Light Exposure & Mood. Getting Into Your Brain In New & Unexpected Ways:
Let’s take a moment to appreciate the fact that just like cats, we are all solar-powered.
The sun is out and we’re all getting enough vitamin d for a change.
Hopefully it’s doing us some good, and we’re not getting too much exposure.
But in a while things will change, and people most sensitive to sunlight are really going to notice its absence.
-After they come down off a 3-day pumpkin-spice bender of course.
And while SCIENCE so far has only vitamins, anti-depressants, and fancy light-boxes for those affected,
They might just get a lot more help in the future if Brown University researchers have anything to say about it…
The Short Answer:
- Mood disorders like SAD can be a big problem.
- Brown researchers previously discovered special cells that only communicate light-levels to the brain.
- They just recently discovered that light exposure affects not 3, but 26 different regions of the brain.
- So far, science only has divided the brain into 180.
- This suggests light exposure is impacting about 14% of the brain one way or another.
- The affected regions are everywhere from the newest to oldest parts.
- The types of regions affected included everything from image formation, to motor control, to executive function, and even emotion.
- One of these regions even has its activity suppressed, the more light you’re exposed to.
- Weirdly enough, it’s the newest & most sophisticated part of the brain.
- If meditation calms the mind, perhaps sunlight does also?
- Other work suggests the right light exposure can lead to better hormone function & sleep.
- Now that scientists have a bigger list of leads to follow, perhaps they can come up with even better solutions to mood-disorders like SAD and depression.
Read on to find out the details…
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So Seasonal Affective Disorder, or a type of depression that makes its visit around the winter months,
Is believed to stem from a lack of sunlight and the triggers that it would normally set off for neurotransmitters and hormones in the brain.
Those effects might even be more or less severe for different levels of The Big 5 personality traits.
Unfortunately, humans have not yet mastered the art of hibernation as well as bears.
Although some SAD sufferers feel so sluggish they probably wouldn’t mind doing exactly that for about 3 months.
But as straightforward as it sounds, there is a chance that it might not be.
So if you had to guess, how many different regions of the brain would you think SAD affects?
I would say 3. Mood centers, Vision Centers, and maybe something to do with Night & Day.
Well a team of Brown researchers put 20 subjects in brain-scanners to see.
And they found out, it’s actually 26.
Twenty-Six different regions out of 180 [14%]!
Not only had one of their colleagues discovered previously-unknown cells in the retina specifically-tasked at communicating only light-levels to the brain,
They built on his work to measure brain activity when subjects were subjected to different light-levels with special goggles,
And lo and behold, all kinds of unexpected functional-centers across the brain were activated.
These included the cerebral cortex, many of the cortex’s sub-structures, and all the way back in the cerebellum right next to the main vision centers.
But these weren’t restricted to just image formation as you might guess,
They also included wacky things like motor control, separate areas of cognition, and for some also-wacky reason probably most telling of all: Emotion.
Wait a sec! If it’s not January, why the hell is an emotional center getting affected by whether or not someone sees a little or a lot of light through some goggles?
No idea, but now we know your emotional centers are being affected by light all the time, now here’s something else that’s wacky.
Guess what the researchers found out from the light-response tests?
Activity in the brain’s “Logical Decisions & Planning Traffic Cop” center (the PFC) was slowed down in direct proportion to how much light subjects were shown.
So is this working like GABA, Glycine, or mild psychedelics then?
I mean, it sounds a little bit like calming things down and freeing your mind again, right?
Note also, the PFC is the newest and most-advanced part of the brain there is. It does all the really fancy stuff.
-But wait again, if the PFC is fancy enough to do things like deciding between Cool Ranch and Screamin Sriracha Doritos, WTH is it doing running emotional-processing based on light again?
Dr. Sanes & his team also went on to say that not only does this study show for -the very first time- there are light-sensitive components to the PFC,
That may have quite a bit more to do with mood and SAD than anyone thought before.
But also weirdly, that they have no idea how the light signals got around to all the 26 regions,
-Aside from the really obvious ones that are well-known to process vision back in the occipital lobe, conspicuously-located right above the cerebellum from the previous list of affected regions.
So maybe the big conclusion could be something like: If you don’t get enough of the right type of light,
Something like your brain’s Default Mode Network goes almost haywire and bums you out.
But as all late-night computer users might tell you, there’s something else to it.
As Andrew Huberman talks about in this video with Joe Rogan, it’s all about -when- you get light and when you don’t.
If you listen to everything he explains about testosterone, estrogen, when to get what light, and the great effects it has on sleep,
You could be forgiven for thinking there’s a hell of a lot more stuff going on there besides just vitamin d.
How does it seem to affect so many other things than just circadian-rhythms of day, night, wake, and sleep?
So then we come full-circle with those implications and bring them back to the current Brown study.
The Sanes team clearly found that there is a lot more going on than anyone thought.
Research is moving science a lot closer to better, more complete, and effective fixes for SAD because of all the new leads they can start chasing down.
And the antidote to it might even be more like solar-powered mindfulness meditation, than it is just to do with brain chemicals only, like serotonin or melatonin.
Just as one final note to recap, anyone who’s been near SAD or depression knows that quality, quantity, & timing of sleep plays a huge part in the disorder.
• Source: U.Copenhagen
• More Coverage: YT- Andrew Huberman on JRE | Harvard
• Source Study: PNAS – Luxotonic signals in human prefrontal cortex as a possible substrate for effects of light on mood and cognition