flashing images and h&s/epilepsy

[unjulation]

just been asked if the work i show is epeleptic fraindly or not anyone got any links to some officall info on the subject, need the info for this weekend

[robotfunk]

anything over 5 and under 25 luma changes per second can be dangerous for (certain kinds of) epileptics.
(some say up to 70hz tho which i find unlikely)

the most dangerous part for epilleptics is 15-20hz it seems

it has to do with the brain states and their accompanying brainwave frequencies

60 hz is maximal neuronal firings
25 hz is the normal active mind ...
below this you go from beta to alpha waves, at
11.5 hz and below you are into alpha,lowering consciousness, below
8 hz into REM sleep

it is more likely that your brain will resonate at a frequency if it is already close to that frequency.

so lower than 5 you enter deep sleep territory which is unlikely for a punter on the dance floor.

some useful links
http://www.epilepsynse.org.uk/pages/info/leaflets/photo.cfm#lights
http://www.birket.com/strobes/Library/Strobes%20v%20Epilepsy.pdf

ive had my only ever epileptic attack while trying to simulate a brainwave generator with sound, altho I have been told it was a 'kundalindi awakening' by others ... (I still had control over my other hand so I could throw off my headphones, the other was shaking at unlikely speed and incredible amplitude)

[unjulation]

ah chears for that robo much apriciated

[akira_k]

This is very, very good info.
At my iBook's speed I'll never get anyone into an epilleptic attack, it seems ;D

Cheers!

[robotfunk]

Well it could, even if it was displaying a still image.

The type of epilepsy mentioned above is photo-sensitive epilepsy, this affects about 5% of epileptics.

Another type of epilepsy is pattern-sensitive epilepsy.
This can be induced by still images of high-contrast striped patterns (or square-wave gratings). In this case, even a printed flyer (if large enough) could be dangerous. This type of epilepsy is closely related to photo-sensitive epilepsy, and I have a hunch that the strobes trigger mental patterns that in turn trigger the epileptic attack.

[akira_k]

Time to try some stuff :D

[BerzalonFlange]

It seems that somone suffering from such a condition would know to stay away from such events.

Good to know though.

[unjulation]

i used to go out with a las who suferd from epalepsiy, and was well into the party sceen all she did was put her hooded top hood up and keep her head down when the strobes got to bad, mind there were some amusing incidents from not being able to see ware she was danceing ;) she now makes a sucsefull liveing doing circus skills in partys and the like, but the position she is now in allowes her to have more controle over the light and such like
as for a banket indervidual self imposed ban on going to gigs like this i would disagre, what i got from the promoters was a request from an indervidual who whanted to know what the lighting/visuals were like so that they could make an informed choice as to wether to attend or not and as i have come accross this through personal experiance of friend then i knew that it was not an unreasonable request and that peeps with epalepsy can go and enjoy gigs such as this
of course i personaly carnt make any garantees as to wether an indervidual with epalepsy will have a fit trigerd by my visuals but a least i can make make a more informed answere to the question and they in tern can do the same as to wether they are willing to take the risk and come to the gig
which after all is all anyone of us can do, i.e. make informed disicision for there own actions

[kallisti]

unfortunately, it's not just shows... i have known several epileptics and there are tons of things in everyday life that would trigger a seizure... stuff that most of us wouldn't even notice... a lot of it was repetitive type patterns.. sound and visuals... i've seen episodes triggered by the flow of traffic in the street, a merry go round, movies with a lot of jump cuts..., and a lot of stuff i couldn't figure out why it triggered an episode....

anyway, my whole point is...all of the epileptics i've known, know that they have a medical condition, and as such are careful about what the do/see/experience.. most of life isn't exactly epileptic friendly... (altho certain things are more likely to trigger an episode).. and they try to screen their input....

you could put up some epilepsy warning posters tho...

[revjrbobdodds]

Originally posted by kallisti
all of the epileptics i've known, know that they have a medical condition, and as such are careful about what the do/see/experience.. most of life isn't exactly epileptic friendly... (altho certain things are more likely to trigger an episode).. and they try to screen their input...

Originally posted by BerzalonFlange
It seems that somone suffering from such a condition would know to stay away from such events.

Actually, many people have epilepsy and will not know it until they have a dangerous seizure. Just as many VJs, by attempting to absolve themselves of their responsibility, will never know how devastating this will be to their sense of self-worth until they bring someone down with an attack in a club.

If you rig kit, make sure it's safe. If you do visuals, make sure they are safe as well.

There's nothing "cool" or "rebellious" in injuring or killing a member of your audience when it could have been prevented with a little consideration and a few precautions. It's more like something George Bush would do.

[unjulation]

hence the post :)

[sortedmedia]

This one was interesting for me,

Good few years ago, I got knocked around by a few guys with an Iron bar, anyhow, I ended up in hospital for a few weeks with a hemmorage on the right side of my brain and a fractured skull.

Afterwards I was under observation for quite a while and one of the things I was told by the specialists to watch for was epilepsy attacks.

I was a lampy in a club at the time so you can imagine the first thing I asked, would the strobe / flashing lighting bring this on ?

Top specialists answer .... No that i need not be concerned that it is only in a small number of epileptic cases that attacks are brought on by flashing lights, and that percentage was so low, that he wouldnt even consider it a probelm.

Needless to say I continued working in the club and never had an attack.

I guess it totally depends on the kind of epilepsy and as mentioned before, persons who have it and know it should know better than to tempt fate. (dont see too many daibetics indulging in a crate of chocolate do ya ?)

I guess if you really wanted to make a point of it you could mention (as with some TV shows now) "The show you are about to see contains bright flashing lights" ?

If it were really an issue I'm sure H&S would impose restrictions on the use / duration/ FPS of strobe and certain flashing images in a nightclub environment. And that strobes / fixtures and videos would require some sort of certification from the relavent board.

Yes I know that the thought of someone having an attack on the floor is not a pleasent, then again either is the thought of doing a gig where someone OD's, or collapeses due to dehydration which is much more probable given the enviornment we are working in.

And TBH I reckon the lampy would cause a far greater health risk with his strobes /lazers / intelligent fixtures

My 2 cents..

Steve C

[syzygy]

Originally posted by sortedmedia
If it were really an issue I'm sure H&S would impose restrictions on the use / duration/ FPS of strobe and certain flashing images in a nightclub environment. And that strobes / fixtures and videos would require some sort of certification from the relavent board.


There are no laws directly covering strobesi n the UK, but health and safety guidelines do recommend that strobes should not be used for more that 30 seconds and that warning notices should be displayed.

Apparently, some licensing authorities do impose limitations on strobe use as part of public entertainment licenses.

Many venues (mostly theatres rather than nightclubs) have strobe rules in their conditions of use.

We're doing a strobe heavy set at a night soon so we're going to post a warning message so that if anyone is there who is photo-sensitive eppileptic they let us know so we can avoid the strobe effects. Following this thread, I think we'll post a warning by the door of each night we play at to say "strobes might be used and we might be filming, so let us know if either of these things is a problem for you"

Dan.