BackgroundThe logopenic variant of primary progressive aphasia (lvPPA) is a language-led neurodegenerative syndrome commonly associated with Alzheimer's disease pathology and temporo-parietal degeneration. Although acalculia has been reported in lvPPA, numerical cognition has not been systematically investigated, and the specific profile of impairment remains poorly defined.ObjectiveTo characterize numerical cognition impairment in lvPPA using a comprehensive, theory-driven assessment battery and to examine its clinical relevance for diagnosis and cognitive characterization.MethodsFourteen individuals with lvPPA and twenty-eight demographically matched healthy controls completed the dCALQ, a standardized battery assessing number recognition and comprehension, number production (transcoding), and calculation. Participants also underwent global cognitive screening (Montreal Cognitive Assessment), language assessment (Detection Test for Language Impairments in Adults and the Aged), and measures of working memory and executive functioning. Group comparisons, intra-group domain analyses, correlation analyses, and receiver operating characteristic (ROC) analyses were performed.ResultsIndividuals with lvPPA showed significant impairments across all numerical domains compared with controls, with the most severe deficits in calculation, followed by transcoding, and milder impairment in number recognition and comprehension. Within the lvPPA group, performance differed significantly across domains, revealing a graded pattern of impairment. ROC analyses demonstrated excellent diagnostic accuracy for the dCALQ total score and strong discrimination for the calculation and transcoding domains.ConclusionsNumerical impairment is a robust and systematic feature of lvPPA rather than an incidental finding. The distinct numerical profile identified highlights the contribution of parietal-based cognitive dysfunction and supports the clinical utility of structured numerical assessment for cognitive characterization and diagnosis in dementia syndromes.

Spatial-numerical associations (SNAs), such as the SNARC effect, reflect the tendency to associate smaller numbers with the left side of space and larger numbers with the right. While robust in hand-based tasks, SNAs are flexible and influenced by sensorimotor context. This study examined how static hand posture shapes the SNARC effect in a foot-response paradigm by providing task-irrelevant postural cues, thereby isolating the influence of postural configuration from motor execution. Grounded in embodied cognition, we hypothesized that passive visual and proprioceptive cues would bias spatial-numerical mappings. These cues were provided by task-irrelevant hand postures. Participants (N = 103) completed a magnitude classification task using left and right foot pedals to indicate whether digits (1-4, 6-9) were smaller or larger than 5. Hand posture was manipulated between subjects: fingers interlaced (control), palms down, or palms up. The results revealed significant SNARC effects in the palms-down and palms-up conditions, but not in the control condition, while numerical distance effects were observed across all conditions. These findings indicate that static bodily configurations, even when unrelated to the response effector, can influence SNAs. The results support embodied accounts of numerical cognition, demonstrate that current sensorimotor states influence number-space mappings, and show the methodological utility of foot-based paradigms in disentangling posture effects from response modality.

Dual Neural Foundations of Coding Cognition: Language Comprehension Scaffolds Initial Learning Before Mathematical Systems Engage.

A meta-analysis on mathematical deficits among Chinese children with mathematical learning difficulties.

In research on animal numerical cognition, newly hatched domestic chicks have been shown to rely on distinct strategies when confronted with quantitative choices. In some conditions, such as after imprinting on a specific set of objects, chicks preferentially approach the larger set of familiar items, indicating sensitivity to magnitude. In other conditions, however, their responses are governed not by magnitude per se, but by the degree of similarity between the test objects and a previously experienced set, where similarity is defined in terms of conformity to specific perceptual constraints, such as the possibility of a symmetrical division into identical subsets (as in composite versus prime sets of items). In the present study, we sought to replicate both phenomena while aligning key methodological features, including the test arena, the comparison (5 vs. 9), and the age at testing. One group of chicks was imprinted on a set of identical objects to test preference for larger familiar set; another group was habituated to even-numbered sets to assess sensitivity to perceptual asymmetry in prime-numbered ones. We successfully replicated both effects: chicks preferred the larger set after imprinting and showed longer inspection of the prime-numbered set after habituation, despite its smaller magnitude. Our results show that different mechanisms supporting quantity discrimination are available from the earliest stages of life and can be triggered by task- or environment-specific factors.

Symbolic numerical thinking is a signature human cognition, yet its foundations remain unclear. The prevailing perspective holds that numerical abilities build on a non-symbolic visual number sense that extracts numerosity from the environment. However, recent evidence suggests a sensorimotor number system also tracks the numerosity of internally self-generated actions. Whether this system supports the development of mathematical skills is unknown. In a series of psychophysical tasks, we measured precision (Weber fraction) for estimating, without counting, the number of (i) self-generated hand actions, (ii) visual-temporal flashes, and (iii) dot ensembles. Precision in the action-based numerosity estimation task explained about 30% of the variance in mental calculation ability — three and 15 times higher than spatial and temporal visual numerosity, respectively. This link remained strong even after regressing out the variance explained by natural development (age), verbal and non-verbal reasoning, non-numerical motor abilities, and visual numerosity estimation precision (R2 ≈ 26%). These findings provide the first evidence for a specific link between the sensorimotor number system and mathematical competence, suggesting a foundational role of sensorimotor numerical processes in the development of symbolic human numerical cognition.

The neuronal mechanisms by which the brain flexibly transforms perceived numerical values into corresponding numbers of self-generated actions remain poorly understood. Here, we investigated this sensorimotor transformation process in the parietal cortex of two male rhesus macaques performing a manual counting task. Monkeys viewed visual numerical cues and produced a corresponding number of hand movements. Single-neuron recordings from the ventral intraparietal area (VIP)-a region known to represent perceived numerosity-revealed tuning to the number of intended actions during motor planning. These neurons showed both sustained and transient activity patterns, reflecting static and dynamic codes that support numerical sensorimotor transformation. Population decoding confirmed that VIP encoded intended action number and reflected systematic over- and underestimation errors. Our findings reveal a neural mechanism by which the primate brain converts abstract numerical input into goal-directed motor output, providing insight into the sensorimotor foundations of numerical cognition.

Numeral systems in Bantu languages reflect both linguistic structure and socio cultural functions. This paper explores the structure and socio-cultural functions of the Bena numeral system. The research employed a qualitative approach whereby the data were gathered through elicitation, and non-participant observation. The study was guided by the cognitive linguistics theory, which reveals how language shapes numerical cognition; testing linguistic relativity by showing how structural features like bases and classifiers influence thinking, memory, and arithmetic acquisition across cultures. The results show that numerals in Bena depict agreements with the noun class system, and follow additive structures in compound forms. The traditional counting system using fingers, head, and stones is also attested among elder speakers. However, the influence of Swahili has led to a gradual erosion of the numeral structure and traditional numeral usage, especially among younger generations. Also, the results show that numerals hold symbolic meanings in various socio-cultural functions. The study recommends an investigation of prosodic features in Bena numerals borrowed from Kiswahili, a documentation of native numeral systems, and further comparative research on numeral systems in other under documented Tanzanian Bantu languages.

Numerical cognition in speakers of an Amazonian language with exactly twenty number words.

Fraction processing presents an important test case for investigating the development of numerical cognition, as fraction proficiency in elementary school is a unique predictor of later mathematical achievement. Building on previous mouse-tracking research investigating the dynamics of fraction processing in adults, we used three-dimensional hand tracking to assess the dynamics of fraction processing in preadolescents (n = 30, 10-12 years of age) and young adults (n = 30, 18-22 years of age) performing a fraction magnitude comparison task. Preadolescents and adults showed limited evidence of global magnitude representations of fractions featuring congruent components and magnitudes (e.g., fractions like 1/3 and 1/4 in which the size of the components and the magnitudes of the fractions cued the same "small" response). However, clear evidence of global magnitude representations was observed on trials featuring incongruent components and magnitudes (e.g., fractions like 2/3 and 3/4 in which the size of the components cued a "small" response, but the magnitudes of the fraction cued a "large" response). The component-magnitude congruency effect observed in movement times was significantly larger in preadolescents than in adults, and the distance effect used to identify global magnitude representations was significantly larger in large magnitude fractions for preadolescents than for adults. Taken together, these results suggest that age-related changes in fraction processing reflect improved inhibitory control. More generally, our results challenge recent dual-process models of fraction processing, with performance more parsimoniously accounted for by differences in strategy rather than the involvement of distinct processes. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Understanding the mechanisms underlying animal cognition requires experimental designs and analyses that respect the biological and perceptual constraints of the species being studied. We address an ongoing debate regarding the role of visual spatial frequency in numerical cognition studies, using honeybees (Apis mellifera) as a model system. Prior analyses that excluded the low spatial frequencies known to be fundamental to how these insects use their spatial vision may have introduced spurious correlations between visual features and numerical cues. By recalculating stimulus properties while incorporating the biologically relevant spectrum of spatial frequencies perceivable by a bee, our results suggest that numerical cognition in honeybees is not driven by spatial frequency but instead reflects true numerosity processing. This work highlights the necessity of aligning experimental design and analysis with the sensory and perceptual abilities of the studied species to ensure biologically meaningful conclusions. To support this goal, we provide a general framework for designing experiments that respect the psychophysical constraints of animal models in numerical cognition studies.

Quantity discrimination is an important aspect of numerical cognition that is utilized across taxa in various ecological contexts, including foraging and predator avoidance. Recent research has identified that the developing young of several species possess spontaneous quantity discrimination abilities, though these are often limited compared with adults. These studies have been conducted exclusively in captivity using visual stimuli, and so there is a need for studies investigating quantity discrimination abilities in developing young in the wild. In this study, we presented post-fledgling juvenile great tits (Parus major) with the mobbing calls of one, three or five conspecific callers, and one, three or five heterospecific (blue tit, Cyanistes caeruleus) callers to investigate their quantity discrimination abilities in an anti-predator context. Juvenile great tits were more likely to respond to playbacks of multiple callers compared with one caller, regardless of whether callers were conspecific or heterospecific. These findings support those of previous work in captivity and suggest that quantity discrimination abilities are present from an early age. As the first study to our knowledge to investigate quantity discrimination in developing young in the wild, our results have important implications for the ontogeny of quantity discrimination, as well as its adaptive value to wild animals.

Introduction A negative correlation between math anxiety and mathematical performance is well-established. Yet, some studies suggest that math anxiety tends to impact more symbolic tasks, such as calculations and verbally formulated problems, than nonsymbolic math skills, such as number sense. Since most of these studies were conducted with older school children and young adults, this raises the question of whether the effect of math anxiety is widespread in early mathematics learning. The present study investigates how math anxiety manifests itself in first graders and whether its influence varies according to the different components of mathematics (symbolic vs. nonsymbolic). Method 229 Brazilian first-grade students from 10 public elementary schools participated in this study (mean age = 6.28, SD = 0.55; 55% female). Mathematical skills were assessed using the Zareki-R, which evaluates intuitive skills such as number sense (e.g., visual estimation of quantities), and symbolic skills such as numerical comprehension (e.g., number comparison), number production (e.g., reading number), and calculation (e.g., problem-solving). Participants also completed measures of math anxiety (EES-AMAS), nonverbal reasoning (Raven’s Progressive Matrices), reading, and writing skills. Multiple linear regression was performed to examine how math anxiety impacts symbolic vs. nonsymbolic mathematical skills while controlling for nonverbal reasoning, language skills, age, and gender. Results Higher math anxiety was correlated with lower performance in number production and comprehension but not number sense, and calculation. Discussion The findings suggest that the impacts of math anxiety vary across math skills as early as in the first grade, affecting more some symbolic math skills linked to number production and comprehension than calculation. Based on this, we discuss how different cognitive demands (e.g., working memory and attention), along with the neurodevelopment of numerical cognition, may contribute to the selective relationship observed in early elementary school.

French number words provide a unique window into the relationship between numerical cognition and language, because numbers above 60 follow a vigesimal (base-20) word structure (e.g., 72 = “60–12”). In a two-digit magnitude comparison task with sixty French native speakers, we replicated the classic unit-decade compatibility effect (UDCE; slower responses when unit and decade comparisons conflict) and within-decade effect (faster responses when decades are identical), reflecting the place-value structure of Arabic numerals. Given the French vigesimal system, we expected not only the classic UDCE and within-decade effect but also their vigesimal counterparts driven by magnitudes of number words: a unit-vigintade compatibility effect (UVCE) and a within-vigintade effect, in which pairs sharing the same decade word (e.g., “soixante” for the 60s and 70s) are processed faster than other between-decade pairs. Linear mixed models revealed both a UDCE for numbers larger than 60 and a UVCE, indicating that number words were accessed during processing. Participants also responded faster to within-vigintade items (86 vs. 95) than to between-vigintade items (76 vs. 85) and as fast as to within-decade items (82 vs. 85), indicating a verbal equivalent of the within-decade effect. This effect is unaffected by decade distance and can only be explained by access to number words so that the decades were identical (“80–6” vs. “80–15”). Overall, our data indicate that verbal representations can shape basic numerical judgments and that number processing may be more closely tied to language than previously assumed.

This article memorializes David A. Washburn (1961-2025), one of Washburn's most important accomplishments was the development and training of nonhuman primates to use computers to provide insights into their cognitive abilities. David was an expert on executive attention, and he also published seminal articles on the numerical cognition, working memory, and metacognitive abilities of nonhuman primates in comparison to humans. Highlights of Washburn's career and professional contributions are noted. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Ordinal processing is a core component of numerical cognition, and its behavioral signature is the Reverse Distance Effect (RDE). However, previous studies indicate that the RDE is influenced by sequence composition, and it is unclear whether it is similarly affected by sequence types. Prior research has largely focused on non-repeating sequences (e.g., 1-2-3), while the processing of repeated item sequences (i.e., non-strict sequences; e.g., 1-2-2-3) remains unexplored. Experiment 1 (numbers) showed a significant RDE in the first and last repetition conditions. However, the middle repetition condition resulted in a null effect, suggesting that the middle repeated item interferes differentially with ordinal representation. In contrast, Experiment 2 (letters) showed a significant RDE regardless of repetition position. Overall, the RDE extends to repeated item sequences when interference is comparable between distance conditions. Moreover, the presence of the RDE in the letter task indicates that the effect observed in repeated item sequences extends to non-numerical materials. This study provides the first systematic investigation of repeated item sequences, highlighting the role of repeated items in order judgment and expanding the scope of ordinal processing research.

Number sense is the intuitive, non-verbal ability to perceive and process numerical quantities without formal counting. This evolutionarily conserved trait, shared by different animal species, is supported by two mechanisms: the object tracking system (OTS) for small sets and the approximate number system (ANS) for larger quantities. Although historically viewed as distinct, these systems interact dynamically; their disruption is implicated in developmental dyscalculia and disorders such as Williams-Beuren syndrome (WBS), a chromosome microdeletion characterised by marked numerical and visuospatial deficits. Here, we synthesise neurobiological advances to provide an integrative perspective on the neural substrates of number sense. Field studies provide ecological validity, while laboratory procedures offer tighter precision; together, they illuminate the biological foundations of numerical cognition. Although number sense is conserved, human studies indicate only moderate heritability likely reflecting directional selection. Nonetheless, genetic findings converge on neurodevelopmental and synaptic mechanisms. Zebrafish (Danio rerio) offer a powerful platform to bridge genes, circuits and behaviour. For instance, manipulating zebrafish genes linked to WBS reveals gene-specific effects on quantity processing. At the neural level, numerical cognition is largely supported by specialised number-selective neurons. Whole-brain calcium imaging in larval zebrafish demonstrates that these neurons emerge by 3 days postfertilisation and follow a trajectory where representations of small numerosities precede larger ones. Altogether, integrating genetic, behavioural and circuit-level approaches provides a powerful framework for uncovering conserved mechanisms of numerosity supporting higher-level cognitive functions, including mathematics.

Number-action mapping in human newborns.

Accurate numerical cognition relies on representing and comparing quantities, a fundamental skill for adaptive behavior. In nonhuman primates, the parieto-frontal network, including the ventral intraparietal area (VIP) and prefrontal cortex (PFC), supports this process, but the functional dynamics and directionality of communication between these regions remain unclear. We examine population-level interactions of simultaneously recorded neuronal activity between VIP and PFC in two male macaques performing a numerosity task. Using time-lagged canonical correlation analyses, we show that correct trials exhibit sustained correlations driven by numerosity-selective neurons, with early feedforward dominance from VIP to PFC following sample onset. By contrast, error trials show weaker correlations, reduced VIP-to-PFC feedforward signaling, and transient breakdowns during the late working memory period. These findings show that coordinated parieto-frontal population activity enables accurate numerical judgments, whereas disrupted interactions impair performance, highlighting the critical role of dynamic, task-dependent interareal communication in categorical decisions.

Human numerical cognition relies on two core systems: the Approximate Number System (ANS), supporting approximate magnitude estimation, and the Object Tracking System (OTS), enabling precise individuation of up to 3 or 4 items. This study tested 32 healthy, full-term newborns (0-3 days old; 18 females) recruited from a maternity ward serving a socioeconomically and ethnically diverse population. Newborns familiarized with 2 elements (OTS range) preferred 1 element on the left, whereas those familiarized with 4 elements (ANS range) preferred 12 elements on the right. This pattern (η²p = 0.462) indicates that both numerical systems exhibit a shared spatial signature from birth, suggesting that spatial organization is a fundamental property of early numerical cognition.