Egan, C. , Thierry, G. . & Jones, M.
In linguistics, the relationship between word form and meaning is mostly considered arbitrary. Why, then, do literary authors traditionally craft sound relationships between words? We set out to investigate these dynamic interactions between word form and meaning in both typical readers, and readers with dyslexia. Event-related brain potentials and pupil dilation (PD) were simultaneously measured whilst participants were presented with adjective-noun phrases. Stimuli were manipulated on semantic relatedness (congruent, incongruent) and form repetition (alliterating, non-alliterating) orthogonally, as in ?dazzling-diamond?; ?sparkling-diamond?; ?dangerous-diamond?; and ?creepy-diamond?. We establish that for typical readers, whilst semantic incongruency increased N400 amplitude as expected, it reduced PD, an index of attentional engagement. Second, alliteration affected semantic evaluation of word pairs, since it reduced N400 amplitude even in the case of unrelated items. Third, alliteration specifically boosted attentional engagement for related words, as shown by a sustained negative correlation between N400 amplitudes and PD change after the window of lexical integration. Preliminary results from participants with dyslexia revealed a similar pattern for both N400 amplitudes and PD, though to a lesser extent. Thus, alliteration strategically arouses attention during reading and when comprehension is challenged, phonological information helps readers to link concepts beyond the level of literal semantics.