Mike Teacher
08-10-2003, 02:31 PM
Was doing research this week and found an old paper. This thread may have been done here, if so, soar-y. It includes the passage:
1 in 10000 people are prone to photic seizures. A photic seizure is an epileptic event that is provoked by flashing lights. A bright light pulsing at the rate of 1 to 10 Hz can drive repetitive firing of neural cells in large groups.
If enough of these cells start firing in synchrony, the activity acts in a chain reaction spreading throughout reasonably large portions of the brain. The person generally shows a brief period of absense where they are awake but do not respond. Rarely, photic seizures will become generalized convulsions. In standard neurological tests for epilepsy or the tendency for epilepsy, pulsed bright lights are used to see if seizure activity can be induced and recorded on an electroencephalograph. Some of these events are triggered accidentally in a seizure prone driver passing a picket fence with the sun behind it, or with other sources of repetitive light flashes. 50-60 Hz video images showing striped patterns have been used to induce seizures.
I'd like to hear from anyone who has experienced even the most Mild episodes of this. I used to use a strobe light for some science demonstrations, but the amount of people who have strong negative reactions to these is increasing.
I'm one. I can't really take them anymore. Never even really noticed them before that. I even had the test descibed above, it's called Evoked Response; they wire your head and hit you with strobes of different frequencies [Edit. The '1 to 10Hz' is the fancy way of saying how many times a second. So at 1Hz the strobe is firing once a second, and so on. Damn fancy science terms]. That was Not Fun.
Anyone have problem with flashing lights? PS2 Games? Bright Lights?
<IMG SRC="http://members.aol.com/miketeachr/MikeTheTeacher">
This message was edited by Mike Teacher on 8-10-03 @ 6:34 PM
1 in 10000 people are prone to photic seizures. A photic seizure is an epileptic event that is provoked by flashing lights. A bright light pulsing at the rate of 1 to 10 Hz can drive repetitive firing of neural cells in large groups.
If enough of these cells start firing in synchrony, the activity acts in a chain reaction spreading throughout reasonably large portions of the brain. The person generally shows a brief period of absense where they are awake but do not respond. Rarely, photic seizures will become generalized convulsions. In standard neurological tests for epilepsy or the tendency for epilepsy, pulsed bright lights are used to see if seizure activity can be induced and recorded on an electroencephalograph. Some of these events are triggered accidentally in a seizure prone driver passing a picket fence with the sun behind it, or with other sources of repetitive light flashes. 50-60 Hz video images showing striped patterns have been used to induce seizures.
I'd like to hear from anyone who has experienced even the most Mild episodes of this. I used to use a strobe light for some science demonstrations, but the amount of people who have strong negative reactions to these is increasing.
I'm one. I can't really take them anymore. Never even really noticed them before that. I even had the test descibed above, it's called Evoked Response; they wire your head and hit you with strobes of different frequencies [Edit. The '1 to 10Hz' is the fancy way of saying how many times a second. So at 1Hz the strobe is firing once a second, and so on. Damn fancy science terms]. That was Not Fun.
Anyone have problem with flashing lights? PS2 Games? Bright Lights?
<IMG SRC="http://members.aol.com/miketeachr/MikeTheTeacher">
This message was edited by Mike Teacher on 8-10-03 @ 6:34 PM