Presentations

Abstract

Conversation often involves simultaneous production and comprehension, yet little research has investigated whether these two processes interfere with one another. We tested participants’ ability to dual-task with production and comprehension tasks. Task one (production task) was picture naming. Task two (comprehension task) was either syllable identification (linguistic condition) or tone identification (non-linguistic condition). The two identification tasks were matched for difficulty. Three SOAs (50ms, 300ms, and 1800ms) resulted in different amounts of overlap between the production and comprehension tasks. We hypothesized that as production and comprehension use similar resources there would be greater interference with concurrent linguistic than non-linguistic tasks.
At the 50ms SOA, picture naming latencies were slower in the linguistic compared to the non-linguistic condition, suggesting that the resources required for production and comprehension overlap more in the linguistic condition. As the syllables were non-words without lexical representations, this interference likely occurs primarily at the phonological level. Across all SOAs, identification RTs were longer in the linguistic condition, showing that such phonological interference percolates through to the comprehension task, regardless of SOA. In sum, these results demonstrate that concurrent access to the phonological level in production and comprehension results in measurable interference in both speaking and comprehending.

Abstract

Listeners are continuously exposed to a broad range of speech rates. Earlier work has shown that listeners perceive phonetic category boundaries relative to contextual speech rate. This process of rate-dependent speech perception has been suggested to occur across talker changes, with the speech rate of talker A influencing perception of talker B. This study tested whether a ‘global’ speech rate calculated over multiple talkers and over a longer period of time affected perception of the temporal Dutch vowel contrast /ɑ/-/a:/. First, Experiment 1 demonstrated that listeners more often reported hearing long /a:/ in fast contexts than in ‘neutral rate’ contexts, replicating earlier findings. Then, in Experiment 2, one participant group was exposed to ‘neutral’ speech from talker A intermixed with slow speech from talker B. Another group listened to the same ‘neutral’ speech from talker A, but to fast speech from talker B. Between-group comparison in the ‘neutral’ condition revealed that Group 1 reported more long /a:/ than Group 2, indicating that A’s ‘neutral’ speech sounded faster when B was slower. Finally, Experiment 3 tested whether talking at slow or fast rates oneself elicits the same ‘global’ rate effects. However, no evidence was found that self-produced speech modulated perception of talker A. This study corroborates the idea that ‘global’ rate-dependent effects occur across talkers, but are insensitive to one’s own speech rate. Results are interpreted in light of the general auditory mechanisms thought to underlie rate normalization, with implications for our understanding of dialogue.

Abstract

Speech rate is known to modulate perception of temporally ambiguous speech sounds. For instance, a vowel may be perceived as short when the immediate speech context is slow, but as long when the context is fast. Yet, effects of long-term tracking of speech rate are largely unexplored. Two experiments tested whether long-term tracking of rate influences perception of the temporal Dutch vowel contrast /A/-/a:/. In Experiment 1, one low-rate group listened to ‘neutral’ rate speech from talker A and to slow speech from talker B. Another high-rate group was exposed to the same neutral speech from A, but to fast speech from B. Between-group comparison of the ‘neutral’ trials revealed that the low-rate group reported a higher proportion of /a:/ in A’s ‘neutral’ speech, indicating that A sounded faster when B was slow. Experiment 2 tested whether one’s own speech rate also contributes to effects of long-term tracking of rate. Here, talker B’s speech was replaced by playback of participants’ own fast or slow speech. No evidence was found that one’s own voice affected perception of talker A in larger speech contexts. These results carry implications for our understanding of the mechanisms involved in rate-dependent speech perception and of dialogue.

Abstract

Speech rate is known to modulate perception of temporally ambiguous speech sounds. For instance, a vowel may be perceived as short when the immediate speech context is slow, but as long when the context is fast. Yet, effects of long-term tracking of speech rate are largely unexplored. Two experiments tested whether long-term tracking of rate influences perception of the temporal Dutch vowel contrast /ɑ/-/a:/. In Experiment 1, one low-rate group listened to 'neutral' rate speech from talker A and to slow speech from talker B. Another high-rate group was exposed to the same neutral speech from A, but to fast speech from B. Between-group comparison of the 'neutral' trials revealed that the low-rate group reported a higher proportion of /a:/ in A's 'neutral' speech, indicating that A sounded faster when B was slow. Experiment 2 tested whether one's own speech rate also contributes to effects of long-term tracking of rate. Here, talker B's speech was replaced by playback of participants' own fast or slow speech. No evidence was found that one's own voice affected perception of talker A in larger speech contexts. These results carry implications for our understanding of the mechanisms involved in rate-dependent speech perception and of dialogue.

Abstract

Speech can be produced at different rates. The ability to produce faster or slower speech may be thought to result from executive control processes enlisted to modulate lexical selection and phonological encoding stages of speech planning.

This study used simulations of the model of serial order in language by Dell, Burger and Svec (1997, DBS) to characterise the strategies adopted by speakers when naming pictures at fast, medium and slow prescribed rates. Our new implementation of DBS was able to produce activation patterns that correlated strongly with observed syllable-level timing of disyllabic words from this task.

For each participant, different speaking rates were associated with different regions of the DBS parameter space. The precise placement of the speaking rates in the parameter space differed markedly between participants. Participants applied broadly the same parameter manipulation to accelerate their speech. This was however not the case for deceleration. Hierarchical clustering revealed two distinct patterns of parameter adjustment employed to decelerate speech, suggesting that deceleration is not necessarily achieved by the inverse process of acceleration. In addition, potential refinements to the DBS model are discussed.

Abstract

An important issue in current psycholinguistics is the relationship between the production and comprehension systems. It has been argued that these systems are tightly linked, and that, in particular, listeners use the speech production system to predict upcoming content. We tested this view using a novel version of the visual world paradigm. Participants heard mathematical equations and looked at a clock face showing the numbers 1 to 12. On alternating trials they either heard a complete equation (3+8=11) or they heard the first part (3+8) and had to produce the solution (11, target hereafter) themselves. Participants were encouraged to look at the relevant numbers throughout the trial. On listening trials, the participants typically looked at the target before the onset of target name, and on speaking trials they typically looked at the target before naming it. However, the timing of the looks to the targets was slightly different, with participants looking earlier at the target when they had to speak themselves than when they listened. This suggests that predicting during listening and planning to speak are indeed very similar but not identical. The further methodological and theoretical consequences of the study will be discussed.

Abstract

The generation of an utterance begins with event apprehension and continues with sequential linguistic
encoding of all message elements [2]. The timecourse of formulation, however, is relatively flexible and varies
with the ease of structural encoding [3]. While previous work has shown that syntactic structure may be primed
independently of thematic roles across sentences [1], here we tested whether exposure to conceptually similar
events interacts with structural processes to facilitate the mapping of a message onto a sentence.

Abstract

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Abstract

Recently many authors have stressed that domain-general cognitive processes may affect performance in linguistic tasks. This challenges the traditional view that speaking and listening are fairly modular processes. Going beyond this broad claim, we aim to determine exactly how domain-general processes influence linguistic processes. In the present study we examined the influence of selective inhibition (invoked to suppress responses to potent competitors to target stimuli and taking some time to build up) on performance in two classic word production tasks, the semantic blocking task (naming sets of objects that do vs. do not belong to the same semantic category) and the pictureword interference task (naming pictures accompanied by categorically related vs. unrelated words). Both tasks were completed by the same participants. Analyses of the size of the interference effects for fast and slower responses (using delta plots) and of the correlations of the effect sizes in the two tasks demonstrated that selective inhibition was recruited in both tasks. We propose that the process supported by selective inhibition is lemma selection. We discuss the implications for theories concerning the origin of the interference effects in the two paradigms and the nature of lexical selection processes.

Abstract

Multiple syntactic alternatives are often available to express one message. One of the factors driving the
choice for a syntactic frame is verb bias. This study focuses on the role of verb bias in the process of selecting
a syntactic frame for dative sentences. While some verbs are typically used with one structure (e.g.,
voorleggen [submit] and the prepositional object dative in Dutch), other verbs have a weaker bias towards one
syntactic frame (e.g., voorstellen [propose]): the latter can be used interchangeably in the prepositional object
dative (PD) and double-object dative (DO) construction, and thus allows for some degree of syntactic flexibility
during production. On one view, syntactic flexibility may facilitate production because it enables speakers to fill
the post-verbal sentence slots with either a direct object or an indirect object (the incremental view), while on a
different view, flexibility can lead to competition between structural alternatives, delaying the production of the
sentence until this competition is resolved (the competition view)1. The two views make opposite predictions
regarding the production of sentences featuring verbs with different biases. The incremental view predicts
shorter verb onsets for sentences featuring weak-bias verbs than strong-bias verbs, while the competition view
predicts shorter onsets for sentences with strong-bias verbs. In addition, if the competition view holds,
sentence production may benefit from a mechanism that helps resolve competition between two syntactic
frames by suppressing one frame to enable fast selection of the other frame. We hypothesized that executive
control (EC) can mediate this selection process, facilitating structure selection in the weak verb bias condition.

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