Markedness effects in Norwegian–English bilinguals: Task-dependent use of language-specific letters and bigrams

This study investigates how bilinguals use sublexical language membership information to speed up their word recognition process in different task situations. Norwegian–English bilinguals performed a Norwegian–English language decision task, a mixed English lexical decision task, or a mixed Norwegian lexical decision task. The mixed lexical decision experiments included words from the nontarget language that required a “no” response. The language specificity of the Bokmål (a Norwegian written norm) and English (non)words was varied by including language-specific letters (“smør”, “hawk”) or bigrams (“dusj”, “veal”). Bilinguals were found to use both types of sublexical markedness to facilitate their decisions, language-specific letters leading to larger effects than language-specific bigrams. A cross-experimental comparison indicates that the use of sublexical language information was strategically dependent on the task at hand and that decisions were based on language membership information derived directly from sublexical (bigram) stimulus characteristics instead of indirectly via their lexical representations. Available models for bilingual word recognition fail to handle the observed marker effects, because all consider language membership as a lexical property only.     

Electrophysiological evidence for priming in response to words and pseudowords in first and second language

The study purpose was to indicate when language-specific processing first occurs and how first and second language priming processes interact. Event-related potentials were recorded from 14 normal native Hebrew speakers, in a variation of lexical decision task, to pairs of stimuli (S1, S2) in Hebrew, English, Hebrew pseudowords, and English pseudowords. Although no behavioral priming was observed, priming by pseudowords in either language affected both N400 and the late positive component of event related potential. N1 and P2 latencies were longer to S2 in semantically related pairs, indicating that language-specific processing may take place as early as auditory cortex. Different processing of first and second language was evident only in response to pseudowords.     

语言转换的认知及其神经机制

语言转换是双语研究领域的焦点问题之一,抑制控制模型、语言特异性选择模型、任务设置惯性模型和序列难度效应模型从不同的角度解释了语言转换的认知机制。认知神经科学的一些研究发现,语言转换与任务转换具有类似的神经机制,说明语言转换代价与任务转换代价的本质可能是相同的。抑制控制和语言熟练程度如何影响语言的转换,语言转换代价与任务转换代价的本质是否相同,一般领域的抑制机制是否可以迁移到语言转换领域等问题是未来需要进一步研究的问题。     

The processing of interlexical homographs in translation recognition and lexical decision: Support for non-selective access to bilingual memory

In three experiments we looked at the processing of interlexical homographs by Dutch-English bilinguals. In Experiment 1 we employed the translation recognition task, a task that forces the participants to activate both language systems simultaneously. In this task the processing of interlexical homographs was inhibited substantially compared to the processing of matched control words, especially when the homograph reading to be selected was the less frequent of the homograph's two readings. In Experiments 2 and 3 we used the lexical decision task: In one condition we asked the participants to categorize letter strings as words or nonwords in Dutch; in a second condition we asked them to do so in English. The makeup of the stimulus set in Experiment 2 permitted the participants to ignore the instructions and to instantiate the task in a language-neutral form-that is, to categorize the letter strings as words in either Dutch or English. Under these circumstances a small, frequency-dependent inhibitory effect for homographs was obtained, but only in condition Dutch. In Experiment 3 the participants were forced in a language-specific processing mode by the inclusion of "nonwords" that were in fact words in the non-target language. Large frequency-dependent inhibitory effects for homographs were now obtained in both language conditions. The combined results are interpreted as support for the view that bilingual lexical access is non-selective.     

The bivalency effect: evidence for flexible adjustment of cognitive control

When bivalent stimuli (i.e., stimuli with features for two different tasks) appear occasionally, performance is slower on subsequent univalent stimuli. This "bivalency effect" reflects an adjustment of cognitive control arising from the more demanding context created by bivalent stimuli. So far, it has been investigated only on task switch trials, but not on task repetition trials. Here, we used a paradigm with predictable switches and repetitions on three tasks, with bivalent stimuli occasionally occurring on one task. In three experiments, we found a substantial bivalency effect for all trials with at least one source of conflict. However, this effect was reduced for the repetition trials sharing no features with bivalent stimuli, that is, for those without conflict. This confirms that the bivalency effect reflects an adjustment of cognitive control. The news is that this adjustment of cognitive control is sensitive to the presence of conflict, but neither to its amount nor to its source.     

Selective impairment of grammatical morphology due to induced stress in normal listeners: implications for aphasia

The traditional clinical picture for English nonfluent aphasics has generally presented the deficit as one of total loss of control over grammatical morphology, with some sparing of word order. This is at odds with recent research involving nonfluent aphasic speakers of highly inflected languages, which has shown that agrammatic performance is characterized by morphological substitution rather than omission errors. If the deficit associated with focal brain damage cannot be adequately accounted for in syndrome-specific ways, we may need to look for language-specific processing explanations. One such explanation has to do with language-specific response to global processing difficulty. The current experiment is designed to study the effects of a stress-related limitation on morphological processing. Normal speakers of a language with a relatively rich morphological system (German) are compared with those of a comparatively impoverished system (English) on different forms of a sentence comprehension task. In one form, "clean" stimuli permit full reliance on all available cues to meaning in each language. In another test, a low-level noise mask partially obscured the stimulus sentences. English speakers, who rely almost exclusively on word order cues, were not affected by the noise manipulation. German speakers relied heavily on morphological and semantic information rather than on word order under "clean" conditions. However, under noise Germans made significantly less use of grammatical morphology, with a trend toward compensatory reliance on word order. The results indicate that a global reduction in processing capacity can affect some aspects of language more than others and suggest that such factors must be taken into account in trying to understand specific impairment of morphology in aphasia.     

Task preparation and task repetition: two-component model of task switching.

The switch cost (the disadvantage of performing a new task vs. a repeated task) has been attributed to lack of preparation for the switched task or priming of the repeated task. These sources were examined by manipulating foreknowledge of task transition (repeat or switch), response-to-stimulus interval (RSI), and practice level. Regardless of foreknowledge, the cost decreased with RSI and practice. The reduction was greater with foreknowledge than with no foreknowledge, and the amount of switch cost did not depend on foreknowledge. These results suggest that the switch cost with foreknowledge may consist of both inadequate preparation and repetition benefit but the switch cost with no foreknowledge may reflect repetition benefit only. An ACT-R (adaptive control of thought-rational) model was proposed, accommodating both preparation and priming effect with 2 independent processes: conflict resolution among productions and decay of chunk activation.     

中-英双语者语言理解中非加工语言的自动激活

采用长时重复启动范式探讨母语为汉语的中-英双语者语言理解中非加工语言的激活状况。实验1和实验2使用词汇判断任务, 实验3和实验4使用概念判断任务。在每个实验的第一个小实验中, 非加工语言是英文, 在每个实验的第二个小实验中, 非加工语言是中文。实验1和实验3探讨学习阶段的非加工词在测验阶段呈现时能否出现长时重复启动效应, 从而检验双语者语言理解中非加工语言有没有自动激活; 实验2和实验4探讨学习阶段的非加工词在测验阶段以翻译对等词呈现时能否出现长时重复启动效应, 从而检验双语者语言理解中非加工语言的语义有没有自动激活。总的实验结果表明, 母语为汉语的中-英双语者在语言理解过程中, 加工一种语言(目标语言)时, 非加工语言(要求被试忽略的另一种语言)会自动激活, 但在词汇任务情境中, 非加工语言只在词汇层面上激活, 其语义不会自动激活, 而在概念任务情境中, 非加工语言的词汇层面和语义层面都会自动激活。     

Contrasting contributions of phonological short-term memory and long-term knowledge to vocabulary learning in a foreign language

The contributions of phonological short-term memory and existing foreign vocabulary knowledge to the learning of new words in a second language were compared in a sample of 40 Greek children studying English at school. The children's speed of learning new English words in a paired-associate learning task was strongly influenced by their current English vocabulary, but was independent of phonological memory skill, indexed by nonword repetition ability. However, phonological memory performance was closely linked to English vocabulary scores. The findings suggest that in learners with considerable familiarity with a second language, foreign vocabulary acquisition is mediated largely by use of existing knowledge representations.     

熟练汉-英双语者的语码切换机制—— 来自短语水平的证据

以熟练汉-英双语者为被试, 考察了在短语水平上语码切换的机制及切换代价的来源。结果表明：(1)汉语与英语表示空间方所的短语的差异和表示量的短语的对应与否影响语码切换过程, 但对于两种语言的切换代价的影响不显著, 表明语码切换代价未受特定语言的语法特征影响; (2)熟练汉-英双语者在短语水平上表现出语码切换代价的不对称性：切换至熟练语言的代价比切换至非熟练语言的代价大; (3)熟练汉-英双语者的切换代价源于两种语言短语的激活和竞争, 支持非特定语言选择假说, 可以用抑制控制模型来解释。整个研究表明, 熟练双语者的语码切换代价源于语言表征系统之外。     

A new look at “the hard problem” of bilingual lexical access: evidence for language-switch costs with univalent stimuli

Considerable work has used language-switching tasks to investigate how bilinguals manage competition between languages. Language-switching costs have been argued to reflect persisting inhibition or persisting activation of a non-target language. However, these costs might instead reflect the use of bivalent stimuli (i.e. pictures or digits that can be responded to in either language). That is, language-switching costs may simply reflect a cost of selecting the task-appropriate response for a given item and so may not be reflective of bilingual lexical access [Finkbeiner, M., Almeida, J., Janssen, N., & Carramaza, A. (2006). Lexical selection in bilingual speech production does not involve language suppression. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32(5), 1075–1089]. The present study addresses this concern by having Chinese/English bilinguals switch between languages in response to inherently univalent stimuli (English words and Chinese Characters) as well as lexically univalent, but orthographically bivalent, stimuli (English words and Chinese Pinyin). Speakers showed switch costs when naming both univalent and orthographically bivalent stimuli, showing that switch costs can be found even with inherently univalent stimuli.     

Repetition costs in word identification: evaluating a stimulus–response integration account

Stimulus repetition facilitates performance in many experimental contexts. However, an episodic approach to interpreting repetition effects suggests that repetition effects should depend on how stimuli are encoded. In Experiments 1-3, stimulus repetition in a word identification task led to a cost rather than a benefit in performance, but only when the prime was presented for a relatively long duration. One account of these results is that long prime durations allow integration between stimulus and response codes to occur, which in turn can interfere with responding to a following identical target. In Experiment 4, a stimulus intensity based episodic specificity effect that was insensitive to the proportion of repeated trials supported this stimulus-response integration account.     

Exploring task-set reconfiguration with random task sequences

Switching between two different tasks normally results in an impairment in people's performance known as a switch cost, typically measured as an increase in reaction time (RT) and errors compared to a situation in which no task switch is required. Researchers in task switching have suggested that this switch cost is the behavioural manifestation of the task set reconfiguration processes that are necessary to perform the upcoming task. However, an examination of the literature in task switching reveals apparently contradictory results about the nature of task set reconfiguration processes. In Experiment 1, we addressed this issue by comparing participants' performance in two different experimental conditions: predictable task switching and random task switching. In the predictable switch condition the switch cost completely vanished after the first repetition of the new task. However, in the random switch condition, while the difference between switch and repetition trials was not significant, we observed a significant reduction in RT between the first and second repetition of the new task. In Experiment 2, we further investigated the pattern of task set reconfiguration in the random switch situation. The results showed a progressive reduction of participants' response latencies across repetitions of the same task. The present study demonstrates that, whereas the results in predictable switching conditions are compatible with an exogenous-reconfiguration hypothesis, random task switching produces a more gradual, decay-like switch cost reduction with task repetition.     

Task-switching and long-term priming: role of episodic stimulus-task bindings in task-shift costs

When subjects switch between two tasks, performance is slower after a task switch than after a task repetition. We report five experiments showing that a large part of these "task-shift-costs" cannot be attributed to a control operation, needed to configure the cognitive system for the upcoming task (e.g., ). In all experiments subjects switched between picture-naming and word-reading. We presented different stimuli either in just one of the two tasks, or in both of them. Shift-costs were larger for stimuli presented in both tasks than for those presented in only one task, even after more than 100 intervening trials between prime and probe events. We suggest (as proposed by ) that stimuli acquire associations with the tasks in which they occur. When the current task activation is weak, as on a switch of tasks, stimuli can trigger retrieval of the associated, competing task, provoking larger time costs.     

Contrasting contributions of phonological short‐term memory and long‐term knowledge to vocabulary learning in a foreign language

The contributions of phonological short‐term memory and existing foreign vocabulary knowledge to the learning of new words in a second language were compared in a sample of 40 Greek children studying English at school. The children's speed of learning new English words in a paired‐associate learning task was strongly influenced by their current English vocabulary, but was independent of phonological memory skill, indexed by nonword repetition ability. However, phonological memory performance was closely linked to English vocabulary scores. The findings suggest that in learners with considerable familiarity with a second language, foreign vocabulary acquisition is mediated largely by use of existing knowledge representations.     

Response inhibition under task switching: its strength depends on the amount of task-irrelevant response activation

Under task switch conditions, response repetitions usually produce benefits if the task also repeats, but costs if the task switches. So far, it is largely undecided how to account for these effects. In the present study, we provide additional evidence in favor of the account that each response is inhibited in order to prevent its accidental re-execution. To test this hypothesis, the risk of an accidental re-execution of a given response was manipulated by modulating the activation of the response in the previous task. In Experiment 1, this was done by means of congruent and incongruent stimuli. As expected, on task switch trials, the repetition costs were larger if a congruent rather than an incongruent stimulus occurred in the previous task. In Experiment 2, the same effect occurred for stimulus-response compatible versus incompatible stimuli in the previous task. In Experiment 3, both manipulations were applied together, which produced almost additive effects. Altogether, the results support the inhibition account for the response repetition effects under task switch conditions.     

The shielding function of task sets and its relaxation during task switching

The goal of the presented experiments was to investigate the dynamic interplay of task shielding and its relaxation during task switching. Task shielding refers to the finding that single task sets in terms of 2-choice categorization rules help shielding against distraction from irrelevant stimulus attributes. During task switching, this shielding should temporarily be relaxed to prevent the perseveration of the previous task, on the downside making the system more vulnerable toward the intrusion of irrelevant information. Participants had to switch between a digit and a letter categorization task. An irrelevant stimulus feature (Experiment 1: color, Experiment 2: font) varied randomly, orthogonal to the task. The presence or absence of an interaction of the irrelevant feature (switch vs. repetition) and the response (switch vs. repetition) was taken as evidence for the absence or presence of task shielding, respectively. Replicating previous results, irrelevant feature and response did not interact on task repetitions, indicating successful shielding. On task switches, however, the irrelevant feature interacted with the response, supporting the assumption that task shielding is temporarily relaxed during task switching.     

Letter-specific processing in children and adults matched for reading level

Expert readers perform faster and more accurately during tasks that involve letters from the known language compared to tasks that involve unfamiliar letter-like forms (e.g., pseudoletters). Previous work with typically developing participants suggests that this letter-specific processing emerges as a consequence of increased reading ability, rather than increased age. In contrast, others have suggested that adults rely on visual information to a greater extent than children when reading, despite reading at similar less-than-expert levels, implying that adults may exhibit greater letter specificity than children. The present study aimed to discriminate between these possibilities by comparing the advantage for letters over pseudoletters in children and adults reading at the same less-than-expert (fourth grade) level. Results revealed greater letter specificity in adults than in children in both error rate and response time measures. Moreover, the magnitude of letter specificity did not vary with reading ability. Thus, results suggest that adults are more sensitive than children to the visual forms of letters, and that differences in letter specificity are not necessarily dependent on reading skill.     

Development of cross-linguistic variation in speech and gesture: motion events in English and Turkish

The way adults express manner and path components of a motion event varies across typologically different languages both in speech and cospeech gestures, showing that language specificity in event encoding influences gesture. The authors tracked when and how this multimodal cross-linguistic variation develops in children learning Turkish and English, 2 typologically distinct languages. They found that children learn to speak in language-specific ways from age 3 onward (i.e., English speakers used 1 clause and Turkish speakers used 2 clauses to express manner and path). In contrast, English- and Turkish-speaking children's gestures looked similar at ages 3 and 5 (i.e., separate gestures for manner and path), differing from each other only at age 9 and in adulthood (i.e., English speakers used 1 gesture, but Turkish speakers used separate gestures for manner and path). The authors argue that this pattern of the development of cospeech gestures reflects a gradual shift to language-specific representations during speaking and shows that looking at speech alone may not be sufficient to understand the full process of language acquisition.     

Task switching in a hierarchical task structure: evidence for the fragility of the task repetition benefit

This study examined how task switching is affected by hierarchical task organization. Traditional task-switching studies, which use a constant temporal and spatial distance between each task element (defined as a stimulus requiring a response), promote a flat task structure. Using this approach, Experiment 1 revealed a large switch cost of 238 ms. In Experiments 2-5, adjacent task elements were grouped temporally and/or spatially (forming an ensemble) to create a hierarchical task organization. Results indicate that the effect of switching at the ensemble level dominated the effect of switching at the element level. Experiments 6 and 7, using an ensemble of 3 task elements, revealed that the element-level switch cost was virtually absent between ensembles but was large within an ensemble. The authors conclude that the element-level task repetition benefit is fragile and can be eliminated in a hierarchical task organization.