The time-course of morphological, phonological and semantic processes in reading Modern Standard Arabic

The time-course of morphological, phonological and semantic processes in reading Modern Standard Arabic Sami Boudelaa (sami.boudelaa@mrc-cbu.cam.ac.uk) William Marslen-Wilson (marslen.wilson@mrc-cbu.cam.ac.uk) MRC Cognition and Brain Sciences Unit 15 Chaucer Road, Cambridge CB2 2EF, UK Abstract We investigate deverbal noun and verb morphology in Modern Standard Arabic (MSA), using two masked priming experiments in which the morphological, orthographic and semantic relationship between prime and targets are varied in four SOA conditions (32 ms, 48 ms, 64 ms, and 80 ms). Results show that early in the visual processing of MSA deverbal nouns and verbs, the role played by morphological structure (word patterns and roots), is significantly different from that played by orthographic and semantic factors. Additionally, while word pattern effects are transient and overlap with root morpheme effects only in the early stages of processing, effects of the root are reliably present throughout the recognition process. Introduction Unlike Indo-European languages where morphemic units are linearly strung one after the other to create new forms, Semitic languages like Modern Standard Arabic (MSA), or Hebrew draw on a non-linear word building principle whereby at least two abstract morphemes are interlaced one within the other (Holes, 1995, Versteegh, 1997). Reflecting this, surface word forms in such languages are traditionally analyzed into word patterns and roots. Word patterns are CV structures, primarily specifying vowels, that provide phonological structure and convey syntactic meaning, while roots consist solely of consonants and convey the broad semantic properties of the surface form (Wright, 1995). For example, the word [katama] “conceal” comprises the word pattern {fa ala} 1 with the syntactic meaning “perfective, active”, and the root {ktm} meaning “concealing”. Both of these units recur many times in the language in combination with other units. The word pattern {fa ala} is met in other forms like This is the conventional notation used to describe word patterns, where the letters “f, , l” are place holders indicating where the first, second and third root letters go when this unit is combined with a word pattern, and the vowels (“a, a” here) indicate which vowels are inserted into the surface CV template. [sakaba] “pour”, [daxala] “enter”, [faqada] “miss”. Likewise, the root {ktm} appears in such forms as [kattama] “cause to hide”, [kaatama] “withhold”, and [takattama] “keep mum”. Previous research on the use of word patterns and roots during the processing of Hebrew and MSA has yielded interesting, and largely consistent evidence that these units are actively used during processing (Frost, Forster & Deutsch, et al., 1997, Deutsch, Frost & Forster, 1998, Boudelaa & Marslen-Wilson, 2000). For instance, significant word pattern priming effects were found in Hebrew and MSA, although limited to verb morphology in Hebrew, but applying across syntactic class categories in MSA (Deutsch, et al., 1998, Boudelaa & Marslen-Wilson, 2000). Additionally, reliable root priming was also found in Hebrew and MSA nouns and verbs regardless of semantic transparency (Frost et al., 1997, Boudelaa & Marslen- Wilson, 2000). This research into Semitic morphology has provided some of the most compelling evidence in favour of the view that the role played by morphological structure in lexical processing and representation is distinct from form and meaning effects. Furthermore, the effects of word patterns and roots clearly show that bound and indeed disrupted morphemic units do influence processing. Here we focus on MSA deverbal nouns and verbs and try to go beyond the research reported so far to examine how the prior presentation of a prime word affects lexical decision to a target as a function of (a) the relationship underlying prime and target, and (b) prime display duration. As regards (a), we vary morphological, orthographic and semantic relationships between primes and targets such that the respective contributions of each of these properties can be examined. With respect to (b), we use four display durations (or SOA’s), of 32, 48, 64, and 80 ms, to assess the effects of priming across these dimensions of similarity. In an earlier masked priming investigation of Arabic morphology, we found reliable word pattern and root priming effects at an SOA of 48 ms. Since both morphemic units seem to be involved in the processing