The dark side of incremental learning: a model of cumulative semantic interference during lexical access in speech production

Are brain activity changes underlying rare word production after learning specific or do they extend to semantically related rare words?

Learning words in the mother tongue is a fundamental lifelong skill that involves complex cognitive and neural changes. In adults, newly learned words affect the organization of the lexical-semantic network and, compared to words that have been in the lexicon for longer, they activate the same cortical areas, but more extensively and/or intensively. It is however still unclear (1) which brain and cognitive processes underlying word production change when infrequent/unknown words are compared before and after learning and (2) whether integrating newly learned words impacts word specific processes or has a broader impact on unlearned words. The present study aims to investigate the electrophysiological changes underlying the production of rare words induced by learning and the effect of learning on an unlearned list of rare words belonging to the same semantic categories. To this end, 24 neurotypical adults learned one of two matched lists of 40 concrete rare words from 4 semantic categories. EEG (electroencephalographic) recordings were acquired during a referential word production task (picture naming) of the learned and unlearned words before and after the learning phase. The results show that the production of rare word is associated with event-related (ERP) differences between before and after learning in the period from 300 to 800 msec following the presentation of the imaged concept (picture). These differences consisted in a larger involvement of left temporal and parietal regions after learning between 300 and 400 msec i.e., the time window likely corresponding to lexical and phonological encoding processes. Crucially, the ERP changes are not restricted to the production of the learned rare words, but are also observed when participants try to retrieve words of a list of semantically and lexically matched rare words that they have not learned. The ERP changes on unlearned rare words are weaker and suggest that learning new words induces boarder effects also on unlearned words.

Phonological neighbourhood effects in Italian speech production: Evidence from healthy and neurologically impaired populations

In two speech production studies conducted in Italian, we investigated the impact of phonological neighbourhood properties such as the neighbourhood density and the mean frequency of the neighbours on speech processing. Two populations of healthy (Study 1) and neurologically impaired (Study 2) individuals were tested. We employed multi-regression methods to analyse naming latencies in Study 1 and accuracy rates in Study 2 while controlling for various psycholinguistic predictors. In Study 1, pictures with words from high-density neighbourhoods were named faster than those from low-density neighbourhoods. Additionally, words with high-frequency neighbours were named faster in Study 1 and yielded higher accuracy rates in Study 2. The results suggest facilitatory effects of both the phonological neighbourhood density and frequency neighbourhood variables. Furthermore, we observed interactions between these two phonological neighbourhood variables and name agreement and repetition. Specifically, the facilitation effect was more pronounced for pictures with lower name agreement and during the initial presentation of the pictures. These findings are discussed in the context of previous literature and within the framework of interactive models of speech production.

A modified neural circuit framework for semantic memory retrieval with implications for circuit modulation to treat verbal retrieval deficits

Word finding difficulty is a frequent complaint in older age and disease states, but treatment options are lacking for such verbal retrieval deficits. Better understanding of the neurophysiological and neuroanatomical basis of verbal retrieval function may inform effective interventions. In this article, we review the current evidence of a neural retrieval circuit central to verbal production, including words and semantic memory, that involves the pre-supplementary motor area (pre-SMA), striatum (particularly caudate nucleus), and thalamus. We aim to offer a modified neural circuit framework expanded upon a memory retrieval model proposed in 2013 by Hart et al., as evidence from electrophysiological, functional brain imaging, and noninvasive electrical brain stimulation studies have provided additional pieces of information that converge on a shared neural circuit for retrieval of memory and words. We propose that both the left inferior frontal gyrus and fronto-polar regions should be included in the expanded circuit. All these regions have their respective functional roles during verbal retrieval, such as selection and inhibition during search, initiation and termination of search, maintenance of co-activation across cortical regions, as well as final activation of the retrieved information. We will also highlight the structural connectivity from and to the pre-SMA (e.g., frontal aslant tract and fronto-striatal tract) that facilitates communication between the regions within this circuit. Finally, we will discuss how this circuit and its correlated activity may be affected by disease states and how this circuit may serve as a novel target engagement for neuromodulatory treatment of verbal retrieval deficits.

Adaptive lexical processing of semantic competitors extends to alternative names: Evidence from blocked-cyclic picture naming

Naming a picture (e.g., "duck") in the context of semantically related pictures (e.g., "eagle," "stork," "parrot") takes longer than naming it in the context of unrelated pictures (e.g., "knave," "toast," "atlas"). Adaptive models of word production attribute this semantic interference effect in blocked-cyclic naming (BCN) to an adaptive mechanism that makes competitor words, (e.g., the semantically related word "eagle" for the target word "duck") which are activated but not selected for production, less accessible for future retrieval. Results from a recent picture-word-interference study, however, suggested that alternative names (e.g., "bird" for "duck") might be exempt from this mechanism, challenging adaptive lexical processing as a general mechanism. We tested whether converging evidence is obtained in BCN. In Experiment 1, we embedded pictures responded to with alternative (category) names (e.g., "bird") into contexts composed of pictures responded to with specific (exemplar) names (e.g., "duck," "eagle," "stork," and "parrot"). If alternative names are exempt from adaptive lexical processing, interference in the homogeneous context should be found for specific name items but not for alternative name items. In contrast to this prediction, there was similar-sized interference for both types of items. In Experiment 2, we replaced the alternative name items with unrelated items. For these items, interference was largely diminished, ruling out that the effect found in Experiment 1 is a general set effect. Overall, our data suggest that alternative names are not special with respect to adaptive lexical processing.

Similarity-induced interference or facilitation in language production reflects representation, not selection

Researchers have long interpreted the presence or absence of semantic interference in picture naming latencies as confirming or refuting theoretical claims regarding competitive lexical selection. But inconsistent empirical results challenge any mechanistic interpretation. A behavioral experiment first verified an apparent boundary condition in a blocked picture naming task: when orthogonally manipulating association type, taxonomic associations consistently elicit interference, while thematic associations do not. A plausible representational difference is that thematic feature activations depend more on supporting contexts. Simulations show that context-sensitivity emerges from the distributional statistics that are often used to measure thematic associations: residual semantic activation facilitates the retrieval of words that share semantic features, counteracting learning-based interference, and training a production model with greater sequential cooccurrence for thematically related words causes it to acquire stronger residual activation for thematic features. Modulating residual activation, either directly or through training, allows the model to capture gradient values of interference and facilitation, and in every simulation competitive and noncompetitive selection algorithms produce qualitatively equivalent results.

Recognition memory: The probe, the returned signal, and the decision

In an attempt to better understand recognition memory we look at how three approaches (dual processing, signal detection, and global matching) have addressed the probe, the returned signal and the decision in four recognition paradigms. These are single-item recognition (including the remember/know paradigm), recognition in relational context, associative recognition, and source monitoring. The contrast, with regards to the double-miss rate (the probability of recognizing neither item in intact and rearranged pairs) and the effect of the oldness of the other member of the test pair, between identifying the old words in test pairs (the relational context paradigm) and first identifying the intact test pairs and then identifying the old words (adding associative recognition to the relational context paradigm) suggests that the retrieval of associative information in the relational context paradigm is unintentional, unlike the retrieval of associative information in associative recognition. It also seems possible that the information that is spontaneously retrieved in single-item recognition, possibly including the remember/know paradigm, is also unintentional, unlike the retrieval of information in source monitoring. Probable differences between intentional and unintentional retrieval, together with the pattern of effects with regards to the double-miss rate and the effect of the other member of the test pair, are used to evaluate the three approaches. Our conclusion is that all three approaches have something valid to say about recognition, but none is equally applicable across all four paradigms.

Functional characterization of the language network of polyglots and hyperpolyglots with precision fMRI

How do polyglots-individuals who speak five or more languages-process their languages, and what can this population tell us about the language system? Using fMRI, we identified the language network in each of 34 polyglots (including 16 hyperpolyglots with knowledge of 10+ languages) and examined its response to the native language, non-native languages of varying proficiency, and unfamiliar languages. All language conditions engaged all areas of the language network relative to a control condition. Languages that participants rated as higher proficiency elicited stronger responses, except for the native language, which elicited a similar or lower response than a non-native language of similar proficiency. Furthermore, unfamiliar languages that were typologically related to the participants' high-to-moderate-proficiency languages elicited a stronger response than unfamiliar unrelated languages. The results suggest that the language network's response magnitude scales with the degree of engagement of linguistic computations (e.g. related to lexical access and syntactic-structure building). We also replicated a prior finding of weaker responses to native language in polyglots than non-polyglot bilinguals. These results contribute to our understanding of how multiple languages coexist within a single brain and provide new evidence that the language network responds more strongly to stimuli that more fully engage linguistic computations.

Why is a flamingo named as pelican and asparagus as celery? Understanding the relationship between targets and errors in a speeded picture naming task

Speakers sometimes make word production errors, such as mistakenly saying pelican instead of flamingo. This study explored which properties of an error influence the likelihood of its selection over the target word. Analysing real-word errors in speeded picture naming, we investigated whether, relative to the target, naming errors were more typical representatives of the semantic category, were associated with more semantic features, and/or were semantically more closely related to the target than its near semantic neighbours were on average. Results indicated that naming errors tended to be more typical category representatives and possess more semantic features than the targets. Moreover, while not being the closest semantic neighbours, errors were largely near semantic neighbours of the targets. These findings suggest that typicality, number of semantic features, and semantic similarity govern activation levels in the production system, and we discuss possible mechanisms underlying these effects in the context of word production theories.

The phonological congruency modulated long-term form priming of Chinese characters

Elucidating the interaction between lexical processing and word learning is essential for a complete understanding of the underlying mechanisms of each of them. Long-term priming for words reflects an interplay between lexical processing and word learning. Although robust long-term priming effects have been found between two occurrences of the same word and between semantically similar words, it remains unclear whether long-term priming between orthographically similar words (i.e., long-term form priming) is a reliable effect. Following the theoretical analysis based on the connectionist framework, we articulated the possibility that long-term form priming might be modulated by the phonological congruency between the prime and target words, and that if this modulator was under control, reliable effects of long-term form priming would emerge. However, this hypothesis has not been adequately tested empirically. The present study tested this hypothesis by using Chinese phonograms and the phonetic radicals embedded in them as the prime and target items. In three experiments that varied in the types of stimuli and testing tasks, we consistently found that when the prime and target had the same phonology, naming the prime facilitated later processing of the target, while when they had different phonologies, the priming effect was inhibitory. These observations were consistent with the connectionist account of long-term priming for words. Our findings help confirm the reliability, generalizability, and robustness of long-term form priming and elucidate its underlying mechanisms, and suggesting promising future directions on the interactions between lexical processing and word learning.

Resting state correlates of picture description informativeness in left vs. right hemisphere chronic stroke

Introduction

Despite a growing emphasis on discourse processing in clinical neuroscience, relatively little is known about the neurobiology of discourse production impairments. Individuals with a history of left or right hemisphere stroke can exhibit difficulty with communicating meaningful discourse content, which implies both cerebral hemispheres play a role in this skill. However, the extent to which successful production of discourse content relies on network connections within domain-specific vs. domain-general networks in either hemisphere is unknown.

Methods

In this study, 45 individuals with a history of either left or right hemisphere stroke completed resting state fMRI and the Cookie Theft picture description task.

Results

Participants did not differ in the total number of content units or the percentage of interpretative content units they produced. Stroke survivors with left hemisphere damage produced significantly fewer content units per second than individuals with right hemisphere stroke. Intrinsic connectivity of the left language network was significantly weaker in the left compared to the right hemisphere stroke group for specific connections. Greater efficiency of communication of picture scene content was associated with stronger left but weaker right frontotemporal connectivity of the language network in patients with a history of left hemisphere (but not right hemisphere) stroke. No significant relationships were found between picture description measures and connectivity of the dorsal attention, default mode, or salience networks or with connections between language and other network regions.

Discussion

These findings add to prior behavioral studies of picture description skills in stroke survivors and provide insight into the role of the language network vs. other intrinsic networks during discourse production.

How trial-to-trial learning shapes mappings in the mental lexicon: Modelling lexical decision with linear discriminative learning

Trial-to-trial effects have been found in a number of studies, indicating that processing a stimulus influences responses in subsequent trials. A special case are priming effects which have been modelled successfully with error-driven learning (Marsolek, 2008), implying that participants are continuously learning during experiments. This study investigates whether trial-to-trial learning can be detected in an unprimed lexical decision experiment. We used the Discriminative Lexicon Model (DLM; Baayen et al., 2019), a model of the mental lexicon with meaning representations from distributional semantics, which models error-driven incremental learning with the Widrow-Hoff rule. We used data from the British Lexicon Project (BLP; Keuleers et al., 2012) and simulated the lexical decision experiment with the DLM on a trial-by-trial basis for each subject individually. Then, reaction times were predicted with Generalized Additive Models (GAMs), using measures derived from the DLM simulations as predictors. We extracted measures from two simulations per subject (one with learning updates between trials and one without), and used them as input to two GAMs. Learning-based models showed better model fit than the non-learning ones for the majority of subjects. Our measures also provide insights into lexical processing and individual differences. This demonstrates the potential of the DLM to model behavioural data and leads to the conclusion that trial-to-trial learning can indeed be detected in unprimed lexical decision. Our results support the possibility that our lexical knowledge is subject to continuous changes.

Accumulating evidence for myriad alternatives: Modeling the generation of free association

The associative manner by which thoughts follow one another has intrigued scholars for decades. The process by which an association is generated in response to a cue can be explained by classic models of semantic processing through distinct computational mechanisms. Distributed attractor networks implement rich-get-richer dynamics and assume that stronger associations can be reached with fewer steps. Conversely, spreading activation models assume that a cue distributes its activation, in parallel, to all associations at a constant rate. Despite these models' huge influence, their intractability together with the unconstrained nature of free association have restricted their few previous uses to qualitative predictions. To test these computational mechanisms quantitatively, we conceptualize free association as the product of internal evidence accumulation and generate predictions concerning the speed and strength of people's associations. To this end, we first develop a novel approach to mapping the personalized space of words from which an individual chooses an association to a given cue. We then use state-of-the-art evidence accumulation models to demonstrate the function of rich-get-richer dynamics on the one hand and of stochasticity in the rate of spreading activation on the other hand, in preventing an exceedingly slow resolution of the competition among myriad potential associations. Furthermore, whereas our results uniformly indicate that stronger associations require less evidence, only in combination with rich-get-richer dynamics does this explain why weak associations are slow yet prevalent. We discuss implications for models of semantic processing and evidence accumulation and offer recommendations for practical applications and individual-differences research. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Speech errors in consecutive interpreting: Effects of language proficiency, working memory, and anxiety

Interpreting can be seen as a form of language production, where interpreters extract conceptual information from the source language and express it in the target language. Hence, like language production, interpreting contains speech errors at various (e.g., conceptual, syntactic, lexical and phonological) levels. The current study delved into the impact of language proficiency, working memory, and anxiety on the occurrence of speech errors across these linguistic strata during consecutive interpreting from English (a second language) into Chinese (a first language) by student interpreters. We showed that speech errors in general decreased as a function of the interpreter's proficiency in the source (second) language and increased as a function of the interpreter's anxiety. Conceptual errors, which result from mistaken comprehension of the source language, decreased as a function of language proficiency and working memory. Lexical errors increased as a function of the interpreter's tendency of anxiety. Syntactic errors also decreased as a function of language proficiency and increased as a function of anxiety. Phonological errors were not sensitive to any of the three cognitive traits. We discussed implications for the cognitive processes underlying interpreting and for interpreting training.

The unseen, the seen, and the spoken: Latent and overt priming in cyclic picture naming

Language production entails selecting words in the face of internally, and sometimes externally, driven competition that influences the long-term accessibility of both selected words and competitors. Because both endogenous and externally presented competitors usually result in semantic interference, it is often assumed that they engage the same underlying processes. We question this assumption. Specifically, we propose that latent primes may more naturally commingle with endogenous lexical activation whereas overt primes elicit strong control processes. Two experiments examined the effects of latent (masked) and overt (picture-word) priming in combination with cyclic picture naming of small sets of taxonomically or thematically related or unrelated pictures. A subsequent continuous picture naming phase was designed to assess enduring effects of service as a prime or target. Only taxonomic relations showed substantial interference in cyclic naming. Latent priming tended to increase interference for taxonomic relations, but it produced facilitation for thematic relations. In contrast, overt priming induced interference for both types of relation, indicating exertion of cognitive control. In the continuous picture naming phases, accessibility was hindered for previously presented latent primes (Experiment 1) but enhanced for previously overt primes (Experiment 2). Surprisingly, interference in cyclic naming did not carry forward to the continuous phase. These findings suggest that masked priming may be a viable intervention in the internal dynamics of lexical selection. In contrast, they also add to the body of evidence questioning the validity of using picture-word procedures to study inherent semantic interference.

Inhibitory control of the dominant language: Reversed language dominance is the tip of the iceberg

Theories of speech production have proposed that in contexts where multiple languages are produced, bilinguals inhibit the dominant language with the goal of making both languages equally accessible. This process often overshoots this goal, leading to a surprising pattern: better performance in the nondominant vs. dominant language, or reversed language dominance effects. However, the reliability of this effect in single word production studies with cued language switches has been challenged by a recent meta-analysis. Correcting for errors in this analysis, we find that dominance effects are reliably reduced and reversed during language mixing. Reversed dominance has also consistently been reported in the production of connected speech elicited by reading aloud of mixed language paragraphs. When switching, bilinguals produced translation-equivalent intrusion errors (e.g., saying pero instead of but) more often when intending to produce words in the dominant language. We show this dominant language vulnerability is not exclusive to switching out of the nondominant language and extends to non-switch words, linking connected speech results to patterns first reported in single word studies. Reversed language dominance is a robust phenomenon that reflects the tip of the iceberg of inhibitory control of the dominant language in bilingual language production.

Word Learning as a Window to Memory and Rehabilitation Outcomes in Traumatic Brain Injury

PURPOSE

The purpose of this viewpoint is to advocate for increased study of word learning abilities and word learning interventions in traumatic brain injury (TBI).

METHOD

We describe the word learning process and the unique opportunities afforded by studying each component and stage. Building on discussions at the 2022 International Cognitive-Communication Disorders Conference, we describe how word learning may underlie a variety of functional outcomes after TBI, making it a promising target for rehabilitation. Finally, we discuss principles that may guide study in this critical area to advance outcomes after TBI for children and adults.

RESULTS

Word learning is a dynamic and iterative process taking place over time and in multiple stages. Thus, studying word learning affords the opportunity to parse the relative contributions of multiple memory systems to different phases and components of the process. However, single-timepoint designs are insufficient to capture the full word learning process, which occurs over time and across contexts. Word learning also presents an opportunity to assess the contributions of behavioral and lifestyle factors (e.g., sleep and exercise) to different memory phases. Understanding these interactions could drive clinical interventions aimed at improving memory through manipulable external behaviors.

CONCLUSIONS

Word learning is key to success in functional spheres across the life span. The importance of words to daily life remains after TBI, even as the memory systems that support word learning are disrupted. The empirical study of word learning and rehabilitation of word learning deficits in TBI presents a promising new direction in understanding the breadth of neurogenic cognitive-communication disorders and an opportunity to explore a potential driver of functional outcome and impactful rehabilitation target.

Semantic cognition in healthy ageing: Neural signatures of representation and control mechanisms in naming typical and atypical objects

Effective use of conceptual knowledge engages semantic representation and control processes to access information in a goal-driven manner. Neuropsychological findings of patients presenting either degraded knowledge (e.g., semantic dementia) or disrupted control (e.g., semantic aphasia) converge with neuroimaging evidence from young adults, and delineate the neural segregation of representation and control mechanisms. However, there is still scarce research on the neurofunctional underpinnings of such mechanisms in healthy ageing. To address this, we conducted an fMRI study, wherein young and older adults performed a covert naming task of typical and atypical objects. Three main age-related differences were found. As shown by age group and typicality interactions, older adults exhibited overactivation during naming of atypical (e.g., avocado) relative to typical concepts in brain regions associated to semantic representation, including anterior and medial portions of left temporal lobe (respectively, ATL and MTG). This provides evidence for the reorganization of neural activity in these brain regions contingent to the enrichment of semantic repositories in older ages. The medial orbitofrontal gyrus was also overactivated, indicating that the processing of atypical concepts (relative to typical items) taxes additional control resources in the elderly. Increased activation in the inferior frontal gyrus (IFG) was observed in naming typical items (relative to atypical ones), but only for young adults. This suggests that naming typical items (e.g., strawberry) taxes more on control processes in younger ages, presumably due to the semantic competition set by other items that share multiple features with the target (e.g., raspberry, blackberry, cherry). Together, these results reveal the dynamic nature of semantic control interplaying with conceptual representations as people grow older, by indicating that distinct neural bases uphold semantic performance from young to older ages. These findings may be explained by neural compensation mechanisms coming into play to support neurocognitive changes in healthy ageing.

Executive functioning moderates the decline of retrieval fluency in time

Prevailing theoretical accounts consider that automatic and controlled processes are uniformly engaged in memory retrieval across performance of the semantic verbal fluency (SVF) task. We tested this proposal against the alternative, namely that a rapid automatic retrieval, exploiting stable associative structure in the early stages of the performance, is followed by a slower, more executively demanding, retrieval in later stages. Eighty-five healthy adults completed low- and high-demand SVF tasks that were assessed for retrieval rate, response typicality, and inter-response similarity across the performance. Additional measures of executive functioning were collected to estimate individual differences in executive control. We found that decrease in fluency in time was associated with lower typicality and weaker semantic similarity of the responses. Critically, the time-dependent retrieval slowing was steeper in individuals with less efficient interference control, particularly in high-demand SVF tasks. Steeper retrieval slowing was also associated with poorer working-memory capacity. Our findings show that the relative contribution of automatic and controlled processes to semantic retrieval changes with associative sparsity over time and across task demands, and provide implications for the use of SVF tasks in clinical assessment.

A chimpanzee by any other name: The contributions of utterance context and information density on word choice

An important feature of language production is the flexibility of lexical selection; producers could refer to an animal as chimpanzee, chimp, ape, she, and so on. Thus, a key question for psycholinguistic research is how and why producers make the lexical selections that they do. Information theoretic approaches have argued that producers regulate the uncertainty of the utterance for comprehenders, for example using longer words like chimpanzee if their messages are likely to be misunderstood, and shorter ones like chimp when the message is easy to understand. In this work, we test for the relative contributions of the information theoretic approach and an approach more aligned with psycholinguistic models of language production. We examine the effect on lexical selection of whole utterance-level factors that we take as a proxy for register or style in message-driven production accounts. Using a modern machine learning-oriented approach, we show that for both naturalistic stimuli and real-world corpora, producers prefer words to be longer in systematically different contexts, independent of the specific message they are trying to convey. We do not find evidence for regulation of uncertainty, as in information theoretic approaches. We offer suggestions for modification of the standard psycholinguistic production approach that emphasizes the need for the field to specify how message formulation influences lexical choice in multiword utterances.

Web-based language production experiments: Semantic interference assessment is robust for spoken and typed response modalities

For experimental research on language production, temporal precision and high quality of the recorded audio files are imperative. These requirements are a considerable challenge if language production is to be investigated online. However, online research has huge potential in terms of efficiency, ecological validity and diversity of study populations in psycholinguistic and related research, also beyond the current situation. Here, we supply confirmatory evidence that language production can be investigated online and that reaction time (RT) distributions and error rates are similar in written naming responses (using the keyboard) and typical overt spoken responses. To assess semantic interference effects in both modalities, we performed two pre-registered experiments (n = 30 each) in online settings using the participants' web browsers. A cumulative semantic interference (CSI) paradigm was employed that required naming several exemplars of semantic categories within a seemingly unrelated sequence of objects. RT is expected to increase linearly for each additional exemplar of a category. In Experiment 1, CSI effects in naming times described in lab-based studies were replicated. In Experiment 2, the responses were typed on participants' computer keyboards, and the first correct key press was used for RT analysis. This novel response assessment yielded a qualitatively similar, very robust CSI effect. Besides technical ease of application, collecting typewritten responses and automatic data preprocessing substantially reduce the work load for language production research. Results of both experiments open new perspectives for research on RT effects in language experiments across a wide range of contexts. JavaScript- and R-based implementations for data collection and processing are available for download.

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.

An examination of retrieval practice and production training in the treatment of lexical-semantic comprehension deficits in aphasia

OBJECTIVE

Little research has addressed the treatment of lexical-semantic comprehension deficits (i.e., difficulty retrieving the meanings of words) in people with aphasia (PWA). Research suggests that practice retrieving names for depicted objects from long-term memory (production-based retrieval practice) more strongly benefits word retrieval for production in PWA compared to errorless learning (i.e., word repetition), which eschews retrieval practice. This study assessed whether production-based and comprehension-based retrieval practice enhance performance on errorful word-comprehension items in PWA measured relative to nonretrieval forms of training and untrained control items.

METHOD

In a within-participant group study of PWA, errorful comprehension items were assigned to (a) a production-based training module (retrieval practice vs. errorless learning); (b) a comprehension-based training module (a receptive form of retrieval practice vs. restudy). Each module comprised one training session and a 1-day and 1-week comprehension posttest on the module's trained items and an untrained item set.

RESULTS

The comprehension module conditions produced similar and superior posttest performance relative to untrained items. Both production module conditions improved posttest performance relative to untrained items, with retrieval practice conferring more durable learning and generalization indicative of refinement of semantic representations compared to errorless learning.

CONCLUSIONS

Results suggest comprehension- and production-based forms of training are both beneficial for improving lexical-semantic deficits in aphasia, with production-based retrieval practice conferring additional benefits to the targeted deficit compared to errorless learning. Future studies should examine these learning factors in schedules of training more commensurate with clinical practice and in other neurological populations (e.g., semantic dementia). (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Taxonomic and thematic semantic relationships in picture naming as revealed by Laplacian-transformed event-related potentials

Semantically related concepts co-activate when we speak. Prior research reported both behavioral interference and facilitation due to co-activation during picture naming. Different word relationships may account for some of this discrepancy. Taxonomically related words (e.g., WOLF-DOG) have been associated with semantic interference; thematically related words (e.g., BONE-DOG) have been associated with facilitation. Although these different semantic relationships have been associated with opposite behavioral outcomes, electrophysiological studies have found inconsistent effects on event-related potentials. We conducted a picture-word interference electroencephalography experiment to examine word retrieval dynamics in these different semantic relationships. Importantly, we used traditional monopolar analysis as well as Laplacian transformation allowing us to examine spatially deblurred event-related components. Both analyses revealed greater negativity (150-250 ms) for unrelated than related taxonomic pairs, though more restricted in space for thematic pairs. Critically, Laplacian analyses revealed a larger negative-going component in the 300 to 500 ms time window in taxonomically related versus unrelated pairs which were restricted to a left frontal recording site. In parallel, an opposite effect was found in the same time window but localized to a left parietal site. Finding these opposite effects in the same time window was feasible thanks to the use of the Laplacian transformation and suggests that frontal control processes are concurrently engaged with cascading effects of the spread of activation through semantically related representations.

Language learning in aphasia: A narrative review and critical analysis of the literature with implications for language therapy

People with aphasia (PWA) present with language deficits including word retrieval difficulties after brain damage. Language learning is an essential life-long human capacity that may support treatment-induced language recovery after brain insult. This prospect has motivated a growing interest in the study of language learning in PWA during the last few decades. Here, we critically review the current literature on language learning ability in aphasia. The existing studies in this area indicate that (i) language learning can remain functional in some PWA, (ii) inter-individual variability in learning performance is large in PWA, (iii) language processing, short-term memory and lesion site are associated with learning ability, (iv) preliminary evidence suggests a relationship between learning ability and treatment outcomes in this population. Based on the reviewed evidence, we propose a potential account for the interplay between language and memory/learning systems to explain spared/impaired language learning and its relationship to language therapy in PWA. Finally, we indicate potential avenues for future research that may promote more cross-talk between cognitive neuroscience and aphasia rehabilitation.

Through Thick and Thin: Baseline Cortical Volume and Thickness Predict Performance and Response to Transcranial Direct Current Stimulation in Primary Progressive Aphasia

Objectives

We hypothesized that measures of cortical thickness and volume in language areas would correlate with response to treatment with high-definition transcranial direct current stimulation (HD-tDCS) in persons with primary progressive aphasia (PPA).

Materials and Methods

In a blinded, within-group crossover study, PPA patients (N = 12) underwent a 2-week intervention HD-tDCS paired with constraint-induced language therapy (CILT). Multi-level linear regression (backward-fitted models) were performed to assess cortical measures as predictors of tDCS-induced naming improvements, measured by the Western Aphasia Battery-naming subtest, from baseline to immediately after and 6 weeks post-intervention.

Results

Greater baseline thickness of the pars opercularis significantly predicted naming gains (p = 0.03) immediately following intervention, while greater thickness of the middle temporal gyrus (MTG) and lower thickness of the superior temporal gyrus (STG) significantly predicted 6-week naming gains (p's < 0.02). Thickness did not predict naming gains in sham. Volume did not predict immediate gains for active stimulation. Greater volume of the pars triangularis and MTG, but lower STG volume significantly predicted 6-week naming gains in active stimulation. Greater pars orbitalis and MTG volume, and lower STG volume predicted immediate naming gains in sham (p's < 0.05). Volume did not predict 6-week naming gains in sham.

Conclusion

Cortical thickness and volume were predictive of tDCS-induced naming improvement in PPA patients. The finding that frontal thickness predicted immediate active tDCS-induced naming gains while temporal areas predicted naming changes at 6-week suggests that a broader network of regions may be important for long-term maintenance of treatment gains. The finding that volume predicted immediate naming performance in the sham condition may reflect the benefits of behavioral speech language therapy and neural correlates of its short-lived treatment gains. Collectively, thickness and volume were predictive of treatment gains in the active condition but not sham, suggesting that pairing HD-tDCS with CILT may be important for maintaining treatment effects.

Learning from errors: Exploration of the monitoring learning effect

The present study examined spontaneous detection and repair of naming errors in people with aphasia to advance a theoretical understanding of how monitoring impacts learning in lexical access. Prior work in aphasia has found that spontaneous repair, but not mere detection without repair, of semantic naming errors leads to improved naming on those same items in the future when other factors are accounted for. The present study sought to replicate this finding in a new, larger sample of participants and to examine the critical role of self-generated repair in this monitoring learning effect. Twenty-four participants with chronic aphasia with naming impairment provided naming responses to a 660-item corpus of common, everyday objects at two timepoints. At the first timepoint, a randomly selected subset of trials ended in experimenter-provided corrective feedback. Each naming trial was coded for accuracy, error type, and for any monitoring behavior that occurred, specifically detection with repair (i.e., correction), detection without repair, and no detection. Focusing on semantic errors, the original monitoring learning effect was replicated, with enhanced accuracy at a future timepoint when the first trial with that item involved detection with repair, compared to error trials that were not detected. This enhanced accuracy resulted from learning that arose from the first trial rather than the presence of repair simply signifying easier items. A second analysis compared learning from trials of self-corrected errors to that of trials ending in feedback that were detected but not self-corrected and found enhanced learning after self-generated repair. Implications for theories of lexical access and monitoring are discussed.

The relative balance between languages predicts the degree of engagement of global language control

After naming pictures in their second language (L2), bilinguals experience difficulty in naming pictures in their native language (L1). This phenomenon, the "L2 after-effect", is a lingering consequence of language control mechanisms regulating the activation of L1 and L2 to facilitate L2 production. Building on the Inhibitory Control model proposed by Green (1998), we propose that how much language control is applied depends on the relative balance between the current activation of L1 and L2. In two experiments, Polish-English bilinguals immersed in their L1 performed a blocked picture-naming task. This paradigm provided a continuous measure of the relative balance between the two languages and made it possible to index engagement of control by measuring the L2 after-effect. The results indicate that the higher the activation level of L1 and the lower the activation level of L2, the bigger the L2 after-effect. The results also revealed an enduring down-regulation of L1 activation level in more language-balanced speakers.

Cumulative semantic interference is blind to morphological complexity and originates at the conceptual level

When naming a sequence of pictures of the same semantic category (e.g., furniture), response latencies systematically increase with each named category member. This cumulative semantic interference effect has become a popular tool to investigate the cognitive architecture of language production. However, not all processes underlying the effect itself are fully understood, including the question where the effect originates from. While some researchers assume the interface of the conceptual and lexical level as its origin, others suggest the conceptual-semantic level. The latter assumption follows from the observation that cumulative effects, namely cumulative facilitation, can also be observed in purely conceptual-semantic tasks. Another unanswered question is whether cumulative interference is affected by the morphological complexity of the experimental targets. In two experiments with the same participants and the same material, we investigated both of these issues. Experiment 1, a continuous picture naming task, investigated whether morphologically complex nouns (e.g., kitchen table) elicit identical levels of cumulative interference to morphologically simple nouns (e.g., table). Our results show this to be the case, indicating that cumulative interference is unaffected by lexical information such as morphological complexity. In Experiment 2, participants classified the same target objects as either man-made or natural. As expected, we observed cumulative facilitation. A separate analysis showed that this facilitation effect can be predicted by the individuals’ effect sizes of cumulative interference, suggesting a strong functional link between the two effects. Our results thus point to a conceptual-semantic origin of cumulative semantic interference.

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.

EXPRESS: Representation of others' synchronous and asynchronous sentences interferes with sentence production

In dialogue, people represent each other's utterances in order to take turns and communicate successfully. In previous work [Gambi, C., Van de Cavey, J., & Pickering, M. J. (2015). Interference in joint picture naming. Journal of Experimental Psychology: Learning, Memory, and Cognition, 41(1), 1-21.], speakers who were naming single pictures or picture pairs represented whether another speaker was engaged in the same task (versus a different or no task) concurrently, but did not represent in detail the content of the other speaker's utterance. Here, we investigate co-representation of whole sentences. In three experiments, pairs of speakers imagined each other producing active or passive descriptions of transitive events. Speakers took longer to begin speaking when they believed their partner was also preparing to speak, compared to when they did not. Interference occurred when speakers believed their partners were preparing to speak at the same time as them (synchronous production and co-representation; Experiment 1), and also when speakers believed that their partner would speak only after them (asynchronous production and co-representation; Experiments 2a and 2b). However, interference was generally no greater when speakers believed their partner was preparing a different compared to a similar utterance, providing no consistent evidence that speakers represented what their partners were preparing to say. Taken together, these findings indicate that speakers can represent another's intention to speak even as they are themselves preparing to speak, but that such representation tends to lack detail.

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.

Concurrent semantic priming and lexical interference for close semantic relations in blocked-cyclic picture naming: Electrophysiological signatures

In the present study, we employed event-related brain potentials to investigate the effects of semantic similarity on different planning stages during language production. We manipulated semantic similarity by controlling feature overlap within taxonomical hierarchies. In a blocked-cyclic naming task, participants named pictures in repeated cycles, blocked in semantically close, distant, or unrelated conditions. Only closely related items, but not distantly related items, induced semantic blocking effects. In the first presentation cycle, naming was facilitated, and amplitude modulations in the N1 component around 140-180 ms post-stimulus onset predicted this behavioral facilitation. In contrast, in later cycles, naming was delayed, and a negative-going posterior amplitude modulation around 250-350 ms post-stimulus onset predicted this interference. These findings indicate easier object recognition or identification underlying initial facilitation and increased difficulties during lexical selection. The N1 modulation was reduced but persisted in later cycles in which interference dominated, and the posterior negativity was also present in cycle 1 in which facilitation dominated, demonstrating concurrent effects of conceptual priming and lexical interference in all naming cycles. Our assumptions about the functional role these two opposing forces play in producing semantic context effects are further supported by the finding that the joint modulation of these two ERPs on naming latency exclusively emerged when naming closely related, but not unrelated items. The current findings demonstrate that close relations, but not distant taxonomic relations, induce stronger semantic blocking effects, and that temporally overlapping electrophysiological signatures reflect a trade-off between facilitatory priming and interfering lexical competition.

Facilitating Word Retrieval in Aphasia: Which Type of Cues for Which Aphasic Speakers?

Background: Even if both phonological and semantic cues can facilitate word retrieval in aphasia, it remains unclear if their respective effectiveness varies according to the underlying anomic profile.

Aim: The aim of the present facilitation study is to compare the effect of phonological and semantic cues on picture naming accuracy and speed in different types of anomia.

Methods: In the present within-subject design study, 15 aphasic persons following brain damage underwent picture naming paradigms with semantic cues (categorically- or associatively related) and phonological cues (initial phoneme presented auditorily, visually or both).

Results: At the group level, semantic cueing was as effective as phonological cueing to significantly speed up picture naming. However, while phonological cues were effective regardless of the anomic profile, semantic cueing effects varied depending on the type of anomia. Participants with mixed anomia showed facilitation after both semantic categorical and associative cues, but individuals with lexical-phonological anomia only after categorical cues. Crucially, semantic cues were ineffective for participants with lexical-semantic anomia. These disparities were confirmed by categorical semantic facilitation decreasing when semantic/omission errors prevailed in the anomic profile, but increasing alongside phonological errors.

Conclusion: The effectiveness of phonological vs semantic cues seems related to the underlying anomic profile: phonological cues benefit any type of anomia, but semantic cues only lexical-phonological or mixed anomia.

Modeling Morphology With Linear Discriminative Learning: Considerations and Design Choices

This study addresses a series of methodological questions that arise when modeling inflectional morphology with Linear Discriminative Learning. Taking the semi-productive German noun system as example, we illustrate how decisions made about the representation of form and meaning influence model performance. We clarify that for modeling frequency effects in learning, it is essential to make use of incremental learning rather than the end-state of learning. We also discuss how the model can be set up to approximate the learning of inflected words in context. In addition, we illustrate how in this approach the wug task can be modeled. The model provides an excellent memory for known words, but appropriately shows more limited performance for unseen data, in line with the semi-productivity of German noun inflection and generalization performance of native German speakers.

BONEs not CATs attract DOGs: Semantic context effects for picture naming in the lesioned language network

The breakdown of rapid and accurate retrieval of words is a hallmark of aphasic speech and a prime target of therapeutic intervention. Complementary, psycho- and neurolinguistic research have developed a spectrum of models, how and by which neuronal network uncompromised speakers can rely on remarkable lexical retrieval capacities. Motivated by both lines of research we invited 32 participants with a chronic left hemispheric brain lesion to name pictures in the presence of distractor words. This picture-word-interference (PWI) paradigm is widely used in psycho- and neurolinguistic research. We find that also after brain lesion categorically related words (CAT → [dog]^picture) impede naming, while associatively related words (BONE → [dog]^picture) ease access, when compared to unrelated distractor words. The effects largely affecting latencies in neurotypical populations, are reproduced for error rate in our participants with lesions in the language network. Unsurprisingly, overall naming abilities varied greatly across patients. Notably, however, the two effects (categorical interference / associative facilitation) differ between participants. Correlating performance with lesion patterns we find support for the notion of a divergence of brain areas affording different aspects of the task: (i) lesions in the left middle temporal gyurs (MTG) deteriorate overall naming, confirming previous work; more notably, (ii) lesions comprising the inferior frontal hub (inferior frontal gyrus, IFG) of the language-network increase the interference effect for the categorical condition; on the contrary, (iii) lesions to the mid-to-posterior temporal hub (posterior middle and superior temporal gyri, pMTG/ pSTG) increase the facilitatory effect for the associative condition on error rates. The findings can be accommodated in a neuro-linguistic framework, which localizes lexical activation but also lexical interference in posterior parts of the language network (pMTG/pITG); conversely, selection between co-activated categorically related entries is afforded by frontal language areas (IFG). While purely experimental in nature our study highlights that lesion site differentially influences specific aspects of word retrieval. Since confrontational naming is a cornerstone of aphasia rehabilitation, this may be of note when designing and evaluating novel therapeutic regimes.

The psychological reality of picture name agreement

Picture name agreement is commonly used as both a control variable and independent variable in studies of language production. It describes the proportion of participants who volunteer a picture's modal name in a norming study-a population-level descriptor-but researchers often assume that name agreement also indexes cognitive processes that occur within individuals. For instance, if norms show that 50% of speakers name a picture as couch, then each time a person tries to name the picture, they might have a 50% chance of selecting couch. An alternative, however, is that name agreement may simply reflect population-level sampling of more stable individual preferences (e.g., 50% of speakers prefer the name couch), continually developed through experience. One way to distinguish between these possibilities - and assess the psychological reality of name agreement - is simply to re-norm pictures with the same individuals. In Experiment 1, we therefore collected timed naming norms for a large set of line drawings from the same 25 native British English speakers twice, 1-2 weeks apart. Results show participants' name choices in Session 2 are jointly predicted by population-level name agreement, from our previous norms, and individuals' own productions in Session 1. Experiment 2 replicated this result and further showed that prior selections predicted Session 3 outcomes better than those in Session 2, in line with an incremental learning account. This is the first direct demonstration that picture name agreement has some psychological validity, but also reveals that it does not directly index within-participant lexical competition as previously assumed.

On the lexical representation of compound nouns: Evidence from a picture-naming task with compound targets and gender-marked determiner primes in aphasia

Our study examines the lexical representation and processing of compounds in participants with aphasia (PWA) and language-unimpaired control speakers. Participants were engaged in primed picture-naming in German, a language that marks for grammatical gender. Gender-marked determiners served as primes (der_masc, die_fem, das_neut [the]) and noun-noun compounds as targets (e.g., Gold_neutfisch_masc [goldfish]). Experiment 1 tested whether the compound's constituents are activated at a lexical-syntactic level during production. Primes were gender-congruent either with the morphological head of the target compound (e.g., der_masc for the target Gold_neutfisch_masc), or its modifier (das_neut for Gold_neutfisch_masc), or incongruent with both (die_fem). Head congruency of prime and target produced strong facilitatory effects across groups. Modifier congruent primes produced contrasting effects. Modifier congruency speeded up picture naming in the controls and PWA with isolated deficits of lexical access (PWA-lex) but they delayed picture naming in PWA with additional deficits of phonological encoding (PWA-pho). Both patterns suggest that the lemmas of both constituents of compound targets and their grammatical gender are activated during compound retrieval, in line with a multiple-lemma representation of compounds. Experiment 2 explored the nature of the observed effects compared to a gender-neutral control condition. While facilitatory effects were shown by PWA-lex and the controls, PWA-pho did not profit from congruent primes but showed inhibitory effects by incongruent primes, exclusively. Inhibitory effects were also attested for the controls but not for PWA-lex. The functional origin of determiner priming effects and their theoretical and clinical implications are discussed in the framework of current accounts.

Semantic priming and neurobiology in schizophrenia: A theoretical review

In this theoretical review we bridge the cognitive and neurobiological sciences to shed light on the neurocognitive foundations of the semantic priming effect in schizophrenia. We review and theoretically evaluate the neurotransmitter systems (dopaminergic, GABAergic and glutamatergic) and neurobiological underpinnings of behavioural and electrophysiological (N400) semantic priming in the pathology, and the main hypotheses on their geneses: a disinhibition of the semantic spread of activation, a disorganised semantic storage or noisy lexical-semantic associations, a psychomotor artefact, an artefact of relatedness proportions, or an inability to mobilise contextual information. We further assess the literature on the endophenotype of Formal Thought Disorder from multiple standpoints, ranging from neurophysiology to cognition: considerations are weaved on neuronal (PV basket cell, SST, VIP) and receptor deficits (DRD1, NMDA), neurotransmitter imbalances (dopamine), cortical and dopaminergic lateralisation, inter alia. In conclusion, we put forth novel postulates on the underlying causes of controlled hypopriming, automatic hyperpriming, N400 reversals (larger amplitudes for close associations), indirect versus direct hyperpriming, and the endophenotype of lexical-semantic disturbances in schizophrenia.

Within-language lexical interference can be resolved in a similar way to between-language interference

This study asks if monolinguals can resolve lexical interference within a language with mechanisms similar to those used by bilinguals to resolve interference across languages. These mechanisms are known as bilingual language control, are assumed to be at least in part top-down, and are typically studied with cued language mixing, a version of which we use here. Balanced (Experiment 1) and nonbalanced Spanish-English bilinguals (Experiment 2) named pictures in each of their languages. English monolinguals from two different American cities (Experiments 3 and 4) named pictures in English only with either basic-level (e.g., shoe) or subordinate names (e.g., sneaker). All experiments were identically structured and began with blocked naming in each language or name type, followed by trial-level switching between the two languages or name types, followed again by blocked naming. We analyzed switching, mixing and (introduced here) post-mixing costs, dominance effects and repetition benefits. In the bilingual experiments, we found some signs of dominant deprioritization, the behavioral hallmark of bilingual language control: larger costs for dominant- than for nondominant-language names. Crucially, in the monolingual experiments, we also found signs of dominant deprioritization: larger costs for basic-level than for subordinate names. Unexpectedly and only in the monolingual experiments, we also found a complete dominance reversal: Basic-level names (which otherwise behaved as dominant) were produced more slowly overall than subordinate names. Taken together, these results are hard to explain with the bottom-up mechanisms typically assumed for monolingual interference resolution. We thus conclude that top-down mechanisms might (sometimes) be involved in lexical interference resolution not only between languages but also within a language.

Robots facilitate human language production

Despite recent developments in integrating autonomous and human-like robots into many aspects of everyday life, social interactions with robots are still a challenge. Here, we focus on a central tool for social interaction: verbal communication. We assess the extent to which humans co-represent (simulate and predict) a robot's verbal actions. During a joint picture naming task, participants took turns in naming objects together with a social robot (Pepper, Softbank Robotics). Previous findings using this task with human partners revealed internal simulations on behalf of the partner down to the level of selecting words from the mental lexicon, reflected in partner-elicited inhibitory effects on subsequent naming. Here, with the robot, the partner-elicited inhibitory effects were not observed. Instead, naming was facilitated, as revealed by faster naming of word categories co-named with the robot. This facilitation suggests that robots, unlike humans, are not simulated down to the level of lexical selection. Instead, a robot's speaking appears to be simulated at the initial level of language production where the meaning of the verbal message is generated, resulting in facilitated language production due to conceptual priming. We conclude that robots facilitate core conceptualization processes when humans transform thoughts to language during speaking.

Behavioral and Brain Responses Highlight the Role of Usage in the Preparation of Multiword Utterances for Production

Usage-based theories assume that all aspects of language processing are shaped by the distributional properties of the language. The frequency not only of words but also of larger chunks plays a major role in language processing. These theories predict that the frequency of phrases influences the time needed to prepare these phrases for production and their acoustic duration. By contrast, dominant psycholinguistic models of utterance production predict no such effects. In these models, the system keeps track of the frequency of individual words but not of co-occurrences. This study investigates the extent to which the frequency of phrases impacts naming latencies and acoustic duration with a balanced design, where the same words are recombined to build high- and low-frequency phrases. The brain signal of participants is recorded so as to obtain information on the electrophysiological bases and functional locus of frequency effects. Forty-seven participants named pictures using high- and low-frequency adjective-noun phrases. Naming latencies were shorter for high-frequency than low-frequency phrases. There was no evidence that phrase frequency impacted acoustic duration. The electrophysiological signal differed between high- and low-frequency phrases in time windows that do not overlap with conceptualization or articulation processes. These findings suggest that phrase frequency influences the preparation of phrases for production, irrespective of the lexical properties of the constituents, and that this effect originates at least partly when speakers access and encode linguistic representations. Moreover, this study provides information on how the brain signal recorded during the preparation of utterances changes with the frequency of word combinations.

Semantic Interference through Multiple Distractors in Picture Naming in People with Aphasia

When we refer to an object or concept by its name, activation of semantic and categorical information is necessary to retrieve the correct lexical representation. Whereas in neurotypical individuals it is well established that semantic context can interfere with or facilitate lexical retrieval, these effects are much less studied in people with lesions to the language network and impairment at different steps of lexical-semantic processing. Here, we applied a novel picture naming paradigm, where multiple categorically related and unrelated words were presented as distractors before a to-be-named target picture. Using eye tracking, we investigated preferential fixation on the cohort members versus nonmembers. Thereby, we can judge the impact of explicit acknowledgment of the category and its effect on semantic interference. We found that, in contrast to neurotypical participants [van Scherpenberg, C., Abdel Rahman, R., & Obrig, H. A novel multiword paradigm for investigating semantic context effects in language production. PLoS One, 15, e0230439, 2020], participants suffering from mild to moderate aphasia did not show a fixation preference on category members but still showed a large interference effect of ∼35 msec, confirming the implicit mechanism of categorical interference. However, preferential fixation on the categorically related cohort words correlated with clinical tests regarding nonverbal semantic abilities and integrity of the anterior temporal lobe. This highlights the role of supramodal semantics for explicit recognition of a semantic category, while semantic interference is triggered if the threshold of lexical cohort activation is reached. Confirming psycholinguistic evidence, the demonstration of a large and persistent interference effect through implicit lexico-semantic activation is important to understand deficits in people with a lesion in thelanguage network, potentially relevant for individualized intervention aiming at improving naming skills.

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.

Interference effects of phonological similarity in word production arise from competitive incremental learning

In the blocked cyclic naming task, native Mandarin speakers named pictures with disyllabic names in small sets and blocks, with the critical manipulation whether pictures within a block shared an atonal syllable or not. We found the expected facilitation when the overlapping portion of responses was in word-initial position, but we also replicated a recent observation that with 'inconsistent' overlap (shared syllables could be either in first or second word position), form overlap causes interference. Crucially, interference also occurred when phonologically unrelated filler trials or trials which required a nonlinguistic response were interleaved with the critical pictures. The same pattern was found with written responses and orthographic radical overlap. The results are best explained via "competitive incremental learning" between lexical and phonological representations. A computer simulation confirms that this principle generates interference, and that the result is unaffected by filler trials. We conclude that incremental learning constitutes a universal principle in the mapping from semantics to phonology in language production.

Effects of semantic variables on word production in aphasia

Words differ in the complexity of their semantic representations and their relationships to other words and these differences can be operationalised as a variety of semantic variables. The research presented here investigates how word production in aphasia is influenced by six feature-based semantic variables (number of near semantic neighbours, semantic similarity, number of semantic features, typicality, intercorrelational density, and distinctiveness). Previous research has reported inconsistent findings for some of the semantic variables, while others have not been previously studied in aphasia. Spoken picture naming data from a large group of individuals with aphasia with mixed spoken word production impairments (n = 175) and a sub-group who produced few phonological errors (n = 60) was analysed. We examined effects of the semantic variables on overall naming accuracy and on the occurrence of different error types (semantic errors overall, coordinate errors, omissions), while controlling for other psycholinguistic variables using generalised linear mixed effects models and Bayesian correlations. Across analyses, number of semantic features was the most important predictor with a facilitatory main effect on naming accuracy in the sub-group analysis. Number of semantic features, along with typicality and semantic similarity, also predicted error types and in some analyses these effects depended on the integrity of semantic processing. Effects of the semantic variables and their theoretical explanations and implications are discussed in light of previous research and models of word production.

Evidence of impaired naming in patients with hippocampal amnesia

Object naming involves accessing meaning and retrieving the associated word form from remote semantic memory. Historically, previously acquired semantic knowledge (i.e., remote semantic memory) was thought to be independent of the hippocampus via neocortical consolidation. This view is based on evidence demonstrating a dissociation in behavior in patients with hippocampal amnesia: amnesic patients are impaired in acquiring new vocabulary yet can name and define previously acquired words. More recently, the view that remote semantic memory is hippocampus-independent has been challenged by the documentation of disruptions in aspects of remote semantic memory in patients with hippocampal amnesia, particularly in language use and depth of semantic knowledge. Based on these findings, we hypothesized that the hippocampus plays a long-term role in remote semantic memory. We tested amnesic patients and demographically matched healthy comparison participants in an extensive naming task using photographic images of objects normalized for familiarity, object agreement, and visual complexity. Amnesic patients were less likely to correctly name objects than healthy comparison participants. Further, amnesic patients' performance worsened for words that were less familiar, more visually complex, and had less object agreement. These findings suggest that the hippocampus may play a long-term role in semantic memory processes, rather than a time-limited role in the initial acquisition of semantic information, and that hippocampal damage can disrupt object naming.

Cumulative semantic cost without successful naming

Accessing semantic information has negative consequences for successive recovering attempts of similar information. For instance, in the course of picture-naming tasks, the time required to name an object is determined by the total number of items from the same category that have already been named; naming latencies increase proportionally to the total number of semantically related words named previously. This phenomenon is called cumulative semantic cost (or interference). Two picture-naming experiments with children (4–11 years old, 229 participants) investigate whether having successfully named the previous within-category items is a necessary condition for the cumulative semantic cost to appear. We anticipated that younger children would have a larger rate of nonresponses compared with older children, reflecting the fact that younger children have not yet consolidated many lexical representations. Our results confirmed this prediction. Critically, we also observed that cumulative semantic cost was independent of having successfully retrieved previous within-category lexical items. Furthermore, picture trials for which the previous within-category item elicited a nonresponse showed the same amount of cost as those picture trials for which the previous within-category item elicited a correct naming event. Our findings indicate that it is the attempt to retrieve a lexical unit, and not the successful retrieval of a specific lexical unit, that causes semantic cost in picture naming. This cost can be explained by a mechanism of weakening the semantic-to-lexical mappings of semantic coordinate words. The findings are also discussed in the context of retrieval-induced forgetting effects in memory recall research.

Morphological facilitation and semantic interference in compound production: An ERP study

This study investigates the production of nominal compounds (Experiment 1) and simple nouns (Experiment 2) in a picture-word interference (PWI) paradigm to test models of morpho-lexical representation and processing. The continuous electroencephalogram (EEG) was registered and event-related brain potentials [ERPs] were analyzed in addition to picture-naming latencies. Experiment 1 used morphologically and semantically related distractor words to tap into different pre-articulatory planning stages during compound production. Relative to unrelated distractors, naming was speeded when distractors corresponded to morphemes of the compound (sun or flower for the target sunflower), but slowed when distractors were from the same semantic category as the compound (tulip ➔ sunflower). Distractors from the same category as the compound's first constituent (moon ➔ sunflower) had no influence. The diverging effects for semantic and morphological distractors replicate results from earlier studies. ERPs revealed different effects of morphological and semantic distractors with an interesting time course: morphological effects had an earlier onset. Comparable to the naming latencies, no ERP effects were obtained for distractors from the same semantic category as the compound's first constituent. Experiment 2 investigated the effectiveness of the latter distractors, presenting them with pictures of the compounds' first constituents (e.g., moon ➔ sun). Interference was confirmed both behaviorally and in the ERPs, showing that the absence of an effect in Experiment 1 was not due to the materials used. Considering current models of speech production, the data are best explained by a cascading flow of activation throughout semantic, lexical and morpho-phonological steps of speech planning.