Written Language & Literacy 9:1 (2006), 45–65. issn 1387–6732 / e-issn 1570–6001 © John Benjamins Publishing Company Brahmi-derived scripts, script layout, and segmental awareness Richard Sproat University of Illinois at Urbana-Champaign In earlier work (Sproat 2000), I characterized the layout of symbols in a script in terms of a calculus involving two dimensional catenation operators: I claimed that lefwards, rightwards, upwards, downwards and surround- ing catenation are sufficient to describe the layout of any script. In the first half of this paper I analyze four Indic alphasyllabaries — Devanagari, Oriya, Kannada and Tamil — in terms of this model. A crucial claim is that despite the complexities of layout in alphasyllabic scripts, they are essentially no different in nature than alphabetic scripts, such as Latin. Te second part of the paper explores implications of this view for theories of phonology and human processing of orthography. Apparently problematic is evidence that “phonemic awareness” — the ability for literate speakers to manipulate sounds consciously at the phoneme level — is much stronger with alphabetic scripts, than with alphasyllabaries. But phonemic awareness is not categori- cally absent for readers of Indic scripts; in general, how aware a reader is of a particular phoneme is related to how that phoneme is rendered in the script. Relevant factors appear to include whether the symbol is written inline, whether it is a diacritic, and whether it is ligatured with another symbol. . Introduction Te Brahmi-derived Indic scripts occupy a special place in the study of writing systems. Tey are alphasyllabic scripts (Bright, 1996a), meaning that they are basically segmental in that almost all segments are represented in the script, yet the fundamental organizing principle of the script is the (orthographic) syl- lable. Crudely, an orthographic syllable — aks » ara — in an Indic script consists of a consonantal core consisting of one or more consonant symbols, with the vowels variously arranged around the core. 1 Te one exception to the principle that segments are represented is the inherent vowel, usually a schwa or /a/-like