Studying Individual Differences in Language Comprehension: The Challenges of Item-Level Variability and Well-Matched Control Conditions.

Translating experimental tasks that were designed to investigate differences between conditions at the group-level into valid and reliable instruments to measure individual differences in cognitive skills is challenging (Hedge et al., 2018; Rouder et al., 2019; Rouder & Haaf, 2019). For psycholinguists, the additional complexities associated with selecting or constructing language stimuli, and the need for appropriate well-matched baseline conditions make this endeavour particularly complex. In a typical experiment, a process-of-interest (e.g. ambiguity resolution) is targeted by contrasting performance in an experimental condition with performance in a well-matched control condition. In many cases, careful between-condition matching precludes the same participant from encountering all stimulus items. Unfortunately, solutions that work for group-level research (e.g. constructing counterbalanced experiment versions) are inappropriate for individual-differences designs. As a case study, we report an ambiguity resolution experiment that illustrates the steps that researchers can take to address this issue and assess whether their measurement instrument is both valid and reliable. On the basis of our findings, we caution against the widespread approach of using datasets from group-level studies to also answer important questions about individual differences.

Erratum: "Causal Contributions of the Domain-General (Multiple Demand) and the Language-Selective Brain Networks to Perceptual and Semantic Challenges in Speech Comprehension".

[This corrects the article DOI: 10.1162/nol_a_00081.].

The Role of Sleep in Learning New Meanings for Familiar Words through Stories.

Adults often learn new meanings for familiar words, and in doing so they must integrate information about the newly-acquired meanings with existing knowledge about the prior meanings of the words in their mental lexicon. Numerous studies have confirmed the importance of sleep for learning novel word forms (e.g., "cathedruke") either with or without associated meanings. By teaching participants new meanings for familiar word forms, this is the first study to focus exclusively on the specific role of sleep on learning word meanings. In two experiments participants were trained on new meanings for familiar words through a naturalistic story reading paradigm to minimize explicit learning strategies. Experiment 1 confirmed the benefit of sleep for recall and recognition of word meanings, with better retention after 12 hours including overnight sleep than 12 hours awake. Experiment 2, which was preregistered, further explored this sleep benefit. Recall performance was best in the condition in which participants slept immediately after exposure and were tested soon after they woke up, compared with three conditions which all included an extended period of wake during which they would encounter their normal language environment. The results are consistent with the view that, at least under these learning conditions, a benefit of sleep arises due to passive protection from linguistic interference while asleep, rather than being due to active consolidation.

Diversity of narrative context disrupts the early stage of learning the meanings of novel words.

High quality lexical representations develop through repeated exposures to words in different contexts. This preregistered experiment investigated how diversity of narrative context affects the earliest stages of word learning via reading. Adults (N = 100) learned invented meanings for eight pseudowords, which each occurred in five written paragraphs either within a single coherent narrative context or five different narrative contexts. The words' semantic features were controlled across conditions to avoid influences from polysemy (lexical ambiguity). Posttests included graded measures of word-form recall (spelling accuracy) and recognition (multiple choice), and word-meaning recall (number of semantic features). Diversity of narrative context did not affect word-form learning, but more semantic features were correctly recalled for words trained in a single context. These findings indicate that learning the meanings of novel words is initially boosted by anchoring them to a single coherent narrative discourse.

Episodic memory and sleep are involved in the maintenance of context-specific lexical information.

Familiar words come with a wealth of associated knowledge about their variety of usage, accumulated over a lifetime. How do we track and adjust this knowledge as new instances of a word are encountered? A recent study (Cognition) found that, for homonyms (e.g., bank), sleep-associated consolidation facilitates the updating of meaning dominance. Here, we tested the generality of this finding by exposing participants to (Experiment 1; N = 125) nonhomonyms (e.g., bathtub) in sentences that biased their meanings toward a specific interpretation (e.g., bathtub-slip vs. bathtub-relax), and (Experiment 2; N = 128) word-class ambiguous words (e.g., loan) in sentences where the words were used in their dispreferred word class (e.g., "He will loan me money"). Both experiments showed that such sentential experience influenced later interpretation and usage of the words more after a night's sleep than a day awake. We interpret these results as evidence for a general role of episodic memory in language comprehension such that new episodic memories are formed every time a sentence is comprehended, and these memories contribute to lexical processing next time the word is encountered, as well as potentially to the fine-tuning of long-term lexical knowledge. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Contextual diversity during word learning through reading benefits generalisation of learned meanings to new contexts.

From mid-childhood onwards, most new words are learned through reading. The precise meaning of many words depends upon the linguistic context in which they are encountered, which readers use to infer the appropriate interpretation. However, it is unclear what features of these linguistic contexts best support learning of new word meanings. We investigated whether learning words in contextually diverse sentences benefits word form and meaning learning in adults (n = 239). Participants learned meanings for 8 pseudowords through reading 10 sentences about each. Four pseudowords were learned in a diverse condition (10 sentences on different topics) and four were learned in a non-diverse condition (10 sentences on the same topic). An old-new decision post-test indicated that diversity did not influence word form learning. In a second post-test, participants chose which trained pseudoword completed a sentence from either an unfamiliar, untrained context, or a familiar, trained context. For familiar contexts, accuracy was higher for pseudowords learned in the non-diverse condition, but for unfamiliar contexts, accuracy was higher for pseudowords learned in the diverse condition. These results suggest that diverse contexts may promote development of flexible, decontextualised meaning representations that are easier to generalise to new contexts. Conversely, non-diverse contexts may favour extraction of context-bound representations that are more easily used in the same context.

Learning about the meanings of ambiguous words: evidence from a word-meaning priming paradigm with short narratives.

Fluent language comprehension requires people to rapidly activate and integrate context-appropriate word meanings. This process is challenging for meanings of ambiguous words that are comparatively lower in frequency (e.g., the "bird" meaning of "crane"). Priming experiments have shown that recent experience makes such subordinate (less frequent) word meanings more readily available at the next encounter. These experiments used lists of unconnected sentences in which each ambiguity was disambiguated locally by neighbouring words. In natural language, however, disambiguation may occur via more distant contextual cues, embedded in longer, connected communicative contexts. In the present experiment, participants (N = 51) listened to 3-sentence narratives that ended in an ambiguous prime. Cues to disambiguation were relatively distant from the prime; the first sentence of each narrative established a situational context congruent with the subordinate meaning of the prime, but the remainder of the narrative did not provide disambiguating information. Following a short delay, primed subordinate meanings were more readily available (compared with an unprimed control), as assessed by responses in a word association task related to the primed meaning. This work confirms that listeners reliably disambiguate spoken ambiguous words on the basis of cues from wider narrative contexts, and that they retain information about the outcome of these disambiguation processes to inform subsequent encounters of the same word form.

Dominance Norms and Data for Spoken Ambiguous Words in British English.

Words with multiple meanings (e.g. bark of the tree/dog) have provided important insights into several key topics within psycholinguistics. Experiments that use ambiguous words require stimuli to be carefully controlled for the relative frequency (dominance) of their different meanings, as this property has pervasive effects on numerous tasks. Dominance scores are often calculated from word association responses: by measuring the proportion of participants who respond to the word 'bark' with dog-related (e.g. "woof") or tree-related (e.g. "branch") responses, researchers can estimate people's relative preferences for these meanings. We collated data from a number of recent experiments and pre-tests to construct a dataset of 29,542 valid responses for 243 spoken ambiguous words from participants from the United Kingdom. We provide summary dominance data for the 182 ambiguous words that have a minimum of 100 responses, and a tool for automatically coding new word association responses based on responses in our coded set, which allows additional data to be more easily scored and added to this database. All files can be found at: https://osf.io/uy47w/.

Word-meaning priming extends beyond homonyms.

When a homonym (e.g., bark) is encountered in a sentential context that biases its interpretation towards a less frequent meaning, subsequent interpretations of the word are more likely to favour that subordinate meaning. Such word-meaning priming effects have been shown to be maintained via sleep-related consolidation, leading some to suggest that declarative memory systems play a crucial role in language comprehension, providing a relatively enduring contextually bound memory trace for the ambiguous word. By this account, word-meaning priming effects should be observable for all words, not just homonyms. In three experiments, participants were exposed to non-homonym targets (e.g., "balloon") in sentences that biased interpretation towards a specific aspect of the word's meaning (e.g., balloon­helium vs. balloon-float). After a ~ 10-30 min delay, the targets were presented in relatedness judgement and associate production tasks to assess whether the sentential contexts enhanced access to the primed aspect of the word's meaning. The results reveal that word-meaning priming effects do extend to non-homonyms. Indeed, there was also some evidence of a more generalised priming that did not rely on prior presentation of the non-homonym itself. We argue that context-specific interpretations of words are maintained during recognition in order to facilitate comprehension over longer periods.

Causal Contributions of the Domain-General (Multiple Demand) and the Language-Selective Brain Networks to Perceptual and Semantic Challenges in Speech Comprehension.

Listening to spoken language engages domain-general multiple demand (MD; frontoparietal) regions of the human brain, in addition to domain-selective (frontotemporal) language regions, particularly when comprehension is challenging. However, there is limited evidence that the MD network makes a functional contribution to core aspects of understanding language. In a behavioural study of volunteers (n = 19) with chronic brain lesions, but without aphasia, we assessed the causal role of these networks in perceiving, comprehending, and adapting to spoken sentences made more challenging by acoustic-degradation or lexico-semantic ambiguity. We measured perception of and adaptation to acoustically degraded (noise-vocoded) sentences with a word report task before and after training. Participants with greater damage to MD but not language regions required more vocoder channels to achieve 50% word report, indicating impaired perception. Perception improved following training, reflecting adaptation to acoustic degradation, but adaptation was unrelated to lesion location or extent. Comprehension of spoken sentences with semantically ambiguous words was measured with a sentence coherence judgement task. Accuracy was high and unaffected by lesion location or extent. Adaptation to semantic ambiguity was measured in a subsequent word association task, which showed that availability of lower-frequency meanings of ambiguous words increased following their comprehension (word-meaning priming). Word-meaning priming was reduced for participants with greater damage to language but not MD regions. Language and MD networks make dissociable contributions to challenging speech comprehension: Using recent experience to update word meaning preferences depends on language-selective regions, whereas the domain-general MD network plays a causal role in reporting words from degraded speech.

Learning new word meanings from story reading: the benefit of immediate testing.

This study investigated how word meanings can be learned from natural story reading. Three experiments with adult participants compared naturalistic incidental learning with intentional learning of new meanings for familiar words, and examined the role of immediate tests in maintaining memory of new word meanings. In Experiment 1, participants learned new meanings for familiar words through incidental (story reading) and intentional (definition training task) conditions. Memory was tested with cued recall of meanings and multiple-choice meaning-to-word matching immediately and 24 h later. Results for both measures showed higher accuracy for intentional learning, which was also more time efficient than incidental learning. However, there was reasonably good learning from both methods, and items learned incidentally through stories appeared less susceptible to forgetting over 24 h. It was possible that retrieval practice at the immediate test may have aided learning and improved memory of new word meanings 24 h later, especially for the incidental story reading condition. Two preregistered experiments then examined the role of immediate testing in long-term retention of new meanings for familiar words. There was a strong testing effect for word meanings learned through intentional and incidental conditions (Experiment 2), which was non-significantly larger for items learned incidentally through stories. Both cued recall and multiple-choice tests were each individually sufficient to enhance retention compared to having no immediate test (Experiment 3), with a larger learning boost from multiple-choice. This research emphasises (i) the resilience of word meanings learned incidentally through stories and (ii) the key role that testing can play in boosting vocabulary learning from story reading.

Recovery from misinterpretations during online sentence processing.

Misinterpretations during language comprehension are common. The ability to recover from processing difficulties is therefore crucial for successful day-to-day communication. Previous research on the recovery from misinterpretations has focused on sentences containing syntactic ambiguities. The present study instead investigated the outcome of comprehension processes and online reading behavior when misinterpretations occurred due to lexical-semantic ambiguity. Ninety-six adult participants read "garden-path" sentences in which an ambiguous word was disambiguated toward an unexpected meaning (e.g., "The ball was crowded"), while their eye movements were monitored. A meaning coherence judgment task required them to decide whether or not each sentence made sense. Results suggested that readers did not always engage in reinterpretation processes but instead followed a "good enough" processing strategy. Successful detection of a violation of sentence coherence and associated reinterpretation processes also required additional processing time compared to sentences that did not induce a misinterpretation. Although these reinterpretation-related processing costs were relatively stable across individuals, there was some evidence to suggest that readers with greater lexical expertise benefited from greater sensitivity to the disambiguating information, and were able to flexibly adapt their online reading behavior to recover from misinterpretations more efficiently. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Pupil Dilation Is Sensitive to Semantic Ambiguity and Acoustic Degradation.

Speech comprehension is challenged by background noise, acoustic interference, and linguistic factors, such as the presence of words with more than one meaning (homonyms and homophones). Previous work suggests that homophony in spoken language increases cognitive demand. Here, we measured pupil dilation-a physiological index of cognitive demand-while listeners heard high-ambiguity sentences, containing words with more than one meaning, or well-matched low-ambiguity sentences without ambiguous words. This semantic-ambiguity manipulation was crossed with an acoustic manipulation in two experiments. In Experiment 1, sentences were masked with 30-talker babble at 0 and +6 dB signal-to-noise ratio (SNR), and in Experiment 2, sentences were heard with or without a pink noise masker at -2 dB SNR. Speech comprehension was measured by asking listeners to judge the semantic relatedness of a visual probe word to the previous sentence. In both experiments, comprehension was lower for high- than for low-ambiguity sentences when SNRs were low. Pupils dilated more when sentences included ambiguous words, even when no noise was added (Experiment 2). Pupil also dilated more when SNRs were low. The effect of masking was larger than the effect of ambiguity for performance and pupil responses. This work demonstrates that the presence of homophones, a condition that is ubiquitous in natural language, increases cognitive demand and reduces intelligibility of speech heard with a noisy background.

Settling Into Semantic Space: An Ambiguity-Focused Account of Word-Meaning Access.

Most words are ambiguous: Individual word forms (e.g., run) can map onto multiple different interpretations depending on their sentence context (e.g., the athlete/politician/river runs). Models of word-meaning access must therefore explain how listeners and readers can rapidly settle on a single, contextually appropriate meaning for each word that they encounter. I present a new account of word-meaning access that places semantic disambiguation at its core and integrates evidence from a wide variety of experimental approaches to explain this key aspect of language comprehension. The model has three key characteristics. (a) Lexical-semantic knowledge is viewed as a high-dimensional space; familiar word meanings correspond to stable states within this lexical-semantic space. (b) Multiple linguistic and paralinguistic cues can influence the settling process by which the system resolves on one of these familiar meanings. (c) Learning mechanisms play a vital role in facilitating rapid word-meaning access by shaping and maintaining high-quality lexical-semantic knowledge throughout the life span. In contrast to earlier models of word-meaning access, I highlight individual differences in lexical-semantic knowledge: Each person's lexicon is uniquely structured by specific, idiosyncratic linguistic experiences.

The Neural Time Course of Semantic Ambiguity Resolution in Speech Comprehension.

Semantically ambiguous words challenge speech comprehension, particularly when listeners must select a less frequent (subordinate) meaning at disambiguation. Using combined magnetoencephalography (MEG) and EEG, we measured neural responses associated with distinct cognitive operations during semantic ambiguity resolution in spoken sentences: (i) initial activation and selection of meanings in response to an ambiguous word and (ii) sentence reinterpretation in response to subsequent disambiguation to a subordinate meaning. Ambiguous words elicited an increased neural response approximately 400-800 msec after their acoustic offset compared with unambiguous control words in left frontotemporal MEG sensors, corresponding to sources in bilateral frontotemporal brain regions. This response may reflect increased demands on processes by which multiple alternative meanings are activated and maintained until later selection. Disambiguating words heard after an ambiguous word were associated with marginally increased neural activity over bilateral temporal MEG sensors and a central cluster of EEG electrodes, which localized to similar bilateral frontal and left temporal regions. This later neural response may reflect effortful semantic integration or elicitation of prediction errors that guide reinterpretation of previously selected word meanings. Across participants, the amplitude of the ambiguity response showed a marginal positive correlation with comprehension scores, suggesting that sentence comprehension benefits from additional processing around the time of an ambiguous word. Better comprehenders may have increased availability of subordinate meanings, perhaps due to higher quality lexical representations and reflected in a positive correlation between vocabulary size and comprehension success.

A Database of Dutch-English Cognates, Interlingual Homographs and Translation Equivalents.

To investigate the structure of the bilingual mental lexicon, researchers in the field of bilingualism often use words that exist in multiple languages: cognates (which have the same meaning) and interlingual homographs (which have a different meaning). A high proportion of these studies have investigated language processing in Dutch-English bilinguals. Despite the abundance of research using such materials, few studies exist that have validated such materials. We conducted two rating experiments in which Dutch-English bilinguals rated the meaning, spelling and pronunciation similarity of pairs of Dutch and English words. On the basis of these results, we present a new database of Dutch-English identical cognates (e.g. "wolf"-"wolf"; n = 58), non-identical cognates (e.g. "kat"-"cat"; n = 74), interlingual homographs (e.g. "angel"-"angel"; n = 72) and translation equivalents (e.g. "wortel"-"carrot"; n = 78). The database can be accessed at http://osf.io/tcdxb/.

Towards a distributed connectionist account of cognates and interlingual homographs: evidence from semantic relatedness tasks.

BACKGROUND: Current models of how bilinguals process cognates (e.g., "wolf", which has the same meaning in Dutch and English) and interlingual homographs (e.g., "angel", meaning "insect's sting" in Dutch) are based primarily on data from lexical decision tasks. A major drawback of such tasks is that it is difficult-if not impossible-to separate processes that occur during decision making (e.g., response competition) from processes that take place in the lexicon (e.g., lateral inhibition). Instead, we conducted two English semantic relatedness judgement experiments. METHODS: In Experiment 1, highly proficient Dutch-English bilinguals (N = 29) and English monolinguals (N = 30) judged the semantic relatedness of word pairs that included a cognate (e.g., "wolf"-"howl"; n = 50), an interlingual homograph (e.g., "angel"-"heaven"; n = 50) or an English control word (e.g., "carrot"-"vegetable"; n = 50). In Experiment 2, another group of highly proficient Dutch-English bilinguals (N = 101) read sentences in Dutch that contained one of those cognates, interlingual homographs or the Dutch translation of one of the English control words (e.g., "wortel" for "carrot") approximately 15 minutes prior to completing the English semantic relatedness task. RESULTS: In Experiment 1, there was an interlingual homograph inhibition effect of 39 ms only for the bilinguals, but no evidence for a cognate facilitation effect. Experiment 2 replicated these findings and also revealed that cross-lingual long-term priming had an opposite effect on the cognates and interlingual homographs: recent experience with a cognate in Dutch speeded processing of those items 15 minutes later in English but slowed processing of interlingual homographs. However, these priming effects were smaller than previously observed using a lexical decision task. CONCLUSION: After comparing our results to studies in both the bilingual and monolingual domain, we argue that bilinguals appear to process cognates and interlingual homographs as monolinguals process polysemes and homonyms, respectively. In the monolingual domain, processing of such words is best modelled using distributed connectionist frameworks. We conclude that it is necessary to explore the viability of such a model for the bilingual case. DATA SCRIPTS MATERIALS AND PRE-REGISTRATIONS: Experiment 1: http://www.osf.io/ndb7p; Experiment 2: http://www.osf.io/2at49.

Contextual priming of word meanings is stabilized over sleep.

Evidence is growing for the involvement of consolidation processes in the learning and retention of language, largely based on instances of new linguistic components (e.g., new words). Here, we assessed whether consolidation effects extend to the semantic processing of highly familiar words. The experiments were based on the word-meaning priming paradigm in which a homophone is encountered in a context that biases interpretation towards the subordinate meaning. The homophone is subsequently used in a word-association test to determine whether the priming encounter facilitates the retrieval of the primed meaning. In Experiment 1 (N = 74), we tested the resilience of priming over periods of 2 and 12 h that were spent awake or asleep, and found that sleep periods were associated with stronger subsequent priming effects. In Experiment 2 (N = 55) we tested whether the sleep benefit could be explained in terms of a lack of retroactive interference by testing participants 24 h after priming. Participants who had the priming encounter in the evening showed stronger priming effects after 24 h than participants primed in the morning, suggesting that sleep makes priming resistant to interference during the following day awake. The results suggest that consolidation effects can be found even for highly familiar linguistic materials. We interpret these findings in terms of a contextual binding account in which all language perception provides a learning opportunity, with sleep and consolidation contributing to the updating of our expectations, ready for the next day.

Listeners and readers generalize their experience with word meanings across modalities.

Research has shown that adults' lexical-semantic representations are surprisingly malleable. For instance, the interpretation of ambiguous words (e.g., bark) is influenced by experience such that recently encountered meanings become more readily available (Rodd et al., 2016, 2013). However, the mechanism underlying this word-meaning priming effect remains unclear, and competing accounts make different predictions about the extent to which information about word meanings that is gained within one modality (e.g., speech) is transferred to the other modality (e.g., reading) to aid comprehension. In two Web-based experiments, ambiguous target words were primed with either written or spoken sentences that biased their interpretation toward a subordinate meaning, or were unprimed. About 20 min after the prime exposure, interpretation of these target words was tested by presenting them in either written or spoken form, using word association (Experiment 1, N = 78) and speeded semantic relatedness decisions (Experiment 2, N = 181). Both experiments replicated the auditory unimodal priming effect shown previously (Rodd et al., 2016, 2013) and revealed significant cross-modal priming: primed meanings were retrieved more frequently and swiftly across all primed conditions compared with the unprimed baseline. Furthermore, there were no reliable differences in priming levels between unimodal and cross-modal prime-test conditions. These results indicate that recent experience with ambiguous word meanings can bias the reader's or listener's later interpretation of these words in a modality-general way. We identify possible loci of this effect within the context of models of long-term priming and ambiguity resolution. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Retuning of lexical-semantic representations: Repetition and spacing effects in word-meaning priming.

Current models of word-meaning access typically assume that lexical-semantic representations of ambiguous words (e.g., 'bark of the dog/tree') reach a relatively stable state in adulthood, with only the relative frequencies of meanings and immediate sentence context determining meaning preference. However, recent experience also affects interpretation: recently encountered word-meanings become more readily available (Rodd et al., 2016, 2013). Here, 3 experiments investigated how multiple encounters with word-meanings influence the subsequent interpretation of these ambiguous words. Participants heard ambiguous words contextually-disambiguated towards a particular meaning and, after a 20- to 30-min delay, interpretations of the words were tested in isolation. We replicate the finding that 1 encounter with an ambiguous word biased the later interpretation of this word towards the primed meaning for both subordinate (Experiments 1, 2, 3) and dominant meanings (Experiment 1). In addition, for the first time, we show cumulative effects of multiple repetitions of both the same and different meanings. The effect of a single subordinate exposure persisted after a subsequent encounter with the dominant meaning, compared to a dominant exposure alone (Experiment 1). Furthermore, 3 subordinate word-meaning repetitions provided an additional boost to priming compared to 1, although only when their presentation was spaced (Experiments 2, 3); massed repetitions provided no such boost (Experiments 1, 3). These findings indicate that comprehension is guided by the collective effect of multiple recently activated meanings and that the spacing of these activations is key to producing lasting updates to the lexical-semantic network. (PsycINFO Database Record