Studies showed that two-dimensional (2D) and three-dimensional (3D) educational content contributes to learning. Although there were many studies with 3D stereoscopic learning environments, only a few studies reported on the differences between real, 2D, and 3D scenes, as far as cognitive load and attentional demands were concerned. We used electroencephalographic measurements to study and compare the theta (?), alpha (a), beta (ß) and gamma (?) frequency bands of 36 adult female participants. The participants observed three environments with the same content, a real, a 3D and a 2D environment. Brain activity was recorded for each environment and their two versions, i.e., a before version and an after version, where the position of specific objects changed. Our study's findings indicated that all participants perceived the three environments, their depicted objects, and the change of the objects' position. The participants' cognitive load and attentional demands were higher in all environments before the change of the objects' position. Working memory load, working and spatial memory, were also higher in the two digital environments (3D and 2D) before the change of the objects' position. However, the opposite was observed in the case of the real environment. This was attributed to the participants observing the real environment firstly. Overall, we propose that empirical studies with biometric data on cognitive load and attentional demands will support the design of better learning environments.