Picture naming test through the prism of cognitive neuroscience and linguistics: adapting the test for cerebellar tumor survivors-or pouring new wine in old sacks?

A picture naming test (PNT) has long been regarded as an integral part of neuropsychological assessment. In current research and clinical practice, it serves a variety of purposes. PNTs are used to assess the severity of speech impairment in aphasia, monitor possible cognitive decline in aging patients with or without age-related neurodegenerative disorders, track language development in children and map eloquent brain areas to be spared during surgery. In research settings, picture naming tests provide an insight into the process of lexical retrieval in monolingual and bilingual speakers. However, while numerous advances have occurred in linguistics and neuroscience since the classic, most widespread PNTs were developed, few of them have found their way into test design. Consequently, despite the popularity of PNTs in clinical and research practice, their relevance and objectivity remain questionable. The present study provides an overview of literature where relevant criticisms and concerns have been expressed over the recent decades. It aims to determine whether there is a significant gap between conventional test design and the current understanding of the mechanisms underlying lexical retrieval by focusing on the parameters that have been experimentally proven to influence picture naming. We discuss here the implications of these findings for improving and facilitating test design within the picture naming paradigm. Subsequently, we highlight the importance of designing specialized tests with a particular target group in mind, so that test variables could be selected for cerebellar tumor survivors.

A scoping review of primary research

Pupil dilation has been associated with the effort required to perform various cognitive tasks. At the lexical level, some studies suggest that this neurophysiological measure would provide objective, real-time information during word processing and lexical access. However, due to the scarcity and incipient advancement of this line of research, its applicability, use, and sensitivity are not entirely clear. This scoping review aims to determine the applicability and usefulness of pupillometry in the study of lexical access by providing an up-to-date overview of research in this area. Following the PRISMA protocol, 16 articles were included in this review. The results show that pupillometry is a highly applicable, useful, and sensitive method for assessing lexical skills of word recognition, word retrieval, and semantic activation. Moreover, it easily fits into traditional research paradigms and methods in the field. Because it is a non-invasive, objective, and automated procedure, it can be applied to any population or age group. However, the emerging development of this specific area of research and the methodological diversity observed in the included studies do not yet allow for definitive conclusions in this area, which in turn does not allow for meta-analyses or fully conclusive statements about what the pupil response actually reflects when processing words. Standardized pupillary recording and analysis methods need to be defined to generate more accurate, replicable research designs with more reliable results to strengthen this line of research.

Predictability Associated With Reduction in Phonetic Signals Without Semantics-The Case of Glossolalia

Glossolalia can be regarded as an instance of speech production in which practitioners produce syllables in seemingly random sequences. However, a closer inspection of glossalalia's statistical properties reveals that sequences show a Zipfian pattern similar to natural languages, with some syllables being more probable than others. It is well established that statistical properties of sequences are implicitly learned, and that these statistical properties correlate with changes in kinematic and speech behavior. For speech, this means that more predictable items are phonetically shorter. Accordingly, we hypothesized for glossolalia that if practitioners have learned a serial pattern in glossolalia in the same manner as in natural languages, its statistical properties should correlate with its phonetic characteristics. Our hypothesis was supported. We find significantly shorter syllables associated with higher syllable probabilities in glossolalia. We discuss this finding in relation to theories about the sources of probability-related changes in the speech signal.

The cognate facilitation effect on lexical access in bilingual aphasia: Evidence from the Boston Naming Test

Most cognate research suggests facilitation effects in picture naming, but how these effects manifest in bilinguals after brain damage remains unclear. Additionally, whether this effect is captured in clinical measures is largely unknown. Using data from the Boston Naming Test, we examined the naming of cognates and noncognates, the extent of cognate facilitation produced, and the individual differences in bilingual language experience associated with naming outcomes in forty Spanish-English bilingual persons with aphasia (BPWA) relative to thirty-one Spanish-English healthy bilinguals (HB). Results suggest that naming performance in L1 and L2 in both groups is modulated by lexical frequency, bilingual language experience, and by language impairment in BPWA. Although the two groups showed similarities, they deviated in benefit drawn from the extent of phoneme/grapheme overlap in cognate items. HB showed an association between cognate facilitation and bilingual language experience, while cognate facilitation in BPWA was only associated with L2 language impairment.

Examining Letter Detector Tolerance through Offset Letter Halves: Evidence from Lexical Decision

Neurobiological models of reading assume that the specialized detectors at the letter level (e.g., the arrays of detectors for the letter 'n') possess a certain degree of tolerance (e.g., Local Combination Detectors model, Dehaene et al. 2005). In this study, we designed two lexical decision experiments that examined the limits of tolerance of letter detectors by introducing a novel manipulation involving shifting letter halves (e.g., in Experiment 1; in Experiment 2) relative to intact items. This manipulation alters the transition between upper and lower parts of the letters, adding junctions that do not exist in the intact letter forms. We included high- and low-frequency words in the stimulus list to investigate whether letter distortion affects processing beyond the letter level, reasoning that interactive effects would signal top-down lexical feedback. In Experiment 1, which employed a subtle letter shift, we observed a minimal cost of letter distortion that did not interact with word frequency. Experiment 2, employing a larger letter shift, revealed an overall greater reading cost that affected differentially high- and low-frequency words. Overall, these findings offer insights into the limits of resilience in letter detectors to distortion during word recognition and introduce a novel manipulation of letter distortion.

Lexical Access Restrictions after the Age of 80

BACKGROUND

During the fourth age (80+ years), cognitive difficulties increase. Although language seems to resist the advancement of age, an older person without pathological developments in cognition may exhibit deficits in lexical access. This study examines the restrictions on lexical access in people aged 80 and older in word recognition and retrieval modalities through four lexical tasks.

METHOD

The effect of aging on response time and accuracy was measured using recognition (lexical decision/naming/priming) and retrieval (picture naming) tasks. A fourth age group (>80) and two third age groups (60-69/70-79) were compared according to lexical access modality and type of task employed through linear regression models.

RESULTS

People aged 80 and older exhibit a strong lexical access constraint, as they are slower and less accurate in recognizing and retrieving words than both third age groups. These restrictions are more profound for the word retrieval modality, especially in the picture naming task.

CONCLUSION

Impaired fluid intelligence and internode transmission deficits during advanced aging could further reduce the ability to recognize and/or retrieve words, having an impact on access speed and accuracy. Furthermore, the idea that crystallized intelligence could strengthen the accuracy of lexical access during aging is supported, specifically in word recognition modality.

An Evidence Accumulation Account of Masked Translation Priming in Two Bilingual Populations

This manuscript addresses the phenomenon of masked priming and the cognitive process of switching from Spanish to English while reading in sequential bilingual texts compared to heritage speakers. A lexical decision task was employed in the present study with masked translation priming, which serves as a valuable tool for elucidating the orthographic and lexical processes involved in the initial stages of reading. This study builds upon previous research conducted on monolingual masked priming, which consistently demonstrates shifts in the response time (RT) distributions when comparing related and unrelated primes. Within the framework of a diffusion model, we implemented two theoretical positions. First, we posited that translation priming operates at the orthographic level, resulting in enhanced efficiency during the encoding process. Second, we explored the possibility that translation priming operates at the semantic level, influencing the accumulation of evidence during the lexical decision task. The findings of the present study indicate that translation priming elicits outcomes similar to those observed in monolingual priming paradigms. Specifically, we observed that translation priming facilitation is manifested as shifts in the RT distributions. These findings are interpreted to suggest that the benefits derived from the encoding process are not specific to the accessed lexicon following a brief stimulus presentation.

Breaking the boundaries: the power of ligatures in visual-word recognition

Introduction

Current neurobiological-inspired models of visual-word recognition propose that letter detectors in the word recognition system can tolerate some variations in the visual form of the letters. However, it is unclear whether this tolerance extends to novel ligatures, which combine two letters into a single glyph.

Methods

To investigate this, the present study utilized a masked priming experiment with a lexical decision task to examine whether primes containing novel ligatures are effective in activating their corresponding base word, relative to omitted-letter primes, in the initial stages of word processing. For each target word (e.g., VIRTUAL), were created an identity prime (virtual), a prime containing a novel ligature of two of the letters (e.g., virtual; "ir" in a single glyph), and an omitted-letter prime where one letter was removed (e.g., vrtual [omitted-vowel] in Experiment 1; vitual [omitted-consonant] in Experiment 2).

Results

Results showed that the presence of a novel ligature in the prime resulted in faster lexical decision times compared to a prime with an omitted vowel (Experiment 1), but not with an omitted consonant (Experiment 2). Furthermore, the performance with the primes containing the novel ligature was not different from that of the identity primes.

Discussion

These results suggest that the word recognition system can quickly enable separate letter detectors for novel ligatures. These findings have important implications for our understanding of the front-end of visual-word recognition.

Practice beats age: co-activation shapes heritage speakers' lexical access more than age of onset

Probabilistic associations make language processing efficient and are honed through experience. However, it is unclear what language experience factors explain the non-monolingual processing behaviors typical of L2 learners and heritage speakers (HSs). We investigated whether AoO, language proficiency, and language use affect the recognition of Spanish stress-tense suffix associations involving a stressed syllable that cues a present suffix (SALta "s/he jumps") and an unstressed syllable that cues a past suffix (SALtó "s/he jumped"). Adult Spanish-English HSs, English-Spanish L2 learners, and Spanish monolinguals saw a paroxytone verb (stressed initial syllable) and an oxytone verb (unstressed initial syllable), listened to a sentence containing one of the verbs, and chose the one they heard. Spanish proficiency measured grammatical and lexical knowledge, and Spanish use assessed percentage of current usage. Both bilingual groups were comparable in Spanish proficiency and use. Eye-tracking data showed that all groups fixated on target verbs above chance before hearing the syllable containing the suffix, except the HSs in the oxytones. Monolinguals fixated on targets more and earlier, although at a slower rate, than HSs and L2 learners; in turn, HSs fixated on targets more and earlier than L2 learners, except in oxytones. Higher proficiency increased target fixations in HSs (oxytones) and L2 learners (paroxytones), but greater use only increased target fixations in HSs (oxytones). Taken together, our data show that HSs' lexical access depends more on number of lexical competitors (co-activation of two L1 lexica) and type (phonotactic) frequency than token (lexical) frequency or AoO. We discuss the contribution of these findings to models in phonology, lexical access, language processing, language prediction, and human cognition.

Activating words without language: beta and theta oscillations reflect lexical access and control processes during verbal and non-verbal object recognition tasks

The intention to name an object modulates neural responses during object recognition tasks. However, the nature of this modulation is still unclear. We established whether a core operation in language, i.e. lexical access, can be observed even when the task does not require language (size-judgment task), and whether response selection in verbal versus non-verbal semantic tasks relies on similar neuronal processes. We measured and compared neuronal oscillatory activities and behavioral responses to the same set of pictures of meaningful objects, while the type of task participants had to perform (picture-naming versus size-judgment) and the type of stimuli to measure lexical access (cognate versus non-cognate) were manipulated. Despite activation of words was facilitated when the task required explicit word-retrieval (picture-naming task), lexical access occurred even without the intention to name the object (non-verbal size-judgment task). Activation of words and response selection were accompanied by beta (25-35 Hz) desynchronization and theta (3-7 Hz) synchronization, respectively. These effects were observed in both picture-naming and size-judgment tasks, suggesting that words became activated via similar mechanisms, irrespective of whether the task involves language explicitly. This finding has important implications to understand the link between core linguistic operations and performance in verbal and non-verbal semantic tasks.

Language dominance and order of acquisition affect auditory translation priming in heritage speakers

Late second language (L2) learners show translation priming from the first language (L1) to the second language (L1-L2), while L2-L1 effects are inconsistent. Late L2 learners also acquire the L2 after the L1 and are typically less dominant in the L2. As such, the relative contribution of language dominance and order of acquisition is confounded in these results. Here, Cantonese heritage and native speakers are tested in an auditory translation priming paradigm. As heritage speakers first learn Cantonese (L1) but later become dominant in English (L2), this profile allows for the potential dissociation of dominance and order of acquisition in translation priming. If order of acquisition is the primary factor, stronger priming is expected in the L1-L2 (Cantonese-English) direction; however, if dominance plays a stronger role, priming is expected in the L2-L1 (English-Cantonese) direction. Native speakers showed stronger L1-L2 priming, consistent with previous findings, while heritage speakers showed priming in both directions, and marginally larger L2-L1 priming. Treating language dominance as a continuous variable revealed that L1-L2 priming correlated with increased Cantonese dominance, while L2-L1 priming marginally correlated with increased English dominance. Collectively, these results suggest that both language dominance and order of acquisition help explain translation priming findings and bilingual lexical processing, generally. Overall, they invite a rethinking of the role of both variables in bilingual lexical access for speakers with different language dominance profiles.

Auditory Word Comprehension Is Less Incremental in Isolated Words

Partial speech input is often understood to trigger rapid and automatic activation of successively higher-level representations of words, from sound to meaning. Here we show evidence from magnetoencephalography that this type of incremental processing is limited when words are heard in isolation as compared to continuous speech. This suggests a less unified and automatic word recognition process than is often assumed. We present evidence from isolated words that neural effects of phoneme probability, quantified by phoneme surprisal, are significantly stronger than (statistically null) effects of phoneme-by-phoneme lexical uncertainty, quantified by cohort entropy. In contrast, we find robust effects of both cohort entropy and phoneme surprisal during perception of connected speech, with a significant interaction between the contexts. This dissociation rules out models of word recognition in which phoneme surprisal and cohort entropy are common indicators of a uniform process, even though these closely related information-theoretic measures both arise from the probability distribution of wordforms consistent with the input. We propose that phoneme surprisal effects reflect automatic access of a lower level of representation of the auditory input (e.g., wordforms) while the occurrence of cohort entropy effects is task sensitive, driven by a competition process or a higher-level representation that is engaged late (or not at all) during the processing of single words.

A cautionary note on the studies using the picture-word interference paradigm: the unwelcome consequences of the random use of "in/animates"

The picture-word interference (PWI) paradigm allows us to delve into the process of lexical access in language production with great precision. It creates situations of interference between target pictures and superimposed distractor words that participants must consciously ignore to name the pictures. Yet, although the PWI paradigm has offered numerous insights at all levels of lexical representation, in this work we expose an extended lack of control regarding the variable animacy. Animacy has been shown to have a great impact on cognition, especially when it comes to the mechanisms of attention, which are highly biased toward animate entities to the detriment of inanimate objects. Furthermore, animate nouns have been shown to be semantically richer and prioritized during lexical access, with effects observable in multiple psycholinguistic tasks. Indeed, not only does the performance on a PWI task directly depend on the different stages of lexical access to nouns, but also attention has a fundamental role in it, as participants must focus on targets and ignore interfering distractors. We conducted a systematic review with the terms "picture-word interference paradigm" and "animacy" in the databases PsycInfo and Psychology Database. The search revealed that only 12 from a total of 193 PWI studies controlled for animacy, and only one considered it as a factor in the design. The remaining studies included animate and inanimate stimuli in their materials randomly, sometimes in a very disproportionate amount across conditions. We speculate about the possible impact of this uncontrolled variable mixing on many types of effects within the framework of multiple theories, namely the Animate Monitoring Hypothesis, the WEAVER++ model, and the Independent Network Model in an attempt to fuel the theoretical debate on this issue as well as the empirical research to turn speculations into knowledge.

Investigating the modulation of stimulus types on language switching costs: Do semantic and repetition priming effect matter?

Introduction

In the present study, I investigated the influence of stimulus types on bilingual control in the language switching process. The commonly employed stimuli in language switching studies - Arabic digits and objects - were compared to further investigate the way in which inhibitory control could be modulated by semantic and repetition priming effects. The digit stimuli have two unique characteristics in the language switching paradigm, for example, they are present repeatedly and are semantically related to each other, compared with pictural stimuli. Thus, these unique characteristics might influence the operation of inhibitory control in bilingual language production, modulating the size and asymmetry of switching costs.

Methods

Two picture control sets were set up to match those characteristics: (1) a semantic control set, in which picture stimuli belong to the same category group, such as, animals, occupations or transportation and specific semantic categories were presented in a blocked condition; and (2) a repeated control set, in which nine different picture stimuli were repeatedly presented like the Arabic digits from 1 to 9.

Results

When comparing the digit condition and the standard picture condition, analyses of naming latencies and accuracy rates revealed that switching costs were reliably smaller for digit naming than for picture naming and the L1 elicited more switching costs for picture naming than for digit naming. On the other hand, when comparing the digit condition and the two picture control sets, it was found that the magnitude of switching costs became identical and the asymmetry in switching costs became much smaller between the two languages.

Cross-modal and cross-language activation in bilinguals reveals lexical competition even when words or signs are unheard or unseen

We exploit the phenomenon of cross-modal, cross-language activation to examine the dynamics of language processing. Previous within-language work showed that seeing a sign coactivates phonologically related signs, just as hearing a spoken word coactivates phonologically related words. In this study, we conducted a series of eye-tracking experiments using the visual world paradigm to investigate the time course of cross-language coactivation in hearing bimodal bilinguals (Spanish-Spanish Sign Language) and unimodal bilinguals (Spanish/Basque). The aim was to gauge whether (and how) seeing a sign could coactivate words and, conversely, how hearing a word could coactivate signs and how such cross-language coactivation patterns differ from within-language coactivation. The results revealed cross-language, cross-modal activation in both directions. Furthermore, comparison with previous findings of within-language lexical coactivation for spoken and signed language showed how the impact of temporal structure changes in different modalities. Spoken word activation follows the temporal structure of that word only when the word itself is heard; for signs, the temporal structure of the sign does not govern the time course of lexical access (location coactivation precedes handshape coactivation)-even when the sign is seen. We provide evidence that, instead, this pattern of activation is motivated by how common in the lexicon the sublexical units of the signs are. These results reveal the interaction between the perceptual properties of the explicit signal and structural linguistic properties. Examining languages across modalities illustrates how this interaction impacts language processing.

Investigating the influence of semantic factors on word retrieval: Reservations, results and recommendations

There is consensus that word retrieval starts with activation of semantic representations. However, in adults without language impairment, relatively little attention has been paid to the effects of the semantic attributes of to-be-retrieved words. This paper, therefore, addresses the question of which item-inherent semantic factors influence word retrieval. Specifically, it reviews the literature on a selection of these factors: imageability, concreteness, number of semantic features, typicality, intercorrelational density, featural distinctiveness, concept distinctiveness, animacy, semantic neighbourhood density, semantic similarity, operativity, valence, and arousal. It highlights several methodological challenges in this field, and has a focus on the insights from studies with people with aphasia where the effects of these variables are more prevalent. The paper concludes that further research simultaneously examining the effects of different semantic factors that are likely to affect lexical co-activation, and the interaction of these variables, would be fruitful, as would suitably scaled computational modelling of these effects in unimpaired language processing and in language impairment. Such research would enable the refinement of theories of semantic processing and word production, and potentially have implications for diagnosis and treatment of semantic and lexical impairments.

First-language influence on second language speech perception depends on task demands

While listening to non-native speech, second language users filter the auditory input through their native language. We examined how bilinguals perceived second language (L2 English) sound sequences that conflicted with native-language (L1 Spanish) constraints across three experiments with different task demands. We used the L1 Spanish phonotactic constraint (i.e., rule for combining speech sounds) that vowels must precede s+consonant clusters (e.g., Spanish: estricto, "strict"). This L1 Spanish constraint may influence Spanish-English bilinguals' processing of L2 English words such as strict because of a missing initial vowel, as in estrict. We found that the extent to which bilinguals were influenced by the L1 during L2 processing depended on task demands. When metalinguistic awareness demands were low, as in the AX word discrimination task (Experiment 1), cross-linguistic effects were not observed. When metalinguistic awareness demands were high, as in the vowel detection (Experiment 2) and lexical decision (Experiment 3) tasks, response times demonstrated that bilinguals were influenced by the L1 constraint when processing L2 words beginning with an s+consonant. We conclude that bilinguals are cross-linguistically influenced by L1 phonotactic constraints during L2 processing when metalinguistic demands are higher, suggesting that L2 input may be mapped onto L1 sub-lexical representations during perception. These results extend previous research on language co-activation and speech perception by providing a more fine-grained understanding of task demands and elucidating when and where cross-linguistic phonotactic access is present during bilingual comprehension.

Effortful Retrieval Practice Effects in Lexical Access: A Role for Semantic Competition

Word retrieval difficulty (lexical access deficit) is prevalent in aphasia. Studies have shown that practice retrieving names from long-term memory (retrieval practice) improves future name retrieval for production in people with aphasia (PWA), particularly when retrieval is effortful. To explicate such effects, this study examined a potential role for semantic competition in the learning mechanism(s) underlying effortful retrieval practice effects in lexical access in 6 PWA. Items were trained in a blocked-cyclic naming task, in which repeating sets of pictures drawn from semantically-related versus unrelated categories underwent retrieval practice with feedback. Naming accuracy was lower for the related items at training, but next-day accuracy did not differ between the conditions. However, greater semantic-relatedness of an item to its set in the related condition was associated with lower accuracy at training but higher accuracy at test. Relevance to theories of lexical access and implications for naming treatment in aphasia are discussed.

The Omission of Accent Marks Does Not Hinder Word Recognition: Evidence From Spanish

Recent research has found that the omission of accent marks in Spanish does not produce slower word identification times in go/no-go lexical decision and semantic categorization tasks [e.g., cárcel (prison) = carcel], thus suggesting that vowels like á and a are represented by the same orthographic units during word recognition and reading. However, there is a discrepant finding with the yes/no lexical decision task, where the words with the omitted accent mark produced longer response times than the words with the accent mark. In Experiment 1, we examined this discrepant finding by running a yes/no lexical decision experiment comparing the effects for words and non-words. Results showed slower response times for the words with omitted accent mark than for those with the accent mark present (e.g., cárcel < carcel). Critically, we found the opposite pattern for non-words: response times were longer for the non-words with accent marks (e.g., cárdil > cardil), thus suggesting a bias toward a “word” response for accented items in the yes/no lexical decision task. To test this interpretation, Experiment 2 used the same stimuli with a blocked design (i.e., accent mark present vs. omitted in all items) and a go/no-go lexical decision task (i.e., respond only to “words”). Results showed similar response times to words regardless of whether the accent mark was omitted (e.g., cárcel = carcel). This pattern strongly suggests that the longer response times to words with an omitted accent mark in yes/no lexical decision experiments are a task-dependent effect rather than a genuine reading cost.

Clustering and Switching in Verbal Fluency Across Varying Degrees of Cognitive Control Demands: Evidence From Healthy Bilinguals and Bilingual Patients With Aphasia

Different linguistic contexts place varying amounts of cognitive control on lexical retrieval in bilingual speakers, an issue that is complicated in bilingual patients with aphasia (BPWA) due to subsequent language and cognitive deficits. Verbal fluency tasks may offer insight into the interaction between executive and language control in healthy bilinguals and BPWA, by examining conditions with varying cognitive control demands. The present study examined switching and clustering in verbal fluency tasks in BPWA and healthy bilinguals across single- and dual-language conditions. We also examined the influence of language processing and language proficiency on switching and clustering performance across the dual-language conditions. Thirty-five Spanish-English BPWA and twenty-two Spanish-English healthy bilinguals completed a language use questionnaire, tests of language processing, and two verbal fluency tasks. The semantic category generation task included four conditions: two single-language conditions (No-Switch L1 and No-Switch L2) that required word production in each language separately; one dual-language condition that allowed switching between languages as desired (Self-Switch); and one dual-language condition that required switching between languages after each response (Forced-Switch). The letter fluency task required word production in single-language contexts. Overall, healthy bilinguals outperformed BPWA across all measures. Results indicate that switching is more sensitive to increased control demands than clustering, with this effect being more pronounced in BPWA, underscoring the interaction between semantic executive processes and language control in this group. Additionally, for BPWA switching performance relies on a combination of language abilities and language experience metrics.

Foreign Language Training to Stimulate Cognitive Functions

Adult development throughout a lifetime implies a series of changes in systems, including cognitive and linguistic functioning. The aim of this article is to study the effect of foreign language training on linguistic processing, particularly the frequency of the tip-of-the-tongue (TOT) phenomenon and on other cognitive processes such as processing speed and working memory in adults aged 40 to 60 years. Sixty-six healthy Colombian teachers were enrolled in this study. They were then randomly divided into an experimental group (33 healthy adults who underwent a four-week training period) and a passive control group (33 healthy adults who did not undergo any training). All participants performed induction tasks for the TOT phenomenon, working memory and processing speed before and after the four weeks. Results showed more of an effect in the semantic access, phonological access and processing speed measures with a better performance in the experimental group than in the control group. In Colombia, this type of training is still new and little is known to date about programs to prevent cognitive impairments. The need to conduct more studies confirming or refuting these findings is discussed, thus raising awareness about the extent of this type of training to increase the linguistic and cognitive performance of adults.

The resilience of the developing reading system: multi-modal evidence of incident and recovery after a pediatric stroke

Decades of neuroscientific findings have elucidated the highly specialized brain areas involved in reading, especially along the ventral occipitotemporal stream where the critical step of recognizing words occurs. We report on a 14-year-old female with temporary dyslexia after a left ventral occipitotemporal ischemic stroke. Our longitudinal multimodal findings show that the resolution of the reading impairment was associated with heightened activity in the left posterior superior and inferior temporal gyri. Our findings highlight the role of the left inferior temporal gyrus in reading and the importance of perilesional and ipsilateral cortical areas for functional recovery after childhood stroke.

Thalamic but Not Subthalamic Neuromodulation Simplifies Word Use in Spontaneous Language

Several investigations have shown language impairments following electrode implantation surgery for Deep Brain Stimulation (DBS) in movement disorders. The impact of the actual stimulation, however, differs between DBS targets with further deterioration in formal language tests induced by thalamic DBS in contrast to subtle improvement observed in subthalamic DBS. Here, we studied speech samples from interviews with participants treated with DBS of the thalamic ventral intermediate nucleus (VIM) for essential tremor (ET), or the subthalamic nucleus (STN) for Parkinson’s disease (PD), and healthy volunteers (each n = 13). We analyzed word frequency and the use of open and closed class words. Active DBS increased word frequency in case of VIM, but not STN stimulation. Further, relative to controls, both DBS groups produced fewer open class words. Whereas VIM DBS further decreased the proportion of open class words, it was increased by STN DBS. Thus, VIM DBS favors the use of relatively common words in spontaneous language, compatible with the idea of lexical simplification under thalamic stimulation. The absence or even partial reversal of these effects in patients receiving STN DBS is of interest with respect to biolinguistic concepts suggesting dichotomous thalamic vs. basal ganglia roles in language processing.

Features of low functional load in mono- and bilinguals' lexical access: evidence from Swedish tonal accent

Swedish makes use of tonal accents (Accents 1 and 2) to contrast words, but the functional load is very low, with some regional dialects not even exhibiting the contrast. In particular given the low number of minimal pairs, the question is whether tonal word accent is used in lexical access. Here we present two cross-modal fragment semantic priming studies in order to address this question. Both experiments use first syllable fragments in order to prime semantically related targets. Experiment 1 utilises words whose first syllable occurs with both accent patterns, creating a situation in which there is lexical competition between words that differ solely in terms of accent. Experiment 2 removes this competition by using words that have no such accent competitors. Our results show that native speakers of Swedish use tonal word accent in lexical access: Accent mispronunciations failed to prime semantically related targets, regardless of whether primes had accent competitors or not. Results for a group of early bilingual speakers (who grew up with one Swedish-speaking parent and one other non-tonal language) showed no differences in processing compared to the monolinguals. This indicates that the extraction of accent features during acquisition and their use in lexical access is robust, even in a scenario where multiple input languages lead to tonal word accent being a useful feature for only some of the lexical items that are being acquired. There is no doubt that the accent system is well entrenched into the bilinguals' phonological system.

Cumulative semantic interference across unrelated responses in school-age children's picture naming

Naming semantically related images results in progressively slower responses as more images are named. There is considerable documentation in adults of this phenomenon, known as cumulative semantic interference. Few studies have focused on this phenomenon in children. The present research investigated cumulative semantic interference effects in school-aged children. In Study 1, children named a series of contiguous, semantically related pictures. The results revealed no cumulative interference effects. Study 2 utilized an approach more closely aligned with adult methods, incorporating intervening, unrelated items intermixed with semantically related items within a continuous list. Study 2 showed a linear increase in reaction time as a function of ordinal position within semantic sets. These findings demonstrate cumulative semantic interference effects in young, school-aged children that are consistent with experience-driven changes in the connections that underlie lexical access. They invite further investigation of how children's lexical representation and processing are shaped by speaking experiences.

Phonological Variations Are Compensated at the Lexical Level: Evidence From Auditory Neural Activity

Dealing with phonological variations is important for speech processing. This article addresses whether phonological variations introduced by assimilatory processes are compensated for at the pre-lexical or lexical level, and whether the nature of variation and the phonological context influence this process. To this end, Swedish nasal regressive place assimilation was investigated using the mismatch negativity (MMN) component. In nasal regressive assimilation, the coronal nasal assimilates to the place of articulation of a following segment, most clearly with a velar or labial place of articulation, as in utan mej “without me” > [ʉːtam mɛjː]. In a passive auditory oddball paradigm, 15 Swedish speakers were presented with Swedish phrases with attested and unattested phonological variations and contexts for nasal assimilation. Attested variations – a coronal-to-labial change as in utan “without” > [ʉːtam] – were contrasted with unattested variations – a labial-to-coronal change as in utom “except” > ^∗[ʉːtɔn] – in appropriate and inappropriate contexts created by mej “me” [mɛjː] and dej “you” [dɛjː]. Given that the MMN amplitude depends on the degree of variation between two stimuli, the MMN responses were expected to indicate to what extent the distance between variants was tolerated by the perceptual system. Since the MMN response reflects not only low-level acoustic processing but also higher-level linguistic processes, the results were predicted to indicate whether listeners process assimilation at the pre-lexical and lexical levels. The results indicated no significant interactions across variations, suggesting that variations in phonological forms do not incur any cost in lexical retrieval; hence such variation is compensated for at the lexical level. However, since the MMN response reached significance only for a labial-to-coronal change in a labial context and for a coronal-to-labial change in a coronal context, the compensation might have been influenced by the nature of variation and the phonological context. It is therefore concluded that while assimilation is compensated for at the lexical level, there is also some influence from pre-lexical processing. The present results reveal not only signal-based perception of phonological units, but also higher-level lexical processing, and are thus able to reconcile the bottom-up and top-down models of speech processing.

Altered Inhibitory Mechanisms in Parkinson's Disease: Evidence From Lexical Decision and Simple Reaction Time Tasks

INTRODUCTION

Although the motor signs of Parkinson's disease (PD) are well defined, nonmotor symptoms, including higher-level language deficits, have also been shown to be frequent in patients with PD. In the present study, we used a lexical decision task (LDT) to find out whether access to the mental lexicon is impaired in patients with PD, and whether task performance is affected by bradykinesia.

MATERIALS AND METHODS

Participants were 34 nondemented patients with PD, either without (off) medication (n = 16) or under optimum (on) medication (n = 18). A total of 19 age-matched control volunteers were also recruited. We recorded reaction times (RTs) to the LDT and a simple RT (control) task. In each task, stimuli were either visual or auditory. Statistical analyses consisted of repeated-measures analyses of variance and Tukey's HSD post hoc tests.

RESULTS

In the LDT, participants with PD both off and on medication exhibited intact access to the mental lexicon in both modalities. In the visual modality, patients off medication were just as fast as controls when identifying real words, but slower when identifying pseudowords. In the visual modality of the control task, RTs for pseudowords were significantly longer for PD patients off medication than for controls, revealing an unexpected but significant lexicality effect in patients that was not observed in the auditory modality. Performances of patients on medication did not differ from those of age-matched controls.

DISCUSSION

Motor execution was not slowed in patients with PD either off or on medication, in comparison with controls. Regarding lexical access, patients off medication seemed to (1) have difficulty inhibiting a cognitive-linguistic process (i.e., reading) when it was not required (simple reaction time task), and (2) exhibit a specific pseudoword processing deficit in the LDT, which may have been related to impaired lateral word inhibition within the mental lexicon. These deficits seemed to be compensated by medication.

Word frequency effect in written production: Evidence from ERPs and neural oscillations

It has been widely documented that word frequency (WF) modulates language processing in various input and output modalities. WF effect has also been reported in the domain of written production; however, how WF affects written production is a controversial issue. The present study attempts to investigate the time course of and neural oscillation underlying the WF effect in handwritten production. Participants were asked to handwrite pictures names of high versus low WF, while concurrently recording EEG. EEG trials were extracted time-locked to picture onsets and then submitted to event-related potential analysis and time-frequency analysis. WF affected ERPs in the time windows of around 98-160 and 282-360 ms after picture onsets. More importantly, WF modulated the evoked and induced theta-band (4-8 Hz) neural oscillations in the time window of around 36-240 and 244-472 ms, respectively. Considering the time course of language production and the role of theta-band oscillation in long-term memory retrieval, we suggest that the two stages of the WF effect, respectively, reflect conceptual preparation and retrieval of orthographic word-forms in written production.

Mismatch Negativity Is Not Always Modulated by Lexicality

One factor that is commonly thought to influence MMN amplitude is lexicality; multiple studies have shown that real-word deviants elicit larger MMNs than pseudoword deviants. Here, however, we report data from two experiments challenging this assumption. In the first experiment (N = 48), real-word deviants did not elicit more negative MMNs than pseudoword deviants; the acoustic difference between standard and deviant was identical across these comparisons. In this experiment, the pseudoword deviant [pʰa˨˩] differed from a real-word [pʰa˧˥] in tone only; therefore, to test the possibility that the lexicality effect is real but is restricted to pseudowords that differ from real words by at least one segment, we ran a second experiment which included different items and participants, and also included a control comparison in which the pseudoword ([tsʰei˨˩]) differs from all real words by at least one segment (there is no existing Mandarin morpheme pronounced [tsʰei] in any tone). In the second experiment (N = 36), both types of pseudowords failed to elicit less negative MMNs than real words. These findings, together with other recent studies failing to show lexicality effects in MMN, challenge the assumption that wordhood reliably influences MMN amplitude.

The Predicting Power of Cognitive Fluency for the Development of Utterance Fluency in Simultaneous Interpreting

Although simultaneous interpreting (SI) is generally recognized as a highly demanding cognitive activity in nature, the role of cognitive processes in SI fluency is yet to be determined. While utterance fluency refers to the set of objectively determined oral features of utterances, cognitive fluency means the speaker’s efficient mobilization and integration of underlying cognitive processes responsible for utterance production. An investigation into the relationship of the two dimensions of fluency helps to reveal the cognitive bases of interpreting. This study explores the predicting power of cognitive fluency in the utterance fluency development of L2 (English)–L1 (Chinese) SI output of trainee interpreters. Cognitive fluency was operationalized as measures of lexical access, linguistic attention control, and working memory capacity. Measures of utterance fluency were obtained through simulated SI tasks under conditions of low and high input rates. Twenty-eight trainees interpreted two speeches, one with a high input rate and the other with a low input rate, at the beginning and end of an SI training period of 13 weeks. A bilingual corpus of the participants’ SI output was built, and indicators of SI utterance fluency were annotated systematically. Utterance fluency was indexed by the speech rate, mean length of run, phonation time ratio, mean number of silent pauses, and mean number of disfluencies. Results of analyses indicated that (1) the predicting power of cognitive fluency for SI utterance fluency development was only shown under high cognitive load over a training period of 13 weeks; (2) predictors for the development of SI utterance fluency tended to be the efficiency of cognitive processes involved in the target language production stage; and (3) the inclusion of measures of working memory capacity significantly increased the predicting power of cognitive fluency for SI utterance fluency development. This study for the first time provides evidence for the role of cognitive fluency in trainee interpreters’ SI utterance fluency development, having implications for the theoretical framework of cognitive fluency and the information processing mechanism in interpreting process, as well as for interpreter aptitude tests and interpreting pedagogy.

How Do We Segment Text? Two-Stage Chunking Operation in Reading

Chunking in language comprehension is a process that segments continuous linguistic input into smaller chunks that are in the reader's mental lexicon. Effective chunking during reading facilitates disambiguation and enhances efficiency for comprehension. However, the chunking mechanisms remain elusive, especially in reading, given that information arrives simultaneously yet the written systems may not have explicit cues for labeling boundaries such as Chinese. What are the mechanisms of chunking that mediates the reading of the text that contains hierarchical information? We investigated this question by manipulating the lexical status of the chunks at distinct levels in four-character Chinese strings, including the two-character local chunk and four-character global chunk. Male and female human participants were asked to make lexical decisions on these strings in a behavioral experiment, followed by a passive reading task when their electroencephalography (EEG) was recorded. The behavioral results showed that the lexical decision time of lexicalized two-character local chunks was influenced by the lexical status of the four-character global chunk, but not vice versa, which indicated the processing of global chunks possessed priority over the local chunks. The EEG results revealed that familiar lexical chunks were detected simultaneously at both levels and further processed in a different temporal order, the onset of lexical access for the global chunks was earlier than that of local chunks. These consistent results suggest a two-stage operation for chunking in reading, the simultaneous detection of familiar lexical chunks at multiple levels around 100 ms followed by recognition of chunks with global precedence.

Verbal fluency as a measure of lexical access and cognitive control in bilingual persons with aphasia

BACKGROUND

Lexical access in bilinguals can be influenced by the demands that different interactional contexts pose on cognitive control processes (Green & Abutalebi, 2013: Adaptive Control Hypothesis; Green, 1998: Inhibitory Control Model). However, how varying cognitive control demands impact lexical access in bilingual persons with aphasia (BPWA) remains unclear. Verbal fluency tasks may provide valuable insights into the interplay between cognitive control and lexical access in BPWA by addressing word generation abilities in language contexts that exert varying degrees of cognitive control effort.

AIMS

The present study aimed to examine the performance of BPWA on a semantic category generation task that required word retrieval in single and dual-language contexts under varying cognitive control demands and a traditional letter fluency task conducted in single-language contexts. We also examined the associations between verbal fluency performance and (i) bilingual language history, and (ii) performance on standardized language assessments in both BPWA and healthy bilinguals.

METHODS AND PROCEDURES

Thirteen Spanish-English BPWA and twenty-two Spanish-English healthy bilinguals completed a language use questionnaire, verbal fluency testing and standardized language assessments in each language. The semantic category generation task included four conditions: two conditions examined word retrieval in the first-acquired (L1) and second-acquired language (L2) in single language contexts (No Switch-L1 and No Switch-L2) and two conditions elicited word retrieval in dual-language contexts (Self-Switch and Forced-Switch) with low and high cognitive control demands by allowing or restricting switching across languages. The letter fluency task was administered in single language contexts only (F, A, S for English and P, M, R for Spanish). Verbal fluency performance was compared across conditions and groups using multivariate analyses. Further, correlational analyses were used to examine associations between verbal fluency tasks and bilingual language history, language assessments, and cognitive function.

OUTCOMES AND RESULTS

Overall, the healthy bilinguals produced a higher proportion of accurate words in both verbal fluency tasks relative to the BPWA. Results indicate that BPWA were more sensitive to the effects of increased cognitive control on lexical access relative to healthy bilinguals. BPWA and healthy bilinguals' performance on both verbal fluency tasks was associated with metrics of bilingual language history and standardized language assessments. Additionally, for BPWA, L2 letter fluency performance was associated with cognitive function.

CONCLUSIONS

Our findings suggest that verbal fluency tasks can help characterize the impact of cognitive control on lexical access in BPWA in single and mixed language contexts with important clinical implications.

Longitudinal Patterns of the Tip-of-the-Tongue Phenomenon in People With Subjective Cognitive Complaints and Mild Cognitive Impairment

Background

The Tip-of-the-Tongue (ToTs) state is considered a universal phenomenon and is a frequent cognitive complaint in old age. Previous cross-sectional studies have found that ToT measures successfully discriminate between cognitively unimpaired adults and adults with Mild Cognitive Impairment (MCI). The aim of this study was to identify longitudinal patterns of ToTs in individuals with subjective complaints and with MCI regarding progress of their cognitive status.

Method

The study included 193 participants with subjective cognitive complaints (SCC) and 56 participants with MCI who completed a baseline and two follow-up assessments, with an interval of about 18 months between each assessment. Participants were classified into three groups by considering cognitive stability or deterioration from the baseline diagnosis: SCC-stable, MCI-stable and MCI-worsened. Participants performed a ToT task involving recognition and naming of famous people depicted in 50 photographs. Generalized Linear Mixed Models (GLMM) were used to model longitudinal changes in familiarity, feeling of knowing, semantic access, phonological access and verbal fluency.

Results

Phonological access differentiated MCI patients, stable and worsened, from adults with SCCs at all evaluation times. Phonological access declined over time in the three groups, without significant interactions between groups and time.

Discussion

This study provides the first longitudinal evidence of differences in ToT measures for adults with MCI. The findings indicate that phonological access measures successfully differentiated between the diagnostic groups. However, slopes remain irrespective of the diagnostic group and progression toward more advance stages of cognitive impairment.

Electrophysiological Differentiation of the Effects of Stress and Accent on Lexical Integration in Highly Fluent Bilinguals

Individuals who acquire a second language (L2) after infancy often retain features of their native language (L1) accent. Cross-language priming studies have shown negative effects of L1 accent on L2 comprehension, but the role of specific speech features, such as lexical stress, is mostly unknown. Here, we investigate whether lexical stress and accent differently modulate semantic processing and cross-language lexical activation in Welsh–English bilinguals, given that English and Welsh differ substantially in terms of stress realisation. In an L2 cross-modal priming paradigm, we manipulated the stress pattern and accent of spoken primes, whilst participants made semantic relatedness judgments on visual word targets. Event-related brain potentials revealed a main effect of stress on target integration, such that stimuli with stress patterns compatible with either the L1 or L2 required less processing effort than stimuli with stress incompatible with both Welsh and English. An independent cross-language phonological overlap manipulation revealed an interaction between accent and L1 access. Interestingly, although it increased processing effort, incorrect stress did not significantly modulate semantic priming effects or covert access to L1 phonological representations. Our results are consistent with the concept of language-specific stress templates, and suggest that accent and lexical stress affect speech comprehension mechanisms differentially.

Semantic Function in Mild Cognitive Impairment

It is well-established that semantic deficits are observed in mild cognitive impairment (MCI). However, the extent of impairment in different aspects of semantic function remains unclear, and may be influenced by the tasks used to assess performance. In the present study, people with MCI and cognitively healthy older adults completed a series of tasks assessing lexical access, retrieval, and recognition of semantic information, using different input and output modalities. Control participants outperformed people with MCI in almost all tasks, with the greatest deficits observed in picture naming tasks. This finding is interpreted as reflecting greater deficits in lexical access and/or access to the phonological and orthographic lexicon, and less severe deficits in retrieval and recognition of semantic feature and associative knowledge. In a subset of tasks, relatively greater impairment was also observed in biological compared to man-made items. From a clinical perspective, these results suggest that, while it is preferable that a full semantic battery be included in neuropsychological assessment, in cases where shorter testing time is necessary, picture naming is the task most likely to reveal deficits in people with MCI.

How Do You Deal With Uncertainty? Cochlear Implant Users Differ in the Dynamics of Lexical Processing of Noncanonical Inputs

OBJECTIVES

Work in normal-hearing (NH) adults suggests that spoken language processing involves coping with ambiguity. Even a clearly spoken word contains brief periods of ambiguity as it unfolds over time, and early portions will not be sufficient to uniquely identify the word. However, beyond this temporary ambiguity, NH listeners must also cope with the loss of information due to reduced forms, dialect, and other factors. A recent study suggests that NH listeners may adapt to increased ambiguity by changing the dynamics of how they commit to candidates at a lexical level. Cochlear implant (CI) users must also frequently deal with highly degraded input, in which there is less information available in the input to recover a target word. The authors asked here whether their frequent experience with this leads to lexical dynamics that are better suited for coping with uncertainty.

DESIGN

Listeners heard words either correctly pronounced (dog) or mispronounced at onset (gog) or offset (dob). Listeners selected the corresponding picture from a screen containing pictures of the target and three unrelated items. While they did this, fixations to each object were tracked as a measure of the time course of identifying the target. The authors tested 44 postlingually deafened adult CI users in 2 groups (23 used standard electric only configurations, and 21 supplemented the CI with a hearing aid), along with 28 age-matched age-typical hearing (ATH) controls.

RESULTS

All three groups recognized the target word accurately, though each showed a small decrement for mispronounced forms (larger in both types of CI users). Analysis of fixations showed a close time locking to the timing of the mispronunciation. Onset mispronunciations delayed initial fixations to the target, but fixations to the target showed partial recovery by the end of the trial. Offset mispronunciations showed no effect early, but suppressed looking later. This pattern was attested in all three groups, though both types of CI users were slower and did not commit fully to the target. When the authors quantified the degree of disruption (by the mispronounced forms), they found that both groups of CI users showed less disruption than ATH listeners during the first 900 msec of processing. Finally, an individual differences analysis showed that within the CI users, the dynamics of fixations predicted speech perception outcomes over and above accuracy in this task and that CI users with the more rapid fixation patterns of ATH listeners showed better outcomes.

CONCLUSIONS

Postlingually deafened CI users process speech incrementally (as do ATH listeners), though they commit more slowly and less strongly to a single item than do ATH listeners. This may allow them to cope more flexible with mispronunciations.

Neurophysiological Correlates of Frequency, Concreteness, and Iconicity in American Sign Language

To investigate possible universal and modality-specific factors that influence the neurophysiological response during lexical processing, we recorded event-related potentials while a large group of deaf adults (n = 40) viewed 404 signs in American Sign Language (ASL) that varied in ASL frequency, concreteness, and iconicity. Participants performed a go/no-go semantic categorization task (does the sign refer to people?) to videoclips of ASL signs (clips began with the signer's hands at rest). Linear mixed-effects regression models were fit with per-participant, per-trial, and per-electrode data, allowing us to identify unique effects of each lexical variable. We observed an early effect of frequency (greater negativity for less frequent signs) beginning at 400 ms postvideo onset at anterior sites, which we interpreted as reflecting form-based lexical processing. This effect was followed by a more widely distributed posterior response that we interpreted as reflecting lexical-semantic processing. Paralleling spoken language, more concrete signs elicited greater negativities, beginning 600 ms postvideo onset with a wide scalp distribution. Finally, there were no effects of iconicity (except for a weak effect in the latest epochs; 1,000-1,200 ms), suggesting that iconicity does not modulate the neural response during sign recognition. Despite the perceptual and sensorimotoric differences between signed and spoken languages, the overall results indicate very similar neurophysiological processes underlie lexical access for both signs and words.

Prefix Stripping Re-Re-Revisited: MEG Investigations of Morphological Decomposition and Recomposition

We revisit a long-standing question in the psycholinguistic and neurolinguistic literature on comprehending morphologically complex words: are prefixes and suffixes processed using the same cognitive mechanisms? Recent work using Magnetoencephalography (MEG) to uncover the dynamic temporal and spatial responses evoked by visually presented complex suffixed single words provide us with a comprehensive picture of morphological processing in the brain, from early, form-based decomposition, through lexical access, grammatically constrained recomposition, and semantic interpretation. In the present study, we find that MEG responses to prefixed words reveal interesting early differences in the lateralization of the form-based decomposition response compared to the effects reported in the literature for suffixed words, but a very similar post-decomposition profile. These results not only address a question stretching back to the earliest days of modern psycholinguistics, but also add critical support and nuance to our much newer emerging understanding of spatial organization and temporal dynamics of morphological processing in the human brain.

MVPA Analysis of Intertrial Phase Coherence of Neuromagnetic Responses to Words Reliably Classifies Multiple Levels of Language Processing in the Brain

Neural processing of language is still among the most poorly understood functions of the human brain, whereas a need to objectively assess the neurocognitive status of the language function in a participant-friendly and noninvasive fashion arises in various situations. Here, we propose a solution for this based on a short task-free recording of MEG responses to a set of spoken linguistic contrasts. We used spoken stimuli that diverged lexically (words/pseudowords), semantically (action-related/abstract), or morphosyntactically (grammatically correct/ungrammatical). Based on beamformer source reconstruction we investigated intertrial phase coherence (ITPC) in five canonical bands (α, β, and low, medium, and high γ) using multivariate pattern analysis (MVPA). Using this approach, we could successfully classify brain responses to meaningful words from meaningless pseudowords, correct from incorrect syntax, as well as semantic differences. The best classification results indicated distributed patterns of activity dominated by core temporofrontal language circuits and complemented by other areas. They varied between the different neurolinguistic properties across frequency bands, with lexical processes classified predominantly by broad γ, semantic distinctions by α and β, and syntax by low γ feature patterns. Crucially, all types of processing commenced in a near-parallel fashion from ∼100 ms after the auditory information allowed for disambiguating the spoken input. This shows that individual neurolinguistic processes take place simultaneously and involve overlapping yet distinct neuronal networks that operate at different frequency bands. This brings further hope that brain imaging can be used to assess neurolinguistic processes objectively and noninvasively in a range of populations.

Audiovisual speech segmentation in post-stroke aphasia: a pilot study

Background: Stroke may cause sentence comprehension disorders. Speech segmentation, i.e. the ability to detect word boundaries while listening to continuous speech, is an initial step allowing the successful identification of words and the accurate understanding of meaning within sentences. It has received little attention in people with post-stroke aphasia (PWA).Objectives: Our goal was to study speech segmentation in PWA and examine the potential benefit of seeing the speakers' articulatory gestures while segmenting sentences.Methods: Fourteen PWA and twelve healthy controls participated in this pilot study. Performance was measured with a word-monitoring task. In the auditory-only modality, participants were presented with auditory-only stimuli while in the audiovisual modality, visual speech cues (i.e. speaker's articulatory gestures) accompanied the auditory input. The proportion of correct responses was calculated for each participant and each modality. Visual enhancement was then calculated in order to estimate the potential benefit of seeing the speaker's articulatory gestures.Results: Both in auditory-only and audiovisual modalities, PWA performed significantly less well than controls, who had 100% correct performance in both modalities. The performance of PWA was correlated with their phonological ability. Six PWA used the visual cues. Group level analysis performed on PWA did not show any reliable difference between the auditory-only and audiovisual modalities (median of visual enhancement = 7% [Q1 - Q3: -5 - 39]).Conclusion: Our findings show that speech segmentation disorder may exist in PWA. This points to the importance of assessing and training speech segmentation after stroke. Further studies should investigate the characteristics of PWA who use visual speech cues during sentence processing.

The influence of proficiency and language combination on bilingual lexical access

The present study examines the influence of language proficiency and language combination on bilingual lexical access using category fluency in 109 healthy speakers. Participants completed a category fluency task in each of their languages in three main categories (animals, clothing, and food), each with two subcategories, as well as a language use questionnaire assessing their proficiency. Five language combinations were examined (Hindi-English, Kannada-English, Mandarin-English, Spanish-English, and Turkish-English). Multivariate analyses of variance revealed that the average number of correct items named in the category fluency task across the three main categories varied across the different groups only in English and not the other language. Further, results showed that language exposure composite (extracted from the questionnaire using a principal component analysis) significantly affected the average number of items named across the three main categories. Overall, these results demonstrate the effects of particular language combinations on bilingual lexical access and provide important insights into the role of proficiency on access.

Lexical-Access Ability and Cognitive Predictors of Speech Recognition in Noise in Adult Cochlear Implant Users

Not all of the variance in speech-recognition performance of cochlear implant (CI) users can be explained by biographic and auditory factors. In normal-hearing listeners, linguistic and cognitive factors determine most of speech-in-noise performance. The current study explored specifically the influence of visually measured lexical-access ability compared with other cognitive factors on speech recognition of 24 postlingually deafened CI users. Speech-recognition performance was measured with monosyllables in quiet (consonant-vowel-consonant [CVC]), sentences-in-noise (SIN), and digit-triplets in noise (DIN). In addition to a composite variable of lexical-access ability (LA), measured with a lexical-decision test (LDT) and word-naming task, vocabulary size, working-memory capacity (Reading Span test [RSpan]), and a visual analogue of the SIN test (text reception threshold test) were measured. The DIN test was used to correct for auditory factors in SIN thresholds by taking the difference between SIN and DIN: SRT_diff. Correlation analyses revealed that duration of hearing loss (dHL) was related to SIN thresholds. Better working-memory capacity was related to SIN and SRT_diff scores. LDT reaction time was positively correlated with SRT_diff scores. No significant relationships were found for CVC or DIN scores with the predictor variables. Regression analyses showed that together with dHL, RSpan explained 55% of the variance in SIN thresholds. When controlling for auditory performance, LA, LDT, and RSpan separately explained, together with dHL, respectively 37%, 36%, and 46% of the variance in SRT_diff outcome. The results suggest that poor verbal working-memory capacity and to a lesser extent poor lexical-access ability limit speech-recognition ability in listeners with a CI.

Exploring Different Types of Inhibition During Bilingual Language Production

Multilinguals have to control their languages constantly to produce accurate verbal output. They have to inhibit possible lexical competitors not only from the target language, but also from non-target languages. Bilinguals' training in inhibiting incongruent or irrelevant information has been used to endorse the so-called bilingual advantage in executive functions, assuming a transfer effect from language inhibition to domain-general inhibitory skills. Recent studies have suggested that language control may rely on language-specific inhibitory control mechanisms. In the present study, unbalanced highly proficient bilinguals completed a rapid naming multi-inhibitory task in two languages. The task assessed three types of inhibitory processes: inhibition of the non-target language, inhibition of lexical competitors, and inhibition of erroneous auditory feedback. The results showed an interaction between lexical competition and erroneous auditory feedback, but no interactions with the inhibition of the non-target language. The results suggested that different subcomponents of language inhibition are involved during bilingual language production.

Development of bidirectional phono-semantic activation in toddlers

A mediated priming effect refers to the activation of a target via a mediator previously activated by a prime. This effect has been found at 24 months of age for phono-semantic links: a prime ( cup) activates a target ( dog) via a mediator ( cat), providing evidence of activation in a forward direction (phonological to semantic). Interactive models, however, propose that activation propagates in both forward and backward directions between processing levels. This study investigated the development of bidirectional co-activation of phonological and semantic levels of processing in Spanish-speaking toddlers. In a primed preferential looking task, participants were exposed to an unlabelled prime image, followed by the presentation of two images, a target and a distractor. In Experiment 1, when images with a semantic-phonological relationship were presented, both 24- and 30-month-olds preferred to look at the named target with a relationship to the prime image ( dog- cat- cup). However, when an unrelated target image was named, 24-month-olds preferred to look at the target, but 30-month-olds did not. In Experiment 2, both 24- and 30-month-olds preferred to look at a target with a phono-semantic relationship to the prime ( cup- cat- dog) over an unrelated target. These results provide strong evidence of differences in the development of forward and backward interactions between semantic and phonological processing levels.

In Spoken Word Recognition, the Future Predicts the Past

Speech is an inherently noisy and ambiguous signal. To fluently derive meaning, a listener must integrate contextual information to guide interpretations of the sensory input. Although many studies have demonstrated the influence of prior context on speech perception, the neural mechanisms supporting the integration of subsequent context remain unknown. Using MEG to record from human auditory cortex, we analyzed responses to spoken words with a varyingly ambiguous onset phoneme, the identity of which is later disambiguated at the lexical uniqueness point. Fifty participants (both male and female) were recruited across two MEG experiments. Our findings suggest that primary auditory cortex is sensitive to phonological ambiguity very early during processing at just 50 ms after onset. Subphonemic detail is preserved in auditory cortex over long timescales and re-evoked at subsequent phoneme positions. Commitments to phonological categories occur in parallel, resolving on the shorter timescale of ∼450 ms. These findings provide evidence that future input determines the perception of earlier speech sounds by maintaining sensory features until they can be integrated with top-down lexical information.SIGNIFICANCE STATEMENT The perception of a speech sound is determined by its surrounding context in the form of words, sentences, and other speech sounds. Often, such contextual information becomes available later than the sensory input. The present study is the first to unveil how the brain uses this subsequent information to aid speech comprehension. Concretely, we found that the auditory system actively maintains the acoustic signal in auditory cortex while concurrently making guesses about the identity of the words being said. Such a processing strategy allows the content of the message to be accessed quickly while also permitting reanalysis of the acoustic signal to minimize parsing mistakes.

Is reading automatic? Are the ERP correlates of masked priming really lexical?

Humans have an almost unbounded ability to adapt their behaviour to perform different tasks. In the laboratory, this flexibility is sometimes viewed as a nuisance factor that prevents access to the underlying cognitive mechanisms of interest. For example, in order to study "automatic" lexical processing, psycholinguists have used masked priming or evoked potentials. However, the pattern of masked priming can be radically altered by changing the task. In lexical decision, priming is observed for words but not for nonwords, yet in a same-different matching task, priming is observed for same responses but not for different responses, regardless of whether the target is a word or a nonword [Norris & Kinoshita, 2008. Perception as evidence accumulation and Bayesian inference: Insights from masked priming. Journal of Experimental Psychology: General, 137(3), 434-55. doi:10.1037/a0012799]. Here we show that evoked potentials are equally sensitive to the nature of required decision, with the neural activity normally associated with lexical processing being seen for both words and nonwords on same trials, and for neither on different trials.

Word repetition and retrieval practice effects in aphasia: Evidence for use-dependent learning in lexical access

This study tested the hypothesis that a use-dependent learning mechanism operates at each of two stages of lexical access: retrieval of a word from semantics ("Stage 1"), followed by retrieval of the word's constituent phonemes ("Stage 2"). Two participants with aphasia were selected due to their contrasting types of naming impairment (Stage 1 versus Stage 2 difficulty). For each participant, items were assigned to naming training that involved retrieval practice (retrieval of the name from semantics) or repetition practice (hear the name and orally repeat it). Naming tests were administered one day and one week after training. The results supported the predicted training effects: (a) Because successful naming via retrieval practice requires both Stage 1 and Stage 2, this technique uses and strengthens item-specific connections in both stages. (b) Because word repetition circumvents semantically driven retrieval, this technique primarily uses and strengthens item-specific connections in Stage 2.

The Manipulability Effect in Object Naming

Seeing objects triggers activation of motor areas. The implications of this motor activation in tasks that do not require object-use is still a matter of debate in cognitive sciences. Here we test whether motor activation percolates into the linguistic system by exploring the effect of object manipulability in a speech production task. Italian native speakers name the set of photographs provided by Guérard, Lagacè and Brodeur (Beh Res Meth, 2015). Photographs varied on four motor dimensions concerning on how easily the represented objects can be grasped, moved, or pantomimed, and the number of actions that can be performed with them. The results show classical psycholinguistic phenomena such as the effect of age of acquisition and name agreement in naming latencies. Critically, linear mixed-effects models show an effect of three motor predictors over and above the psycholinguistic effects (replicating, in part, previous findings, Guérard et al., 2015). Further research is needed to address how, and at which level, the manipulability effect emerges in the course of word production.

A cross-linguistic comparison of category and letter fluency: Mandarin and English

Verbal fluency tasks are widely applied in a variety of languages, but whether the quality and quantity of responses are comparable across structurally different writing systems is debatable. For example, since there are no letters in a logographic, non-alphabetic language such as Chinese, the mechanisms speakers use to generate a list of words in a letter fluency task might be structurally different than those used by speakers of alphabetic languages. In this study, we investigated lexical retrieval strategies and approaches in letter and category fluency tasks among monolingual Mandarin speakers compared to monolingual English speakers. We found that the responses of Mandarin speakers are both qualitatively and quantitatively different in letter fluency, and qualitatively different in category fluency. These results suggest that differences in task completion among non-English-speaking populations are important to consider when using this extensively utilised cognitive and linguistic measure in research and clinic.