Garden path sentence

A garden path sentence, such as "The old man the boat" (meaning "Old people are the crew of the boat"), is a grammatically correct sentence that starts in such a way that a reader's most likely interpretation will be incorrect; the reader is lured into a parse that turns out to be a dead end or yields a clearly unintended meaning. "Garden path" refers to the saying "to be led down [or up] the garden path", meaning to be deceived, tricked, or seduced.

Such a sentence leads the reader toward a seemingly familiar meaning that is actually not the one intended. It is a special type of sentence that creates a momentarily ambiguous interpretation because it contains a word or phrase that can be interpreted in multiple ways, causing the reader to begin to believe that a phrase will mean one thing when in reality it means something else. When read, the sentence seems ungrammatical, makes almost no sense, and often requires rereading so that its meaning may be fully understood after careful parsing.

Examples

• "The horse raced past the barn fell."
  • This frequently used, classic example of a garden path sentence is attributed to Thomas Bever.^[1] The difficulty in correctly parsing the sentence results from the fact that race can be interpreted transitively or intransitively. The reader is misled into interpreting horse as the subject and raced as the main verb in the simple past, but when the reader encounters fell they are forced to re-analyse the sentence, concluding that raced is being used as the past participle of race as a transitive verb.^[1] The sentence could be replaced by The horse that was raced past the barn fell, where that was raced past the barn tells the reader which horse is under discussion.^[2] Such examples of initial ambiguity resulting from a "reduced relative with [a] potentially intransitive verb" (The horse raced in the barn fell.) can be contrasted with the lack of ambiguity for a non-reduced relative (The horse that was raced in the barn fell.) or a with "reduced relative with [an unambiguously] transitive verb" (The horse frightened in the barn fell.).^[3] As with other examples, one explanation for the initial misunderstanding by the reader is that a sequence of phrases tends to be analysed in terms of the frequent pattern: agent – action – patient.^[3]
• "The old man the boat."
  • This is another common example that has been the subject of psycholinguistic research and has been used to test the capabilities of artificial intelligence efforts.^[4] The difficulty in correctly parsing the sentence results from the fact that readers tend to interpret old as an adjective. Reading the, they expect a noun or an adjective to follow, and when they then read old followed by man they assume that the phrase the old man is to be interpreted as determiner – adjective – noun. When readers encounter another the following the supposed noun man (rather than the expected verb),^{[lower-alpha 1]} they are forced to re-analyse the sentence.^[5] This example of initial ambiguity (The old man the boat.) can be contrasted with the lack of ambiguity of a similar but unambiguous sentence where man is followed by a verb (The old man washed the boat).^[5] As with other examples, one explanation for the initial misunderstanding by the reader is that a sequence of words or phrases tends to be analysed in terms of a frequent pattern: in this case: determiner – adjective – noun.^[5]
• "The complex houses married and single soldiers and their families."
  • This is another commonly cited example.^[6] Like the previous sentence, the initial parse is to read the complex houses as a noun phrase, but the complex houses married does not make semantic sense (houses do not marry) and the complex houses married and single makes no sense at all (after married and..., the expectation is another verb to form a compound predicate). The correct parsing is The complex [noun phrase] houses [verb] married and single soldiers [noun phrase] and their families [noun phrase]. Rephrased, the sentence could be rewritten as There are both married and single soldiers, and the families of those soldiers, living in the complex.

Parsing

When reading a sentence, readers will analyze the words and phrases they see and make inferences about the sentence’s grammatical structure and meaning in a process called parsing. Generally, readers will parse the sentence chunks at a time and will try to interpret the meaning of the sentence at each interval. As readers are given more information they make an assumption of the contents and meaning of the whole sentence. With each new portion of the sentence encountered, they will try to make that part make sense with the sentence structures that they have already interpreted and their assumption about the rest of the sentence. The garden path sentence effect occurs when the sentence has a phrase or word with an ambiguous meaning that the reader interprets in a certain way, and when they read the whole sentence there is a difference in what has been read and what was expected. The reader must then read and evaluate the sentence again to understand its meaning. The sentence may be parsed and interpreted in different ways due to the influence of pragmatics, semantics, or other factors describing the extralinguistic context.^[7]

Parsing strategies

Various strategies can be used when parsing a sentence, and there is much debate over which parsing strategy humans use. Differences in parsing strategies can be seen from the effects of a reader attempting to parse a part of a sentence that is ambiguous in its syntax or meaning. For this reason, garden path sentences are often studied as a way to test which strategy humans use.^[8] Two debated parsing strategies that humans are thought to use are serial and parallel parsing.

Serial

Serial parsing means that the reader makes one interpretation of the ambiguity, and continues to parse the sentence in the context of the interpretation. The reader will continue to use their initial interpretation as reference for future parsing until disambiguating information is given.^[9]

Parallel

Parallel parsing means that the reader generates multiple interpretations of the sentence and stores them until disambiguating information is given, at which point only the correct interpretation is maintained.^[9]

Reanalysis of a garden path sentence

When ambiguous nouns appear, they can function as both the object of the first item or the subject of the second item. In that case the former use is preferred. It is also found that the reanalysis of a garden path sentence gets more and more difficult with the length of the ambiguous phrase.^[10]

Recovery strategies

A research paper published by Meseguer, Carreiras and Clifton (2002) stated that intensive eye movements are observed when people are recovering from a mild garden path sentence. They proposed that people use two strategies, both of which are consistent with the selective reanalysis process described by Frazier and Rayner in 1982. According to them, the readers predominantly use two alternative strategies to recover from mild garden path sentences.

• The more common one includes the regression of eyes from the first disambiguation directly to the main verb of the sentence. Then the readers reread the remaining of the sentence, fixating their eyes to the next region and the adverb (the beginning of the ambiguous part of the sentence).
• The lesser-used strategy includes the regression from the first disambiguation directly to the adverb.^[11]

Partial reanalysis

Partial reanalysis occurs when analysis is not complete. Frequently, when people can make even a little bit of sense of the later sentence, they stop analyzing further so the former part of the sentence still remains in memory and does not get discarded from it.

Therefore, the original misinterpretation of the sentence remains even after the reanalysis is done; hence participant’s final interpretations are often incorrect.^[12]

Brain processing in computation

One way to determine the brain processes involved is the use of brain electrophysiology. Brain electrophysiology is used to study the impact of disfluencies in sentence processing by the brain, which specifically use event-related potentials (ERPs). ERPs are voltages generated by the brain that can be measured through a device placed on the scalp. It is also observed that specific components of the ERPs can be associated with the activation of different and specific linguistic processes of the brain.^[13] Within ERPs, P600 is the most important component. Its activation occurs when the parser comes across a syntactic violation such as The broker persuaded to sell the stock^[14] or when the parser synthesizes an unsatisfactory disambiguation on an ambiguous string of words such as The doctor charged the patient was lying.^[15] Hence the activation of P600 marks the parser's attempt to revise the sentence's structural mis-match or ambiguity. However it is also observed that the activation of P600 may be low or completely absent if the parser is asked to pay attention only to the semantic aspects of a sentence either through an explicit instruction^[16] or through the use of specific words as a way to force a semantic analysis of the sentence.^[17] The result of yet another study conducted by Osterhout in 1997 reveal that the activation of P600 varies with the parser's own attentions to the syntactic violations of the sentence.^[18]

The effects of disfluency

Disfluent sentences have a direct effect on the way a sentence structure is built in the parser's mind. Depending on its location within a sentence, a disfluency either aids in the computation of a sentence or forces the parser to linger on the sentence for a longer period of time. It is observed that the more an individual lingers on an incorrect parse, the more it is likely that the sentence will end up being interpreted incorrectly.^[19] It also appears that the presence of a disfluency in a sentence—caused by filled and long silent parses—does not elicit the P600. Instead, it elicits another ERP component, N400, which gets activated when people try to integrate a new word into the preceding sentence's context.^[19]

See also

Similar phenomena

• Antanaclasis
• Dangling else, a similar ambiguous parsing issue with some computer programming languages
• Dangling modifier
• Donkey sentence
• False scent
• Paraprosdokian
• Syntactic ambiguity

Other

• Backtracking
• Branch predictor
• Crash blossom – garden path headlines
• List of linguistic example sentences
• Natural language processing
• Transderivational search

Notes

References

External links

• Fernanda Reffeira, Kiel Christianson, Andrew Hollingwirth, Misinterpretations of Garden-Path Sentences: Implications for Models of Sentence Processing and Reanalysis (PDF), J. Psycholinguistic Research, vol. 30, no. 1, 2001