An ERP study of inhibition of non-target languages in trilingual word production

The present study examined the locus where inhibition of non-target languages is exerted during trilingual word production by analyzing the cue-locked and stimulus-locked ERPs respectively in the n-2 language repetition paradigm. During the experiment, Uighur–Chinese–English trilinguals overtly named Arabic digits in one of their three languages according to a visually presented cue while their behavioral and electrophysiological responses were recorded. The behavioral data revealed insignificant n-2 repetition costs. Cue-locked ERPs revealed also only tiny or marginally significant n-2 repetition effects over some midline electrodes. The stimulus-locked ERP data showed a more negative ERP component elicited by the n-2 repetition trials than the n-2 non-repetition trials around 250 ms after stimulus onset, but no significant difference in this ERP effect between different languages was found. The results indicate that inhibition of non-target languages occurs at the lemma selection phase rather than the language task schemas phase during trilingual language production.     

Lexical availability and grammatical encoding scope during spoken sentence production

Three sentence production experiments investigate the relationship between lexical and structural processing scope. Speakers generated sentences with varying phrase structures in response to visual displays (e.g., The dog and the hat move above the fork and the tree/The dog moves above the hat and the fork and the tree). On half of the trials, one of the pictures in the arrays was previewed. Filler sentences varied preview position and sentence structure from trial to trial. When speakers could not anticipate the position of the previewed picture in the upcoming sentence (Experiment 1), preview benefit for pictures corresponding to the second noun to be produced was limited to pictures that fell within the sentence-initial phrase. When the linear position of the previewed picture was predictable, preview benefits were observed for the second noun to be produced, irrespective of phrase position (Experiment 2). However, no preview benefits were observed for the third noun to be produced (Experiment 3). In contrast, significant effects of initial phrase structure were observed in all experiments, with latencies increasing with initial phrase length. The results are consistent with speakers operating a phrasal scope for structural planning within which the scope of lexical access can vary.     

Cumulative and non-cumulative semantic interference in object naming: Evidence from blocked and continuous manipulations of semantic context

Experiments involving blocked and continuous manipulations of the semantic naming context demonstrate that, when speakers name several taxonomically related objects in close succession, they display persistent interference effects. A review of studies using the blocked paradigm shows that, unlike the continuous paradigm, it typically does not induce cumulative interference effects in healthy speakers. This contrasts with the simulation results obtained from a model of semantic context effects recently put forward by Oppenheim and colleagues [Oppenheim, G. M., Dell, G. S., & Schwartz, M. F. (2010). The dark side of incremental learning: A model of cumulative semantic interference during lexical access in speech production. Cognition, 114, 227--262], which generates cumulative effects in both paradigms. We propose that the effects are non-cumulative in the blocked paradigm, because it allows participants to bias top-down the levels of activation of lexical-semantic representations, thereby curtailing the accumulating interference. Indeed, prior research has shown that the interference effects in the blocked paradigm are exacerbated when participants carry out a concurrent digit-retention task, loading on working memory and reducing their capacity to exert a top-down bias. In Experiment 1, combining the continuous paradigm with a digit-retention task, we demonstrate that this does not exacerbate cumulative context effects, corroborating the selective role of working memory and the associated top-down biasing mechanism in the blocked paradigm. A review of neuropsychological and neuroimaging studies demonstrates that left inferior frontal regions may play a critical role in controlling semantic interference top-down. We discuss the implications of these findings for language production research and for models of lexical-semantic encoding.     

Evidence for Age-related Changes to Temporal Attention and Memory from the Choice Time Production Task

ABSTRACT

The effect of aging on interval timing was examined using a choice time production task, which required participants to choose a key response based on the location of the stimulus, but to delay responding until after a learned time interval. Experiment 1 varied attentional demands of the response choice portion of the task by varying difficulty of stimulus–response mapping. Choice difficulty affected temporal accuracy equally in both age groups, but older participants' response latencies were more variable under more difficult response choice conditions. Experiment 2 tested the contribution of long-term memory to differences in choice time production between age groups over 3 days of testing. Direction of errors in time production between the two age groups diverged over the 3 sessions, but variability did not differ. Results from each experiment separately show age-related changes to attention and memory in temporal processing using different measures and manipulations in the same task.     

Effects of divided attention in the word-fragment completion task with unique and multiple solutions

A study with 114 young adults investigated the correlations of intelligence factors and working-memory capacity with reaction time (RT) tasks. Within two sets of four-choice RT tasks, stimulus–response compatibility was varied over three levels: compatible, incompatible, and arbitrary mappings. Two satisfactory measurement models for the RTs could be established: A general factor model without constraints on the loadings and a nested model with two correlated factors, distinguishing compatible from arbitrary mappings, with constraints on the loadings. Structural models additionally including factors for working memory and intelligence showed that the nested model with correlated factors is superior in fit. Working-memory capacity and fluid intelligence were correlated strongly with the nested factor for the RT tasks with arbitrary mappings, and less with the general RT factor. The results support the hypothesis that working memory is needed to maintain arbitrary bindings between stimulus representations and response representations, and this could explain the correlation of working-memory capacity with speed in choice RT tasks.     

Word order does not constrain phonological activation in single word production

It has recently been claimed that the canonical word order of a given language constrains phonological activation processes even in single word production (Janssen, Alario, & Caramazza, 2008). This hypothesis predicts for languages with canonical adjective–noun word order that naming an object (i.e., noun production) is facilitated if the task-irrelevant colour of the object (i.e., adjective) is phonologically similar to the object name (e.g., blue–boat as compared to red–boat). By contrast, there should be no corresponding effect in naming the colour of the object (i.e., adjective production). In an experiment with native speakers of German, however, we observed exactly the opposite pattern. Phonological congruency facilitated colour naming but had no effect on object naming. Together with extant data from other languages our results suggest that object colour naming is affected by the phonology of the object name but not vice versa, regardless of the canonical word order in the given language.     

Syntactic Complexity Effects in Sentence Production

Syntactic complexity effects have been investigated extensively with respect to comprehension (e.g., Demberg & Keller, 2008; Gibson, 1998, 2000; Gordon et al., 2001, 2004; Grodner & Gibson, 2005; King & Just, 1991; Lewis & Vasishth, 2005; Lewis et al., 2006; McElree et al., 2003; Wanner & Maratsos, 1978). According to one prominent class of accounts (experience‐based accounts; e.g., Hale, 2001; Levy, 2008; Gennari & MacDonald, 2008, 2009; Wells et al., 2009), certain structures cause comprehension difficulty due to their scarcity in the language. But why are some structures less frequent than others? In two elicited‐production experiments we investigated syntactic complexity effects in relative clauses (Experiment 1) and wh‐questions (Experiment 2) varying in whether or not they contained non‐local dependencies. In both experiments, we found reliable durational differences between subject‐extracted structures (which only contain local dependencies) and object‐extracted structures (which contain nonlocal dependencies): Participants took longer to begin and produce object‐extractions. Furthermore, participants were more likely to be disfluent in the object‐extracted constructions. These results suggest that there is a cost associated with planning and uttering the more syntactically complex, object‐extracted structures, and that this cost manifests in the form of longer durations and disfluencies. Although the precise nature of this cost remains to be determined, these effects provide one plausible explanation for the relative rarity of object‐extractions: They are more costly to produce.     

How Cognitive Load Influences Speakers' Choice of Referring Expressions

We report on two experiments investigating the effect of an increased cognitive load for speakers on the choice of referring expressions. Speakers produced story continuations to addressees, in which they referred to characters that were either salient or non‐salient in the discourse. In Experiment 1, referents that were salient for the speaker were non‐salient for the addressee, and vice versa. In Experiment 2, all discourse information was shared between speaker and addressee. Cognitive load was manipulated by the presence or absence of a secondary task for the speaker. The results show that speakers under load are more likely to produce pronouns, at least when referring to less salient referents. We take this finding as evidence that speakers under load have more difficulties taking discourse salience into account, resulting in the use of expressions that are more economical for themselves.     

Iconic Prosody in Story Reading

Recent experiments have shown that people iconically modulate their prosody corresponding with the meaning of their utterance (e.g., Shintel et al., 2006). This article reports findings from a story reading task that expands the investigation of iconic prosody to abstract meanings in addition to concrete ones. Participants read stories that contrasted along concrete and abstract semantic dimensions of speed (e.g., a fast drive, slow career progress) and size (e.g., a small grasshopper, an important contract). Participants read fast stories at a faster rate than slow stories, and big stories with a lower pitch than small stories. The effect of speed was distributed across the stories, including portions that were identical across stories, whereas the size effect was localized to size‐related words. Overall, these findings enrich the documentation of iconicity in spoken language and bear on our understanding of the relationship between gesture and speech.     

On predicting others’ words: Electrophysiological evidence of prediction in speech production

The present study investigated whether lexical processes that occur when we name objects can also be observed when an interaction partner is naming objects. We compared the behavioral and electrophysiological responses of participants performing a conditional go/no-go picture naming task in two different conditions: individually and jointly with a confederate participant. To obtain an index of lexical processing, we manipulated lexical frequency, so that half of the pictures had corresponding names of high-frequency and the remaining half had names of low-frequency. Color cues determined whether participants should respond, whether their task-partner should respond, or whether nobody should respond. Behavioral and ERP results showed that participants engaged in lexical processing when it was their turn to respond. Crucially, ERP results on no-go trials revealed that participants also engaged in lexical processing when it was their partner’s turn to act. In addition, ERP results showed increased response inhibition selectively when it was the partner’s turn to act. These findings provide evidence for the claim that listeners generate predictions about speakers’ utterances by relying on their own action production system.