While virtual reality systems are used in training and in mental health treatment to simulate real-world environments, understanding the mental processing differences between artificial and real scenes has been difficult to substantiate. The ability to compare brain processing in virtual and real exposures could provide an objective quantitative comparison. In this paper, we demonstrate that verifiable EEG measurements of mental activity can be obtained while subjects are immersed in a virtual reality headset. Using standard commercial EEG measuring equipment, we recorded EEG activity in similar virtual and real scenes for 14 people encountering four different test conditions. We discuss the systematic exploration of the recording problems and the steps taken to verify the data. This data is further analyzed to conclude that differences do exist between real and virtual image processing, with variations affected more by subject and task than by which area of the brain is processing the image. We discuss some possible reasons for these findings.