Revealing Short–Term Memory Communication Channels Embedded in Alphabetical Texts: Theory and Experiments

The aim of the present paper is to develop further a theory on the flow of linguistic variables making a sentence, namely, the transformation: (a) characters into words; (b) words into word intervals; (c) word intervals into sentences. The relationship between two linguistic variables is studied as a communication channel whose performance is determined by the slope of their regression line and by their correlation coefficient. The theory is applicable to any field/specialty in which a linear relationship holds between two variables. The signal–to–noise ratio Γ is a figure of merit of a channel being deterministic, i.e. a channel in which the scattering of the data around the regression line is negligible. The larger Γ is, the more the channel is deterministic. In conclusion, humans have invented codes whose sequences of symbols making words cannot vary very much for indicating single physical or mental objects of their experience (larger Γ). On the contrary, a large variability (smaller Γ) is achieved by introducing interpunctions to make word intervals, and word intervals to make sentences to communicate concepts