Publications

Abstract

Background

Forced switching between languages poses demands on control abilities, which may be difficult to meet for bilinguals with aphasia. Freely choosing languages has been shown to increase naming efficiency in healthy bilinguals, and lexical accessibility was found to be a predictor for language choice. The overlap between bilingual language switching and other types of switching is yet unclear.

Aims

This study aimed to examine the benefits of free language choice for bilinguals with aphasia and to investigate the overlap of between- and within-language switching abilities.

Methods & Procedures

Seventeen bilinguals with aphasia completed a questionnaire and four web-based picture naming tasks: single-language naming in the first and second language separately; voluntary switching between languages; cued and predictable switching between languages; cued and predictable switching between phrase types in the first language. Accuracy and naming latencies were analysed using (generalised) linear mixed-effects models.

Outcomes & Results

The results showed higher accuracy and faster naming for the voluntary switching condition compared to single-language naming and cued switching. Both voluntary and cued language switching yielded switch costs, and voluntary switch costs were larger. Ease of lexical access was a reliable predictor for voluntary language choice. We obtained no statistical evidence for differences or associations between switch costs in between- and within-language switching.

Conclusions

Several results point to benefits of voluntary language switching for bilinguals with aphasia. Freely mixing languages improved naming accuracy and speed, and ease of lexical access affected language choice. There was no statistical evidence for overlap of between- and within-language switching abilities. This study highlights the benefits of free language choice for bilinguals with aphasia.

Abstract

Previous research examining the factors that determine language choice and voluntary switching mainly involved early bilinguals. Here, using picture naming, we investigated language choice and switching in late Dutch–English bilinguals. We found that naming was overall slower in cued than in voluntary switching, but switch costs occurred in both types of switching. The magnitude of switch costs differed depending on the task and language, and was moderated by L2 proficiency. Self-rated rather than objectively assessed proficiency predicted voluntary switching and ease of lexical access was associated with language choice. Between-language and within-language switch costs were not correlated. These results highlight self-rated proficiency as a reliable predictor of voluntary switching, with language modulating switch costs. As in early bilinguals, ease of lexical access was related to word-level language choice of late bilinguals.

Abstract

Accumulating evidence suggests that some degree of attentional control is required to regulate and monitor processes underlying speaking. Although progress has been made in delineating the neural substrates of the core language processes involved in speaking, substrates associated with regulatory and monitoring processes have remained relatively underspecified. We report the results of an fMRI study examining the neural substrates related to performance in three attention-demanding tasks varying in the amount of linguistic processing: vocal picture naming while ignoring distractors (picture-word interference, PWI); vocal color naming while ignoring distractors (Stroop); and manual object discrimination while ignoring spatial position (Simon task). All three tasks had congruent and incongruent stimuli, while PWI and Stroop also had neutral stimuli. Analyses focusing on common activation across tasks identified a portion of the dorsal anterior cingulate cortex (ACC) that was active in incongruent trials for all three tasks, suggesting that this region subserves a domain-general attentional control function. In the language tasks, this area showed increased activity for incongruent relative to congruent stimuli, consistent with the involvement of domain-general mechanisms of attentional control in word production. The two language tasks also showed activity in anterior-superior temporal gyrus (STG). Activity increased for neutral PWI stimuli (picture and word did not share the same semantic category) relative to incongruent (categorically related) and congruent stimuli. This finding is consistent with the involvement of language-specific areas in word production, possibly related to retrieval of lexical-semantic information from memory. The current results thus suggest that in addition to engaging language-specific areas for core linguistic processes, speaking also engages the ACC, a region that is likely implementing domain-general attentional control.

Abstract

A fundamental ability of speakers is to
quickly retrieve words from long-term memory. According to a prominent theory, concepts activate multiple associated words, which enter into competition for selection. Previous electrophysiological studies have provided evidence for the activation of multiple alternative words, but did not identify brain responses refl ecting competition. We report a magnetoencephalography study examining the timing and neural substrates of lexical activation and competition. The degree of activation of competing words was
manipulated by presenting pictures (e.g., dog) simultaneously with distractor
words. The distractors were semantically related to the picture name (cat), unrelated (pin), or identical (dog). Semantic distractors are stronger competitors to the picture name, because they receive additional activation from the picture, whereas unrelated distractors do not. Picture naming times were longer with semantic than with unrelated and identical distractors. The patterns of phase-locked and non-phase-locked activity were distinct
but temporally overlapping. Phase-locked activity in left middle temporal
gyrus, peaking at 400 ms, was larger on unrelated than semantic and identical trials, suggesting differential effort in processing the alternative words activated by the picture-word stimuli. Non-phase-locked activity in the 4-10 Hz range between 400-650 ms in left superior frontal gyrus was larger on semantic than unrelated and identical trials, suggesting different
degrees of effort in resolving the competition among the alternatives
words, as refl ected in the naming times. These findings characterize distinct
patterns of brain activity associated with lexical activation and competition
respectively, and their temporal relation, supporting the theory that words are selected by competition.

Abstract

First paragraph: A fundamental issue in psycholinguistics concerns how speakers retrieve intended words from long-term memory. According to a selection by competition account (e.g., Levelt
et al., 1999), conceptually driven word retrieval involves the activation of a set of candidate words and a competitive selection
of the intended word from this set.

Abstract

For several decades, context effects in picture naming and word reading have been extensively investigated. However, researchers have found no agreement on the explanation of the effects. Whereas it has long been assumed that several types of effect reflect competition in word selection, recently it has been argued that these effects reflect the exclusion of articulatory responses from an output buffer. Here, we first critically evaluate the findings on context effects in picture naming that have been taken as evidence against the competition account, and we argue that the findings are, in fact, compatible with the competition account. Moreover, some of the findings appear to challenge rather than support the response exclusion account. Next, we compare the response exclusion and competition accounts with respect to their ability to explain data on word reading. It appears that response exclusion does not account well for context effects on word reading times, whereas computer simulations reveal that a competition model like WEAVER++ accounts for the findings.

Abstract

Whereas most theoretical and computational models assume a continuous flow of activation from concepts to lexical items in spoken word production, one prominent model assumes that the mapping of concepts onto words happens in a discrete fashion (Bloem & La Heij, 2003). Semantic facilitation of context pictures on word translation has been taken to support the discrete-flow model. Here, we report results of computer simulations with the continuous-flow WEAVER++ model (Roelofs, 1992, 2006) demonstrating that the empirical observation taken to be in favor of discrete models is, in fact, only consistent with those models and equally compatible with more continuous models of word production by monolingual and bilingual speakers. Continuous models are specifically and independently supported by other empirical evidence on the effect of context pictures on native word production.

Abstract

Roelofs, Piai, and Schriefers argue that several findings on the effect of distractor words and pictures in producing words support a selection-by-competition account and challenge a non-competitive response-exclusion account. Janssen argues that the findings do not challenge response exclusion, and he conjectures that both competitive and non-competitive mechanisms underlie word selection. Here, we maintain that the findings do challenge the response-exclusion account and support the assumption of a single competitive mechanism underlying word selection.

Abstract

The present study examined the relation between nonselective inhibition and selective inhibition in picture naming performance. Nonselective inhibition refers to the ability to suppress any unwanted response, whereas selective inhibition refers to the ability to suppress specific competing responses. The degree of competition in picture naming was manipulated by presenting targets along with distractor words that could be semantically related (e.g., a picture of a dog combined with the word cat) or unrelated (tree) to the picture name. The mean naming response time (RT) was longer in the related than in the unrelated condition, reflecting semantic interference. Delta plot analyses showed that participants with small mean semantic interference effects employed selective inhibition more effectively than did participants with larger semantic interference effects. The participants were also tested on the stop-signal task, which taps nonselective inhibition. Their performance on this task was correlated with their mean naming RT but, importantly, not with the selective inhibition indexed by the delta plot analyses and the magnitude of the semantic interference effect. These results indicate that nonselective inhibition ability and selective inhibition of competitors in picture naming are separable to some extent.

Abstract

Does the naming of clocks always require conceptual preparation? To examine this question, speakers were presented with analog and digital clocks that had to be named in Dutch using either a relative (e.g., “quarter to four”) or an absolute (e.g., “three forty-five”) clock time expression format. Naming latencies showed evidence of conceptual preparation when speakers produced relative time expressions to analog and digital clocks, but not when they used absolute time expressions. These findings indicate that conceptual mediation is not always mandatory for telling time, but instead depends on clock time expression format, supporting a multiple-route account of Dutch clock time naming.

Abstract

Disagreement exists about how speakers monitor their internal speech. Production-based accounts assume that self-monitoring mechanisms exist within the production system, whereas comprehension-based accounts assume that monitoring is achieved through the speech comprehension system. Comprehension-based accounts predict perception-specific effects, like the perceptual uniqueness-point effect, in the monitoring of internal speech. We ran an extensive experiment testing this prediction using internal phoneme monitoring and picture naming tasks. Our results show an effect of the perceptual uniqueness point of a word in internal phoneme monitoring in the absence of such an effect in picture naming. These results support comprehension-based accounts of the monitoring of internal speech.

Abstract

The author contests several claims of La Heij, Starreveld, and Kuipers (this issue) concerning the modelling of spoken word planning. The claims are about the relevance of error findings, the interaction between semantic and phonological factors, the explanation of word-word findings, the semantic relatedness paradox, and production rules.

Abstract

Simple name-retrieval models of spoken word planning (Bloem & La Heij, 2003; Starreveld & La Heij, 1996) maintain (1) that there are two levels in word planning, a conceptual and a lexical phonological level, and (2) that planning a word in both object naming and oral reading involves the selection of a lexical phonological representation. Here, the name retrieval models are compared to more complex models with respect to their ability to account for relevant data. It appears that the name retrieval models cannot easily account for several relevant findings, including some speech error biases, types of morpheme errors, and context effects on the latencies of responding to pictures and words. New analyses of the latency distributions in previous studies also pose a challenge. More complex models account for all these findings. It is concluded that the name retrieval models are too simple and that the greater complexity of the other models is warranted

Abstract

The trigger for shifting gaze between stimuli requiring vocal and manual responses was examined. Participants were presented with picture–word stimuli and left- or right-pointing arrows. They vocally named the picture (Experiment 1), read the word (Experiment 2), or categorized the word (Experiment 3) and shifted their gaze to the arrow to manually indicate its direction. The experiments showed that the temporal coordination of vocal responding and gaze shifting depends on the vocal task and, to a lesser extent, on the type of relationship between picture and word. There was a close temporal link between gaze shifting and manual responding, suggesting that the gaze shifts indexed shifts of attention between the vocal and manual tasks. Computer simulations showed that a simple extension of WEAVER++ [Roelofs, A. (1992). A spreading-activation theory of lemma retrieval in speaking. Cognition, 42, 107–142.; Roelofs, A. (2003). Goal-referenced selection of verbal action: modeling attentional control in the Stroop task. Psychological Review, 110, 88–125.] with assumptions about attentional control in the coordination of vocal responding, gaze shifting, and manual responding quantitatively accounts for the key findings.

Abstract

In 4 chronometric experiments, influences of spoken word planning on speech recognition were examined. Participants were shown pictures while hearing a tone or a spoken word presented shortly after picture onset. When a spoken word was presented, participants indicated whether it contained a prespecified phoneme. When the tone was presented, they indicated whether the picture name contained the phoneme (Experiment 1) or they named the picture (Experiment 2). Phoneme monitoring latencies for the spoken words were shorter when the picture name contained the prespecified phoneme compared with when it did not. Priming of phoneme monitoring was also obtained when the phoneme was part of spoken nonwords (Experiment 3). However, no priming of phoneme monitoring was obtained when the pictures required no response in the experiment, regardless of monitoring latency (Experiment 4). These results provide evidence that an internal phonological pathway runs from spoken word planning to speech recognition and that active phonological encoding is a precondition for engaging the pathway. (PsycINFO Database Record (c) 2007 APA, all rights reserved)

Abstract

The authors discuss the issue of how visual orienting, selective stimulus processing, and vocal response planning are related in Stroop-like tasks. The evidence suggests that visual orienting is dependent on both visual processing and verbal response planning. They also discuss the issue of selective perceptual processing in Stroop-like tasks. The evidence suggests that space-based and object-based attention lead to a Trojan horse effect in the classic Stroop task, which can be moderated by increasing the spatial distance between colour and word and by making colour and word part of different objects. Reducing the presentation duration of the colour-word stimulus or the duration of either the colour or word dimension reduces Stroop interference. This paradoxical finding was correctly simulated by the WEAVER++ model. Finally, the authors discuss evidence on the neural correlates of executive attention, in particular, the ACC. The evidence suggests that the ACC plays a role in regulation itself rather than only signalling the need for regulation.