Publications

Abstract

To answer a question, speakers must determine their response and formulate it in words. But do they decide on a response before formulation, or do they formulate different potential answers before selecting one? We addressed this issue in a verbal question-answering experiment. Participants answered questions more quickly when they had one potential answer (e.g., Which tourist attraction in Paris is very tall?) than when they had multiple potential answers (e.g., What is the name of a Shakespeare play?). Participants also answered more quickly when the set of potential answers were on average short rather than long, regardless of whether there was only one or multiple potential answers. Thus, participants were not affected by the linguistic complexity of unselected but plausible answers. These findings suggest that participants select a single answer before formulation.

Abstract

Research suggests that interlocutors manage the timing demands of conversation by preparing what they want to say early. In three experiments, we used a verbal question-answering task to investigate what aspects of their response speakers prepare early. In all three experiments, participants answered more quickly when the critical content (here, barks) necessary for answer preparation occurred early (e.g., Which animal barks and is also a common household pet?) rather than late (e.g., Which animal is a common household pet and also barks?). In the individual experiments, we found no convincing evidence that participants were slower to produce longer answers, consisting of multiple words, than shorter answers, consisting of a single word. There was also no interaction between these two factors. A combined analysis of the first two experiments confirmed this lack of interaction, and demonstrated that participants were faster to answer questions when the critical content was available early rather than late and when the answer was short rather than long. These findings provide tentative evidence for an account in which interlocutors prepare the content of their answer as soon as they can, but sometimes do not prepare its length (and thus form) until they are ready to speak.

Abstract

Name agreement (NA) refers to the degree to which speakers agree on a picture’s name. A robust finding is that speakers are faster to name pictures with high agreement (HA) than those with low agreement (LA). This NA effect is thought to occur because LA pictures strongly activate several names, and so speakers need time to select one. HA pictures, in contrast, strongly activate a single name and so there is no need to select one name out of several alternatives. Recent models of lexical access suggest that the structure of the mental lexicon changes with experience. Thus, speakers should consider a range of names when naming LA pictures, but the extent to which they consider each of these names should change with experience. We tested these hypotheses in two picture-naming experiments. In Experiment 1, participants were faster to name LA than HA pictures when they named each picture once. Importantly, they were faster to produce modal names (provided by most participants) than alternative names for LA pictures, consistent with the view that speakers activate multiple names for LA pictures. In Experiment 2, participants were familiarised with the modal name before the experiment and named each picture three times. Although there was still an NA effect when participants named the pictures the first time, it was reduced in comparison to Experiment 1 and was further reduced with each picture repetition.Thus, familiarisation and repetition reduced the NA effect, but did not eliminate it, suggesting speakers activate a range of plausible names.

Abstract

Comprehenders predict what a speaker is likely to say when listening to non-native (L2) and native (L1) utterances. But what are the characteristics of L2 prediction, and how does it relate to L1 prediction? We addressed this question in a visual-world eye-tracking experiment, which tested when L2 English comprehenders integrated perspective into their predictions. Male and female participants listened to male and female speakers producing sentences (e.g., I would like to wear the nice…) about stereotypically masculine (target: tie; distractor: drill) and feminine (target: dress; distractor: hairdryer) objects. Participants predicted associatively, fixating objects semantically associated with critical verbs (here, the tie and the dress). They also predicted stereotypically consistent objects (e.g., the tie rather than the dress, given the male speaker). Consistent predictions were made later than associative predictions, and were delayed for L2 speakers relative to L1 speakers. These findings suggest prediction involves both automatic and non-automatic stages.

Abstract

During dialog, interlocutors take turns at speaking with little gap or overlap between their contributions. But language production in monolog is comparatively slow. Theories of dialog tend to agree that interlocutors manage these timing demands by planning a response early, before the current speaker reaches the end of their turn. In the first half of this chapter, I review experimental research supporting these theories. But this research also suggests that planning a response early, while simultaneously comprehending, is difficult. Does response planning need to be this difficult during dialog? In other words, is early-planning always necessary? In the second half of this chapter, I discuss research that suggests the answer to this question is no. In particular, corpora of natural conversation demonstrate that speakers do not directly respond to the immediately preceding utterance of their partner—instead, they continue an utterance they produced earlier. This parallel talk likely occurs because speakers are highly incremental and plan only part of their utterance before speaking, leading to pauses, hesitations, and disfluencies. As a result, speakers do not need to engage in extensive advance planning. Thus, laboratory studies do not provide a full picture of language production in dialog, and further research using naturalistic tasks is needed.

Abstract

Word frequency plays a key role in theories of lexical access, which assume that the word frequency effect (WFE, faster access to high-frequency than low-frequency words) occurs as a result of differences in the representation and processing of the words. In a seminal paper, Jescheniak and Levelt (1994) proposed that the WFE arises during the retrieval of word forms, rather than the retrieval of their syntactic representations (their lemmas) or articulatory commands. An important part of Jescheniak and Levelt's argument was that they found a stable WFE in a picture naming task, which requires complete lexical access, but not in a gender decision task, which only requires access to the words' lemmas and not their word forms. We report two attempts to replicate this pattern, one with new materials, and one with Jescheniak and Levelt's orginal pictures. In both studies we found a strong WFE when the pictures were shown for the first time, but much weaker effects on their second and third presentation. Importantly these patterns were seen in both the picture naming and the gender decision tasks, suggesting that either word frequency does not exclusively affect word form retrieval, or that the gender decision task does not exclusively tap lemma access.

Abstract

Although previous research has demonstrated that language comprehension can be egocentric, there is little evidence for egocentricity during prediction. In particular, comprehenders do not appear to predict egocentrically when the context makes it clear what the speaker is likely to refer to. But do comprehenders predict egocentrically when the context does not make it clear? We tested this hypothesis using a visual-world eye-tracking paradigm, in which participants heard sentences containing the gender-neutral pronoun They (e.g. They would like to wear…) while viewing four objects (e.g. tie, dress, drill, hairdryer). Two of these objects were plausible targets of the verb (tie and dress), and one was stereotypically compatible with the participant's gender (tie if the participant was male; dress if the participant was female). Participants rapidly fixated targets more than distractors, but there was no evidence that participants ever predicted egocentrically, fixating objects stereotypically compatible with their own gender. These findings suggest that participants do not fall back on their own egocentric perspective when predicting, even when they know that context does not make it clear what the speaker is likely to refer to.

Abstract

Comprehenders often predict what they are going to hear. But do they make the best predictions possible? We addressed this question in three visual-world eye-tracking experiments by asking when comprehenders consider perspective. Male and female participants listened to male and female speakers producing sentences (e.g., I would like to wear the nice…) about stereotypically masculine (target: tie; distractor: drill) and feminine (target: dress, distractor: hairdryer) objects. In all three experiments, participants rapidly predicted semantic associates of the verb. But participants also predicted consistently – that is, consistent with their beliefs about what the speaker would ultimately say. They predicted consistently from the speaker’s perspective in Experiment 1, their own perspective in Experiment 2, and the character’s perspective in Experiment 3. This consistent effect occurred later than the associative effect. We conclude that comprehenders consider perspective when predicting, but not from the earliest moments of prediction, consistent with a two-stage account.

Abstract

Corpus analyses have shown that turn-taking in conversation is much faster than laboratory studies of speech planning would predict. To explain fast turn-taking, Levinson and Torreira (2015) proposed that speakers are highly proactive: They begin to plan a response to their interlocutor's turn as soon as they have understood its gist, and launch this planned response when the turn-end is imminent. Thus, fast turn-taking is possible because speakers use the time while their partner is talking to plan their own utterance. In the present study, we asked how much time upcoming speakers actually have to plan their utterances. Following earlier psycholinguistic work, we used transcripts of spoken conversations in Dutch, German, and English. These transcripts consisted of segments, which are continuous stretches of speech by one speaker. In the psycholinguistic and phonetic literature, such segments have often been used as proxies for turns. We found that in all three corpora, large proportions of the segments comprised of only one or two words, which on our estimate does not give the next speaker enough time to fully plan a response. Further analyses showed that speakers indeed often did not respond to the immediately preceding segment of their partner, but continued an earlier segment of their own. More generally, our findings suggest that speech segments derived from transcribed corpora do not necessarily correspond to turns, and the gaps between speech segments therefore only provide limited information about the planning and timing of turns.

Abstract

Determining when a partner’s spoken or musical turn will end requires well-honed predictive abilities. Evidence suggests that our motor systems are activated during perception of both speech and music, and it has been argued that motor simulation is used to predict turn-ends across domains. Here we used a dual-task interference paradigm to investigate whether motor simulation of our partner’s action underlies our ability to make accurate turn-end predictions in speech and in music. Furthermore, we explored how specific this simulation is to the action being predicted. We conducted two experiments, one investigating speech turn-ends, and one investigating music turn-ends. In each, 34 proficient pianists predicted turn-endings while (1) passively listening, (2) producing an effector-specific motor activity (mouth/hand movement), or (3) producing a task- and effector-specific motor activity (mouthing words/fingering a piano melody). In the speech experiment, any movement during speech perception disrupted predictions of spoken turn-ends, whether the movement was task-specific or not. In the music experiment, only task-specific movement (i.e., fingering a piano melody) disrupted predictions of musical turn-ends. These findings support the use of motor simulation to make turn-end predictions in both speech and music but suggest that the specificity of this simulation may differ between domains.

Abstract

During conversation, interlocutors often produce their utterances with little overlap or gap between their turns. But what mechanism underlies this striking ability to time articulation appropriately? In 2 verbal yes/no question-answering experiments, we investigated whether listeners use the speech rate of questions to time articulation of their answers. In Experiment 1, we orthogonally manipulated the speech rate of the context (e.g., Do you have a . . .) and final word (e.g., dog?) of questions using time-compression, so that each component was spoken at the natural rate or twice as a fast. Listeners responded earlier when the context was speeded rather than natural, suggesting they used the speaker’s context rate to time answer articulation. Additionally, listeners responded earlier when the speaker’s final syllable was speeded than natural, regardless of context rate, suggesting they adjusted the timing of articulation after listening to a single syllable produced at a different rate. We replicated this final word effect in Experiment 2, which also showed that our speech rate manipulation did not influence the timing of response preparation. Together, these findings suggest listeners use speech rate information to time articulation when answering questions

Abstract

Listeners quickly learn to understand speech that has been distorted, and this process is enhanced when comprehension is constrained by higher-level knowledge. In three experiments, we investigated whether this knowledge enhances comprehension of distorted speech because it allows listeners to predict (1) the meaning of the distorted utterance, or (2) the lower-level wordforms. Participants listened to question-answer sequences, in which questions were clearly-spoken but answers were noise-vocoded. Comprehension (Experiment 1) and learning (Experiment 2) were enhanced when listeners could use the question to predict the semantics of the distorted answer, but were not enhanced by predictions of answer form. Form predictions enhanced comprehension only when questions and answers were significantly separated by time and intervening linguistic material (Experiment 3). Together, these results suggest that high-level semantic predictions enhance comprehension and learning, with form predictions playing only a minimal role.

Abstract

Research suggests that during conversation, interlocutors coordinate their utterances by predicting the speaker’s forthcoming utterance and its end. In two experiments, we used a button-pressing task, in which participants pressed a button when they thought a speaker reached the end of their utterance, to investigate what role the wider discourse plays in turn-end prediction. Participants heard two-utterance sequences, in which the content of the second utterance was or was not constrained by the content of the first. In both experiments, participants responded earlier, but not more precisely, when the first utterance was constraining rather than unconstraining. Response times and precision were unaffected by whether they listened to dialogues or monologues (Experiment 1) and by whether they read the first utterance out loud or silently (Experiment 2), providing no indication that activation of production mechanisms facilitates prediction. We suggest that content predictions aid comprehension but not turn-end prediction.

Abstract

During conversation, interlocutors rapidly switch between speaker and listener
roles and take turns at talk. How do they achieve such fine coordination?
Most research has concentrated on the role of prediction, but listeners
must also prepare a response in advance (assuming they wish to respond)
and articulate this response at the appropriate moment. Such mechanisms
may overlap with the processes of comprehending the speaker’s incoming
turn and predicting its end. However, little is known about the stages of
response preparation and production. We discuss three questions pertaining
to such stages: (1) Do listeners prepare their own response in advance?,
(2) Can listeners buffer their prepared response?, and (3) Does buffering
lead to interference with concurrent comprehension? We argue that fine
coordination requires more than just an accurate prediction of the interlocutor’s
incoming turn: Listeners must also simultaneously prepare their own
response.

Abstract

During conversation, there is often little gap between interlocutors’ utterances. In two pairs of experiments, we manipulated the content predictability of yes/no questions to investigate whether listeners achieve such coordination by (i) preparing a response as early as possible or (ii) predicting the end of the speaker’s turn. To assess these two mechanisms, we varied the participants’ task: They either pressed a button when they thought the question was about to end (Experiments 1a and 2a), or verbally answered the questions with either yes or no (Experiments 1b and 2b). Predictability effects were present when participants had to prepare a verbal response, but not when they had to predict the turn-end. These findings suggest content prediction facilitates turn-taking because it allows listeners to prepare their own response early, rather than because it helps them predict when the speaker will reach the end of their turn.