[PS-1.19] Effects of surprisal in Garden-Path sentences: an additional source of difficulty

Besserman, A. & Kaiser, E.

University of Southern California

Sentences like 'While the man hunted the deer ran into the woods' cause difficulty during parsing due to the temporal ambiguity of the noun (e.g. 'the deer'): comprehenders first interpret it as the object of 'hunt' but are forced to re-analyze it as the subject of 'ran' (Ferreira/Henderson'91). This effect has been found with optionally transitive ('hunt') and reflexive absolute verbs ('bathe').

Prior work has attributed the processing disruption to noun phrase re-analysis. However, given that both verb types can occur without overt objects, comprehenders might expect them to be intransitive; thus, part of the processing difficulty might be due to surprisal at the presence of an object.

A sentence-completion study (N=34) showed people frequently use both verb types intransitively (hunt-type: 35%, bathe-type: 49%).

To investigate signs of surprisal upon encountering an object during comprehension, we conducted a self-paced reading experiment (N=48) with garden-path sentences using both verb types. Results support the object-surprisal account: Reading times at the ambiguous noun, immediately before the disambiguating verb, show significant ambiguity effects.

These findings suggest processing difficulty of garden-path constructions is not solely due to the strain of noun phrase re-analysis, as the surprisal at encountering an object contributes to disruption during parsing.