Communicative context, expectations, and adaptation in prosodic production and comprehension

It is generally assumed that prosodic cues that provide linguistic information are driven primarily by the linguistic content of an utterance. However, research has shown that information from different levels of language often interact and affect the production and comprehension of an utterance (e.g., Brown-Schmidt, 2009; Remez, 1981; Ganong, 1980). If prosody operates in a similar manner to other levels of language, speakers and listeners should be sensitive to things such as communicative context, sentence structure, and listener expectations. This paper explores this possibility through a variety of studies. Part 1 investigates whether speakers have the capacity to adjust subtle acoustic-phonetic properties of the prosodic signal when they find themselves in contexts in which accurate communication is important. Thus, we examine whether the communicative context, in addition to discourse structure, modulates prosodic choices when speakers produce acoustic prominence. We manipulated the discourse status of target words in the context of a highly communicative task (i.e., working with a partner to solve puzzles in the computer game Minecraft), and in the context of a less communicative task more typical of psycholinguistic experiments (i.e., picture description). Speakers in the more communicative task produced prosodic cues to discourse structure that were more discriminable than those in the less communicative task. In a second experiment, we found that the presence or absence of a conversational partner drove some, but not all, of these effects. Together, these results suggest that speakers can modulate the prosodic signal in response to the communicative and social context. Part 2 investigates whether listener expectations influence the processing of intonational boundaries. In a boundary detection task, we manipulated a) the strength of cues to the presence of a boundary and b) whether or not a location in the sentence was a plausible location for an intonational boundary to occur given the syntactic structure. In Experiment 1, listeners are instructed to report where they heard disfluencies, even though there were no disfluencies present in the recordings. Listeners report hearing disfluencies at the locations that had intonational boundaries, and they are equally likely to report them in licensed and unlicensed locations for boundaries. This suggests that listeners can interpret prosodic cues to boundaries as disfluencies, and that their expectations as to where disfluencies might occur are more flexible than they are for where boundaries might occur. Experiment 2 makes use of a 2 trial version of the boundary detection paradigm to investigate whether listeners who reported hearing boundaries at unlicensed locations in previous studies (Buxó-Lugo & Watson, 2016) had done so because of adaptation to new types of input. The results replicate previous studies, and find no evidence for adaptation having occurred throughout those experiments. Lastly, we propose 2 studies to investigate whether listeners can adapt to new mappings between prosodic and syntactic structure

Multidimensional signals and analytic flexibility: Estimating degrees of freedom in human speech analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling, but also from decisions regarding the quantification of the measured behavior. In the present study, we gave the same speech production data set to 46 teams of researchers and asked them to answer the same research question, resulting insubstantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further find little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system and calibrate their (un)certainty in their conclusions