areas will not be current in new borns, begin to develop at 11 months, and are largely mature in nine-year olds.
One other new discovering is that inside every physique part, the outermost physique half is within the heart, with inside components radiating outwards. Thus, the fingers and toes are within the heart of the decrease and higher physique sections, with the hips and shoulders on the skin. I wonder if the central location of the fingers and toes has one thing to do with the truth that these are the areas the place we work together with the atmosphere.
The intereffector areas may additionally be concerned in ache notion, and additional analysis will look additional into this connection.
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That’s the precise title of recent scientific examine. The proof? Researchers browsed YouTube movies like this:
And this:
So why do the apes do that? Right here’s the reason from the paper:
When spinning, the apes achieved speeds enough to change self-perception and situational consciousness that have been corresponding to these tapped for transcendent experiences in people (e.g. Sufi whirling), and the variety of revolutions spun predicted behavioural proof for dizziness. Thus, spinning serves as a self-sufficient means of adjusting body-mind responsiveness in hominids. A proclivity for such experiences is shared between people and nice apes, and gives an entry level for the comparative examine of the mechanisms, features, and adaptive worth of altered states of thoughts in human evolution.
So the apes have been on the lookout for self-transcendence? Hmm. I believe a greater rationalization was that they have been taking part in. Bodily play usually includes actions that create some sort of threat. The animals profit from participating with this threat as a result of it develops their motion expertise and confidence. Right here’s a great quote from the psychologist Peter Grey:
Of their motor play and rough-and-tumble play, juvenile mammals seem to place themselves intentionally into awkward, reasonably horrifying conditions. . . . Once they leap, for instance, they twist and switch in ways in which make it troublesome to land. They appear to be dosing themselves with reasonable levels of worry, as if intentionally studying cope with each the bodily and emotional challenges of the reasonably harmful situations they generate.
For extra on dangerous play, right here’s a earlier publish.
Stress from train can both construct the physique up or break it down, relying on its frequency, quantity, depth, and kind.
Now we have a good suggestion concerning the sorts of stresses that make muscle groups stronger, as a result of the well being and performance of muscle groups is pretty simple to measure and assess. What about intervertebral discs? It is onerous to collect proof about how they reply to stress due to their deep location within the physique.
Degeneration of the disks is mostly overrated as a explanation for again ache, however it may be a contributing issue, so we want them to be as wholesome as potential. It could due to this fact be good to know one thing how they adapt to bodily stress, and what sorts of train have a tendency to construct them up versus break them down.
This paper (h/t David Poulter) examines the out there proof and tries to make suggestions. It seems to be at research inspecting cadavers, the disc well being of varied sorts of athletes, and the response of animals to train. Listed here are some fascinating findings.
Research on cadavers recommend that discs can stand up to excessive a great deal of axial compression, however usually tend to be broken when these masses contain end-range flexion. Torsion and rotation could harm the disc by way of shearing forces.
Research on disc cells recommend that they reply positively to dynamic axial loading. Static loading and immobilization will not be useful.
Disc degeneration is extra widespread in sports activities involving the chance of traumatic damage (e.g. gymnastics and soccer), repetitive loading of the backbone in the long run vary of flexion and extension (e.g. gymnastics, cricket, weightlifting, and rowing), repetitive loading into rotation (e.g. baseball and swimming) and frequent unpredictable touchdown forces (e.g. volleyball and horseback using.)
Working sports activities seem like both not detrimental or useful.
Greater ranges of sport participation are related to extra harm. However too little bodily exercise can be an issue:
It seems there’s a U-shaped relationship between lifetime bodily exercise and IVD degeneration: sedentary occupations and heavy occupations can enhance the chance of IVD degeneration [50], with the least quantity of degenerative adjustments in individuals who carried out reasonable ranges of bodily exercise.
A number of examine on animals have proven useful results of operating on disc well being.
From this proof the authors concluded that some types of stress on the discs construct them up, and others break them down:
General, this physique of literature helps to underscore the purpose that the IVD does adapt to loading and that this response could ‘strengthen’ the IVD, however that loading can even have destructive (catabolic) results
Here’s a abstract of the sorts of loading that seem like extra useful:
loading varieties which might be probably beneficial to the IVD are dynamic, axial, at sluggish to reasonable motion speeds, and of a magnitude skilled in strolling and jogging. Static loading, torsional loading, flexion with compression, fast loading, high-impact loading and explosive duties are probably detrimental for the IVD. Decreased bodily exercise and disuse seem like detrimental for the IVD.
All of this information helps the concept strolling and operating at a reasonable stage of exercise are one of the best workouts for preserving the discs wholesome.
From an evolution perspective, that is precisely what we might anticipate. Like all different animal, human animals are designed for locomotion.
Replace: I forgot to level out that though many sports activities are related to greater threat of disc harm, this doesn’t indicate that it’s best to keep away from them or worry them! In lots of of those sports activities, again ache ranges stay low, and this can be very widespread for atheists to have a lot of tissue harm and no ache. For a lot of people the final well being advantages (and certainly ache killing advantages) of train will outweigh any harm it does to the physique.
When you needed to foretell whether or not somebody had nervousness or melancholy primarily based on their Fitbit information, which metrics could be most helpful in making your prediction? Would you have a look at steps per day, lively minutes per day, whole energy burned, or common coronary heart price?
Based on this examine, the reply is steps, and it’s not even shut.
Extra proof that strolling is one of the best type of train.
When AIs ultimately get higher than people at diagnosing and recommending therapies for medical issues, the people will nonetheless have a bonus as a result of they’ve extra empathy, proper? Perhaps not.
In a new examine, researchers at UCSD randomly chosen 195 affected person questions from a social media discussion board, and these have been answered by ChatGPT and actual docs. A panel of well being care professionals scored the solutions for high quality and empathy on a 5-point scale.
In regard to high quality, 80% of the ChatGPT solutions have been thought-about good or superb, and this determine was solely 22% for the medical doctors.
For empathy, 45% of the ChatGPT solutions have been thought-about empathetic or very empathetic, and this determine was solely 4.5% for the docs.
For extra on the examine and what it means, right here’s a good article from Eric Topol.