Transcranial Doppler is a tool to measure blood flow velocity (BFV) in the main arteries of the brain that has been used in previous studies to analyze brain activity during virtual reality (VR) experiences. Increments in BFV were found during the exposure to virtual environments in comparison with baseline periods. However, due to the complexity of VR experiences, there are several factors that can be having an influence in these variations, so it is necessary to separately analyze those different aspects. In this work, we summarize our results related to visual perception. A method based on spectral analysis was used to analyze the magnitude and temporal evolution of the maximum BFV signal. Results showed that, in the presence of visual stimuli, BFV quickly rises to a maximum that is achieved after a few seconds. The contribution of the visual stimuli factor to the observed BFV variations during a VR experience can be estimated from the results of the developed work.