Lexical Processing

Retrieving word-level information, either during spoken language comprehension or reading, requires mapping a sensory stimulus to a stored mental representation. In reading, an important question is the extent to which the orthographic representation of a word is connected to its phonological form. In my neurolinguistic reasearch, I have identified an early magnetoencephalography (MEG) response (~200 ms) that dissociated the visual processing of words from legal nonwords (Almeida & Poeppel, 2013). I interpreted this response as reflecting the contact between an orthographic form with its phonological form in the mental lexicon.

I am currently building on this finding by studying reading in Arabic, as it allows us to tease apart the roles of familiarity (how often readers encounter an orthographic form) and specificity (the extent to which an orthographic form is uniquely mapped to a phonological form in the mental lexicon). These two variables are generally confounded in alphabetic writing systems, but at odds with each other in the Arabic writing system. The Arabic writing system expresses short vowels and geminated consonants via optional – and generally omitted – diacritics. Therefore, forms without diacritics are at once the most familiar and least specific, as they are often ambiguous as to their phonological and/or morphological content. Conversely, forms with diacritics are the least familiar but the most specific. Research from my lab has shown that the time it takes to recognize a word is largely determined by orthographic form familiarity, but not its specificity (Almeida, Schluter, Tucker & Idrissi, in prep).

A recent NYUAD capstone student (Rosy Tahan) has extend this research in Arabic and ran an electroencephalogram (EEG) study using the paradigm I have developed in Almeida & Poeppel (2013) to refine our understanding of this particular brain response, as well as other reading-related brain responses (Tahan & Almeida, in prep).

Another recent NYUAD capstone student (Kefei Wu) has completed an MEG study comparing the reading of Chinese characters and their Pinyin transliteration by fluent Chinese readers, Chinese learners and English speakers naïve to Chinese. The goal was to compare how the early visual brain responses change as a function of expertise with different types of writing systems that privilege different types of word-level information, such as meaning versus sound (Wu & Almeida, in prep).

Publications

(2009). A lexical basis for N400 context effects: Evidence from MEG. Brain & Lge.

PDF Project Project doi:10.1016/j.bandl.2009.08.007