Misaligned vowels – is there a processing cost?

In Thai vowels can be written non-linearly above, below or to either side of the consonant.Of particular interest to the current study is that some vowels can precede the consonant in writing but follow it in speech, hence a mismatch between the spoken and written sequence occurs, e.g. the word pen would be written as epn or camel written as ecaml. A processing cost has been found for these misaligned vowels in Devanagari in Hindi speakers (Vaid & Gupta, 2002). In order to investigate this discrepancy between spatial positioning and temporal sequencing for vowels in Thai, eye movements of twenty university students reading 50 pairs of words with misaligned and aligned vowel words matched for length and frequency embedded in same sentence frames was conducted. In addition, rapid naming data from 40 adults was collected. Behavioural data from children 6 to 9 years old reading and spelling comparable words was also analysed. Results from these studies will be discussed in relation to the overriding question whether there is an additional processing cost due to this mismatch and the implications this has in relation to the grain size used when reading Thai.