Time underlies many interesting human behaviors. Thus, the question of how to represent time in connectionist models is very important. One approach is to represent time implicitly by its effects on processing rather than explicitly (as in a spatial representation). The current report develops a proposal along these lines first described by Jordan (1986) which involves the use of recurrent links in order to provide networks with a dynamic memory. In this approach, hidden unit patterns are fed back to themselves; the internal representations which develop thus reflect task demands in the context of prior internal states. A set of simulations is reported which range from relatively simple problems (temporal version of XOR) to discovering syntactic/semantic features for words. The networks are able to learn interesting internal representations which incorporate task demands with memory demands; indeed, in this approach the notion of memory is inextricably bound up with task processing. These representations reveal a rich structure, which allows them to be highly context-dependent while also expressing generalizations across classes of items. These representations suggest a method for representing lexical categories and the type/token distinction.

The results of two self-paced reading studies of a syntactic ambiguity involving conjoined noun phrases to three potential noun phrase sites were compared to the corpus frequencies of the resolutions of the same ambiguity. The reading times for the attachment to the first noun phrase were faster than for the attachment to the second noun phrase, but, to the extent that any differences were observed in the corpus frequencies, attachments to the second noun phrase were more frequent. We therefore argue that the sentence comprehension mechanism is not using corpus frequencies in arriving at its preference in this ambiguity, and hence the decision principles of sentence comprehension and sentence production must be partially distinct. It is proposed that there is a factor operative in sentence comprehension that is not operative in sentence production, and this factor favors attachment to the first noun phrase. © 1999 Academic Press According to an influential proposal by Don Mitchell, Fernando Cuetos, and their colleagues, initial parsing preferences in syntactically ambiguous structures are determined by people’s exposure to similar structures in the

Understanding Constraints 2 We measured eye movements as people read short stories. The target sentences contained noun/verb homographs (e.g. “duck”) and were preceded by a biasing context sentence. The homograph in the target sentence was always disambiguated by a case-marked pronoun: e.g., “She saw his/him duck. ” Lexical bias effects (reflecting the relative frequency of the noun and verb forms) were found in the initial fixations on the homograph. In contrast, discourse congruency effects were first observed several words downstream in the probability of a regressive eye movement. Strong discourse congruency effects were also observed in the second pass reading times. We concluded that the lexical bias effects reflect processing difficulty during the initial generation of syntactic structure, while the discourse congruency effects reflect later anomaly detection. Thus, the data challenge syntactic processing models in which all relevant and available constraints are brought to bear uniformly and simultaneously.

This thesis develops a cognitive linguistic approach to language comprehension. The cognitive approach differs from traditional linguistic approaches in that linguistic description is seen as an integral part of the description of cognition, and that the object of description is the nature of conceptual structures, the processes which relate these conceptual structures, and the effect of context upon these processes. As a cognitive description within cognitive science, a computational approach is adopted: language comprehension is described in terms of two modules, a linguistic processing module and a discourse processing module. Within these modules, conceptual structures and processes are given a uniform characterization: structures are characterized as partial objects which are extended by processes into (potentially) less partial objects. In the linguistic processing module, linguistic expressions are characterized as signs which combine as head and modifier. The conceptual structu...

We propose that speech comprehension involves the activation of token representations of the phonological forms of current lexical hypotheses, separately from the ongoing construction of a conceptual interpretation of the current utterance. In a series of cross-modal priming experiments, facilitation of lexical decision responses to visual target words (e.g., time) was found for targets that were semantic associates of auditory prime words (e.g., date) when the primes were isolated words, but not when the same primes appeared in sentence contexts. Identity priming (e.g., faster lexical decisions to visual date after spoken date than after an unrelated prime) appeared, however, both with isolated primes and with primes in prosodically neutral sentences. Associative priming in sentence contexts only emerged when sentence prosody involved contrastive accents, or when sentences were terminated immediately after the prime. Associative priming is therefore not an automatic consequence of speech processing. In no experiment was there associative priming from embedded words (e.g., sedate-time), but there was inhibitory identity priming (e.g., sedate-date) from embedded primes in sentence contexts. Speech comprehension therefore appears

journal homepage: www.elsevier.com/locate/neuropsychologia Modulation of motor and premotor cortices by actions, action words and

Three eye movement studies with novel lexicons investigated the role of semantic context in spoken word recognition, contrasting 3 models: restrictive access, access–selection, and continuous integration. Actions directed at novel shapes caused changes in motion (e.g., looming, spinning) or state (e.g., color, texture). Across the experiments, novel names for the actions and the shapes varied in frequency, cohort density, and whether the cohorts referred to actions (Experiment 1) or shapes with action-congruent or action-incongruent affordances (Experiments 2 and 3). Experiment 1 demonstrated effects of frequency and cohort competition from both displayed and non-displayed competitors. In Experiment 2, a biasing context induced an increase in anticipatory eye movements to congruent referents and reduced the probability of looks to incongruent cohorts, without the delay predicted by access–selection models. In Experiment 3, context did not reduce competition from non-displayed incompatible neighbors as predicted by restrictive access models. The authors conclude that the results are most consistent with continuous integration models.