Probability and surprisal in auditory comprehension of morphologically complex words

► We extend the uniqueness point concept to complex words. ► Two different uniqueness points predict auditory lexical decision to complex words. ► We argue that these uniqueness point effects arise due to large surprisal (Levy, 2008). ► Moreover, how cumulative surprisal builds up in a word co-determines response time. ► Surprisal measures cognitive cost in sequence processing at word and sentence level.