The word superiority effect (WSE) refers to a phenomenon where it can be demonstrated that people can more easily recognize letters presented within words as compared to isolated letters and to letters presented within non-word strings. The effect was first described by Cattell (1886), and later contributions came from Reicher (1969) and Wheeler (1970).

Source:

Chase, C. H. and Tallal, P.: 1990, ‘A developmental, interactive activation model of the word superiority effect’, Journal of Experimental Child Psychology 49, 448-487