This paper proposes a new theory of the relationship between the sentence processing mechanism and the available computational resources. This theory -- the Syntactic Prediction Locality Theory (SPLT) -- has two components: an integration cost component and a component for the memory cost associated with keeping track of obligatory syntactic requirements. Memory cost is

Many theories have been proposed to explain difficulty with center embedded constructions, most attributing the problem to some kind of limited capacity short-term memory. However, these theories have developed for the most part independently of more traditional memory research, which has focused on uncovering general principles such as chunking and interference. This article attempts to gain some unification with this research by suggesting that an interesting range of core sentence processing phenomena can be explained as interference effects in a sharply limited syntactic working memory. These include difficult and acceptable embeddings, as well as certain limitations on ambiguity resolution, length effects in garden path structures, and the requirement for locality in syntactic structure. The theory takes the form of an architecture for parsing which can index no more than two constituents under the same syntactic relation. A limitation of two or three items shows up in a variety o...

We present a detailed process theory of the moment-by-moment working-memory retrievals and associated control structure that subserve sentence comprehension. The theory is derived from the application of independently motivated principles of memory and cognitive skill to the specialized task of sentence parsing. The resulting theory construes sentence processing as a series of skilled associative memory retrievals modulated by similarity-based interference and fluctuating activation. The cognitive principles are formalized in computational form in the Adaptive Control of Thought–Rational (ACT–R) architecture, and our process model is realized in ACT–R. We present the results of 6 sets of simulations: 5 simulation sets provide quantitative accounts of the effects of length and structural interference on both unambiguous and garden-path structures. A final simulation set provides a graded taxonomy of double center embeddings ranging from relatively easy to extremely difficult. The explanation of center-embedding difficulty is a novel one that derives from the model’s complete reliance on discriminating retrieval cues in the absence of an explicit representation of serial order information. All fits were obtained with only 1 free scaling parameter fixed across the simulations; all other parameters were ACT–R defaults. The modeling results support the hypothesis that fluctuating activation and similarity-based interference are the key factors shaping working memory in sentence processing. We contrast the theory and empirical predictions with several related accounts of sentence-processing complexity.

This paper presents three self-paced, word-by-word reading experiments that test for the existence of on-line syntactic storage costs in English. To investigate this issue, we compared reading times for sentence regions in which storage costs varied, keeping other factors constant. Experiment 1 manipulated the number of verbs needed to form a grammatical sentence. Experiment 2 investigated whether filler-gap dependencies incur storage costs, and Experiment 3 investigated whether prepositional phrase arguments of verbs incur storage costs. The results of all three experiments demonstrate the role of online storage costs in sentence comprehension. Taken together with other results in the literature, the results also support a theory of sentence comprehension which includes empty categories mediating filler-gap dependencies. 2

What precisely is the universal nature of the human syntactic parser, such that it copes easily with some embedded structures, yet fails so dramatically on others (e.g., classic double center-embeddings)? A theory is proposed in the form of an architecture for parsing based on two simple ideas. The first is that human short-term memory is an indexing structure which can give rise to interference effects (storage limitations) when contents overlap with respect to the indices. For parsing, the contents are syntactic structures, and the indices are potential structural relations. The second idea is that the capacity of STM is the minimum capacity required to support the basic functions of parsing. The theory successfully accounts for the contrasts between over 50 difficult and acceptable constructions from English, French, German, Hebrew, Japanese, Mandarin, and Spanish. The theory has independent psychological and computational motivation, and is a functional part of a broader cognitive ...

M. A. Just and P. A. Carpenter’s (1992) capacity theory of comprehension posits a linguistic working memory functionally separated from the representation of linguistic knowledge. G. S. Waters and D. Caplan’s (1996) critique of this approach retained the notion of a separate working memory. In this article, the authors present an alternative account motivated by a connectionist approach to language comprehension. In their view, processing capacity emerges from network architecture and experience and is not a primitive that can vary independently. Individual differences in comprehension do not stem from variations in a separate working memory capacity; instead they emerge from an interaction of biological factors and language experience. This alternative is argued to provide a superior account of comprehension results previously attributed to a separate working memory capacity. The concept of a working memory resource or capacity for temporary storage and manipulation of information has played an important role in many theories of cognition, particularly theories of language processing (e.g., Baddeley, 1986; Engle, Cantor, &

It has previously been assumed in the psycholinguistic literature that finite-state models of language are crucially limited in their explanatory power by the locality of the probability distribution and the narrow scope of information used by the model. We show that a simple computational model (a bigram part-of-speech tagger based on the design used by Corley and Crocker (2000)) makes correct predictions on processing difficulty observed in a wide range of empirical sentence processing data. We use two modes of evaluation: one that relies on comparison with a control sentence, paralleling practice in human studies; another that measures probability drop in the disambiguating region of the sentence. Both are surprisingly good indicators of the processing difficulty of garden-path sentences. The sentences tested are drawn from published sources and systematically explore five different types of ambiguity: previous studies have been narrower in scope and smaller in scale. We do not deny the limitations of finite-state models, but argue that our results show that their usefulness has been underestimated. 1

Just & Carpenter's (1992) Capacity Theory of sentence comprehension posits a linguistic working memory that is functionally separated from the representation of linguistic knowledge. Waters & Caplan (1996) critiqued aspects of this approach, without abandoning the notion of a separate working memory. In this paper, we present an alternative account of language processing, motivated by a connectionist approach to language comprehension. In our view "processing capacity" emerges from network architecture and experience and is not a primitive that can be manipulated independently of linguistic knowledge or processing. Individual differences in processing abilities are not described in terms of variations in a separate working memory capacity; instead they emerge from an interaction of biological factors and experience with language. This alternative approach is argued to provide a superior account of comprehension results that were previously thought to implicate a separate working memory...

We present a series of simulations of behavioral data by casting a simple parsing model in the cognitive architecture ACT-R. We show that constraints defined in ACT-R, specifically those relating to activation, can account for a range of facts about human sentence processing. In doing so, we argue that resource limitation in working memory is better defined as an artefact of very general and independently motivated principles of cognitive processing. 1

This paper reports a self-paced reading study that compares the processing difficulity between object-gap and subject-gap relative clauses (RCs) in Japanese. The higher complexity of object-gap RCs compared with subjectgap RCs in SVO languages with postnominal relatives, such as English and French, is a well-established phenomenon in sentence processing. Two theories have been proposed to account for this phenomenon. One is in terms of resource, such as temporary storage or integration costs. The other is in terms of depth of embedding of the extracted element. Both accounts can explain the pattern of data from Englih and French, since the amount of resource in terms of linear distance is correlated with the depth-of-embedding. In this paper, Japanese, an SOV language with prenominal relatives, was tested in order to differentiate these two cost metrics. The resource theory predicts object-gap RCs to be easier due to fewer intervening words between the gap and the head noun, whereas the depth-of-embedding theory predicts subject-gap RCs to be easier. The results show that subject-gap RCs are easier than object-gap RCs in Japanese. The results are compatible with the depth-of-embedding theory. Other possible accounts are considered besides the depth-of embedding theory. 1.