Word Form Retrieval in Spoken Word Production

<p>In the auditory picture-word interference task, participants name pictures whilst ignoring auditory distractor words. Previous studies have reported faster naming latencies when distractors are phonologically related to the target (e.g., tiger-typist) than when they are unrelated. By varying the position of overlap of the shared phonemes and the onset of the distractor, this task may provide valuable insights into the time course of phonological encoding. In the current study, participants named pictures while hearing distractor words that were: begin-related (e.g., letter-lesson); end-related (e.g., letter-otter); or unrelated to the target (e.g., letter-cabin). Distractor onsets varied from -200ms (before target) to +400ms (after target). The study was carried out in two phases: in the first phase, the task was administered to a group of 24 young control participants; in the second phase, it was administered to an individual with aphasia, NP, and a group of six older controls. Phonological facilitation effects of begin-related distractors displayed a fairly consistent pattern across the four distractor onsets for all participant groups. In almost all instances, these effects were significant but were noticeably stronger at early onsets especially around the onset of the target presentation, consistent with previous findings in the literature. Only NP showed strong begin-related facilitation effects at the latest onset. The end-related distractors however, produced somewhat different facilitation effects across the different groups. For the young controls and NP, these effects were stronger and significant at later onsets. The older controls only displayed marginally significant effects at 200ms after the target. Findings from the current study provide support for serial pattern of phoneme retrieval in multisyllabic words, in which a word‟s first syllable becomes available before later syllable(s).</p>

Word Form Retrieval in Spoken Word Production

<p>In the auditory picture-word interference task, participants name pictures whilst ignoring auditory distractor words. Previous studies have reported faster naming latencies when distractors are phonologically related to the target (e.g., tiger-typist) than when they are unrelated. By varying the position of overlap of the shared phonemes and the onset of the distractor, this task may provide valuable insights into the time course of phonological encoding. In the current study, participants named pictures while hearing distractor words that were: begin-related (e.g., letter-lesson); end-related (e.g., letter-otter); or unrelated to the target (e.g., letter-cabin). Distractor onsets varied from -200ms (before target) to +400ms (after target). The study was carried out in two phases: in the first phase, the task was administered to a group of 24 young control participants; in the second phase, it was administered to an individual with aphasia, NP, and a group of six older controls. Phonological facilitation effects of begin-related distractors displayed a fairly consistent pattern across the four distractor onsets for all participant groups. In almost all instances, these effects were significant but were noticeably stronger at early onsets especially around the onset of the target presentation, consistent with previous findings in the literature. Only NP showed strong begin-related facilitation effects at the latest onset. The end-related distractors however, produced somewhat different facilitation effects across the different groups. For the young controls and NP, these effects were stronger and significant at later onsets. The older controls only displayed marginally significant effects at 200ms after the target. Findings from the current study provide support for serial pattern of phoneme retrieval in multisyllabic words, in which a word‟s first syllable becomes available before later syllable(s).</p>

EXPRESS: Rethinking attentional reset: Task sets determine the boundaries of adaptive control

Adaptive control processes that minimize distraction often operate in a context-specific manner. For example, they may minimize distraction from irrelevant conversations during a lecture but not in the hallway afterwards. It remains unclear, however, whether (a) salient perceptual features or (b) task sets based on such features serve as contextual boundaries for adaptive control in standard distractor-interference tasks. To distinguish between these possibilities, we manipulated whether the structure of a standard, visual distractor-interference task allowed (Experiment 1) or did not allow (Experiment 2) participants to associate salient visual features (i.e., color patches and color words) with different task sets. We found that changing salient visual features across consecutive trials reduced a popular measure of adaptive control in distractor-interference tasks – the congruency sequence effect (CSE) – only when the task structure allowed participants to associate these visual features with different task sets. These findings extend prior support for the task set hypothesis from somewhat atypical cross-modal tasks to a standard unimodal task. Conversely, they pose a challenge to an alternative “attentional reset” hypothesis, and related views, wherein changing salient perceptual features always results in a contextual boundary for the CSE.

Lexical selection in bilingual language production

The goal of this study is to examine whether bilingual speakers can inhibit one language while naming pictures in the other. In two picture-word interference task experiments, Spanish-English and English-Spanish bilinguals named pictures in Spanish. We used language-neutral (nonword) interfering stimuli to probe the phonological activation of the nontarget language (English). Three different interfering stimulus conditions were presented: nonwords phonologically related to the Spanish picture name (Phono-Spanish), nonwords phonologically related to the English picture name (Phono-English) and phonologically unrelated nonwords (Unrelated). When participants named pictures in Spanish (Experiment 1), facilitation was found for both groups in the Phono-Spanish condition. No interference was found in the Phono-English condition for either group. From this result and the results of a control experiment in which participants named pictures in English (Experiment 2), we argue that under some circumstances, bilinguals are able to effectively inhibit the nontarget language during language production.

Bilateral Interference in Motor Performance in Homologous vs. Non-homologous Proximal and Distal Effectors

Performance of bimanual motor actions requires coordinated and integrated bilateral communication, but in some bimanual tasks, neural interactions and crosstalk might cause bilateral interference. The level of interference probably depends on the proportions of bilateral interneurons connecting homologous areas of the motor cortex in the two hemispheres. The neuromuscular system for proximal muscles has a higher number of bilateral interneurons connecting homologous areas of the motor cortex compared to distal muscles. Based on the differences in neurophysiological organization for proximal vs. distal effectors in the upper extremities, the purpose of the present experiment was to evaluate how the level of bilateral interference depends on whether the bilateral interference task is performed with homologous or non-homologous effectors as the primary task. Fourteen participants first performed a unilateral primary motor task with the dominant arm with (1) proximal and (2) distal controlled joysticks. Performance in the unilateral condition with the dominant arm was compared to the same effector’s performance when two different bilateral interference tasks were performed simultaneously with the non-dominant arm. The two different bilateral interference tasks were subdivided into (1) homologous and (2) non-homologous effectors. The results showed a significant decrease in performance for both proximal and distal controlled joysticks, and this effect was independent of whether the bilateral interference tasks were introduced with homologous or non-homologous effectors. The overall performance decrease as a result of bilateral interference was larger for proximal compared to distal controlled joysticks. Furthermore, a proximal bilateral interference caused a larger performance decrement independent of whether the primary motor task was controlled by a proximal or distal joystick. A novel finding was that the distal joystick performance equally interfered with either homologous (distal bilateral interference) or non-homologous (proximal bilateral interference) interference tasks performed simultaneously. The results indicate that the proximal–distal distinction is an important organismic constraint on motor control and for understanding bilateral communication and interference in general and, in particular, how bilateral interference caused by homologous vs. non-homologous effectors impacts motor performance for proximal and distal effectors. The results seem to map neuroanatomical and neurophysiological differences for these effectors.

Do Cross-Language Script Differences Enable Bilinguals to Function Selectively When Speaking in One Language Alone?

The present study examined the role of script in bilingual speech planning by comparing the performance of same and different-script bilinguals. Spanish-English bilinguals (Experiment 1) and Japanese-English bilinguals (Experiment 2) performed a picture-word interference task in which they were asked to name a picture of an object in English, their second language, while ignoring a visual distractor word in Spanish or Japanese, their first language. Results replicated the general pattern seen in previous bilingual picture-word interference studies for the same-script, Spanish-English bilinguals but not for the different-script, Japanese-English bilinguals. Both groups showed translation facilitation, whereas only Spanish-English bilinguals demonstrated semantic interference, phonological facilitation, and phono-translation facilitation. These results suggest that when the script of the language not in use is present in the task, bilinguals appear to exploit the perceptual difference as a language cue to direct lexical access to the intended language earlier in the process of speech planning.

Cross-linguistic interactions across modalities: Effects of the oral language on sign production

To investigate cross-linguistic interactions in bimodal bilingual production, behavioural and electrophysiological measures (ERPs) were recorded from 24 deaf bimodal bilinguals while naming pictures in Catalan Sign Language (LSC). Two tasks were employed, a picture-word interference and a picture-picture interference task. Cross-linguistic effects were explored via distractors that were either semantically related to the target picture, to the phonology/orthography of the Spanish name of the target picture, or were unrelated. No semantic effects were observed in sign latencies, but ERPs differed between semantically related and unrelated distractors. For the form-related manipulation, a facilitation effect was observed both behaviourally and at the ERP level. Importantly, these effects were not influenced by the type of distractor (word/picture) presented providing the first piece of evidence that deaf bimodal bilinguals are sensitive to oral language in sign production. Implications for models of cross-linguistic interactions in bimodal bilinguals are discussed.