Explicit syntactic markers
Sentence processing can be helped by words or affixes which explicitly mark the syntactic structure, but these are often left out in English, without making the utterance ungrammatical. So in (10.21) a complementiser (that) and a relative pronoun (who) have been left out compared to (10.22), but the sentence in (10.21) remains grammatical.
But leaving out syntactic markers can affect processing. For instance, response times in a phoneme monitoring task were faster when explicit markers of syntactic structure were present (Hakes, 1972). Phoneme monitoring is similar to word monitoring, but requires participants to listen for a particular speech sound rather than for a word. When participants listened to a version of sentence (10.23) with the structure made explicit by the words shown in square brackets in the example, they took less time to detect the target phoneme (/p/, shown in bold) than when those words were left out. The claim is that listeners find it easier to complete the syntactic analysis when syntactic structure is more explicitly marked and are therefore better able to pay attention to the phonemes in the input.
As we will see in the next section, there have been a considerable number of studies of sentence processing that have used eye movement measurements with reading tasks. These studies also show the usefulness of the explicit marking of syntax. For example, the sentence in (10.24) has effectively the same syntactic structure as that in (10.25). The only difference is the presence of the explicit marker that in (10.25). This marker makes it clear that the whole clause (that) the answer was wrong is the subject of the verb knew, rather than the answer being a noun phrase object as it is in (10.26). The difference is perhaps more obvious if you realise that in (10.24) and (10.25) it is not claimed that John knew the answer, merely that he knew it to be wrong. Evidence for the effect on processing of the presence of the complementiser (that) is that reading times for the word was were much longer in (10.24) than in (10.25) (Rayner & Frazier, 1987). This is because it is only at that point in 10.24 that the sentence structure becomes clear and different from that in (10.26).
Not surprisingly, the more complex a sentence structure is, the more helpful explicit markers of syntax tend to be (Morgan, Meier & Newport, 19870. Since explicit markers are words and grammatical endings that occur very frequently in the language inflectional endings, determiners, con junctions, etc., as well as generally being short, they are also easier to recognise and provide useful anchor points during processing Valian Coulson, 1988.
Prosody and punctuation
Evidence presented in Chapter 11 shows that spoken sentences also carry further cues to syntactic structure, through the intonation and phrasing used in speech. Such prosodic phrase-structure cues perform much the same function as syntactic markers, i.e. they make the syntactic structure of an utterance more explicit. It is clear that they do not simplify processing simply by providing arbitrary chunking of utterances, since prosodic phrasing is not as helpful if it is not syntactically motivated.
Punctuation provides a similar marking of syntactic structure. Consider for example the sentences in (10.27)–(10.29), which would all be identical if it were not for punctuation. Note also that as you read these out or hear them in your head you will also notice how their prosody and phrasing reflects the punctuation differences. Chapter 11 presents research that shows that our processing during silent reading can be affected by this implicit’ prosody.
Line breaks can also have an effect on sentence processing (Kennedy, Murray, Jennings & Reid, 1989). You should find that the sentence in (10.30) has been made more difficult by the position of the line break, compared with (10.31). Reading time studies confirm this finding. Formatting issues such as these have practical implications, such as in the design of signs.
