A commercially available device suppresses photic driving: implications for EEG recording

Area of Science:

• Neuroscience
• Clinical Electrophysiology

Background:

• Intermittent photic stimulation (IPS) is a standard EEG activation technique.
• Distinguishing physiological photic driving (PPD) from photoparoxysmal response (PPR) can be difficult, particularly for posterior region-limited PPR.
• Zeiss Clarlet F133 lenses (ZEISS lenses) are known to suppress PPR, but their effect on PPD is uncharacterized.

Purpose of the Study:

• To investigate the impact of ZEISS lenses on PPD across a range of flash frequencies.
• To determine if ZEISS lenses can aid in differentiating PPD from PPR.

Main Methods:

• Prospective collection of 97 EEGs exhibiting PPD during IPS (3-24 Hz, eyes open/closed).
• IPS was repeated with ZEISS lenses in subjects with pre-existing PPD.
• McNemar's test was used to compare PPD presence with and without ZEISS lenses.

Main Results:

• PPD was most frequently observed at 6-12 Hz flash frequencies.
• ZEISS lenses significantly reduced the proportion of subjects showing PPD at all tested frequencies (p < 0.001).
• This reduction occurred irrespective of eye condition (open or closed).

Conclusions:

• ZEISS lenses significantly suppress PPD across all stimulus frequencies.
• ZEISS lenses do not facilitate the distinction between PPD and PPR.
• The similar effects of ZEISS lenses on PPR suppression and PPD reduction suggest shared underlying mechanisms, potentially involving neural oscillator entrainment in the visual cortex.