Publications

Abstract

In conversation, interlocutors rarely leave long gaps between turns, suggesting that next speak- ers begin to plan their turns while listening to the previous speaker. The present experiment used analyses of speech onset latencies and eye-movements in a task-oriented dialogue paradigm to investigate when speakers start planning their response. Adult German participants heard a confederate describe sets of objects in utterances that either ended in a noun (e.g. Ich habe eine Tür und ein Fahrrad (‘I have a door and a bicycle’)) or a verb form (Ich habe eine Tür und ein Fahrrad besorgt (‘I have gotten a door and a bicycle’)), while the presence or absence of the final verb either was or was not predictable from the preceding sentence structure. In response, participants had to name any unnamed objects they could see in their own display in utterances such as Ich habe ein Ei (‘I have an egg’). The main question was when participants started to plan their response. The results are consistent with the view that speakers begin to plan their turn as soon as sufficient information is available to do so, irrespective of further incoming words.

Abstract

Many studies have shown that a supportive context facilitates language comprehension. A currently influential view is that language production may support prediction in language comprehension. Experimental evidence for this, however, is relatively sparse. Here we explored whether encouraging prediction in a language production task encourages the use of predictive contexts in an interleaved comprehension task. In Experiment 1a, participants listened to the first part of a sentence and provided the final word by naming aloud a picture. The picture name was predictable or not predictable from the sentence context. Pictures were named faster when they could be predicted than when this was not the case. In Experiment 1b the same sentences, augmented by a final spill-over region, were presented in a self-paced reading task. No difference in reading times for predictive vs. non-predictive sentences was found. In Experiment 2, reading and naming trials were intermixed. In the naming task, the advantage for predictable picture names was replicated. More importantly, now reading times for the spill-over region were considerable faster for predictive vs. non-predictive sentences. We conjecture that these findings fit best with the notion that prediction in the service of language production encourages the use of predictive contexts in comprehension. Further research is required to identify the exact mechanisms by which production exerts its influence on comprehension.

Abstract

Fluctuations in pupil size have been shown to reflect variations in processing demands during lexical and syntactic processing in language comprehension. An issue that has not received attention is whether pupil size also varies due to pragmatic manipulations. In two pupillometry experiments, we investigated whether pupil diameter was sensitive to increased processing demands as a result of comprehending an indirect request versus a direct statement. Adult participants were presented with 120 picture–sentence combinations that could be interpreted either as an indirect request (a picture of a window with the sentence “it's very hot here”) or as a statement (a picture of a window with the sentence “it's very nice here”). Based on the hypothesis that understanding indirect utterances requires additional inferences to be made on the part of the listener, we predicted a larger pupil diameter for indirect requests than statements. The results of both experiments are consistent with this expectation. We suggest that the increase in pupil size reflects additional processing demands for the comprehension of indirect requests as compared to statements. This research demonstrates the usefulness of pupillometry as a tool for experimental research in pragmatics

Abstract

When children learn their native language, they have to deal with a confusing array of dependencies between various elements in an utterance. The dependent elements may be adjacent to one another or separated by intervening material. Prior studies suggest that nonadjacent dependencies are hard to learn when the intervening material has little variability, which may be due to a trade-off between adjacent and nonadjacent learning. In this study, we investigate the statistical learning of adjacent and nonadjacent dependencies under low intervening variability using a modified serial reaction time (SRT) task. Young adults were trained on mixed sets of materials comprising equally probable adjacent and nonadjacent dependencies. Offline tests administered after training showed better performance for adjacent than nonadjacent dependencies. However, online SRT data indicated that the participants developed sensitivity to both types of dependencies during training, with no significant differences between dependency types. The results demonstrate the value of online measures of learning and suggest that adjacent and nonadjacent learning can occur together even when there is low variability in the intervening material

Abstract

The present study concerns individual differences in gesture production. We used correlational and multiple regression analyses to examine the relationship between individuals’ cognitive abilities and empathy levels and their gesture frequency and saliency. We chose predictor variables according to experimental evidence of the functions of gesture in speech production and communication. We examined 3 types of gestures: representational gestures, conduit gestures, and palm-revealing gestures. Higher frequency of representational gestures was related to poorer visual and spatial working memory, spatial transformation ability, and conceptualization ability; higher frequency of conduit gestures was related to poorer visual working memory, conceptualization ability, and higher levels of empathy; and higher frequency of palm-revealing gestures was related to higher levels of empathy. The saliency of all gestures was positively related to level of empathy. These results demonstrate that cognitive abilities and empathy levels are related to individual differences in gesture frequency and saliency

Abstract

Sentence production requires mapping preverbal messages onto linguistic structures. Because sentences are normally built incrementally, the information encoded in a sentence-initial increment is critical for explaining how the mapping process starts and for predicting its timecourse. Two experiments tested whether and when speakers prioritize encoding of different types of information at the outset of formulation by comparing production of descriptions of transitive events (e.g., A dog is chasing the mailman) that differed on two dimensions: the ease of naming individual characters and the ease of apprehending the event gist (i.e., encoding the relational structure of the event). To additionally manipulate ease of encoding, speakers described the target events after receiving lexical primes (facilitating naming; Experiment 1) or structural primes (facilitating generation of a linguistic structure; Experiment 2). Both properties of the pictured events and both types of primes influenced the form of target descriptions and the timecourse of formulation: character-specific variables increased the probability of speakers encoding one character with priority at the outset of formulation, while the ease of encoding event gist and of generating a syntactic structure increased the likelihood of early encoding of information about both characters. The results show that formulation is flexible and highlight some of the conditions under which speakers might employ different planning strategies.

Abstract

We investigated the neural basis of inhibitory control during lexical selection. Participants overtly named pictures while response times (RTs) and event-related brain potentials (ERPs) were recorded. The difficulty of lexical selection was manipulated by using object and action pictures with high name agreement (few response candidates) versus low name agreement (many response candidates). To assess the involvement of inhibition, we conducted delta plot analyses of naming RTs and examined the N2 component of the ERP. We found longer mean naming RTs and a larger N2 amplitude in the low relative to the high name agreement condition. For action naming we found a negative correlation between the slopes of the slowest delta segment and the difference in N2 amplitude between the low and high name agreement conditions. The converging behavioral and electrophysiological evidence suggests that selective inhibition is engaged to reduce competition during lexical selection in picture naming.

Abstract

The present study provides Dutch norms for age of acquisition, familiarity, imageability, image agreement, visual complexity, word frequency, and word length (in syllables) for 124 line drawings of actions. Ratings were obtained from 117 Dutch participants. Word frequency was determined on the basis of the SUBTLEX-NL corpus (Keuleers, Brysbaert, & New, Behavior Research Methods, 42, 643–650, 2010). For 104 of the pictures, naming latencies and name agreement were determined in a separate naming experiment with 74 native speakers of Dutch. The Dutch norms closely corresponded to the norms for British English. Multiple regression analysis showed that age of acquisition, imageability, image agreement, visual complexity, and name agreement were significant predictors of naming latencies, whereas word frequency and word length were not. Combined with the results of a principal-component analysis, these findings suggest that variables influencing the processes of conceptual preparation and lexical selection affect latencies more strongly than do variables influencing word-form encoding.

Abstract

This study examined the contributions of verbal ability and executive control to verbal fluency performance in older adults (n=82). Verbal fluency was assessed in letter and category fluency tasks, and performance on these tasks was related to indicators of vocabulary size, lexical access speed, updating, and inhibition ability. In regression analyses the number of words produced in both fluency tasks was predicted by updating ability, and the speed of the first response was predicted by vocabulary size and, for category fluency only, lexical access speed. These results highlight the hybrid character of both fluency tasks, which may limit their usefulness for research and clinical purposes.

Abstract

When formulating simple sentences to describe pictured events, speakers look at the referents they are describing in the order of mention. Accounts of incrementality in sentence production rely heavily on analyses of this gaze-speech link. To identify systematic sources of variability in message and sentence formulation, two experiments evaluated differences in formulation for sentences describing “easy” and “hard” events (more codable and less codable events) with preferred and dispreferred structures (actives and passives). Experiment 1 employed a subliminal cuing manipulation and a cumulative priming manipulation to increase production of passive sentences. Experiment 2 examined the influence of event codability on formulation without a cuing manipulation. In both experiments, speakers showed an early preference for looking at the agent of the event when constructing active sentences. This preference was attenuated by event codability, suggesting that speakers were less likely to prioritize encoding of a single character at the outset of formulation in “easy” events than in “harder” events. Accessibility of the agent influenced formulation primarily when an event was “harder” to describe. Formulation of passive sentences in Experiment 1 also began with early fixations to the agent but changed with exposure to passive syntax: speakers were more likely to consider the patient as a suitable sentential starting point after cumulative priming. The results show that the message-to-language mapping in production can vary with the ease of encoding an event structure and of generating a suitable linguistic structure.

Abstract

In sentence production, grammatical advance planning scope depends on contextual factors (e.g., time pressure), linguistic factors (e.g., ease of structural processing), and cognitive factors (e.g., production speed). The present study tests the influence of the availability of multiple syntactic alternatives (i.e., syntactic flexibility) on the scope of advance planning during the recall of Dutch dative phrases. We manipulated syntactic flexibility by using verbs with a strong bias or a weak bias toward one structural alternative in sentence frames accepting both verbs (e.g., strong/weak bias: De ober schotelt/serveert de klant de maaltijd [voor] “The waiter dishes out/serves the customer the meal”). To assess lexical planning scope, we varied the frequency of the first post-verbal noun (N1, Experiment 1) or the second post-verbal noun (N2, Experiment 2). In each experiment, 36 speakers produced the verb phrases in a rapid serial visual presentation (RSVP) paradigm. On each trial, they read a sentence presented one word at a time, performed a short distractor task, and then saw a sentence preamble (e.g., De ober…) which they had to complete to form the presented sentence. Onset latencies were compared using linear mixed effects models. N1 frequency did not produce any effects. N2 frequency only affected sentence onsets in the weak verb bias condition and especially in slow speakers. These findings highlight the dependency of planning scope during sentence recall on the grammatical properties of the verb and the frequency of post-verbal nouns. Implications for utterance planning in everyday speech are discussed.

Abstract

The generation of subject–verb agreement is a central component of grammatical encoding. It is sensitive to conceptual and grammatical influences, but the interplay between these factors is still not fully understood. We investigate how semantic integration of the subject noun phrase (‘the secretary of/with the governor’) and the Local Noun Number (‘the secretary with the governor/governors’) affect the ease of selecting the verb form. Two hypotheses are assessed: according to the notional hypothesis, integration encourages the assignment of the singular notional number to the noun phrase and facilitates the choice of the singular verb form. According to the lexical interference hypothesis, integration strengthens the competition between nouns within the subject phrase, making it harder to select the verb form when the nouns mismatch in number. In two experiments, adult speakers of Dutch completed spoken preambles (Experiment 1) or selected appropriate verb forms (Experiment 2). Results showed facilitatory effects of semantic integration (fewer errors and faster responses with increasing integration). These effects did not interact with the effects of the Local Noun Number (slower response times and higher error rates for mismatching than for matching noun numbers). The findings thus support the notional hypothesis and a model of agreement where conceptual and lexical factors independently contribute to the determination of the number of the subject noun phrase and, ultimately, the verb.

Abstract

Compared to the large body of work on lexical access, little research has been done on grammatical encoding in language production. An exception is the generation of subject-verb agreement. Here, two key findings have been reported: (1) Speakers make more agreement errors when the head and local noun of a phrase mismatch in number than when they match (e.g., the key to the cabinet(s)); and (2) this attraction effect is asymmetric, with stronger attraction for singular than for plural head nouns. Although these findings are robust, the cognitive processes leading to agreement errors and their significance for the generation of correct agreement are not fully understood. We propose that future studies of agreement, and grammatical encoding in general, may benefit from using paradigms that tightly control the variability of the lexical content of the material. We report two experiments illustrating this approach. In both of them, the experimental items featured combinations of four nouns, four color adjectives, and two prepositions. In Experiment 1, native speakers of Dutch described pictures in sentences such as the circle next to the stars is blue. In Experiment 2, they carried out a forced-choice task, where they read subject noun phrases (e.g., the circle next to the stars) and selected the correct verb-phrase (is blue or are blue) with a button press. Both experiments showed an attraction effect, with more errors after subject phrases with mismatching, compared to matching head and local nouns. This effect was stronger for singular than plural heads, replicating the attraction asymmetry. In contrast, the response times recorded in Experiment 2 showed similar attraction effects for singular and plural head nouns. These results demonstrate that critical agreement phenomena can be elicited reliably in lexically-reduced contexts. We discuss the theoretical implications of the findings and the potential and limitations of studies using lexically simple materials.

Abstract

A. Caramazza, A. Costa, M. Miozzo, and Y. Bi(2001) reported a series of experiments demonstrating that the ease of producing a word depends only on the frequency of that specific word but not on the frequency of a homophone twin. A. Caramazza, A. Costa, et al. concluded that homophones have separate word form representations and that the absence of frequency-inheritance effects for homophones undermines an important argument in support of 2-stage models of lexical access, which assume that syntactic (lemma) representations mediate between conceptual and phonological representations. The authors of this article evaluate the empirical basis of this conclusion, report 2 experiments demonstrating a frequency-inheritance effect, and discuss other recent evidence. It is concluded that homophones share a common word form and that the distinction between lemmas and word forms should be upheld.

Abstract

According to Levelt, Roelofs, and Meyer (1999) speakers generate the phonological and phonetic representations of successive syllables of a word in sequence and only begin to speak after having fully planned at least one complete phonological word. Therefore, speech onset latencies should be longer for long than for short words. We tested this prediction in four experiments in which Dutch participants named or categorized objects with monosyllabic or disyllabic names. Experiment 1 yielded a length effect on production latencies when objects with long and short names were tested in separate blocks, but not when they were mixed. Experiment 2 showed that the length effect was not due to a difference in the ease of object recognition. Experiment 3 replicated the results of Experiment 1 using a within-participants design. In Experiment 4, the long and short target words appeared in a phrasal context. In addition to the speech onset latencies, we obtained the viewing times for the target objects, which have been shown to depend on the time necessary to plan the form of the target names. We found word length effects for both dependent variables, but only when objects with short and long names were presented in separate blocks. We argue that in pure and mixed blocks speakers used different response deadlines, which they tried to meet by either generating the motor programs for one syllable or for all syllables of the word before speech onset. Computer simulations using WEAVER++ support this view.