Aphasias and theories of linguistic representation: representing frequency, hierarchy, constructions, and sequential structure.

Error and preservation patterns in aphasic speech show that the brain makes use of the frequencies of words, constructions, and collocations, as well as category membership and hierarchical structure, during language processing. Frequency effects are evident along two quasi-independent axes: syntagmatic (the sequential context, e.g., deploying correct functors, categories, and utterance-level intonation) and paradigmatic (the choice at any given linguistic level, e.g., selecting content words and modifying structures). Frequency along the syntagmatic axis is shown to play a role in errors involving idioms, constructions, and collocations that cross major phrasal boundaries. Along the paradigmatic axis, frequency affects errors involving lexical selection, competing functors and inflected forms (e.g., using plural where singular is required). An account of language representation and processing that encompasses frequency as well as categorization and structure is compatible with what we know about how the brain works: increased experience with a linguistic structure results in increased activation-and strengthening-of the neural networks involved in processing that structure. These claims are supported by the literature on experimental work in normal speakers. Parsimony, plus the unexamined assumption that mental representation is like a written record (entries either present or absent, structure displayable in two dimensions), has been a misleading guide to modeling language representation. The substantial redundancy in representations and processing that is introduced by incorporating both frequency-based and hierarchy-based information is in fact appropriate for the brain as a fast, reliable, massively parallel error-correcting network with very large storage capacity and gradient representation strength. WIREs Cogn Sci 2013, 4:651-663. doi: 10.1002/wcs.1257 CONFLICT OF INTEREST: The authors have declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.

Comprehending conventional and novel metaphors: an ERP study.

The neural mechanisms underlying the processing of conventional and novel conceptual metaphorical sentences were examined with event-related potentials (ERPs). Conventional metaphors were created based on the Contemporary Theory of Metaphor and were operationally defined as familiar and readily interpretable. Novel metaphors were unfamiliar and harder to interpret. Using a sensicality judgment task, we compared ERPs elicited by the same target word when it was used to end anomalous, novel metaphorical, conventional metaphorical and literal sentences. Amplitudes of the N400 ERP component (320-440 ms) were more negative for anomalous sentences, novel metaphors, and conventional metaphors compared with literal sentences. Within a later window (440-560 ms), ERPs associated with conventional metaphors converged to the same level as literal sentences while the novel metaphors stayed anomalous throughout. The reported results were compatible with models assuming an initial stage for metaphor mappings from one concept to another and that these mappings are cognitively taxing.

Primary progressive aphasia in a bilingual woman.

Multilingual aphasias are common because most people in the world know more than one language, but little is known of these syndromes except in patients who have had a stroke. We present a 76-year-old right-handed woman, fluent in English and Chinese, who developed anomia at age 70 and then progressed to aphasia. Functional neuroimaging disclosed mild left temporoparietal hypometabolism. Neurolinguistic testing was performed in both English and Chinese, representing a unique contribution to the literature. Results revealed conduction-like aphasia that was comparable in the two languages, although English was slightly better preserved. Primary progressive aphasia has disrupted 2 languages in a similar manner, suggesting their close neuroanatomic relationship in this case.

What "mice trap" tells us about the mental lexicon.

Level ordering has proven inadequate as a morphological theory, leaving unexplained the experimental results taken to support it as a component of innate grammar-young children's acceptance of irregular plurals in English compounds. The present study demonstrates that these results can be explained by slower access to the grammatically preferred singulars of irregular nouns when compounds are created on-line from plural stimuli. Experiments on English noun-noun compound production and on production of either singular or plural forms from the same or opposite form confirmed that more irregular than regular plurals were used in compounds, and showed that producing irregular singulars from plurals was slower than producing regular singulars. Plural responses were also slower when cue and required response number differed.

Up close and personal: a case study of the development of three English fillers.

As Peters (2001) has suggested, the young child's use of fillers seems to indicate awareness of distributionally-defined slots in which some as yet unidentified material belongs. One may view a filler as an emergent transitional form; as a slot that serves as an underspecified lexical entry for the accumulation of phonological and functional information; or as prosodic 'sentence padding'. We trace the development of three fillers in one English-acquiring child through seven months, from their first appearance about 1;9 through their re-analysis as English functors about age 2;4. We show how the description of these fillers requires an elaboration of the current framework for describing the emergence of morphology, from a one-dimensional to a multi-dimensional model. Finally, we argue that the neglect of such transitional and under-defined elements gives a false picture of development, making it appear as if language development takes place in discontinuous steps.

Syntactic frame and verb bias in aphasia: plausibility judgments of undergoer-subject sentences.

This study investigates three factors that have been argued to define "canonical form" in sentence comprehension: Syntactic structure, semantic role, and frequency of usage. We first examine the claim that sentences containing unaccusative verbs present difficulties analogous to those of passive sentences. Using a plausibility judgment task, we show that a mixed group of aphasics performed significantly better on unaccusatives than on passives. We then turn to the observation that passives are generally harder than actives for aphasics. We show that this effect is modulated by lexical bias, i.e., the likelihood that a verb appears in a given syntactic structure: Passives of passive-bias verbs were significantly easier than passives of active-bias verbs. More generally, sentences whose structure matches the lexical bias of the main verb are significantly easier than sentences in which structure and lexical bias do not match. These findings suggest that "canonical form" reflects frequency and lexical biases.