Interpreting prosodic cues in discourse context

The Intonation and Pragmatics of Greek wh-Questions

We experimentally tested three hypotheses regarding the pragmatics of two tunes (one high-ending, one flat-ending) used with Greek wh-questions: (a) the high-ending tune is associated with information-seeking questions, while the flat-ending tune is also appropriate when wh-questions are not information-seeking, in which case their function can instead be akin to that of a statement; (b) the high-ending tune is more polite, and (c) more appropriate for contexts leading to information-seeking questions. The wh-questions used as experimental stimuli were elicited from four speakers in contexts likely to lead to either information-seeking or non-information-seeking uses. The speakers produced distinct tunes in response to the contexts; acoustic analysis indicates these are best analysed as L*+H L-!H% (rising), and L+H* L-L% (flat). In a perception experiment where participants heard the questions out of context, they chose answers providing information significantly more frequently after high-ending than flat-ending questions, confirming hypothesis (a). In a second experiment testing hypotheses (b) and (c), participants evaluated wh-questions for appropriateness and politeness in information- and non-information-seeking contexts. High-ending questions were rated more appropriate in information-seeking contexts, and more polite independently of context relative to their flat-ending counterparts. Finally, two follow-up experiments showed that the interpretation of the two tunes was not affected by voice characteristics of individual speakers, and confirmed a participant preference for the high-ending tune. Overall, the results support our hypotheses and lead to a compositional analysis of the meaning of the two tunes, while also showing that intonational meaning is determined by both tune and pragmatic context.

A Hierarchical Generative Framework of Language Processing: Linking Language Perception, Interpretation, and Production Abnormalities in Schizophrenia

Language and thought dysfunction are central to the schizophrenia syndrome. They are evident in the major symptoms of psychosis itself, particularly as disorganized language output (positive thought disorder) and auditory verbal hallucinations (AVHs), and they also manifest as abnormalities in both high-level semantic and contextual processing and low-level perception. However, the literatures characterizing these abnormalities have largely been separate and have sometimes provided mutually exclusive accounts of aberrant language in schizophrenia. In this review, we propose that recent generative probabilistic frameworks of language processing can provide crucial insights that link these four lines of research. We first outline neural and cognitive evidence that real-time language comprehension and production normally involve internal generative circuits that propagate probabilistic predictions to perceptual cortices - predictions that are incrementally updated based on prediction error signals as new inputs are encountered. We then explain how disruptions to these circuits may compromise communicative abilities in schizophrenia by reducing the efficiency and robustness of both high-level language processing and low-level speech perception. We also argue that such disruptions may contribute to the phenomenology of thought-disordered speech and false perceptual inferences in the language system (i.e., AVHs). This perspective suggests a number of productive avenues for future research that may elucidate not only the mechanisms of language abnormalities in schizophrenia, but also promising directions for cognitive rehabilitation.

Form-to-expectation matching effects on first-pass eye movement measures during reading

Recent Electroencephalography/Magnetoencephalography (EEG/MEG) studies suggest that when contextual information is highly predictive of some property of a linguistic signal, expectations generated from context can be translated into surprisingly low-level estimates of the physical form-based properties likely to occur in subsequent portions of the unfolding signal. Whether form-based expectations are generated and assessed during natural reading, however, remains unclear. We monitored eye movements while participants read phonologically typical and atypical nouns in noun-predictive contexts (Experiment 1), demonstrating that when a noun is strongly expected, fixation durations on first-pass eye movement measures, including first fixation duration, gaze duration, and go-past times, are shorter for nouns with category typical form-based features. In Experiments 2 and 3, typical and atypical nouns were placed in sentential contexts normed to create expectations of variable strength for a noun. Context and typicality interacted significantly at gaze duration. These results suggest that during reading, form-based expectations that are translated from higher-level category-based expectancies can facilitate the processing of a word in context, and that their effect on lexical processing is graded based on the strength of category expectancy.

Prosody and language comprehension

This review provides a summary of the most recent advances on the study of how prosody is used during language comprehension. Prosody is characterized as an abstract structure composed of discrete tonal elements aligned with the segmental composition of the sentence organized in constituents of increasing size, and this structure is influenced by the phonological, syntactic, and informational structures of the sentence. Here, we discuss evidence that listeners are affected by prosody when establishing those linguistic structures. Prosody has been shown to influence the segmentation of the utterance into syllables and words, and, in some cases, whether a syllable or word is judged to be present or not. The literature on how prosody informs the structural relationship between words and phrases is also discussed, contrasting views that assume a direct (albeit probabilistic) link between syntax and prosody with those that posit a complex interface between syntax and prosodic structure. Finally, the role of prosody in conveying important aspects pertaining to the sentence's information structure (i.e., which parts of the sentence's meaning are highlighted and brought forward to the discourse, which ones are presupposed and left in the background, which attitudes are being conveyed about the concepts or propositional content) has long been recognized. Current research focuses on which prosodic elements contribute to marking the dimensions (or semantic primitives) of the information structure.

Metrical expectations from preceding prosody influence perception of lexical stress

Two visual-world experiments tested the hypothesis that expectations based on preceding prosody influence the perception of suprasegmental cues to lexical stress. The results demonstrate that listeners' consideration of competing alternatives with different stress patterns (e.g., 'jury/gi'raffe) can be influenced by the fundamental frequency and syllable timing patterns across material preceding a target word. When preceding stressed syllables distal to the target word shared pitch and timing characteristics with the first syllable of the target word, pictures of alternatives with primary lexical stress on the first syllable (e.g., jury) initially attracted more looks than alternatives with unstressed initial syllables (e.g., giraffe). This effect was modulated when preceding unstressed syllables had pitch and timing characteristics similar to the initial syllable of the target word, with more looks to alternatives with unstressed initial syllables (e.g., giraffe) than to those with stressed initial syllables (e.g., jury). These findings suggest that expectations about the acoustic realization of upcoming speech include information about metrical organization and lexical stress and that these expectations constrain the initial interpretation of suprasegmental stress cues. These distal prosody effects implicate online probabilistic inferences about the sources of acoustic-phonetic variation during spoken-word recognition.

Immediate effects of anticipatory coarticulation in spoken-word recognition

Two visual-world experiments examined listeners' use of pre word-onset anticipatory coarticulation in spoken-word recognition. Experiment 1 established the shortest lag with which information in the speech signal influences eye-movement control, using stimuli such as "The … ladder is the target". With a neutral token of the definite article preceding the target word, saccades to the referent were not more likely than saccades to an unrelated distractor until 200-240 ms after the onset of the target word. In Experiment 2, utterances contained definite articles which contained natural anticipatory coarticulation pertaining to the onset of the target word (" The ladder … is the target"). A simple Gaussian classifier was able to predict the initial sound of the upcoming target word from formant information from the first few pitch periods of the article's vowel. With these stimuli, effects of speech on eye-movement control began about 70 ms earlier than in Experiment 1, suggesting rapid use of anticipatory coarticulation. The results are interpreted as support for "data explanation" approaches to spoken-word recognition. Methodological implications for visual-world studies are also discussed.