Ambiguity and garden path sentences

Mohammad SALEHI

Numerous humorous witty expressions have long been used by people based on the concept of lexical and structural ambiguities. But ambiguity is not a simple phenomenon to be used just for entertaining the listeners. It favorably lends itself to cognitive psychology and psycholinguistics. Also, within the realm of cognitive psychology and psycholinguistics are garden path sentences. A garden path sentence is a sentence “that ends with an interpretation that differs from the interpretation that the reader or the listener initially expected” (Lee et al., 2012). The garden path phenomenon is identified by Bever (1970) and it happens when the processor encounters a temporarily ambiguous sentence that is eventually disambiguated “toward a less preferred interpretation” (Lee et al., 2012). Garden path sentences are used in psycholinguistics to illustrate the fact that when human beings read, they process language one word at a time. “Garden path” refers to the saying “to be led down the garden path”, meaning to be deceived, tricked, or seduced (Sanz, Laka, & Tanenhaus, 2013).

Reaction time (RT) is a measure of duration from stimulus to response that can be classified as either simple (press a button when stimulus appears), recognition (press a button when certain stimuli appear, while ignoring others), or choice (press corresponding button when specific stimulus appears).

To carry out the study,  a special computer software was developed with the accuracy of micro seconds and also a set of 25 items were prepared with the acceptable levels of reliability and validity. Forty seven highly proficient subjects, all undergraduate students of Air Traffic Control, participated in this study.

In this study the reaction time of subjects to come to an understanding of five categories of items were compared. Those five categories include items with:

1. lexical ambiguity

2. grouping ambiguity

3. function ambiguity

as well as

4. garden path sentences, and

5. unambiguous sentences.

The results of the study revealed that there is no significant difference between the reaction times of items with grouping and function ambiguity. Hudson (1999) had already categorized them under the term of structural ambiguity and this study also approves of their go togetherness. All the other comparisons revealed significant differences. The greatest of those differences related to the pairs including garden path sentences. To put it in other words, garden path sentences significantly took more time to be processed than all other four categories.

Not only was a quantitative data analysis conducted, but also a number of interviews were conducted to access the underlying processes performed by the respondents. The interviews confirmed the repetitive parsing of garden path sentences to find the main verb (with a single individual exception) and the determinative role of comma placement in items with grouping ambiguity. The simplicity of unambiguous items compared with the other categories was also acknowledged by the interviewees. In case of items with function ambiguity the logical analysis of the mind was stated to be required.

The number of mistakes made by the respondents in answering the test items confirmed the higher complexity of garden path sentences in comparison with ambiguous statements. While the language proficiency level proved to affect the number of mistakes made by the subjects, it did not affect the relative reaction times of different categories in terms of within-subject variation.