Decision processes during sentence comprehension: Effects of surf ace structure on decision times

Sentence comprehension is considered to be a set of decisions concerning the identification of entities at the various linguistic “levels.” Such decisions utilize overlapping fixed capacity psychological mechanisms. To the extent that one decision is difficult, others should take longer. This framework received support in two studies in which Ss’ reaction times (RT) to the presence of a phoneme in a sentence were measured. When surface structure syntax was difficult, as in self-embedded sentences, RT was longer (given that S comprehended the sentence) than when surface structure syntax was relatively easy. Additionally, the presence in surface structure of a putative cue for underlying structure did not affect RT, though comprehension was significantly inferior.