Abstract
Space, time, and number are important parts of our experiences and they are crucial for maintaining our behaviors in daily life. Comprehending the spatial and numerical features of our environment and perceiving and constructing the temporal framework are critical for healthy cognitive functioning and also survival. Although the problem of how these three perceptual processes work was initially studied separately, the emergence of behavioral interactions between these perceptions led to the idea that they could be run by a "common system". Besides the behavioral interactions for space, time, and number perception, the lesion and neuroimaging studies investigating the neural basis of these perceptions suggest the existence of a common size perception system represented in a fronto-parietal network formed around the intraparietal sulcus. However, on the other side of the coin, there are different views proposed based on findings that contradict this common magnitude system theory. The purpose of this review is to evaluate suggested ideas together and to examine whether the representation of space, time, and number perception in the brain can be explained by a common magnitude system theory.