This thesis belongs to the study of the nature of human numerical cognition. In particular, it focuses on the interaction between literacy and cultural conventions, such as the direction of writing systems and the use of finger counting for spatial representation of numbers. It dwells on both the cultural and epistemological aspects of this interaction, but with an emphasis on the most recent scientific discoveries, such as the mental number-line concept. A prominent signature of this work is its concentration on investigating further the subtle relationships among numerical quantities, finger counting, and spatial direction of reading and writing in new experimental populations recruited from the United Arab Emirates. More specifically, the project was mapped on two axes: (1) testing children of primary and lower secondary–school age, university students, and illiterate adults; and (2) considering two different cultural contexts, namely, Western culture and Middle Eastern culture. Altogether, the results of the present thesis indicate that mapping of numbers onto space is a universal intuition and the concept of a linear number line appears to be a cultural invention that seems to develop out of school experiences. However, learning to read and write numerals has a decisive influence on spatial numerical association coding in human brains. Our findings also promote the view that the sensory-motor system may contribute to such conceptual processes as those involved in number representation.