It is not what you say but how you say it: Evidence from Russian shows robust effects of the structural prior on noisy channel inferences.

Under the noisy-channel framework of language comprehension, comprehenders infer the speaker's intended meaning by integrating the perceived utterance with their knowledge of the language, the world, and the kinds of errors that can occur in communication. Previous research has shown that, when sentences are improbable under the meaning prior (implausible sentences), participants often interpret them nonliterally. The rate of nonliteral interpretation is higher when the errors that could have transformed the intended utterance into the perceived utterance are more likely. However, previous experiments on noisy channel processing mostly relied on implausible sentences, and it is unclear whether participants' nonliteral interpretations were evidence of noisy channel processing or the result of trying to conform to the experimenter's expectations in an experiment with nonsensical sentences. In the current study, we used the unique properties of Russian, an understudied language in the psycholinguistics literature, to test noisy-channel comprehension using only simple plausible sentences. The prior plausibility of sentences was tied only to their word order; subject-verb-object (SVO) sentences were more probable under the structural prior than object-verb-subject (OVS) sentences. In two experiments, we show that participants often interpret OVS sentences nonliterally, and the probability of nonliteral interpretations depended on the Levenshtein distance between the perceived sentence and the (potentially intended) SVO version of the sentence. The results show that the structural prior guides people's final interpretation, independent of the presence of semantic implausibility. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Prediction during language comprehension: what is next?

Prediction is often regarded as an integral aspect of incremental language comprehension, but little is known about the cognitive architectures and mechanisms that support it. We review studies showing that listeners and readers use all manner of contextual information to generate multifaceted predictions about upcoming input. The nature of these predictions may vary between individuals owing to differences in language experience, among other factors. We then turn to unresolved questions which may guide the search for the underlying mechanisms. (i) Is prediction essential to language processing or an optional strategy? (ii) Are predictions generated from within the language system or by domain-general processes? (iii) What is the relationship between prediction and memory? (iv) Does prediction in comprehension require simulation via the production system? We discuss promising directions for making progress in answering these questions and for developing a mechanistic understanding of prediction in language.

The effect of context on noisy-channel sentence comprehension.

The process of sentence comprehension must allow for the possibility of noise in the input, e.g., from speaker error, listener mishearing, or environmental noise. Consequently, semantically implausible sentences such as The girl tossed the apple the boy are often interpreted as a semantically plausible alternative (e.g., The girl tossed the apple to the boy). Previous investigations of noisy-channel comprehension have relied exclusively on paradigms with isolated sentences. Because supportive contexts alter the expectations of possible interpretations, the noisy channel framework predicts that context should encourage more inference in interpreting implausible sentences, relative to null contexts (i.e. a lack of context) or unsupportive contexts. In the present work, we tested this prediction in four types of sentence constructions: two where inference is relatively frequent (double object - prepositional object), and two where inference is rare (active-passive). We found evidence that in the two sentence types that commonly elicit inference, supportive contexts encourage noisy-channel inferences about the intended meaning of implausible sentences more than non-supportive contexts or null contexts. These results suggest that noisy-channel inference may be more pervasive in everyday language processing than previously assumed based on work with isolated sentences.

The human language system, including its inferior frontal component in "Broca's area," does not support music perception.

Language and music are two human-unique capacities whose relationship remains debated. Some have argued for overlap in processing mechanisms, especially for structure processing. Such claims often concern the inferior frontal component of the language system located within "Broca's area." However, others have failed to find overlap. Using a robust individual-subject fMRI approach, we examined the responses of language brain regions to music stimuli, and probed the musical abilities of individuals with severe aphasia. Across 4 experiments, we obtained a clear answer: music perception does not engage the language system, and judgments about music structure are possible even in the presence of severe damage to the language network. In particular, the language regions' responses to music are generally low, often below the fixation baseline, and never exceed responses elicited by nonmusic auditory conditions, like animal sounds. Furthermore, the language regions are not sensitive to music structure: they show low responses to both intact and structure-scrambled music, and to melodies with vs. without structural violations. Finally, in line with past patient investigations, individuals with aphasia, who cannot judge sentence grammaticality, perform well on melody well-formedness judgments. Thus, the mechanisms that process structure in language do not appear to process music, including music syntax.

Real-time inference in communication across cultures: Evidence from a nonindustrialized society.

In everyday communication, speakers and listeners make sophisticated inferences about their conversation partner's intended meaning. They combine their knowledge of the visuospatial context with reasoning about the other person's knowledge state and rely on shared assumptions about how language is used to express communicative intentions. However, these assumptions may differ between languages of nonindustrialized-where conversations often primarily take place within a, so-called, society of intimates-and industrialized cultures-societies of strangers. Here, we study inference in communication in the Tsimane', an indigenous people of the Bolivian Amazon, who have little contact with industrialization or formal education. Using a referential communication task, we probe how Tsimane' speakers refer to objects in the world around them when there are potential ambiguities (e.g., referring to a cup when there are multiple cups in view) across different visual contexts. Using an eye-tracking task, we probe the real-time inferences that Tsimane' listeners make about the speaker's intentions. We find that Tsimane' speakers use visual (color, size) contrasts to disambiguate referents (e.g., "Hand me the small cup"), much like English speakers, and they predictively direct their gaze to objects in a contrast set when they hear a modifier (e.g., "small"). Despite myriad cultural and linguistic dissimilarities between the two populations, the qualitative patterns of behavior and eye-gaze of Tsimane' and English speakers were strikingly similar, suggesting that the communicative expectations underlying many everyday inferences may be shared across cultures. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Scalar Implicature is Sensitive to Contextual Alternatives.

The quantifier "some" often elicits a scalar implicature during comprehension: "Some of today's letters have checks inside" is often interpreted to mean that not all of today's letters have checks inside. In previous work, Goodman and Stuhlmüller (G&S) proposed a model that predicts that this implicature should depend on the speaker's knowledgeability: If the speaker has only examined some of the available letters (e.g., two of three letters), people are less likely to infer that "some" implies "not all" than if the speaker has examined all of the available letters. G&S also provided behavioral evidence in support of their model. In this paper, we first show that a simple extension of G&S's model (1) predicts G&S's knowledgeability effects, and in addition, (2) predicts that the knowledgeability effect will be reduced when the speaker's usage indicates numeral alternatives are available. We tested the new model's predictions in four preregistered experiments. All experiments supported the first model prediction, replicating G&S's finding of a main effect of the speaker's knowledge. Further, Experiments 2 and 4 supported the second model prediction showing that the words that a speaker tends to use affect the strength of scalar implicature that comprehenders make. In particular, when the speaker has partial knowledge (e.g., has only examined two of three letters), comprehenders think that "some" is more likely to mean "not all" when the speaker also tends to produce number words in similar sentences (e.g., "2 of today's rooms have working smoke detectors."). These results have important ramifications for theories of meaning: the context beyond the sentence (e.g., the speaker's tendency to use particular words) affects the set of alternatives that comprehenders consider when inferring meaning.

A noisy-channel approach to depth-charge illusions.

The "depth-charge" sentence, No head injury is too trivial to be ignored, is often interpreted as "no matter how trivial head injuries are, we should not ignore them" while the literal meaning is the opposite - "we should ignore them". Four decades of research have failed to resolve the source of this entrenched semantic illusion. Here we adopt the noisy-channel framework for language comprehension to provide a potential explanation. We hypothesize that depth-charge sentences result from inferences whereby comprehenders derive the interpretation by weighing the plausibility of possible readings of the depth-charge sentences against the likelihood of plausible sentences being produced with errors. In four experiments, we find that (1) the more plausible the intended meaning of the depth-charge sentence is, the more likely the sentence is to be misinterpreted; and (2) the higher the likelihood of our hypothesized noise operations, the more likely depth-charge sentences are to be misinterpreted. These results suggest that misinterpretation is affected by both world knowledge and the distance between the depth-charge sentence and a plausible alternative, which is consistent with the noisy-channel framework.

Agrammatic output in non-fluent, including Broca's, aphasia as a rational behavior.

Background: Speech of individuals with non-fluent, including Broca's, aphasia is often characterized as "agrammatic" because their output mostly consists of nouns and, to a lesser extent, verbs and lacks function words, like articles and prepositions, and correct morphological endings. Among the earliest accounts of agrammatic output in the early 1900s was the "economy of effort" idea whereby agrammatic output is construed as a way of coping with increases in the cost of language production. This idea resurfaced in the 1980s, but in general, the field of language research has largely focused on accounts of agrammatism that postulated core deficits in syntactic knowledge. Aims: We here revisit the economy of effort hypothesis in light of increasing emphasis in cognitive science on rational and efficient behavior. Main contribution: The critical idea is as follows: there is a cost per unit of linguistic output, and this cost is greater for patients with non-fluent aphasia. For a rational agent, this increase leads to shorter messages. Critically, the informative parts of the message should be preserved and the redundant ones (like the function words and inflectional markers) should be omitted. Although economy of effort is unlikely to provide a unifying account of agrammatic output in all patients-the relevant population is too heterogeneous and the empirical landscape too complex for any single-factor explanation-we argue that the idea of agrammatic output as a rational behavior was dismissed prematurely and appears to provide a plausible explanation for a large subset of the reported cases of expressive aphasia. Conclusions: The rational account of expressive agrammatism should be evaluated more carefully and systematically. On the basic research side, pursuing this hypothesis may reveal how the human mind and brain optimize communicative efficiency in the presence of production difficulties. And on the applied side, this construal of expressive agrammatism emphasizes the strengths of some patients to flexibly adapt utterances in order to communicate in spite of grammatical difficulties; and focusing on these strengths may be more effective than trying to "fix" their grammar.

A syntax-lexicon trade-off in language production.

Spoken language production involves selecting and assembling words and syntactic structures to convey one's message. Here we probe this process by analyzing natural language productions of individuals with primary progressive aphasia (PPA) and healthy individuals. Based on prior neuropsychological observations, we hypothesize that patients who have difficulty producing complex syntax might choose semantically richer words to make their meaning clear, whereas patients with lexicosemantic deficits may choose more complex syntax. To evaluate this hypothesis, we first introduce a frequency-based method for characterizing the syntactic complexity of naturally produced utterances. We then show that lexical and syntactic complexity, as measured by their frequencies, are negatively correlated in a large (n = 79) PPA population. We then show that this syntax-lexicon trade-off is also present in the utterances of healthy speakers (n = 99) taking part in a picture description task, suggesting that it may be a general property of the process by which humans turn thoughts into speech.

A verb-frame frequency account of constraints on long-distance dependencies in English.

Going back to Ross (1967) and Chomsky (1973), researchers have sought to understand what conditions permit long-distance dependencies in language, such as between the wh-word what and the verb bought in the sentence 'What did John think that Mary bought?'. In the present work, we attempt to understand why changing the main verb in wh-questions affects the acceptability of long-distance dependencies out of embedded clauses. In particular, it has been claimed that factive and manner-of-speaking verbs block such dependencies (e.g., 'What did John know/whisper that Mary bought?'), whereas verbs like think and believe allow them. Here we provide 3 acceptability judgment experiments of filler-gap constructions across embedded clauses to evaluate four types of accounts based on (1) discourse; (2) syntax; (3) semantics; and (4) our proposal related to verb-frame frequency. The patterns of acceptability are most simply explained by two factors: verb-frame frequency, such that dependencies with verbs that rarely take embedded clauses are less acceptable; and construction type, such that wh-questions and clefts are less acceptable than declaratives. We conclude that the low acceptability of filler-gap constructions formed by certain sentence complement verbs is due to infrequent linguistic exposure.

An ERP index of real-time error correction within a noisy-channel framework of human communication.

Recent evidence suggests that language processing is well-adapted to noise in the input (e.g., spelling or speech errors, misreading or mishearing) and that comprehenders readily correct the input via rational inference over possible intended sentences given probable noise corruptions. In the current study, we probed the processing of noisy linguistic input, asking whether well-studied ERP components may serve as useful indices of this inferential process. In particular, we examined sentences where semantic violations could be attributed to noise-for example, in "The storyteller could turn any incident into an amusing antidote", where the implausible word "antidote" is orthographically and phonologically close to the intended "anecdote". We found that the processing of such sentences-where the probability that the message was corrupted by noise exceeds the probability that it was produced intentionally and perceived accurately-was associated with a reduced (less negative) N400 effect and an increased P600 effect, compared to semantic violations which are unlikely to be attributed to noise ("The storyteller could turn any incident into an amusing hearse"). Further, the magnitudes of these ERP effects were correlated with the probability that the comprehender retrieved a plausible alternative. This work thus adds to the growing body of literature that suggests that many aspects of language processing are optimized for dealing with noise in the input, and opens the door to electrophysiologic investigations of the computations that support the processing of imperfect input.

Talker-specific predictions during language processing.

Language comprehension is shaped by world knowledge. After hearing about "a farm animal," meanings of typical ("cow") versus atypical exemplars ("ox") are more accessible, as evidenced by N400 responses. Moreover, atypical exemplars elicit a larger post-N400 frontal positivity than typical and incongruous ("ivy") exemplars, indexing the integration of unexpected information. Do listeners adapt this category knowledge to specific talkers? We first replicated typicality effects in the auditory modality. Then, we extended the design to a two-talker context: talkers alternated cueing (Bob: "Susan, name a farm animal") and answering (Susan: "cow"). Critically, participants first heard interviews in which one talker revealed strong associations with atypical exemplars (Susan works on an ox farm). We observed increased frontal positivity to a typical exemplar ("cow") said by Susan compared to Bob, indicating participants appreciated that the typical exemplar was atypical for Susan. These results suggest that comprehenders can tailor their expectations to the talker.

Do domain-general executive resources play a role in linguistic prediction? Re-evaluation of the evidence and a path forward.

Most current accounts of language comprehension agree on a role for prediction, but they disagree on the importance of domain-general executive resources in predictive behavior. In this opinion piece, we briefly review the evidence for linguistic prediction, and the findings that have been used to argue that prediction draws on domain-general executive resources. The most compelling evidence is an apparent reduction in predictive behavior during language comprehension in populations with lower executive resources, such as children, older adults, and second language (L2) learners. We propose that these between-population differences can be explained without invoking executive resources. Instead, differences in the quantity and kind of language experience that these populations bring to bear may affect the probability of engaging in predictive behavior, or simply make prediction effects more difficult to detect in paradigms designed for young adult native speakers. Thus, domain-specific prediction mechanisms remain a viable possibility. We discuss ways to further test accounts of linguistic prediction that do vs. do not require domain-general executive resources, using behavioral, computational, and brain imaging approaches.

Information Integration in Modulation of Pragmatic Inferences During Online Language Comprehension.

Upon hearing a scalar adjective in a definite referring expression such as "the big…," listeners typically make anticipatory eye movements to an item in a contrast set, such as a big glass in the context of a smaller glass. Recent studies have suggested that this rapid, contrastive interpretation of scalar adjectives is malleable and calibrated to the speaker's pragmatic competence. In a series of eye-tracking experiments, we explore the nature of the evidence necessary for the modulation of pragmatic inferences in language comprehension, focusing on the complementary roles of top-down information - (knowledge about the particular speaker's pragmatic competence)  and bottom-up cues  (distributional information about the use of scalar adjectives in the environment). We find that bottom-up evidence alone (e.g., the speaker says "the big dog" in a context with one dog), in large quantities, can be sufficient to trigger modulation of the listener's contrastive inferences, with or without top-down cues to support this adaptation. Further, these findings suggest that listeners track and flexibly combine multiple sources of information in service of efficient pragmatic communication.

Comprehenders model the nature of noise in the environment.

In everyday communication, speakers make errors and produce language in a noisy environment. Recent work suggests that comprehenders possess cognitive mechanisms for dealing with noise in the linguistic signal: a noisy-channel model. A key parameter of these models is the noise model: the comprehender's implicit model of how noise affects utterances before they are perceived. Here we examine this noise model in detail, asking whether comprehension behavior reflects a noise model that is adapted to context. We asked readers to correct sentences if they noticed errors, and manipulated context by including exposure sentences containing obvious deletions (A bystander was rescued by the fireman in the nick time.), insertions, exchanges, mixed errors, or no errors. On test sentences (The bat swung the player.), participants' corrections differed depending on the exposure condition. The results demonstrate that participants model specific types of errors and make inferences about the intentions of the speaker accordingly.

Knowledge and learning of verb biases in amnesia.

Verb bias-the co-occurrence frequencies between a verb and the syntactic structures it may appear with-is a critical and reliable linguistic cue for online sentence processing. In particular, listeners use this information to disambiguate sentences with multiple potential syntactic parses (e.g., Feel the frog with the feather.). Further, listeners dynamically update their representations of specific verbs in the face of new evidence about verb-structure co-occurrence. Yet, little is known about the biological memory systems that support the use and dynamic updating of verb bias. We propose that hippocampal-dependent declarative (relational) memory represents a likely candidate system because it has been implicated in the flexible binding of relational co-occurrences and in statistical learning. We explore this question by testing patients with severe and selective deficits in declarative memory (anterograde amnesia), and demographically matched healthy participants, in their on-line interpretation of ambiguous sentences and the ability to update their verb bias with experience. We find that (1) patients and their healthy counterparts use existing verb bias to successfully interpret on-line ambiguity, however (2) unlike healthy young adults, neither group updated these biases in response to recent exposure. These findings demonstrate that using existing representations of verb bias does not necessitate involvement of the declarative memory system, but leave open the question of whether the ability to update representations of verb-specific biases requires hippocampal engagement.

Verb biases are shaped through lifelong learning.

Verbs often participate in more than 1 syntactic structure, but individual verbs can be biased in terms of whether they are used more often with 1 structure or the other. For instance, in a sentence such as "Bop the bunny with the flower," the phrase "with the flower" is more likely to indicate an instrument with which to "bop," rather than which "bunny" to bop. Conversely, in a sentence such as "Choose the cow with the flower," the phrase "with the flower" is more likely to indicate which "cow" to choose. An open question is where these biases come from and whether they continue to be shaped in adulthood in a way that has lasting consequences for real-time processing of language. In Experiment 1 we replicated previous findings that these language-wide biases guide online syntactic processing in a computer-based visual-world paradigm. In Experiment 2, we tested the malleability of these biases by exposing adults to initially unbiased verbs situated in unambiguous contexts that led to either instrument or modifier interpretations. During test, participants interpreted sentences containing either modifier- or instrument-trained verbs in ambiguous contexts. Eye-movement and action data show that participants' considerations of the candidate interpretations of the ambiguous with-phrases were guided by the newly learned verb biases. These results suggest that co-occurrence information about specific verbs and syntactic structures embedded in language experiences plays a role in forming, and continuously shaping, the verb biases that constitute a part of the broader representation of the language. (PsycINFO Database Record

The malleability of linguistic representations poses a challenge to the priming-based experimental approach.

Recent findings show that experience with a syntactic structure has long-term consequences for how that structure will be processed in the future, which suggests that linguistic representations are not static entities that can be probed reliably without alteration. Thus, leveraging the effect of previous exposure to a syntactic structure appears to be an inappropriate method for studying invariant properties of language.

Listeners use speaker identity to access representations of spatial perspective during online language comprehension.

Little is known about how listeners represent another person's spatial perspective during language processing (e.g., two people looking at a map from different angles). Can listeners use contextual cues such as speaker identity to access a representation of the interlocutor's spatial perspective? In two eye-tracking experiments, participants received auditory instructions to move objects around a screen from two randomly alternating spatial perspectives (45° vs. 315° or 135° vs. 225° rotations from the participant's viewpoint). Instructions were spoken either by one voice, where the speaker's perspective switched at random, or by two voices, where each speaker maintained one perspective. Analysis of participant eye-gaze showed that interpretation of the instructions improved when each viewpoint was associated with a different voice. These findings demonstrate that listeners can learn mappings between individual talkers and viewpoints, and use these mappings to guide online language processing.