Yuki Kamide, Gerry T.M. Altman, and Sarah L. Haywood (2003)

The time-course of prediction in incremental sentence processing: Evidence from anticipatory eye movements

Yuki Kamide, Gerry T.M. Altman, and Sarah L. Haywood (2003)

Incremental processing The incoming inputs are processed

incrementally on a word-by-word basis; relevant constraints are applied in parallel to the analysis of the input as it unfolds.

Prediction of thematic roles The processor can anticipate thematic role

assignments drawing on different sources of information: Lexical information about the verb coupled

with discourse-based information about available entities (Boland et al., 1995; Altmann, 1999)

E.g., Which preschool nursery/military base did Hank deliver the machine guns to _ last week?

Slower reading times in the ‘preschool nursery’ condition

Prediction of thematic roles

Selectional restrictions (Altmann & Kamide, 1999)

E.g., The boy will eat the cake. The boy will move the cake. More anticipatory eye-movements to the target in

the selective condition.

Overview of the study The present study explores the extent to which

the incremental analysis of a sentence can lead to the assignment of thematic roles in advance of linguistic input at which that assignment is unambiguously signaled. Verb-based information (in combination with a pre-

verbal argument) in English (Experiments 1 and 2) In the absence of the verb, morphosyntactic and

semantic constraints extracted from pre-verbal arguments in Japanese (Experiment 3)

Experiment 1

Does the processor anticipate information pertaining to the Goal argument?

Can anticipatory eye movements be found during an expression that refers to a different object in the scene?

Can anticipatory eye movements be obtained even if there is no explicit task other than to look and listen?

Experiment 1

AgentAnimate Goal

Theme

Inanimate GoalDistractor

Inanimate goal

Animate goal

Methods

64 subjects 18 experimental pictures each paired with

the animate condition and the inanimate condition

SMI EyeLink head-mounted eye-tracker

Results

Region 1: No evidence of anticipatory eye movements towards the Goal

Region 2: More anticipatory eye-movements towards the appropriate Goal

Discussion The processor can anticipate Goal arguments

even during reference to some other object in the scene in a ‘look and listen’ task.

Some 3-place Vs with an animate Goal allowed an alternating constituent order casting doubt on whether the processor anticipated the Goal to be referred in the 1st or in 2nd post-verbal position.

It is not sure whether the verb alone, or the combination of the verb with its direct object led to the anticipatory eye movements.

Experiment 2

Can the arguments of a verb be predicted on the basis of combinatory information derived from the semantics of the Agent in combination with the verbs’ selectional restrictions?

The boy ate … vs. The cat ate …

Experiment 2

Method

64 subjects 24 scenes with 4 sentential conditions

Analyses

Results

Combinatory effects: More looks to the motorbike in the man ride condition than in the girl ride condition (Regions 1 and 2) and in the man ride condition than in the man taste condition (Region 2)

Discussion

The semantic properties of a forthcoming Theme are predicted on the basis of the combination of information about the Agent and about the verb.

Relatively small number of looks to the target objects overt shifts in attention as evidenced by eye movements may underestimate the true extent of attentional shifts

Does the prediction of a verb’s arguments have to be based on the verb itself?

Experiment 3

In Japanese, all arguments of the verb appear prior to the verb and each argument is case-marked.

E.g., syoojo-ga neko-ni sakana-o yatta. girl-nom cat-dat fish-acc gave Is there pre-head (pre-verb) prediction in

Japanese?

Experiment 3

Dative condition

Accusative condition

Prediction: More anticipatory looks towards the hamburger in the Dative condition than in the Accusative condition.

Method

24 native speakers of Japanese 16 experimental scenes

Results

Significantly more looks to the Target in the Dative condition than in the Accusative condition during the adverb

Discussion Prediction of forthcoming arguments is possible even in

the absence of the grammatical head. This prediction was in part based on syntactic information

regarding case-structure in Japanese. ?? Combinatory information derived across different NPs

Evidence against head-driven parsing accounts; support for incremental pre-head attachment.

Preference for analyzing ‘NP-dat’ as the Goal of a 3-place verb over analyzing it as the Theme or Goal of a monotransitive verb Sensitivity to the statistical distributions of particular verb types The availability in the concurrent visual scene of an object that

could plausibly take on the Theme role.

General discussion Experiment 1: verb-based info is not limited to

anticipating Themes, but can also anticipate Goals.

Experiment 2: In combination with info conveyed by the verb, the Agent can constrain the anticipation of a subsequent Theme.

Experiment 3: In a head-final construction in Japanese, properties of the Theme can be anticipated on the basis of the combination of lexico-semantic and case-marking information.

General discussion Is it the linguistic structure or the visual context

that triggers a predictive process? The processor uses accruing constraints to

compute the likely thematic relationships amongst the entities already referred to in the linguistic input and amongst the entities concurrently available in the visual context. Incremental, probabilistic processing drawing on

different sources of information at the earliest possible opportunity to establish the fullest possible interpretation of the input at each moment in time.