Measurement of temporal frequency characteristics of VEP using pseudorandom binary sequence and their correlation with cerebral blood flow in human visual cortex

Steady-state visual evoked potentials (S-VEP) have been used to derive temporal frequency characteristics, which are effective in detecting sensitivity loss for high-frequency stimuli in early glaucoma. However, this method requires independent measurements of VEPs for various frequencies. In this study, an improved technique using pseudorandom binary sequence (PRBS) stimulation to elicit VEPs (PRBS-VEP) was proposed and compared with the S-VEP. Regional cerebral blood flow (CBF) was also measured with positron emission tomography (PET), and its response to stimulation was compared with the VEP. Results showed that PRBS-VEP yielded temporal frequency characteristics similar to those obtained by S-VEP, but in a much shorter time. Furthermore, CBF response in the primary visual cortex was well correlated with the VEP amplitude, suggesting that VEPs originate in the primary visual cortex.