Abstract This study investigated the degree to which cognitive mechanisms support word recognition and word inflection in aging and how this changes in Alzheimer’s disease (AD). We tested competing hypotheses regarding the functional organization of language within the broader cognitive system. One set of hypotheses, derived from dual-system theories like the Declarative/Procedural (DP) model, predicts a functional architecture segregated by linguistic function. An alternative set of hypotheses posits a more integrated architecture, organized by task demands and resource availability. We analyzed participants’ performance on a lexical decision task and a word inflection task, alongside neuropsychological tests, using both behavioral and network analyses. In healthy controls (HC), the network analysis revealed a highly integrated architecture where language tasks were clustered by functional demands (e.g., speed vs. accuracy) rather than segregated along a strict lexicon/grammar divide. In the AD group, behavioral results showed a classic dissociation, with disproportionate impairment on irregular word inflection — a pattern traditionally seen as evidence for a modular memory failure. However, our network analysis revealed a different underlying mechanism. We observed a dramatic network reorganization where a core declarative memory module became functionally isolated, causing language tasks to form new, compensatory alliances with remaining frontal-executive resources. This provides clear evidence of a shift where executive functions are recruited to support language abilities when dedicated memory systems decline. These findings suggest that the cognitive substrate for language is not static but adapts dynamically in neurodegeneration, shifting its reliance from failing declarative memory systems to domain-general executive control pathways.

Abstract Cortical memory circuits that represent words in the brain form the foundation of our mental lexicon; yet, their architecture remains poorly understood. A valuable approach to probing these representations is measuring the Mismatch Negativity (MMN), an electrophysiological brain response sensitive to various psycholinguistic variables; however, its specificity to lexical processing remains debated. To scrutinise its properties as a neural index of word-specific memory trace activity, we adapted the classical passive auditory oddball design to fMRI and recorded the BOLD (blood oxygenation level-dependent) correlate of the MMN elicited by words of different lexical frequencies and by phonologically matched control pseudowords. The results showed significant BOLD-MMN responses in bilateral superior-temporal and middle-temporal cortices. Crucially, these activations were more expressed for meaningful words than meaningless pseudowords, indicating BOLD-MMN sensitivity to the stimulus’ lexicality. We also found the left temporal activity to be more pronounced for high- than low-frequency words, the effect not found for their pseudoword analogues, further confirming the lexical nature of these responses. This pattern of results is best explained by the automatic activation of long-term memory traces for real words formed in the process of previous linguistic experience whose intensity determines the strength of connectivity within these circuits and thus the magnitude of their activation, which thereby reflects the respective stimuli’s status in the brain's mental lexicon.

Abstract This study explores gender assignment strategies in Russian-Hebrew code-mixed adjective-noun phrases. Russian features a three-gender system (masculine, feminine, neuter), while Hebrew uses a two-gender system (masculine, feminine). Despite these differences, both languages share transparent gender assignment cues: nouns ending in -a are typically feminine, while those ending in consonants are generally masculine. Both languages also feature opaque nouns. Eighty Russian-Hebrew speakers participated, divided into heritage language (HL) speakers (age of bilingualism onset [AoB]: 0–6 years, dominant in Hebrew) and immigrant (IMM) speakers (AoB: 9+ years, dominant in Russian). Participants rated the acceptability of code-mixed sentences featuring Russian nouns within Hebrew matrix sentences. Results showed a preference for strategies combining shape-based and insertion approaches with transparent nouns, reflecting overlapping linguistic cues in both languages. The same strategies were preferred for opaque congruent nouns, where no gender conflict existed. For opaque gender-incongruent nouns, strategy use was shaped by the degree of overlap between the languages’ gender systems. Although differences between HL and IMM speakers were expected, no group variation in strategy use was found. These findings advance our understanding of gender assignment in code-switching contexts and shed light on how bilinguals represent and process gender when two linguistic gender systems are involved.

Abstract Morphological effects are consistently reported in written word recognition but their theoretical explanation is still debated. The paper aims to disentangle the specific role of morphological information from orthography during written word recognition. We exploit the “morphemic ambiguity” of stem-homographs, words that share formally identical but morphologically and semantically unrelated stems (e.g., mor-a, “blackberry” and mor-ire, “to die”). Two unmasked visual priming lexical decision experiments are described. The results replicate the inhibitory priming effects elicited by stem-homographs, extend it to their allomorphic variants in Italian (e.g., mor-a, and muor-e, “he/she dies”, verb form deriving from an allomorph ( muor -) of the homographic stem mor - of morire) and differentiate the stem-homographs and the stem-allomorphs inhibition from the positional effects of orthographic overlap in prime-target pairs. The pattern of data confirms the presence of mechanisms of morphological segmentation in word recognition. On the other hand, the effects fit with hypotheses of graded morphology where word stems are supposed to affect the processing of words on the basis of multiple connections between regular and irregular forms included in their inflectional paradigms and derivational families.

Abstract According to the affix-chunking hypothesis, a letter search should be more difficult for a letter embedded in an affix compared with a non-affixed letter sequence because affixes have a functional significance. On the other hand, the decomposition hypothesis claims that derived (e.g., hunter) and pseudo-derived words (e.g., corner) are processed similarly, with lexical access being driven by affix stripping followed by the activation of the remaining stem to reach the mental lexicon. We conducted a letter-search task to test these hypotheses using both prefixed (e.g., détour ‘detour’), suffixed (e.g., acteur ‘actor’) words, compared with matched pseudo-prefixed (e.g., décor ‘decor’), pseudo-suffixed (e.g., fleur ‘flower’) words. Decision latencies on letter targets were compared to non-affixed words for each type of affix (e.g., drogue ‘drug’ for détour, décor and tâche ‘task’ for acteur, fleur). Our results revealed an asymmetry in the processing of suffixed versus prefixed words. While a significant facilitation effect was found for suffixed words relative to pseudo-suffixed words, no similar advantage was observed for prefixed over pseudo-prefixed words. The asymmetry in identifying letters in prefixes and suffixes is interpreted in terms of the differing functional salience of affixes in French.

Abstract This study investigates whether the recognition advantage of proper names (PN) over common nouns (CN) — reported in several languages — is also observed in Spanish, and whether different types of PN (e.g., personal vs. geographical) are affected to the same extent. Drawing on semantic theories that assign different presuppositional meanings to subcategories of PN, we designed four experiments to examine PN processing patterns: a lexical decision task, two categorization tasks, and a semantic priming task. To explore which semantic factors account for variability within each subcategory, we also conducted a series of regression analyses. The results confirm a cross-linguistic recognition advantage for PN in categorization tasks; however, this effect is limited to personal PN — even after controlling for affective factors and familiarity — while the advantage for geographical PN appears to be language-specific. Participants’ behavioral responses to geographical PN resembled those elicited by CN. These findings suggest that PN is a semantically heterogeneous category, and that their recognition lies on a continuum with that of CN.

Abstract This study aims to model lexical attrition in L2 mental lexicon for Chinese EFL learners using a network science technique. To this end, we constructed a large lexical network with 5746 English words with free association data collected from Chinese EFL college students. The attrition process was modeled by removing connections progressively from the network, leaving words less connected or isolated. Further, we controlled the order in which connections underwent attrition to explore whether order of attrition affected the attrition process. The results showed that: (1) The modeled L2 lexicon was a complex network, whose structure was different from random networks in terms of connectedness, average path lengths, clustering coefficient, power-law degree distribution; (2) Attrition events weakened the structure of L2 mental lexicon by increasingly reducing the number of interconnected words, increasing path lengths between words, and diminishing overall network efficiency, but the process was not linear; (3) The order in which attrition events occur affects the attrition process; specifically, attrition starting from peripheral connections dismantled the lexical network more slowly when compared with random and central-to-peripheral orderings. These findings add to our understanding of the cognitive organization of words in the mind, and provide fresh insight into lexical attrition.

Abstract Semantic dimensions such as context availability, imageability and valence, form core components of many theoretical accounts of lexical processing. Typically, normative data for such semantic dimensions are drawn from subjective ratings, however, questions have been raised regarding the reliability and validity of these ratings. In this paper, we discuss this issue with a focus on context availability norms. Using data collected for another study, we show that context availability ratings required significantly higher rates of data exclusions at the level of both participants and items compared to other variables. In addition, high standard deviations at the item level, indicated a substantial degree of disagreement between participants. This suggested that some participants may have had difficulty understanding the concept of context availability which hindered their ability to complete the ratings. We provide recommendations for future research focusing on context availability and for norm collection procedures more broadly in order that the validity of such norms can be improved. In particular, we suggest that clear guidelines are required for data cleaning in order that the reliability of such norms is maximised and to facilitate replication across studies.

Abstract The Bouba/Kiki (BK) effect is observed when a linguistic sound is associated with a shape. People usually associate the nonword bouba with a round shape, and kiki with a sharp shape (Ramachandran & Hubbard, 2001). In 2011, Nielsen and Rendall found that certain English letters (/k/, /p/, and /t/) and (/b/, /l/, /m/, and /n/) were associated with sharp and round shapes respectively. The BK effect was investigated in depth for the first time in Arabic in 2022 (Nassereddine) using Arabic Analogs to the English letters. Arabic participants’ performance was not consistent with previous research (Nielsen & Rendall, 2011). The goal of the present study was to determine the roundest and sharpest Arabic letters by presenting all letters both visually and auditorily to Arabic speakers and have them say whether a letter shape or sound best maps on to the standard bouba and kiki shapes. The results revealed that Arabic does have both round and sharp letters, and that there is a strong influence of phonological features on this BK effect.