The concreteness effect: evidence for dual coding and context availability

Effectiveness of production and drawing as encoding techniques on recall using mixed- and pure-list designs

We compared the benefit of production and drawing on recall of concrete and abstract words, using mixed- and pure-list designs. We varied stimulus and list types to examine whether the memory benefit from these strategies was sustained across these manipulations. For all experiments, the memory retrieval task was free recall. In Experiment 1, participants studied concrete and abstract words sequentially, with prompts to either silently-read, read aloud, write, or draw each target (intermixed). Reading aloud, writing, and drawing improved recall compared to silent reading, with drawing leading to the largest boost. Performance, however, was at floor in all but the drawing condition. In Experiment 2, the number of targets was reduced, and each strategy (between-subjects) was compared to silent-reading. We eliminated floor effects and replicated results from Experiment 1. In Experiment 3, we manipulated strategy in a pure-list-design. The drawing benefit was maintained while that from production was eliminated. In all experiments, recall was higher for concrete than abstract words that were drawn; no such effect was found for words produced. Results suggest that drawing facilitates memory by enhancing semantic elaboration, whereas the production benefit is largely perceptually based. Importantly, the memory benefit conferred by drawing at encoding, unlike production, cannot be explained by a distinctiveness account as it was relatively unaffected by study design.

Investigating Acoustic and Psycholinguistic Predictors of Cognitive Impairment in Older Adults: Modeling Study

BACKGROUND

About one-third of older adults aged 65 years and older often have mild cognitive impairment or dementia. Acoustic and psycho-linguistic features derived from conversation may be of great diagnostic value because speech involves verbal memory and cognitive and neuromuscular processes. The relative decline in these processes, however, may not be linear and remains understudied.

OBJECTIVE

This study aims to establish associations between cognitive abilities and various attributes of speech and natural language production. To date, the majority of research has been cross-sectional, relying mostly on data from structured interactions and restricted to textual versus acoustic analyses.

METHODS

In a sample of 71 older (mean age 83.3, SD 7.0 years) community-dwelling adults who completed qualitative interviews and cognitive testing, we investigated the performance of both acoustic and psycholinguistic features associated with cognitive deficits contemporaneously and at a 1-2 years follow up (mean follow-up time 512.3, SD 84.5 days).

RESULTS

Combined acoustic and psycholinguistic features achieved high performance (F1-scores 0.73-0.86) and sensitivity (up to 0.90) in estimating cognitive deficits across multiple domains. Performance remained high when acoustic and psycholinguistic features were used to predict follow-up cognitive performance. The psycholinguistic features that were most successful at classifying high cognitive impairment reflected vocabulary richness, the quantity of speech produced, and the fragmentation of speech, whereas the analogous top-ranked acoustic features reflected breathing and nonverbal vocalizations such as giggles or laughter.

CONCLUSIONS

These results suggest that both acoustic and psycholinguistic features extracted from qualitative interviews may be reliable markers of cognitive deficits in late life.

Semantic processing in older adults is associated with distributed neural activation which varies by association and abstractness of words

The extent to which the neural systems underlying semantic processes degrade with advanced age remains unresolved, which motivated the current study of neural activation on functional magnetic resonance imaging (fMRI) during semantic judgments of associated vs. unassociated, semantic vs. rhyme, and abstract vs. rhyme word pairs. Thirty-eight older adults, 55-85 years of age, performed semantic association decision tasks in a mixed event-related block fMRI paradigm involving binary judgments as to whether word pairs were related (i.e., semantically associated). As hypothesized, significantly greater activation was evident during processing of associated (vs. unassociated) word pairs in cortical areas implicated in semantic processing, including the angular gyrus, temporal cortex, and inferior frontal cortex. Cortical areas showed greater activation to unassociated (vs. associated) word pairs, primarily within a large occipital cluster. Greater activation was evident in cortical areas when response to semantic vs. phonemic word pairs. Contrasting activation during abstract vs. concrete semantic processing revealed areas of co-activation to both semantic classes, and areas that had greater response to either abstract or concrete word pairs. Neural activation across conditions did not vary as a function of greater age, indicating only minimal age-associated perturbation in neural activation during semantic processing. Therefore, the response of the semantic hubs, semantic control, and secondary association areas appear to be largely preserved with advanced age among older adults exhibiting successful cognitive aging. These findings may provide a useful clinical contrast if compared to activation among adults experiencing cognitive decline due Alzheimer's, frontal-temporal dementia, and other neurodegenerative diseases.

Regionally specific cortical lateralization of abstract and concrete verb processing: Magnetic mismatch negativity study

The neural underpinnings of processing concrete and abstract semantics remain poorly understood. Previous fMRI studies have shown that multimodal and amodal neural networks respond differentially to different semantic types; importantly, abstract semantics activates more left-lateralized networks, as opposed to more bilateral activity for concrete words. Due to the lack of temporal resolution, these fMRI results do not allow to easily separate language- and task-specific brain responses and to disentangle early processing stages from later post-comprehension phenomena. To tackle this, we used magnetoencephalography (MEG), a time-resolved neuroimaging technique, in combination with a task-free oddball mismatch negativity (MMN) paradigm, an established approach to tracking early automatic activation of word-specific memory traces in the brain. We recorded the magnetic MMN responses in 30 healthy adults to auditorily presented abstract and concrete action verbs to assess lateralization of word-specific lexico-semantic processing in a set of neocortical areas. We found that MMN responses to these stimuli showed different lateralization patterns of activity in the upper limb motor area (BA4) and parts of Broca's area (BA45/BA47) within ∼100-350 ms after the word disambiguation point. Importantly, the greater leftward response lateralization for abstract semantics was due to the lesser involvement of the right-hemispheric homologues, not increased left-hemispheric activity. These findings suggest differential region-specific involvement of bilateral sensorimotor systems already in the early automatic stages of processing abstract and concrete action semantics.

Specificity ratings for Italian data

Abstraction enables us to categorize experience, learn new information, and form judgments. Language arguably plays a crucial role in abstraction, providing us with words that vary in specificity (e.g., highly generic: tool vs. highly specific: muffler). Yet, human-generated ratings of word specificity are virtually absent. We hereby present a dataset of specificity ratings collected from Italian native speakers on a set of around 1K Italian words, using the Best-Worst Scaling method. Through a series of correlation studies, we show that human-generated specificity ratings have low correlation coefficients with specificity metrics extracted automatically from WordNet, suggesting that WordNet does not reflect the hierarchical relations of category inclusion present in the speakers' minds. Moreover, our ratings show low correlations with concreteness ratings, suggesting that the variables Specificity and Concreteness capture two separate aspects involved in abstraction and that specificity may need to be controlled for when investigating conceptual concreteness. Finally, through a series of regression studies we show that specificity explains a unique amount of variance in decision latencies (lexical decision task), suggesting that this variable has theoretical value. The results are discussed in relation to the concept and investigation of abstraction.

Symbol superiority: Why $ is better remembered than 'dollar'

Memory typically is better for information presented in picture format than in word format. Dual-coding theory (Paivio, 1969) proposes that this is because pictures are spontaneously labelled, leading to the creation of two representational codes-image and verbal-whereas words often lead to only a single (verbal) code. With this perspective as motivation, the present investigation asked whether common graphic symbols (e.g.,!@#$%&) are afforded primarily verbal coding, akin to words, or whether they also invoke visual imagery, as do pictures. Across four experiments, participants were presented at study with graphic symbols or words (e.g., $ or 'dollar'). In Experiment 1, memory was assessed using free recall; in Experiment 2, memory was assessed using old-new recognition. In Experiment 3, the word set was restricted to a single category. In Experiment 4, memory for graphic symbols, pictures, and words was directly compared. All four experiments demonstrated a memory benefit for symbols relative to words. In a fifth experiment, machine learning estimations of inherent stimulus memorability were found to predict memory performance in the earlier experiments. This study is the first to present evidence that, like pictures, graphic symbols are better remembered than words, in line with dual-coding theory and with a distinctiveness account. We reason that symbols offer a visual referent for abstract concepts that are otherwise unlikely to be spontaneously imaged.

Structural and functional neural substrates underlying the concreteness effect

The concreteness effect refers to the advantage in speed and accuracy of processing concrete words over abstract words. Previous studies have shown that the processing of the two types of words is mediated by distinct neural mechanisms, but these studies were mainly conducted with task-based functional magnetic resonance imaging. This study investigates the associations between the concreteness effect and grey matter volume (GMV) of brain regions as well as resting-state functional connectivity (rsFC) of these identified regions. The results show that the GMV of left inferior frontal gyrus (IFG), right middle temporal gyrus (MTG), right supplementary motor area and right anterior cingulate cortex (ACC) negatively correlates with the concreteness effect. The rsFC of the left IFG, the right MTG and the right ACC with the nodes, mainly in default mode network, frontoparietal network and dorsal attention network positively correlates with the concreteness effect. The GMV and rsFC jointly and respectively predict the concreteness effect in individuals. In conclusion, stronger connectivity amongst functional networks and higher coherent engagement of the right hemisphere predict a greater difference in the verbal memory of abstract and concrete words.

The influence of conceptual concreteness on the reading acquisition and integration of novel words into semantic memory via thematic relations

Plenty of studies have been conducted to reveal neurocognitive underpinnings of conceptual representation. Compared with that of concrete concepts, the neurocognitive correlates of abstract concepts remain elusive. The current study aimed to investigate the influence of conceptual concreteness on the reading acquisition and integration of novel words into semantic memory. We constructed two-sentence contexts in which two-character pseudowords were embedded as novel words. Participants read the contexts to infer the meaning of novel words which were either concrete or abstract, and then performed a lexical decision task and a cued-recall memory task. In lexical decision task, primed by the learned novel words, their corresponding concepts, thematically related or unrelated words as well as unlearned pseudowords were judged whether they were words or not. In memory task, participants were presented with the novel words and asked to write down their meaning. The contextual reading and memory test can demonstrate the modulation of conceptual concreteness on novel word learning and the lexical decision task can reveal whether concrete and abstract novel words are integrated into semantic memory similarly or not. During contextual reading, abstract novel words presented for the first time elicited a larger N400 than concrete ones. In memory task, the meaning of concrete novel words was recollected better than abstract novel words. These results indicate that abstract novel words are more difficult to acquire during contextual reading, and to retain afterwards. For lexical decision task behavioral and ERPs were graded, with the longest reaction time, the lowest accuracy and the largest N400s for the unrelated words, then the thematically related words and finally the corresponding concepts of the novel words, regardless of conceptual concreteness. The results suggest that both concrete and abstract novel words can be integrated into semantic memory via thematic relations. These findings are discussed in terms of differential representational framework which posits that concrete words connect with each other via semantic similarities, and abstract ones via thematic relations.

Verbal recall in amnesia: Does scene construction matter?

The hippocampus plays a critical role in episodic memory and imagination. One theoretical model posits that the hippocampus is important for scene construction, namely, the ability to conjure and maintain a scene-based representation in one's mind. To test one idea put forth by this view, we examined whether amnesia is associated with more severe impairment in memory when the to-be-remembered content places high demands on scene construction. To do so, we examined free recall performance for abstract (i.e., low scene imagery) and concrete, high scene-imagery single words in seven amnesic patients with hippocampal lesions and concomitant scene-construction deficits, and compared their performance to demographically matched healthy controls. As expected, amnesic patients were severely impaired in their free recall performance; however, their impairment did not differ as a function of word type. That is, their impairment was equally severe for words that evoke high versus low scene imagery. These findings suggest that the role of the hippocampus in verbal memory extends to content that does not place high demands on scene construction. Theoretical implications of these findings are discussed.

When a Sunny Day Gives You Butterflies: An Electrophysiological Investigation of Concreteness and Context Effects in Semantic Word Processing

Theories on controlled semantic cognition assume that word concreteness and linguistic context interact during semantic word processing. Methodological approaches and findings on how this interaction manifests at the electrophysiological and behavioral levels are heterogeneous. We measured ERPs and RTs applying a validated cueing paradigm with 19 healthy participants, who performed similarity judgments on concrete or abstract words (e.g., "butterfly" or "tolerance") after reading contextual and irrelevant sentential cues. Data-driven analyses showed that concreteness increased and context decreased negative-going deflections in broadly distributed bilateral clusters covering the N400 and N700/late positive component time range, whereas both reduced RTs. Crucially, within a frontotemporal cluster in the N400 time range, contextual (vs. irrelevant) information reduced negative-going amplitudes in response to concrete but not abstract words, whereas a contextual cue reduced RTs only in response to abstract but not concrete words. The N400 amplitudes did not explain additional variance in the RT data, which showed a stronger contextual facilitation for abstract than concrete words. Our results support separate but interacting effects of concreteness and context on automatic and controlled stages of contextual semantic processing and suggest that effects on the electrophysiological versus behavioral level obtained with this paradigm are dissociated.

Spontaneous, controlled acts of reference between friends and strangers

Speakers enjoy considerable flexibility in how they refer to a given referent--referring expressions can vary in their form (e.g., "she" vs. "the cat"), their length (e.g., "the (big) (orange) cat"), and more. What factors drive a speaker's decisions about how to refer, and how do these decisions shape a comprehender's ability to resolve the intended referent? Answering either question presents a methodological challenge; researchers must strike a balance between experimental control and ecological validity. In this paper, we introduce the SCARFS (Spontaneous, Controlled Acts of Reference between Friends and Strangers) Database: a corpus of approximately 20,000 English nominal referring expressions (NREs), produced in the context of a communication game. For each NRE, the corpus lists the concept the speaker was trying to convey (from a set of 471 possible target concepts), formal properties of the NRE (e.g., its length), the relationship between the interlocutors (i.e., friend vs. stranger), and the communicative outcome (i.e., whether the expression was successfully resolved). Researchers from diverse disciplines may use this resource to answer questions about how speakers refer and how comprehenders resolve their intended referent--as well as other fundamental questions about dialogic speech, such as whether and how speakers tailor their utterances to the identity of their interlocutor, how second-degree associations are generated, and the predictors of communicative success.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10579-022-09619-y.

Distinct roles for the anterior temporal lobe and angular gyrus in the spatiotemporal cortical semantic network

Semantic knowledge is supported by numerous brain regions, but the spatiotemporal configuration of the network that links these areas remains an open question. The hub-and-spokes model posits that a central semantic hub coordinates this network. In this study, we explored distinct aspects that define a semantic hub, as reflected in the spatiotemporal modulation of neural activity and connectivity by semantic variables, from the earliest stages of semantic processing. We used source-reconstructed electro/magnetoencephalography, and investigated the concreteness contrast across three tasks. In a whole-cortex analysis, the left anterior temporal lobe (ATL) was the only area that showed modulation of evoked brain activity from 100 ms post-stimulus. Furthermore, using Dynamic Causal Modeling of the evoked responses, we investigated effective connectivity amongst the candidate semantic hub regions, that is, left ATL, supramarginal/angular gyrus (SMG/AG), middle temporal gyrus, and inferior frontal gyrus. We found that models with a single semantic hub showed the highest Bayesian evidence, and the hub region was found to change from ATL (within 250 ms) to SMG/AG (within 450 ms) over time. Our results support a single semantic hub view, with ATL showing sustained modulation of neural activity by semantics, and both ATL and AG underlying connectivity depending on the stage of semantic processing.

Concreteness and levels of processing: a test of the dual-coding hypothesis using dynamic visual noise

Concreteness and levels of processing (LOP) effects have been attributed to the differential availability of visual images for concrete words, and at deeper levels of processing, respectively. Interestingly, the concreteness effect has been shown to disappear under conditions involving dynamic visual noise (DVN), which is thought to suppress the generation of visual images from long-term memory. The present study further investigated the role of visual imagery in concreteness and LOP effects. Across four experiments, DVN was manipulated during study, and participants' memory for concrete and abstract words was measured using recall and recognition tests. Although some support for dual-coding was found, concreteness and LOP effects were not fully explained by visual imagery because they were present under DVN conditions. We conclude that concreteness and LOP effects may be better explained by an "extended dual-coding theory" that incorporates the role of context availability in accounting for this pattern of results.

Neuroepigenetic impact on mentalizing in childhood

Mentalizing, or the ability to understand the mental states and intentions of others, is an essential social cognitive function that children learn and continue to cultivate into adolescence. While most typically developing children acquire sufficient mentalizing skills, individual differences in mentalizing persist throughout childhood and are likely influenced by a combination of cognitive functioning, the social environment, and biological factors. DNA methylation of the oxytocin receptor gene (OXTRm) impacts gene expression and is associated with increased brain activity in mentalizing regions during displays of animacy in healthy young adults. The establishment, fine-tuning, and implications of such associations in the context of broader social functioning remain unclear. Using a developmental neuroimaging epigenetic approach, we investigated the contributions of OXTRm to individual variability in brain function during animate motion perception in middle childhood. We find that higher levels of OXTRm are associated with increased neural responses in the left temporo-parietal junction and inferior frontal gyrus. We also find a positive association between neural activity in LTPJ and social skills. These findings provide evidence of epigenetic influence on the developing child brain and demonstrate that variability in neural social perception in childhood is multifaceted with contributions from individual social experience and the endogenous oxytocin system.

Evidence for the Concreteness of Abstract Language: A Meta-Analysis of Neuroimaging Studies

The neural mechanisms subserving the processing of abstract concepts remain largely debated. Even within the embodiment theoretical framework, most authors suggest that abstract concepts are coded in a linguistic propositional format, although they do not completely deny the role of sensorimotor and emotional experiences in coding it. To our knowledge, only one recent proposal puts forward that the processing of concrete and abstract concepts relies on the same mechanisms, with the only difference being in the complexity of the underlying experiences. In this paper, we performed a meta-analysis using the Activation Likelihood Estimates (ALE) method on 33 functional neuroimaging studies that considered activations related to abstract and concrete concepts. The results suggest that (1) concrete and abstract concepts share the recruitment of the temporo-fronto-parietal circuits normally involved in the interactions with the physical world, (2) processing concrete concepts recruits fronto-parietal areas better than abstract concepts, and (3) abstract concepts recruit Broca's region more strongly than concrete ones. Based on anatomical and physiological evidence, Broca's region is not only a linguistic region mainly devoted to speech production, but it is endowed with complex motor representations of different biological effectors. Hence, we propose that the stronger recruitment of this region for abstract concepts is expression of the complex sensorimotor experiences underlying it, rather than evidence of a purely linguistic format of its processing.

An ALE meta-analytical review of the neural correlates of abstract and concrete words

Several clinical studies have reported a double dissociation between abstract and concrete concepts, suggesting that they are processed by at least partly different networks in the brain. However, neuroimaging data seem not in line with neuropsychological reports. Using the ALE method, we run a meta-analysis on 32 brain-activation imaging studies that considered only nouns and verbs. Five clusters were associated with concrete words, four clusters with abstract words. When only nouns were selected three left activation clusters were found to be associated with concrete stimuli and only one with abstract nouns (left IFG). These results confirm that concrete and abstract words processing involves at least partially segregated brain areas, the IFG being relevant for abstract nouns and verbs while more posterior temporoparietal-occipital regions seem to be crucial for processing concrete words, in contrast with the neuropsychological literature that suggests a temporal anterior involvement for concrete words. We investigated the possible reasons that produce different outcomes in neuroimaging and clinical studies.

How well imageability, concreteness, perceptual strength, and action strength predict recognition memory, lexical decision, and reading aloud performance

We examined how well imageability, concreteness, perceptual strength, and action strength predicted recognition memory, lexical decision, and reading aloud performance. We used our imageability estimates [Cortese, M. J., & Fugett, A. (2004). Imageability ratings for 3,000 monosyllabic words. Behavior Methods and Research, Instrumentation, & Computers, 36(3), 384-387. https://doi.org/10.3758/BF03195585; Schock, J., Cortese, M. J., & Khanna, M. M. (2012a). Imageability ratings for 3,000 disyllabic words. Behavior Research Methods, 44(2), 374-379. https://doi.org/10.3758/s13428-011-0162-0], concreteness norms of Brysbaert and colleagues [Brysbaert, M., Warriner, A. B., & Kuperman, V. (2014). Concreteness ratings for 40 thousand generally known English lemmas. Behavior Research Methods, 46(3), 904-911. https://doi.org/10.3758/s13428-013-0403-5], and perceptual and action strength ratings of Lynott and colleagues [Lynott, D., Connell, L., Brysbaert, M., Brand, J., & Carney, J. (2020). The lancaster sensorimotor norms: Multidimensional measures of perceptual and action strength for 40,000 English words. Behavior Research Methods, 52(3), 1271-1291. https://doi.org/10.3758/s13428-019-01316-z]. Our results indicate imageability is the best predictor, but methodological differences between ratings studies may contribute to the results. Surprisingly, action strength was negatively (albeit weakly) related to recognition memory. Analyses of item zRTs from the English lexicon project indicate these variables were not strong predictors of reading aloud or lexical decision performance. However, there is a small, consistent positive relationship between concreteness and zRTs (i.e., a facilitative abstractness effect). We believe researchers should either employ or control for imageability rather than concreteness, perceptual strength, or action strength when conducting recognition memory experiments. In addition, image-based codes generated at encoding strengthen memory traces but do not provide major inputs into reading aloud and lexical decision processes. Also, the facilitative abstractness effect on lexical decision and reading aloud zRTs may reflect more robust lexical representations for abstract words than concrete words, and that these two constructs are distinct.

Corroborating behavioral evidence for the interplay of representational richness and semantic control in semantic word processing

This study aimed to replicate and validate concreteness and context effects on semantic word processing. In Experiment 1, we replicated the behavioral findings of Hoffman et al. (Cortex 63,250–266, https://doi.org/10.1016/j.cortex.2014.09.001, 2015) by applying their cueing paradigm with their original stimuli translated into German. We found concreteness and contextual cues to facilitate word processing in a semantic judgment task with 55 healthy adults. The two factors interacted in their effect on reaction times: abstract word processing profited more strongly from a contextual cue, while the concrete words’ processing advantage was reduced but still present. For accuracy, the descriptive pattern of results suggested an interaction, which was, however, not significant. In Experiment 2, we reformulated the contextual cues to avoid repetition of the to-be-processed word. In 83 healthy adults, the same pattern of results emerged, further validating the findings. Our corroborating evidence supports theories integrating representational richness and semantic control mechanisms as complementary mechanisms in semantic word processing.

Propofol and sevoflurane affect intra-operative memory formation of words differently: A prospective cohort study

BACKGROUND

Memory priming seems possible even during apparently adequate anaesthesia. However, the effects of different anaesthetics and type of stimuli, by virtue of their specific neural underpinnings, have not been considered.

OBJECTIVE

To determine if intra-operative implicit memory is affected by the type of anaesthesia (propofol or sevoflurane) or by the type of stimuli (abstract or concrete words).

DESIGN

Two consecutive, randomised controlled experiments.

SETTING

Neurological institute in Milan, Italy.

PATIENTS

Forty-three patients undergoing anaesthesia with propofol (experiment 1) and 32 patients undergoing anaesthesia with sevoflurane (experiment 2). Patients were ASA I or II, age 18 to 65 years, native Italian speakers, right-handed and without any condition affecting memory or hearing.

INTERVENTION

During anaesthesia, the patients heard a list of either concrete or abstract words or no words at all (controls). Explicit memory was tested with an explicit recall task and the Brice Interview; implicit memory was assessed through a word stem completion test.

OUTCOME MEASURES

The number of explicitly recalled words, positivity to the Brice Interview, the proportion of target and nontarget hits, and a derived implicit memory score.

RESULTS

With propofol, the proportion of target hits was significantly greater than the proportion of nontarget hits for the concrete word experimental group (P = 0.018). The implicit memory score of the concrete word experimental group was significantly higher than the score of both the abstract word experimental group (P  = 0.000) and the concrete word control group (P = 0.023). With sevoflurane, the proportion of target hits was significantly higher than the proportion of nontarget hits for the abstract word experimental group only (P = 0.027). No patients had a BIS above 60 and no one could recall intra-operative events or words.

CONCLUSION

Intra-operative memory for words can form during apparently adequate BIS-guided anaesthesia but is modified by propofol or sevoflurane acting on different brain targets. Further studies on larger samples and using neuroimaging techniques are needed.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT03727464.

Acquisition of concrete and abstract words is modulated by tDCS of Wernicke's area

Previous behavioural and neuroimaging research suggested distinct cortical systems involved in processing abstract and concrete semantics; however, there is a dearth of causal evidence to support this. To address this, we applied anodal, cathodal, or sham (placebo) tDCS over Wernicke’s area before a session of contextual learning of novel concrete and abstract words (n = 10 each), presented five times in short stories. Learning effects were assessed at lexical and semantic levels immediately after the training and, to attest any consolidation effects of overnight sleep, on the next day. We observed successful learning of all items immediately after the session, with decreased performance in Day 2 assessment. Importantly, the results differed between stimulation conditions and tasks. Whereas the accuracy of semantic judgement for abstract words was significantly lower in the sham and anodal groups on Day 2 vs. Day 1, no significant performance drop was observed in the cathodal group. Similarly, the cathodal group showed no significant overnight performance reduction in the free recall task for either of the stimuli, unlike the other two groups. Furthermore, between-group analysis showed an overall better performance of both tDCS groups over the sham group, particularly expressed for abstract semantics and cathodal stimulation. In sum, the results suggest overlapping but diverging brain mechanisms for concrete and abstract semantics and indicate a larger degree of involvement of core language areas in storing abstract knowledge. Furthermore, they demonstrate a possiblity to improve learning outcomes using neuromodulatory techniques.

Non-verbal Enrichment in Vocabulary Learning With a Virtual Pedagogical Agent

Non-verbal enrichment in the form of pictures or gesture can support word learning in first and foreign languages. The present study seeks to compare the effects of viewing pictures vs. imitating iconic gestures on learning second language (L2) vocabulary. In our study participants learned L2 words (nouns, verbs, and adjectives) together with a virtual, pedagogical agent. The to-be-learned items were either (i) enriched with pictures, or (ii) with gestures that had to be imitated, or (iii) without any non-verbal enrichment as control. Results showed that gesture imitation was particularly supportive for learning nouns, whereas pictures showed to be most beneficial for memorizing verbs. These findings, suggesting that the type of vocabulary learning strategy has to match with the type of linguistic material to be learned, have important educational implications for L2 classrooms and technology-enhanced tutoring systems.

Word Form Processing in Primary School Children: A Psycholinguistic Perspective

Purpose From a psycholinguistic perspective, the quality of the stored word form in the phonological input lexicon, as well as its effective retrieval from the phonological output lexicon, is of great importance in lexical processing. This study aimed at gaining a deeper understanding of (a)typical word form processing in primary school children. In particular, age-related development and profiles of word form processing including children's response behavior were investigated. Method A sample of 164 monolingual primary school children (6-9 years of age) was tested in a cross-sectional design using two word form-related tasks (auditory lexical decision and rapid naming) with carefully controlled stimuli in combination with traditional vocabulary tests and a nonword repetition task. Results First, an age-related improvement (better performance and acceleration of reaction times) was found for both word form-related tasks. Second, a cluster analysis revealed five clusters with different profiles of word processing. Beside a cluster with overall results of above average, we found two clusters including children with typical lexical abilities who applied specific strategies to deal with the tasks (speed-accuracy trade-offs). Two other clusters represented weak lexical abilities at different levels of word processing. Conclusions Children's abilities in word form processing develop over time and are characterized by developmental boosts that occur at different times in development. The uncovered profiles document patterns of (a)typical lexical processing. Since difficulties with word form processing are easily overlooked in clinical assessment, lexical decision and rapid naming tasks offer valuable tools for an in-depth evaluation of lexical skills. Supplemental Material https://doi.org/10.23641/asha.12986036.

Oscillatory dynamics of perception of emotional sentences in healthy subjects with different severity of depressive symptoms

The aim of the study was to investigate the characteristics of the oscillatory dynamics of brain activity during the perception of negative, positive, and neutral sentences in healthy individuals with differing severity of depressive symptoms at the preclinical stage. The study involved 34 healthy people (22 women). The severity of the symptoms of depression was assessed using Beck's Depression Inventory (BDI II). Using independent component analysis and the function of dipfit in the EEGlab software, the EEG was divided into components and their localizations were calculated. To assess the induced responses, event-related spectral perturbations were calculated. The perception of emotional sentences was accompanied by a more pronounced increase in theta rhythm in the group with lower severity of depressive symptoms. The perception of all types of sentences was accompanied by a decrease in beta rhythm in the group with lower severity of depressive symptoms. The effects were localized to the precuneus. The decrease of oscillatory responses in the theta and beta ranges in individuals with a high severity of depressive symptoms suggests a reduction of attention to the emotional content and meaning of the sentences.

Overlapping connectivity patterns during semantic processing of abstract and concrete words revealed with multivariate Granger Causality analysis

. Abstract, unlike concrete, nouns refer to notions beyond our perception. Even though there is no consensus among linguists as to what exactly constitutes a concrete or abstract word, neuroscientists found clear evidence of a "concreteness" effect. This can, for instance, be seen in patients with language impairments due to brain injury or developmental disorder who are capable of perceiving one category better than another. Even though the results are inconclusive, neuroimaging studies on healthy subjects also provide a spatial and temporal account of differences in the processing of abstract versus concrete words. A description of the neural pathways during abstract word reading, the manner in which the connectivity patterns develop over the different stages of lexical and semantic processing compared to that of concrete word processing are still debated. We conducted a high-density EEG study on 24 healthy young volunteers using an implicit categorization task. From this, we obtained high spatio-temporal resolution data and, by means of source reconstruction, reduced the effect of signal mixing observed on scalp level. A multivariate, time-varying and directional method of analyzing connectivity based on the concept of Granger Causality (Partial Directed Coherence) revealed a dynamic network that transfers information from the right superior occipital lobe along the ventral and dorsal streams towards the anterior temporal and orbitofrontal lobes of both hemispheres. Some regions along these pathways appear to be primarily involved in either receiving or sending information. A clear difference in information transfer of abstract and concrete words was observed during the time window of semantic processing, specifically for information transferred towards the left anterior temporal lobe. Further exploratory analysis confirmed a generally stronger connectivity pattern for processing concrete words. We believe our study could guide future research towards a more refined theory of abstract word processing in the brain.

Visual and auditory perceptual strength norms for 3,596 French nouns and their relationship with other psycholinguistic variables

Perceptual experience plays a critical role in the conceptual representation of words. Higher levels of semantic variables such as imageability, concreteness, and sensory experience are generally associated with faster and more accurate word processing. Nevertheless, these variables tend to be assessed mostly on the basis of visual experience. This underestimates the potential contributions of other perceptual modalities. Accordingly, recent evidence has stressed the importance of providing modality-specific perceptual strength norms. In the present study, we developed French Canadian norms of visual and auditory perceptual strength (i.e., the modalities that have major impact on word processing) for 3,596 nouns. We then explored the relationship between these newly developed variables and other lexical, orthographic, and semantic variables. Finally, we demonstrated the contributions of visual and auditory perceptual strength ratings to visual word processing beyond those of other semantic variables related to perceptual experience (e.g., concreteness, imageability, and sensory experience ratings). The ratings developed in this study are a meaningful contribution toward the implementation of new studies that will shed further light on the interaction between linguistic, semantic, and perceptual systems.

Task-specific signatures in the expert brain: Differential correlates of translation and reading in professional interpreters

Insights on the neurocognitive particularities of expert individuals have benefited from language studies on professional simultaneous interpreters (PSIs). Accruing research indicates that behavioral advantages in this population are restricted to those skills that are directly taxed during professional practice (e.g., translation as opposed to reading), but little is known about the neural signatures of such selective effects. To illuminate the issue, we recruited 17 PSIs and 15 non-interpreter bilinguals and compared behavioral and electrophysiological markers of word reading and translation from and into their native and non-native languages (L1 and L2, respectively). PSIs exhibited greater delta-theta (1-8 ​Hz) power across all tasks over varying topographies, but these were accompanied by faster performance only in the case of translation conditions. Moreover, neural differences in PSIs were most marked for L2-L1 translation (the dominant interpreting direction in their market), which exhibited maximally widespread modulations that selectively correlated with behavioral outcomes. Taken together, our results suggest that interpreting experience involves distinct neural signatures across reading and translation mechanisms, but that these are systematically related with processing efficiency only in domains that face elevated demands during everyday practice (i.e., L2-L1 translation). These findings can inform models of simultaneous interpreting, in particular, and expert cognitive processing, in general.

Degree and not type of iconicity affects sign language vocabulary acquisition

Lexical iconicity-signs or words that resemble their meaning-is overrepresented in children's early vocabularies. Embodied theories of language acquisition predict that symbols are more learnable when they are grounded in a child's firsthand experiences. As such, pantomimic iconic signs, which use the signer's body to represent a body, might be more readily learned than other types of iconic signs. Alternatively, the structure mapping theory of iconicity predicts that learners are sensitive to the amount of overlap between form and meaning. In this exploratory study of early vocabulary development in American Sign Language (ASL), we asked whether type of iconicity predicts sign acquisition above and beyond degree of iconicity. We also controlled for concreteness and relevance to babies, two possible confounding factors. Highly concrete referents and concepts that are germane to babies may be amenable to iconic mappings. We reanalyzed a previously published set of ASL Communicative Development Inventory (CDI) reports from 58 deaf children learning ASL from their deaf parents (Anderson & Reilly, 2002). Pantomimic signs were more iconic than other types of iconic signs (perceptual, both pantomimic and perceptual, or arbitrary), but type of iconicity had no effect on acquisition. Children may not make use of the special status of pantomimic elements of signs. Their vocabularies are, however, shaped by degree of iconicity, which aligns with a structure mapping theory of iconicity, though other explanations are also compatible (e.g., iconicity in child-directed signing). Previously demonstrated effects of type of iconicity may be an artifact of the increased degree of iconicity among pantomimic signs. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Construção e Avaliação para 15 Listas de Palavras Baseadas no Paradigma Deese-Roediger-McDermott

Resumo Com base nos estudos conduzidos de acordo com o paradigma Deese-Roediger-McDermott (DRM), em quais palavras de uma lista tendem a evocar outros itens relacionados, utilizado em pesquisas de falsas memórias, neste estudo elaborou-se 15 listas de palavras semanticamente relacionadas para o português. Para a elaboração das listas, foram considerados critérios como frequência de palavras no corpus de português brasileiro e extensão de palavras. A pré-seleção guiada por características linguísticas visava controlar possíveis vieses por parte dos voluntários. Testes de associação semântica e concretude de palavras foram realizados para apurar a conveniência dos itens selecionados, e um teste de recordação livre foi conduzido para avaliar características de evocação. Sugerimos a utilização das listas de palavras em pesquisas que avaliem falsas memórias.

Somatic and visceral effects of word valence, arousal and concreteness in a continuum lexical space

Although affective and semantic word properties are known to independently influence our sensorimotor system, less is known about their interaction. We investigated this issue applying a data-driven mixed-effects regression approach, evaluating the impact of lexical-semantic properties on electrophysiological parameters, namely facial muscles activity (left corrugator supercilii, zygomaticus major, levator labii superioris) and heartbeat, during word processing. 500 Italian words were acoustically presented to 20 native-speakers, while electrophysiological signals were continuously recorded. Stimuli varied for affective properties, namely valence (the degree of word positivity), arousal (the amount of emotional activation brought by the word), and semantic ones, namely concreteness. Results showed that the three variables interacted in predicting both heartbeat and muscular activity. Specifically, valence influenced activation for lower levels of arousal. This pattern was further modulated by concreteness: the lower the word concreteness, the larger affective-variable impact. Taken together, our results provide evidence for bodily responses during word comprehension. Crucially, such responses were found not only for voluntary muscles, but also for the heartbeat, providing evidence to the idea of a common emotional motor system. The higher impact of affective properties for abstract words supports proposals suggesting that emotions play a central role in the grounding of abstract concepts.

Fine Subdivisions of the Semantic Network Supporting Social and Sensory-Motor Semantic Processing

Neuroimaging studies have consistently indicated that semantic processing involves a brain network consisting of multimodal cortical regions distributed in the frontal, parietal, and temporal lobes. However, little is known about how semantic information is organized and processed within the network. Some recent studies have indicated that sensory-motor semantic information modulates the activation of this network. Other studies have indicated that this network responds more to social semantic information than to other information. Using fMRI, we collectively investigated the brain activations evoked by social and sensory-motor semantic information by manipulating the sociality and imageability of verbs in a word comprehension task. We detected 2 subgroups of brain regions within the network showing sociality and imageability effects, respectively. The 2 subgroups of regions are distinct but overlap in bilateral angular gyri and adjacent middle temporal gyri. A follow-up analysis of resting-state functional connectivity showed that dissociation of the 2 subgroups of regions is partially associated with their intrinsic functional connectivity differences. Additionally, an interaction effect of sociality and imageability was observed in the left anterior temporal lobe. Our findings indicate that the multimodal cortical semantic network has fine subdivisions that process and integrate social and sensory-motor semantic information.

Duality of Function: Activation for Meaningless Nonwords and Semantic Codes in the Same Brain Areas

Studies of the neural substrates of semantic (word meaning) processing have typically focused on semantic manipulations, with less consideration for potential differences in difficulty across conditions. While the idea that particular brain regions can support multiple functions is widely accepted, studies of specific cognitive domains rarely test for co-location with other functions. Here we start with standard univariate analyses comparing words to meaningless nonwords, replicating our recent finding that this contrast can activate task-positive regions for words, and default-mode regions in the putative semantic network for nonwords, pointing to difficulty effects. Critically, this was followed up with a multivariate analysis to test whether the same areas activated for meaningless nonwords contained semantic information sufficient to distinguish high- from low-imageability words. Indeed, this classification was performed reliably better than chance at 75% accuracy. This is compatible with two non-exclusive interpretations. Numerous areas in the default-mode network are task-negative in the sense of activating for less demanding conditions, and the same areas contain information supporting semantic cognition. Therefore, while areas of the default mode network have been hypothesized to support semantic cognition, we offer evidence that these areas can respond to both domain-general difficulty effects, and to specific aspects of semantics.

On the role of retrieval processes in the survival processing effect: Evidence from ROC and ERP analyses

Memory is enhanced for words encoded in the context of an imagined survival scenario, an effect modulated by word imageability or concreteness. However, the mechanisms underlying this "survival processing effect" are still controversial. To address this issue, we used receiver operating characteristic (ROC) curves and event-related potentials (ERPs) to examine the recognition retrieval processes associated with words previously encoded in either a survival or a control scenario. More specifically, we investigated how recollection- and familiarity-based retrieval are influenced by survival processing of high- and low-imageability words. Participants incidentally encoded words and then completed a surprise recognition test while their EEG was recorded. The encoding of concrete, high-imageability words in a survival context lead to improved recognition memory compared to the control context, and this improvement was associated with an increase in both the ROC and ERP measures of recollection-based memory retrieval. Survival processing was also associated with an increase in the ERP familiarity signal for these words, but the ROC analysis indicated that recognition judgments relied upon recollection rather than familiarity. These findings provide evidence that survival processing increases elaboration during encoding, leading to greater recollection at retrieval and, in turn, enhanced memory.

Verb and sentence processing patterns in healthy Italian participants: Insight from the Northwestern Assessment of Verbs and Sentences (NAVS)

We developed an Italian version of the Northwestern Assessment of Verbs and Sentences (NAVS, Thompson, 2011), a test assessing verb and sentence deficits typically found in aphasia, by focusing on verb-argument structure and syntactic complexity effects, rarely captured by standard language tests. Twenty-one young healthy individuals underwent a computerized experimental version of the NAVS, including three subtests assessing production/comprehension of verbs with different number (one, two, three) and type (obligatory or optional) of arguments, and two investigating production/comprehension of sentences with canonical/non-canonical word order. The number of verb arguments affected participants' reaction times (RTs) in verb naming and comprehension. Furthermore, verbs with optional arguments were processed faster than verbs with only obligatory arguments. Comprehension accuracy was lower for object-cleft vs. subject-cleft sentences. Object clefts and object relatives also elicited longer RTs than subject clefts and subject relatives, respectively. The study shows that the NAVS is sensitive to linguistic aspects of verb/sentence processing in Italian as in the English language. The study also highlights some differences between languages in the verb/sentence processing patterns of healthy individuals. Finally, the study contributes to the understanding of how information about verb-argument structure is represented and processed in healthy individuals, with reference to current models of verb processing.

Distinct Functional Network Connectivity for Abstract and Concrete Mental Imagery

In several behavioral psycholinguistic studies, it has been shown that concrete words are processed more efficiently. They can be remembered faster, recognized better, and can be learned easier than abstract words. This fact is called concreteness effect. There are fMRI studies which compared the neural representations of concrete and abstract concepts in terms of activated regions. In the present study, a comparison has been made between the condition-specific connectivity of functional networks (obtained by group ICA) during imagery of abstract and concrete words. The obtained results revealed that the functional network connectivity between three pairs of networks during concrete imagery is significantly different from that of abstract imagery (FDR correction at the significance level of 0.05). These results suggest that abstract and concrete concepts have different representations in terms of functional network connectivity pattern. Remarkably, in all of these network pairs, the connectivity during concrete imagery is significantly higher than that of abstract imagery. These more coherent networks include both linguistic and visual regions with a higher engagement of the right hemisphere, so the results are in line with dual coding theory. Additionally, these three pairs of networks include the contrasting regions which have shown stronger activation either in concrete or abstract word processing in former studies. The findings imply that the brain is more integrated and synchronized at the time of concrete imagery and it may explain the reason of faster concrete words processing. In order to validate the results, we used functional network connectivity distributions (FNCD). Wilcoxon rank-sum test was used to check if the abstract and concrete FNCDs extracted from whole subjects are the same. The result revealed that the corresponding distributions are different which indicates two different patterns of connectivity for abstract and concrete word processing. Also, the mean of FNCD is significantly higher at the time of concrete imagery than that of abstract imagery. Furthermore, FNCDs at the single-subject level are significantly more left-skewed or equally, include more strong connectivity for concrete imagery.

Written-Word Concreteness Effects in Non-attend Conditions: Evidence From Mismatch Responses and Cortical Oscillations

It has been widely reported that concrete words have processing advantages over abstract words in terms of speed and efficiency of processing, a phenomenon known as the concreteness effect. However, little is still known about the early time-course of processing concrete and abstract words and whether this concreteness effect can still persist in conditions where attention is not focused on the words presented (automatic processing). This study aimed to shed light on these issues by examining the electrophysiological brain responses to concrete and abstract words. While participants were engaged in a non-linguistic color tracking task presented in the center of the monitor screen, matched Chinese concrete and abstract single-character words appeared within a passive oddball paradigm, out of the focus of attention. In calculating visual Mismatch Negativity (vMMN), Event-related potentials (ERPs) to words of the same semantic category were compared when these words were presented as deviants and standards. Before 320 ms, both abstract and concrete words yielded vMMN with left-lateralized distribution, suggesting similar verbal processing at an initial processing stage. After 320 ms, only concrete words additionally elicited vMMN with a central distribution. Time frequency (TF) analysis of the results also revealed larger theta power increase (200-300 ms) and theta power phase locking (200-450 ms) for concrete than for abstract words. Interestingly, there was more alpha power decrease for abstract than for concrete words from 300 to 450 ms. This may reflect the greater difficulty in processing abstract meaning. Taken together, our ERP and TF results point to the existence of different neural mechanisms underlying non-attentive processing of abstract and concrete words.

Investigating the functional neuroanatomy of concrete and abstract word processing through direct electric stimulation (DES) during awake surgery

Neuropsychological, neuroimaging and electrophysiological studies demonstrate that abstract and concrete word processing relies not only on the activity of a common bilateral network but also on dedicated networks. The neuropsychological literature has shown that a selective sparing of abstract relative to concrete words can be documented in lesions of the left anterior temporal regions. We investigated concrete and abstract word processing in 10 patients undergoing direct electrical stimulation (DES) for brain mapping during awake surgery in the left hemisphere. A lexical decision and a concreteness judgment task were added to the neuropsychological assessment during intra-operative monitoring. On the concreteness judgment, DES delivered over the inferior frontal gyrus significantly decreased abstract word accuracy while accuracy for concrete words decreased when the anterior temporal cortex was stimulated. These results are consistent with a lexical-semantic model that distinguishes between concrete and abstract words related to different neural substrates in the left hemisphere.

In defense of abstract conceptual representations

An extensive program of research in the past 2 decades has focused on the role of modal sensory, motor, and affective brain systems in storing and retrieving concept knowledge. This focus has led in some circles to an underestimation of the need for more abstract, supramodal conceptual representations in semantic cognition. Evidence for supramodal processing comes from neuroimaging work documenting a large, well-defined cortical network that responds to meaningful stimuli regardless of modal content. The nodes in this network correspond to high-level "convergence zones" that receive broadly crossmodal input and presumably process crossmodal conjunctions. It is proposed that highly conjunctive representations are needed for several critical functions, including capturing conceptual similarity structure, enabling thematic associative relationships independent of conceptual similarity, and providing efficient "chunking" of concept representations for a range of higher order tasks that require concepts to be configured as situations. These hypothesized functions account for a wide range of neuroimaging results showing modulation of the supramodal convergence zone network by associative strength, lexicality, familiarity, imageability, frequency, and semantic compositionality. The evidence supports a hierarchical model of knowledge representation in which modal systems provide a mechanism for concept acquisition and serve to ground individual concepts in external reality, whereas broadly conjunctive, supramodal representations play an equally important role in concept association and situation knowledge.

The Influence of Concreteness of Concepts on the Integration of Novel Words into the Semantic Network

On the basis of previous studies revealing a processing advantage of concrete words over abstract words, the current study aimed to further explore the influence of concreteness on the integration of novel words into semantic memory with the event related potential (ERP) technique. In the experiment during the learning phase participants read two-sentence contexts and inferred the meaning of novel words. The novel words were two-character non-words in Chinese language. Their meaning was either a concrete or abstract known concept which could be inferred from the contexts. During the testing phase participants performed a lexical decision task in which the learned novel words served as primes for either their corresponding concepts, semantically related or unrelated targets. For the concrete novel words, the semantically related words belonged to the same semantic categories with their corresponding concepts. For the abstract novel words, the semantically related words were synonyms of their corresponding concepts. The unrelated targets were real words which were concrete or abstract for the concrete or abstract novel words respectively. The ERP results showed that the corresponding concepts and the semantically related words elicited smaller N400s than the unrelated words. The N400 effect was not modulated by the concreteness of the concepts. In addition, the concrete corresponding concepts elicited a smaller late positive component (LPC) than the concrete unrelated words. This LPC effect was absent for the abstract words. The results indicate that although both concrete and abstract novel words can be acquired and linked to their related words in the semantic network after a short learning phase, the concrete novel words are learned better. Our findings support the (extended) dual coding theory and broaden our understanding of adult word learning and changes in concept organization.

Production of verbs related to body movement in amyotrophic lateral sclerosis (ALS) and Parkinson's Disease (PD)

Theories of grounded cognition propose that action verb knowledge relies in part on motor processing regions, including premotor cortex. Accordingly, impaired action verb knowledge in patients with amyotrophic lateral sclerosis (ALS) and Parkinson's Disease (PD) is thought to be due to motor system degeneration. Upper motor neuron disease in ALS degrades the motor cortex and related pyramidal motor system, while disease in PD is centered in the basal ganglia and can spread to frontostriatal areas that are important to language functioning. These anatomical distinctions in disease may yield subtle differences in the action verb impairment between patient groups. Here we compare verbs where the body is the agent of the action to verbs where the body is the theme. To examine the role of motor functioning in body verb production, we split patient groups into patients with high motor impairment (HMI) and those with low motor impairment (LMI), using disease-specific measures of motor impairment. Regression analyses assessed how verb production in ALS and PD was related to motor system atrophy. We find a dissociation between agent- and theme-body verbs in ALS: ALS HMI were impaired for agent body verbs but not theme verbs, compared to ALS LMI. This dissociation was not present in PD patients, who instead show depressed production for all body verbs. Although patients with cognitive impairment were excluded from this study, cognitive performance significantly correlated with the production of theme verbs in ALS and cognitive/stative verbs in PD. Finally, regression analyses related the agent-theme dissociation in ALS to grey matter atrophy of premotor cortex. These findings support the view that motor dysfunction and disease in premotor cortex contributes to the agent body verb deficit in ALS, and begin to identify some distinct characteristics of impairment for verbs in ALS and PD.

Recently learned foreign abstract and concrete nouns are represented in distinct cortical networks similar to the native language

In the native language, abstract and concrete nouns are represented in distinct areas of the cerebral cortex. Currently, it is unknown whether this is also the case for abstract and concrete nouns of a foreign language. Here, we taught adult native speakers of German 45 abstract and 45 concrete nouns of a foreign language. After learning the nouns for 5 days, participants performed a vocabulary translation task during functional magnetic resonance imaging. Translating abstract nouns in contrast to concrete nouns elicited responses in regions that are also responsive to abstract nouns in the native language: the left inferior frontal gyrus and the left middle and superior temporal gyri. Concrete nouns elicited larger responses in the angular gyri bilaterally and the left parahippocampal gyrus than abstract nouns. The cluster in the left angular gyrus showed psychophysiological interaction (PPI) with the left lingual gyrus. The left parahippocampal gyrus showed PPI with the posterior cingulate cortex. Similar regions have been previously found for concrete nouns in the native language. The results reveal similarities in the cortical representation of foreign language nouns with the representation of native language nouns that already occur after 5 days of vocabulary learning. Furthermore, we showed that verbal and enriched learning methods were equally suitable to teach foreign abstract and concrete nouns. Hum Brain Mapp 38:4398-4412, 2017. © 2017 Wiley Periodicals, Inc.

Word Imageability Enhances Association-memory by Increasing Hippocampal Engagement

The hippocampus is thought to support association-memory, particularly when tested with cued recall. One of the most well-known and studied factors that influences accuracy of verbal association-memory is imageability; participants remember pairs of high-imageability words better than pairs of low-imageability words. High-imageability words are also remembered better in tests of item-memory. However, we previously found that item-memory effects could not explain the enhancement in cued recall, suggesting that imageability enhances association-memory strength. Here we report an fMRI study designed to ask, what is the role of the hippocampus in the memory advantage for associations due to imageability? We tested two alternative hypotheses: (1) Recruitment Hypothesis: High-imageability pairs are remembered better because they recruit the underlying hippocampal association-memory function more effectively. Alternatively, (2) Bypassing Hypothesis: Imageability functions by making the association-forming process easier, enhancing memory in a way that bypasses the hippocampus, as has been found, for example, with explicit unitization imagery strategies. Results found, first, hippocampal BOLD signal was greater during study and recall of high- than low-imageability word pairs. Second, the difference in activity between recalled and forgotten pairs showed a main effect, but no significant interaction with imageability, challenging the bypassing hypothesis, but consistent with the predictions derived from the recruitment hypothesis. Our findings suggest that certain stimulus properties, like imageability, may leverage, rather than avoid, the associative function of the hippocampus to support superior association-memory.

Imaging Imageability: Behavioral Effects and Neural Correlates of Its Interaction with Affect and Context

The construct of imageability refers to the extent to which a word evokes a tangible sensation. Previous research (Westbury et al., 2013) suggests that the behavioral effects attributed to a word's imageability can be largely or wholly explained by two objective constructs, contextual density and estimated affect. Here, we extend these previous findings in two ways. First, we show that closely matched stimuli on the three measures of contextual density, estimated affect, and human-judged imageability show a three-way interaction in explaining variance in LD RTs, but that imagebility accounts for no additional variance after contextual density and estimated affect are entered first. Secondly, we demonstrate that the loci and functional connectivity (via graphical models) of the brain regions implicated in processing the three variables during that task are largely over-lapping and similar. These two lines of evidence support the conclusion that the effect usually attributed to human-judged imageability is largely or entirely due to the effects of other correlated measures that are directly computable.

Cognitive and anatomic double dissociation in the representation of concrete and abstract words in semantic variant and behavioral variant frontotemporal degeneration

We examine the anatomic basis for abstract and concrete lexical representations in semantic memory by assessing patients with focal neurodegenerative disease. Prior evidence from healthy adult studies suggests that there may be an anatomical dissociation between abstract and concrete representations: abstract words more strongly activate the left inferior frontal gyrus relative to concrete words, while concrete words more strongly activate left anterior-inferior temporal regions. However, this double dissociation has not been directly examined. We test this dissociation in two patient groups with focal cortical atrophy in each of these regions, the behavioral variant of Frontotemporal Degeneration (bvFTD) and the semantic variant of Primary Progressive Aphasia (svPPA). We administered an associativity judgment task for abstract and concrete words, where subjects select which of two words is best associated with a given target word. Both bvFTD and svPPA patients were significantly impaired in their overall performance compared to controls. While controls treated concrete and abstract words equally, we found a category-specific double dissociation in patients' judgments: bvFTD patients showed a concreteness effect (CE), with significantly worse performance for abstract compared to concrete words, while svPPA patients showed reversal of the CE, with significantly worse performance for concrete over abstract words. Regression analyses also revealed an anatomic double dissociation: The CE is associated with inferior frontal atrophy in bvFTD, while reversal of the CE is associated with left anterior-inferior temporal atrophy in svPPA. These results support a cognitive and anatomic model of semantic memory organization where abstract and concrete representations are supported by dissociable neuroanatomic substrates.

Abstract Conceptual Feature Ratings Predict Gaze Within Written Word Arrays: Evidence From a Visual Wor(l)d Paradigm

The Abstract Conceptual Feature (ACF) framework predicts that word meaning is represented within a high-dimensional semantic space bounded by weighted contributions of perceptual, affective, and encyclopedic information. The ACF, like latent semantic analysis, is amenable to distance metrics between any two words. We applied predictions of the ACF framework to abstract words using eyetracking via an adaptation of the classical "visual word paradigm" (VWP). Healthy adults (n = 20) selected the lexical item most related to a probe word in a 4-item written word array comprising the target and three distractors. The relation between the probe and each of the four words was determined using the semantic distance metrics derived from ACF ratings. Eye movement data indicated that the word that was most semantically related to the probe received more and longer fixations relative to distractors. Importantly, in sets where participants did not provide an overt behavioral response, the fixation rates were nonetheless significantly higher for targets than distractors, closely resembling trials where an expected response was given. Furthermore, ACF ratings which are based on individual words predicted eye fixation metrics of probe-target similarity at least as well as latent semantic analysis ratings which are based on word co-occurrence. The results provide further validation of Euclidean distance metrics derived from ACF ratings as a measure of one facet of the semantic relatedness of abstract words and suggest that they represent a reasonable approximation of the organization of abstract conceptual space. The data are also compatible with the broad notion that multiple sources of information (not restricted to sensorimotor and emotion information) shape the organization of abstract concepts. While the adapted "VWP" is potentially a more metacognitive task than the classical visual world paradigm, we argue that it offers potential utility for studying abstract word comprehension.