intermittent photic stimulation
[ˌɪntəˈmitənt ˈfəutik ˌstimjuˈleiʃən]
In medicine, Intermittent Photic Stimulation, or IPS, is a form of visual stimulation used in conjunction with electroencephalography to investigate anomalous brain activity triggered by specific visual stimuli, such as flashing lights or patterns.