Rational adaptation in word production: Strong conceptual ability reduces the effect of lexical impairments on verb retrieval in aphasia.

Language users rely on both linguistic and conceptual processing abilities to efficiently comprehend or produce language. According to the principle of rational adaptation, the degree to which a cognitive system relies on one process vs. another can change under different conditions or disease states with the goal of optimizing behavior. In this study, we investigated rational adaptation in reliance on linguistic versus conceptual processing in aphasia, an acquired disorder of language. In individuals living with aphasia, verb-retrieval impairments are a pervasive deficit that negatively impacts communicative function. As such, we examined evidence of adaptation in verb production, using parallel measures to index impairment in two of verb naming's critical subcomponents: conceptual and linguistic processing. These component processes were evaluated using a standardized assessment battery designed to contrast non-linguistic (picture input) and linguistic (word input) tasks of conceptual action knowledge. The results indicate that non-linguistic conceptual action processing can be impaired in people with aphasia and contributes to verb-retrieval impairments. Furthermore, relatively unimpaired conceptual action processing can ameliorate the influence of linguistic processing deficits on verb-retrieval impairments. These findings are consistent with rational adaptation accounts, indicating that conceptual processing plays a key role in language function and can be leveraged in rehabilitation to improve verb retrieval in adults with chronic aphasia.

Does negation influence the choice of sentence continuations? Evidence from a four-choice cloze task.

Event plausibility facilitates the processing of affirmative sentences, but little is known about how it affects negative sentences. In six behavioural experiments, we investigated negation's impact on the choice of sentence continuations that differ with respect to event plausibility. In a four-choice cloze task, participants saw affirmative and negative sentence fragments (The child will [not] eat the . . .) in combination with four potential continuations: yoghurt (a plausible word), shellfish (a weak world knowledge violating word), branch (a severe world knowledge violating word), and minivan (a word resulting in a semantic violation). Across all experiments the plausible word was highly preferred in both affirmative and negative sentences. Experiment 2 replicated Experiment 1 while ruling out the possibility that the lack of effect of negation in Experiment 1 stemmed from participants not fully processing the negation. Experiment 3 showed that the observed plausibility effects can be generalised to other aspectual forms (The child has [not] eaten the yoghurt). Experiment 4 ruled out the possibility that the choices were mainly driven by lexical associations and additionally suggested a role for informativity. Experiment 5 replicated Experiment 4 and reinforced the general pattern according to which negative sentences express the denial of plausible positive events. Experiment 6 provided evidence that informativity might be driving patterns of choices in the negative sentences. All in all, these findings suggest that upcoming continuations are chosen to maximise the plausibility of the event in the affirmative sentences and to deny that event in the negative sentences. The observed plausibility effects do not seem to be modulated by the internal representation of events, but they can be modulated by changes to the expected informativity of the sentence.

Collective nouns are conceptually plural: Evidence from the grammatical SNARC effect.

To develop theories of how comprehenders extract the message from a linguistic stream, it is critical to understand how they conceptually represent referents. The experiments reported here focus on singular collective nouns (e.g., committee, team), which introduce a single group into the discourse and test whether they nonetheless are conceptually plural (i.e., construed as consisting of multiple entities) by using the spatial-numerical association of response codes (SNARC) paradigm (Dehaene & Changeux, 1993). In this paradigm, participants are typically faster to respond to smaller numbers or numerical stimuli when making a response on their left and faster to respond to larger numbers or numerical stimuli when making a response on their right. In three experiments, participants saw German words on a computer screen and decided whether each one described a single entity or something that could be subdivided into multiple entities (Experiment 1) or whether they would use "ist" or "sind" ("is" or "are") in combination with the word if it were the subject of a sentence (Experiments 2 and 3). The mapping of responses to participants' left and right hands was counterbalanced. Experiment 1 failed to show a grammatical SNARC effect. Experiments 2 and 3 showed a grammatical SNARC effect that extended to collective noun phrases. The results of these experiments suggest that collective noun phrases are instantiated as conceptually plural in comprehenders' minds. We discuss the differential task effects and the implications of these data on theories of language comprehension. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Increased reliance on world knowledge during language comprehension in healthy aging: evidence from verb-argument prediction.

Cognitive aging negatively impacts language comprehension performance. . However, there is evidence that older adults skillfully use linguistic context and their crystallized world knowledge to offset age-related changes that negatively impact comprehension. Two visual-world paradigm experiments examined how aging changes verb-argument prediction, a comprehension process that relies on world knowledge but has rarely been examined in the cognitive-aging literature. Older adults did not differ from younger adults in their activation of an upcoming likely verb argument, particularly when cued by a semantically-rich agent+verb combination (Experiment 1). However, older adults showed elevated activation of previously-mentioned agents (Experiment 1) and of unlikely but verb-congruent referents (Experiment 2). This is novel evidence that older adults exploit semantic context and world knowledge during comprehension to successfully activate upcoming referents. However, older adults also show elevated activation of irrelevant information, consistent with previous findings demonstrating that older adults may experience greater proactive interference and competition from task-irrelevant information.

Rational Adaptation in Using Conceptual Versus Lexical Information in Adults With Aphasia.

The information theoretic principle of rational adaptation predicts that individuals with aphasia adapt to their language impairments by relying more heavily on comparatively unimpaired non-linguistic knowledge to communicate. This prediction was examined by assessing the extent to which adults with chronic aphasia due to left-hemisphere stroke rely more on conceptual rather than lexical information during verb retrieval, as compared to age-matched neurotypical controls. A primed verb naming task examined the degree of facilitation each participant group received from either conceptual event-related or lexical collocate cues, compared to unrelated baseline cues. The results provide evidence that adults with aphasia received amplified facilitation from conceptual cues compared to controls, whereas healthy controls received greater facilitation from lexical cues. This indicates that adaptation to alternative and relatively unimpaired information may facilitate successful word retrieval in aphasia. Implications for models of rational adaptation and clinical neurorehabilitation are discussed.

White-Matter Neuroanatomical Predictors of Aphasic Verb Retrieval.

Background: Current neurocognitive models of language function have been primarily built from evidence regarding object naming, and their hypothesized white-matter circuit mechanisms tend to be coarse grained. Methods: In this cross-sectional, observational study, we used novel correlational tractography to assess the white-matter circuit mechanism behind verb retrieval, measured through action picture-naming performance in adults with chronic aphasia. Results: The analysis identified tracts implicated in current neurocognitive dual-stream models of language function, including the left inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, and arcuate fasciculus. However, the majority of tracts associated with verb retrieval were not ones included in dual-stream models of language function. Instead, they were projection pathways that connect frontal and parietal cortices to subcortical regions associated with motor functions, including the left corticothalamic pathway, frontopontine tract, parietopontine tract, corticostriatal pathway, and corticospinal tract. Conclusions: These results highlight that corticosubcortical projection pathways implicated in motor functions may be importantly related to language function. This finding is consistent with grounded accounts of cognition and may furthermore inform neurocognitive models. Impact statement This study suggests that in addition to traditional dual-stream language fiber tracts, the integrity of projection pathways that connect frontal and parietal cortices to subcortical motor regions may be critically associated with verb-retrieval impairments in adults with aphasia. This finding challenges neurological models of language function.

Semantic memory for objects, actions, and events: A novel test of event-related conceptual semantic knowledge.

People possess significant knowledge about how real-world events typically unfold. Such event-related semantic memory connects action and object knowledge, is essential for multiple stages of language processing, and may be impaired in neurological conditions like aphasia. However, current assessments are not well designed for measuring this knowledge. This study presents and tests a novel measure of event-related semantic memory. Task-performance data were collected from unimpaired adults across the lifespan and a sample of stroke survivors with aphasia. Individuals with aphasia also completed measures of language processing and action-/object-related semantic memory, to establish the novel measure's convergent validity. Results demonstrate that performance on the event-knowledge measure correlated with action and object semantic-memory measures and was also associated with a broader range of language-processing performance than other semantic-memory measures. These findings suggest that the novel measure can be used to detect the presence and impact of event-knowledge impairments in neurological conditions.

Idioms show effects of meaning relatedness and dominance similar to those seen for ambiguous words.

Does the language comprehension system resolve ambiguities for single- and multiple-word units similarly? We investigate this question by examining whether two constructs with robust effects on ambiguous word processing - meaning relatedness and meaning dominance - have similar influences on idiom processing. Eye tracking showed that: (1) idioms with more related figurative and literal meanings were read faster, paralleling findings for ambiguous words, and (2) meaning relatedness and meaning dominance interacted to drive eye movements on idioms just as they do on polysemous ambiguous words. These findings are consistent with a language comprehension system that resolves ambiguities similarly regardless of literality or the number of words in the unit.

Idiom comprehension in aphasia: Literal interference and abstract representation.

We investigate three potential mechanisms underlying the deficit in idiom comprehension seen in aphasia: difficulty inhibiting literal meanings, inability to recognize that a figurative interpretation is required, and difficulty processing abstract words and concepts. Unimpaired adults and PWA read high and moderate familiarity idioms either preceded or followed by a figuratively biasing context sentence. They then completed a string-to-word probe selection task, choosing between a figurative target, a literal lure, and unrelated concrete and abstract lures. PWA chose the figurative target more often for more familiar idioms and after figuratively biasing contexts, suggesting that difficulty accessing figurative meanings may be a key contributor to idiom impairment in aphasia. Importantly, PWA chose abstract lures at the same rate as they chose literal lures, suggesting that abstract lures may be considered equally good matches for weak idiomatic representations in PWA, and therefore that idiomatic figurative meanings may be represented similarly to abstract concepts for PWA. These results have implications for models of idiom comprehension in aphasia, as well as the design of future studies of idiom comprehension in PWA.

A rational inference approach to group and individual-level sentence comprehension performance in aphasia.

The rational inference, or noisy channel, account of language comprehension predicts that comprehenders are sensitive to the probabilities of different interpretations for a given sentence and adapt as these probabilities change (Gibson, Bergen & Piantadosi, 2013). This account provides an important new perspective on aphasic sentence comprehension: aphasia may increase the likelihood of sentence distortion, leading people with aphasia (PWA) to rely more on the prior probability of an interpretation and less on the form or structure of the sentence (Gibson, Sandberg, Fedorenko, Bergen & Kiran, 2015). We report the results of a sentence-picture matching experiment that tested the predictions of the rational inference account and other current models of aphasic sentence comprehension across a variety of sentence structures. Consistent with the rational inference account, PWA showed similar sensitivity to the probability of particular kinds of form distortions as age-matched controls, yet overall their interpretations relied more on prior probability and less on sentence form. As predicted by rational inference, but not by other models of sentence comprehension in aphasia, PWA's interpretations were more faithful to the form for active and passive sentences than for direct object and prepositional object sentences. However contra rational inference, there was no evidence that individual PWA's severity of syntactic or semantic impairment predicted their sensitivity to form versus the prior probability of a sentence, as cued by semantics. These findings confirm and extend previous findings that suggest the rational inference account holds promise for explaining aphasic and neurotypical comprehension, but they also raise new challenges for the account.

A Closer Look at Strengthened Readings of Scalars.

The majority of the extensive experimental and theoretical literature on scalar strengthening assumes that the phenomenon is uniform across all types of scalars. The experiment reported here contributes to the growing evidence against scalar uniformity, while also exploring the suggestion of van Tiel at al. 2014 of the role of boundedness in the observed variation. The current experiment utilizes a novel approach to exploring the interpretation of scalars, and also investigates the content of strengthened interpretations.

Looking for a Location: Dissociated Effects of Event-Related Plausibility and Verb-Argument Information on Predictive Processing in Aphasia.

Purpose: This study examined the influence of verb-argument information and event-related plausibility on prediction of upcoming event locations in people with aphasia, as well as older and younger, neurotypical adults. It investigated how these types of information interact during anticipatory processing and how the ability to take advantage of the different types of information is affected by aphasia. Method: This study used a modified visual-world task to examine eye movements and offline photo selection. Twelve adults with aphasia (aged 54-82 years) as well as 44 young adults (aged 18-31 years) and 18 older adults (aged 50-71 years) participated. Results: Neurotypical adults used verb argument status and plausibility information to guide both eye gaze (a measure of anticipatory processing) and image selection (a measure of ultimate interpretation). Argument status did not affect the behavior of people with aphasia in either measure. There was only limited evidence of interaction between these 2 factors in eye gaze data. Conclusions: Both event-related plausibility and verb-based argument status contributed to anticipatory processing of upcoming event locations among younger and older neurotypical adults. However, event-related likelihood had a much larger role in the performance of people with aphasia than did verb-based knowledge regarding argument structure.

World knowledge affects prediction as quickly as selectional restrictions: Evidence from the visual world paradigm.

There has been considerable debate regarding the question of whether linguistic knowledge and world knowledge are separable and used differently during processing or not (Hagoort, Hald, Bastiaansen, & Petersson, 2004; Matsuki et al., 2011; Paczynski & Kuperberg, 2012; Warren & McConnell, 2007; Warren, McConnell, & Rayner, 2008). Previous investigations into this question have provided mixed evidence as to whether violations of selectional restrictions are detected earlier than violations of world knowledge. We report a visual-world eye-tracking study comparing the timing of facilitation contributed by selectional restrictions versus world knowledge. College-aged adults (n=36) viewed photographs of natural scenes while listening to sentences. Participants anticipated upcoming direct objects similarly regardless of whether facilitation was provided by only world knowledge or a combination of selectional restrictions and world knowledge. These results suggest that selectional restrictions are not available earlier in comprehension than world knowledge.

Structural Prediction in Aphasia: Evidence from either.

Young neurotypical adults engage in prediction during language comprehension (e.g., Altmann & Kamide, 1999; Staub & Clifton, 2006; Yoshida, Dickey & Sturt, 2013). The role of prediction in aphasic comprehension is less clear. Some evidence suggests that lexical prediction may be spared in aphasia (Dickey et al., 2014; Love & Webb, 1977; cf. Mack et al, 2013), and there is even indication that structural prediction may be spared in some people with aphasia (PWA; e.g. Hanne, Burchert, De Bleser, & Vashishth, 2015). The current self-paced reading experiment manipulated the presence of either to examine structural prediction among PWA and a set of similar-aged neurotypical control participants. Consistent with intact structural prediction for both groups of participants, when either preceded a disjunction, reading times were faster on the or and second disjunct (cf. Staub & Clifton, 2006). For neurotypical controls, this effect of the presence vs. absence of either shrank reliably as more experimental items were encountered, whereas for PWA there was a non-significant trend for it to grow as more experimental items were encountered. These findings indicate that PWA and older neurotypical individuals can use a lexical cue to predict the structural form of upcoming material during comprehension, but that on-line adaptation to patterns in the local context may be different for the two groups.

Comprehending the impossible: what role do selectional restriction violations play?

To elucidate how different kinds of knowledge are used during comprehension, readers' eye movements were monitored as they read sentences that were: plausible, impossible because of a selectional restriction violation, or impossible because of a violation of general world knowledge. Eye movements on the pre-critical, critical, and post-critical words evidenced disruption in the selectional restriction violation condition compared to the other two conditions. These findings suggest that disruption associated with reading about impossible events is not directly determined by how impossible the event seems. Rather, the relationship between the verb and arguments in the sentence seems to matter. These findings are the strongest evidence to date that processing effects associated with selectional restrictions can dissociate from those associated with general world knowledge about events.

Cue strength in second-language processing: an eye-tracking study.

This study used eye-tracking and grammaticality judgement measures to examine how second-language (L2) learners process syntactic violations in English. Participants were native Arabic and native Mandarin Chinese speakers studying English as an L2, and monolingual English-speaking controls. The violations involved incorrect word order and differed in two ways predicted to be important by the unified competition model [UCM; MacWhinney, B. (2005). A unified model of language acquisition. In J. F. Kroll & A. M. B. de Groot (Eds.), Handbook of bilingualism: Psycholinguistic approaches (pp. 49-67). Oxford: Oxford University Press.]. First, one violation had more and stronger cues to ungrammaticality than the other. Second, the grammaticality of these word orders varied in Arabic and Mandarin Chinese. Sensitivity to violations was relatively quick overall, across all groups. Sensitivity also was related to the number and strength of cues to ungrammaticality regardless of native language, which is consistent with the general principles of the UCM. However, there was little evidence of cross-language transfer effects in either eye movements or grammaticality judgements.

The mental representation of plural events.

A growing body of work suggests that in the absence of strong cues to individuation, comprehenders leave their mental representations of plural entities underspecified-that is, they mentally represent plural noun phrases (NPs) as groups or nondifferentiated sets. The current paper investigates whether this also holds for plural events. Experiments 1a-1b used an aspectual coercion manipulation to provide evidence that event plurality can be indexed by the number-of-words judgement task that Patson and Warren [2010. Evidence for distributivity effects in comprehension. Journal of Experimental Psychology: Learning, Memory and Cognition, 36, 782-789] used to investigate the mental representation of plural nouns. Experiment 2 confirmed this by showing that comprehenders mentally represent predicates associated with distributive quantifiers as plural, and they do so immediately at the verb rather than waiting until the completion of the predicate. Experiment 3 probed inherently distributed verbs and showed that inherent distributivity is not enough to push comprehenders to mentally represent multiple events. Only when the subject of an inherently distributed verb is a conjoined NP, rather than a plural definite description, do comprehenders mentally represent multiple events. Experiment 4 replicated and extended Experiment 3. This body of findings suggests that in the absence of strong cues to individuation, plural events are left underspecified. However, when disambiguating information is provided, comprehenders do mentally represent number information explicitly and incrementally.

The influence of event-related knowledge on verb-argument processing in aphasia.

Event-related conceptual knowledge outside the language system rapidly affects verb-argument processing in unimpaired adults (McRae and Matsuki, 2009). Some have argued that verb-argument processing is in fact reducible to the activation of such event-related knowledge. However, data favoring this conclusion have come primarily from college-aged healthy adults, for whom both linguistic and conceptual semantic processing is fast and automatic. This study examined the influence of event-related knowledge on verb-argument processing among adults with aphasia (n = 8) and older unimpaired controls (n = 60), in two self-paced reading studies. Participants read sentences containing a plausible verb-argument combination (Mary used a knife to chop the large carrots before dinner), a combination that violated event-related world knowledge (Mary used some bleach to clean the large carrots before dinner), or a combination that violated the verb's selectional restrictions (Mary used a pump to inflate the large carrots before dinner). The participants with aphasia naturally split into two groups: Group 1 (n = 4) had conceptual-semantic impairments (evidenced by poor performance on tasks like Pyramids & Palm Trees) but reasonably intact language processing (higher Western Aphasia Battery Aphasia Quotients), while Group 2 (n = 4) had intact conceptual semantics but poorer language processing. Older unimpaired controls and aphasic Group 1 showed rapid on-line disruption for sentences with selectional-restriction violations (SRVs) and event-related knowledge violations, and also showed SRV-specific penalties in sentence-final acceptability judgments (Experiment 1) and comprehension questions (Experiment 2). In contrast, Group 2 showed very few reliable differences across conditions in either on-line or off-line measures. This difference between aphasic groups suggests that verb-related information and event-related knowledge may be dissociated in aphasia. Furthermore, it suggests that intact language processing is more critical for successful verb-argument integration than intact access to event-related world knowledge. This pattern is unexpected if verb-argument processing is reducible to activation of event-related conceptual knowledge.

The conceptual representation of number.

The experiments reported here investigated the format of plural conceptual representations using a picture-matching paradigm. In Experiment 1, participants read sentences that ended with a singular noun phrase (NP), a two-quantified plural NP, or a plural definite description [The parents handed the child the (two) crayon/s] and then saw a picture of one or multiple referents for the NP. Judgement times to confirm that there was overlap between the pictured object(s) and a noun in the sentence showed an interaction between the NP's number and NP-picture match. For singular NPs and two-quantified NPs, participants were reliably faster to respond "yes" to a picture that had the exact number of objects specified by the NP, but for plural definite descriptions, the effect of the number of pictured items was not reliable. Experiment 2 extended this finding to conceptual plurals. Participants read sentences biased toward either a collective (Together the men carried a box-box is interpreted as singular) or distributed (Each of the men carried a box-box is likely interpreted as plural) reading. Experiment 2 showed the same interaction between NP conceptual plurality and NP-picture match as that in Experiment 1. These results suggest that: (a) our default conceptual representations for plural definite descriptions are no more similar to images of small sets of multiple items than to images of singular items; and (b) the difference between singular and plural conceptual representations is unlikely to be simply the presence or absence of a plural feature. The results are consistent with theories in which plurality is unmarked, such that some plural NPs can refer to singular referents [e.g., Sauerland, U., Anderssen, J., & Yatsushiro, J. (2005). The plural is semantically unmarked. In S. Kepser & M. Reis (Eds.), Linguistic evidence (pp. 413-434). Berlin: de Gruyter].