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> Operating on the theory that exposure to blue light has a calming effect on one’s mood, rail stations installed these LED panels as a suicide-prevention measu

by tbabb 8y ago

> Operating on the theory that exposure to blue light has a calming effect on one’s mood, rail stations installed these LED panels as a suicide-prevention measure Color me completely skeptical. That sounds like superstition to me. It reports that rates declined after installation, but if they preferentially installed the lights in areas with high rates of suicide, then we should expect to see https://en.wikipedia.org/wiki/Regression_toward_the_mean https://en.wikipedia.org/wiki/Regression_toward_the_mean .

pwaivers 8y ago
It said that the lights led to a 84 percent decline in suicides attempts. That may not be true, but it is definitely way higher than "regression towards the mean" would cause.
- tbabb 8y ago
  One could not say what is "expected" without knowing either the statistics of suicides in Japanese train stations, or the statistics of where installations happened. If per-station variance is high, or if the installed stations were significant outliers (or both), 84% would be perfectly within expectation. I find it very hard to believe that the color of the light in the train station would sway a person's life-and-death decision. Plenty of things could, but "it's blue here" does not seem like one of them. "Colors have 'magical' effects on emotion" is a very woo-y thing to believe.
  - jpatokal 8y ago
    While I share your skepticism, there's is pretty solid evidence that strong white/blue light is effective in treating seasonal affective disorder, a type of depression: https://en.wikipedia.org/wiki/Seasonal_affective_disorder#Management https://en.wikipedia.org/wiki/Seasonal_affective_disorder#Ma...
    - mcherm 8y ago
      That fact along with any reason to believe that 84% of suicides are caused by SAD might help explain things. But that "fact" isn't remotely true.
  - mistermann 8y ago
    Emotions themselves are very woo-y things.
- deleted 8y ago
  [deleted]
Aardwolf 8y ago
Yes, another article on HN a few days ago said blue light wakes you up while red light makes you sleepy (and I follow the science of that one more): https://news.ycombinator.com/item?id=17117656 https://news.ycombinator.com/item?id=17117656
rdtsc 8y ago
> exposure to blue light has a calming effect on one’s mood, That did sound strange. I know that light therapy is used for treating seasonal depression (a sibling comment already mentioned that). 84% reduction in attempts seem pretty significant. They even quoted the accompanying study which showed that it didn't simply shift the suicides to other station that didn't yet have a light installed. I wonder if there is another reason besides just the immediate "blue light make the depression subside" effect. Maybe something like "someone is aware of my pain and they tried to stop me by installing this silly light".
- tbabb 8y ago
  > Maybe something like "someone is aware of my pain and they tried to stop me by installing this silly light". That is an explanation that is much more believable to me than "mysterious color-based calming effect".

by tbabb 8y ago

pwaivers 8y ago

It said that the lights led to a 84 percent decline in suicides attempts. That may not be true, but it is definitely way higher than "regression towards the mean" would cause.

tbabb 8y ago
One could not say what is "expected" without knowing either the statistics of suicides in Japanese train stations, or the statistics of where installations happened. If per-station variance is high, or if the installed stations were significant outliers (or both), 84% would be perfectly within expectation. I find it very hard to believe that the color of the light in the train station would sway a person's life-and-death decision. Plenty of things could, but "it's blue here" does not seem like one of them. "Colors have 'magical' effects on emotion" is a very woo-y thing to believe.
- jpatokal 8y ago
  While I share your skepticism, there's is pretty solid evidence that strong white/blue light is effective in treating seasonal affective disorder, a type of depression: https://en.wikipedia.org/wiki/Seasonal_affective_disorder#Management https://en.wikipedia.org/wiki/Seasonal_affective_disorder#Ma...
  - mcherm 8y ago
    That fact along with any reason to believe that 84% of suicides are caused by SAD might help explain things. But that "fact" isn't remotely true.
- mistermann 8y ago
  Emotions themselves are very woo-y things.
deleted 8y ago
[deleted]

Aardwolf 8y ago

Yes, another article on HN a few days ago said blue light wakes you up while red light makes you sleepy (and I follow the science of that one more): https://news.ycombinator.com/item?id=17117656 https://news.ycombinator.com/item?id=17117656

rdtsc 8y ago

> exposure to blue light has a calming effect on one’s mood, That did sound strange. I know that light therapy is used for treating seasonal depression (a sibling comment already mentioned that). 84% reduction in attempts seem pretty significant. They even quoted the accompanying study which showed that it didn't simply shift the suicides to other station that didn't yet have a light installed. I wonder if there is another reason besides just the immediate "blue light make the depression subside" effect. Maybe something like "someone is aware of my pain and they tried to stop me by installing this silly light".

tbabb 8y ago
> Maybe something like "someone is aware of my pain and they tried to stop me by installing this silly light". That is an explanation that is much more believable to me than "mysterious color-based calming effect".