Are lexical representations graded or discrete?

Most research on mental lexical representations (lemmas) assumes they are discrete and correspond in number to a word's number of distinct meanings. Thus, homophones (bat), whose meanings are unrelated, have separate lemmas for each meaning (one for baseball bat, another for flying bat), whereas polysemes (paper), whose senses are related, have shared lemmas (the same lemma for printer paper and term paper). However, most aspects of cognition are thought to be graded, not discrete; could lemmas be graded too? We conducted a preregistered picture-word interference study with pictures of words whose meanings ranged from unrelated (homophones) to very related (regular polysemes). Whereas semantic competitors to picture names slow picture naming, semantic competitors to non-depicted meanings of homophones facilitate naming, suggesting distinct lemmas for homophones' meanings. We predicted that competitors to non-depicted senses of polysemes would slow naming, as polysemes' depicted and non-depicted senses presumably share a lemma. Crucially, we aimed to examine the transition from facilitation to inhibition: two groupings (where competitors to non-depicted senses led to facilitation for words with two lemmas but inhibition for words with one lemma) would imply that lemmas are indeed discrete. But a transition that varies continuously by sense relatedness would imply that lemmas are graded. Unexpectedly, competitors to non-depicted senses of both homophones and polysemes facilitated naming. Although these results do not indicate whether lemmas are graded or discrete, they do inform a long-standing question on the nature of polysemes, supporting a multiple-lemma (vs. core-lemma) account.

Lexico-syntactic constraints influence verbal working memory in sentence-like lists.

We test predictions from the language emergent perspective on verbal working memory that lexico-syntactic constraints should support both item and order memory. In natural language, long-term knowledge of lexico-syntactic patterns involving part of speech, verb biases, and noun animacy support language comprehension and production. In three experiments, participants were presented with randomly generated dative-like sentences or lists in which part of speech, verb biases, and animacy of a single word were manipulated. Participants were more likely to recall words in the correct position when presented with a verb over a noun in the verb position, a good dative verb over an intransitive verb in the verb position, and an animate noun over an inanimate noun in the subject noun position. These results demonstrate that interactions between words and their context in the form of lexico-syntactic constraints influence verbal working memory.

A chimpanzee by any other name: The contributions of utterance context and information density on word choice.

An important feature of language production is the flexibility of lexical selection; producers could refer to an animal as chimpanzee, chimp, ape, she, and so on. Thus, a key question for psycholinguistic research is how and why producers make the lexical selections that they do. Information theoretic approaches have argued that producers regulate the uncertainty of the utterance for comprehenders, for example using longer words like chimpanzee if their messages are likely to be misunderstood, and shorter ones like chimp when the message is easy to understand. In this work, we test for the relative contributions of the information theoretic approach and an approach more aligned with psycholinguistic models of language production. We examine the effect on lexical selection of whole utterance-level factors that we take as a proxy for register or style in message-driven production accounts. Using a modern machine learning-oriented approach, we show that for both naturalistic stimuli and real-world corpora, producers prefer words to be longer in systematically different contexts, independent of the specific message they are trying to convey. We do not find evidence for regulation of uncertainty, as in information theoretic approaches. We offer suggestions for modification of the standard psycholinguistic production approach that emphasizes the need for the field to specify how message formulation influences lexical choice in multiword utterances.

Masking auditory feedback does not eliminate repetition reduction.

Repetition reduces word duration. Explanations of this process have appealed to audience design, internal production mechanisms, and combinations thereof (e.g. Kahn & Arnold, 2015). Jacobs, Yiu, Watson, and Dell (2015) proposed the auditory feedback hypothesis, which states that speakers must hear a word, produced either by themselves or another speaker, in order for duration reduction on a subsequent production. We conducted a strong test of the auditory feedback hypothesis in two experiments, in which we used masked auditory feedback and whispering to prevent speakers from hearing themselves fully. Both experiments showed that despite limiting the sources of normal auditory feedback, repetition reduction was observed to equal extents in masked and unmasked conditions, suggesting that repetition reduction may be supported by multiple sources, such as somatosensory feedback and feedforward signals, depending on their availability.

Prosody indexes both competence and performance.

Prosody is an important feature of language that conveys a wide range of information. However, prosody is widely considered to be a difficult domain of study within the language sciences. One consequence of this is that existing grammatical theories of prosody fail to explain prosodic choices that seem to arise from nonlinguistic cognitive demands, such as communicative context, top-down expectations, and recent articulatory and acoustic experience. We provide an account of some of these phenomena and argue that linguistic theories that do not incorporate these factors into models of prosody are likely to mischaracterize its role in language. This article is categorized under: Linguistics > Language in Mind and Brain Psychology > Language Linguistics > Linguistic Theory.

Downstream Behavioral and Electrophysiological Consequences of Word Prediction on Recognition Memory.

When people process language, they can use context to predict upcoming information, influencing processing and comprehension as seen in both behavioral and neural measures. Although numerous studies have shown immediate facilitative effects of confirmed predictions, the downstream consequences of prediction have been less explored. In the current study, we examined those consequences by probing participants' recognition memory for words after they read sets of sentences. Participants read strongly and weakly constraining sentences with expected or unexpected endings ("I added my name to the list/basket"), and later were tested on their memory for the sentence endings while EEG was recorded. Critically, the memory test contained words that were predictable ("list") but were never read (participants saw "basket"). Behaviorally, participants showed successful discrimination between old and new items, but false alarmed to the expected-item lures more often than to new items, showing that predicted words or concepts can linger, even when predictions are disconfirmed. Although false alarm rates did not differ by constraint, event-related potentials (ERPs) differed between false alarms to strongly and weakly predictable words. Additionally, previously unexpected (compared to previously expected) endings that appeared on the memory test elicited larger N1 and LPC amplitudes, suggesting greater attention and episodic recollection. In contrast, highly predictable sentence endings that had been read elicited reduced LPC amplitudes during the memory test. Thus, prediction can facilitate processing in the moment, but can also lead to false memory and reduced recollection for predictable information.

Self-Priming in Production: Evidence for a Hybrid Model of Syntactic Priming.

Syntactic priming in language production is the increased likelihood of using a recently encountered syntactic structure. In this paper, we examine two theories of why speakers can be primed: error-driven learning accounts (Bock, Dell, Chang, & Onishi, 2007; Chang, Dell, & Bock, 2006) and activation-based accounts (Pickering & Branigan, 1999; Reitter, Keller, & Moore, 2011). Both theories predict that speakers should be primed by the syntactic choices of others, but only activation-based accounts predict that speakers should be able to prime themselves. Here we test whether speakers can be primed by their own productions in three behavioral experiments and find evidence of structural persistence following both comprehension and speakers' own productions. We also find that comprehension-based priming effects are larger for rarer syntactic structures than for more common ones, which is most consistent with error-driven accounts. Because neither error-driven accounts nor activation-based accounts fully explain the data, we propose a hybrid model.

Phrase frequency effects in free recall: Evidence for redintegration.

Four experiments examined the effects of word and phrase frequency on free recall. Word frequency did not affect word recall, but when participants studied and recalled lists of compositional adjective-noun phrases (e.g. alcoholic beverages), phrase frequency had a consistently beneficial effect: both words from frequent phrases were more likely to be recalled than for infrequent phrases, providing evidence that long-term memory for phrases can aid in pattern completion, or redintegration. We explain these results and those of a previous study of phrase frequency effects in recognition memory (Jacobs et al., 2016) by assuming that the language processing system provides features that are linked to episodic contexts. Recall tasks map from these contexts to linguistic elements, and recognition maps from linguistic elements to contexts. Word and phrase frequency effects in both memory tasks emerge both within the language processing system and from multiple stored episodes, and the fact that the representations of phrases are tied to knowledge of their component words, rather than being representational islands.

Why are repeated words produced with reduced durations? Evidence from inner speech and homophone production.

Acoustic reduction for repeated words could be the result of articulation and motor practice (Lam & Watson, 2014), facilitated production (Kahn & Arnold, 2015; Gahl et al., 2012), or audience design and shared common ground (Galati & Brennan, 2010). We sought to narrow down what kind of facilitation leads to repetition reduction. Repetition could, in principle, facilitate production on a conceptual, lexical, phonological, articulatory, or acoustic level (Kahn & Arnold, 2015). We compared the durations of the second utterance of a target word when the initial production was aloud or silent. The silent presentation either involved unmouthed or mouthed inner speech. Overt production, unmouthed and mouthed inner speech all led to reduction in target word onsets, but target word durations were only shortened when a word was initially said aloud. In an additional experiment, we found that prior naming of a homophone of the target word also led to duration reduction. The results suggest that repetition reduction occurs when there is a recently experienced auditory memory of the item. We propose that duration may be controlled in part by auditory feedback during production, the use of which can be primed by recent auditory experience.

"hotdog", not "hot" "dog": The phonological planning of compound words.

Do we say dog when we say hotdog? In five experiments using the implicit priming paradigm, we assessed whether nominal compounds composed of two free morphemes like sawdust or fishbowl are prepared for production at the segmental level in the same way that two-syllable monomorphemic words (e.g. bandit) are, or instead as sequences of separable words (e.g. full bowl or grey dust). The experiments demonstrated that nominal compounds are planned as a single sequence, not as two sequences. Specifically, the onset of the second component of the compound (e.g. /d/ in sawdust) did not act as a primeable starting point, although comparable onsets did when that component was an independent word (grey dust). We conclude that there may be a dog in hotdog at the morpheme level, but not when phonological segments are prepared for production.