Habituation measured by pattern reversal visual evoked potentials depends more on check size than reversal rate

Abstract

Objective: Results have varied between studies of pattern-reversal visual evoked potential (PR-VEP) habituation, possibly caused by differences in stimulation parameters. Our aim was to estimate the interaction between check size and reversal rate on PR-VEP-habituation in healthy subjects.

Methods: Thirty-four healthy volunteers participated. Mid-occipital monocular PR-VEP was recorded in six consecutive blocks of 50 responses. Four conditions were applied in a random order: 1.5 reversals per second (rps) with 8' checks, 1.5 rps with 65' checks, 3.0 rps with 8' checks and 3.0 rps with 65' checks. N70-P100 and P100-N145 peak-to-peak amplitudes were blindly measured. ANOVA and regression slopes across the six blocks were used to test for habituation.

Results: Significant habituation slopes were found with small 8' checks while responses were stable with large 65' checks for the fast reversal rate. We found a strong trend (p = 0.06) towards a significant interaction between reversal rate and check size on habituation for N70-P100.

Conclusion: Habituation may not be detectable in healthy subjects using large 65' checks. Reversal rate had less influence than check size on habituation. The faster 3.0 rps reversal rate will reduce examination time and probably prevent drowsiness.

Significance: Small checks and fast reversal rate may be preferable in PR-VEP habituation studies.