Meaning and sentence processing
Some of the early psycholinguistic research confirmed the intuitive notion that meaning plays a role in the processing of sentences. One study (Slobin, 1966) compared reading times for reversible sentences (11.1) with those for non-reversible sentences (11.3). Because both chickens and horses can see, both (11.1) and (11.2) are acceptable sentences, though clearly different in meaning. However, since chickens peck and horses typically do not, the reversed version of (11.3), shown in (11.4), is less acceptable, even though it is still a syntactically well-formed sentence.
The results of sentence–picture matching tasks indicated that passive versions of the reversible sentences, such as (11.5), are more difficult to proc ess than passive versions of the non-reversible sentences (11.6).
It is argued that this is because for the passive versions of reversible sentences there is a plausible active sentence which has the same superficial sequence of the words horse … see … chicken, but a different meaning i.e. for (11.5) there is (11.2). The corresponding sentence for the non-reversible sentence, i.e. (11.4) for (11.6), is implausible. The result suggests that some aspects of grammar i.e. the elements that mark the sentence as a passive sentence are not highly constraining of the analysis.
In other experiments, overall reading times for a range of sentences were recorded, as a measure of how easy they are to process. Shorter overall reading times were found for sentences such as (11.7) in comparison with (11.8), despite the fact that the syntactic analyses would be identical.
It was argued that semantic factors, i.e. plausibility, were influencing the ease of processing for sentences that were syntactically indistinguishable.
Steedman & Johnson-Laird 1978 also used sentence reading time to investigate the effect of plausibility, in their case in the processing of double-object sentences such as (11.9) and (11.10). Participants in this study read a sentence, pressed a button to indicate that they had understood it, and then answered a question that gauged what they had taken it to mean. Both sentences should be interpreted as having the girl as the recipient, since when there are two objects after a verb in English and neither is introduced by a preposition, contrast, to the boy, then the first is the indirect object or recipient. The sentences differ in that the indirect object interpretation of the girl in (11.10) is really the only plausible interpretation, since coats would not usually be expected to be recipients. In comparison, the objects in (11.9) are not constrained by plausibility, since either could be a recipient. The researchers found that the sentence in (11.10) took less time to understand.
However, both of the experimental paradigms described above sentence picture matching time and overall reading time could be argued to tap into processes that occur quite late during the interpretation of a sentence. That is, they are offline measures, contrasting with the more direct online measures obtained from the eye-movement studies discussed in Chapter 10.
