Semantic Disorders Research Articles

Direct current stimulation over the anterior temporal areas boosts semantic processing in primary progressive aphasia.

Noninvasive brain stimulation in primary progressive aphasia (PPA) is a promising approach. Yet, applied to single cases or insufficiently controlled small-cohort studies, it has not clarified its therapeutic value. We here address the effectiveness of transcranial direct current stimulation (tDCS) on the semantic PPA variant (sv-PPA), applying a rigorous study design to a large, homogeneous sv-PPA cohort. Using a double-blind, sham-controlled counterbalanced cross-over design, we applied three tDCS conditions targeting the temporal poles of 12 sv-PPA patients. Efficiency was assessed by a semantic matching task orthogonally manipulating "living"/"nonliving" categories and verbal/visual modalities. Conforming to predominantly left-lateralized damage in sv-PPA and accounts of interhemispheric inhibition, we applied left hemisphere anodal-excitatory and right hemisphere cathodal-inhibitory tDCS, compared to sham stimulation. Prestimulation data, compared to 15 healthy controls, showed that patients had semantic disorders predominating with living categories in the verbal modality. Stimulation selectively impacted these most impaired domains: Left-excitatory and right-inhibitory tDCS improved semantic accuracy in verbal modality, and right-inhibitory tDCS improved processing speed with living categories and accuracy and processing speed in the combined verbal × living condition. Our findings demonstrate the efficiency of tDCS in sv-PPA by generating highly specific intrasemantic effects. They provide "proof of concept" for future applications of tDCS in therapeutic multiday regimes, potentially driving sustained improvement of semantic processing. Our data also support the hotly debated existence of a left temporal-pole network for verbal semantics selectively modulated through both left-excitatory and right-inhibitory brain stimulation. Ann Neurol 2016;80:693-707.

La retórica y el discurso administrativo

The goal that has this paper is to show that the administrative discourse, exposed in its basic texts, can be located in the field of rhetoric, particularly when seeking to persuade; and when they make their heuristic proposals (Lakatos, 1989; Laudan, 1986; Polanyi, 1958). I understand the rhetoric, with Perelman (1989) and Toulmin (2007) as an argumentation theory that seeks to persuade or convince so as to produce models or viable constructs. This in the field of performative propositions, not demonstrative empirically (Austin, 1955) recovering the Aristotelian practical rationality. Sampling in this work from rhetoric, persuasive passion in administrative texts such as Harold Koontz on how to solve “the semantic jungle” or administrative semantic disorder; and Reyes Ponce proposing to raise and include a sixth element in the administrative process, which is forecast; heuristics and passion in “normative” not descriptive, proposed first by Harold Koontz, in its five functions of management, second by Mary Parker Follett three models of command, in open dispute with the authoritarian model. Both passions allow the understanding of social reality construction, in particular organizational.

Neuropragmatic Speech-Language Deficits Specific To Speech Act Type Following Left-Hemispheric Lesion

Neuropragmatic Speech-Language Deficits Specific To Speech Act Type Following Left-Hemispheric Lesion

Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy.

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon.

The SQK: a semantic knowledge questionnaire to specify the severity of semantic deterioration in Alzheimer's disease patients

Lexico-semantic difficulties are common in Alzheimer's disease (AD). The bottom-up process theory is today well accepted: superordinate attributes tend to decline slower than subordinate ones. However, a specific issue in semantic memory investigation in AD is to determine the severity of the semantic impairment. Given that the regularity of the semantic disorder in early AD is uncertain, we argue that the constitution of experimental AD groups must consider the semantic deterioration stage. We thus propose a specific semantic knowledge questionnaire (SKQ), based on Laiacona et al.'s work (1993). SKQ was proposed to 49 AD patients and 33 healthy old people. Three experimental AD groups were created, based on the global cognitive deterioration. In a second study, we explore the possibility for early AD to display different semantic deterioration profile. Our results show a significant group effect, a significant type of question effect (superordinate vs subordinate) and a significant interaction effect. Moreover, a significant correlation between the total errors at the SKQ and the MMSE score is observed. Finally, we observe that early AD patients can show different semantic alteration, with mild or very mild semantic deterioration without any differences in the global cognitive alteration. The SKQ seems adapted to highlight the semantic deterioration and the bottom-up process in AD: superordinate information are better preserved than subordinate information. It can also distinguish different semantic deterioration in early AD. Our result clearly show that research on semantic deterioration in early stage of AD must take into account the severity of the semantic alteration.

Inborn and experience-dependent models of categorical brain organization. A position paper.

The present review aims to summarize the debate in contemporary neuroscience between inborn and experience-dependent models of conceptual representations that goes back to the description of category-specific semantic disorders for biological and artifact categories. Experience-dependent models suggest that categorical disorders are the by-product of the differential weighting of different sources of knowledge in the representation of biological and artifact categories. These models maintain that semantic disorders are not really category-specific, because they do not respect the boundaries between different categories. They also argue that the brain structures which are disrupted in a given type of category-specific semantic disorder should correspond to the areas of convergence of the sensory-motor information which play a major role in the construction of that category. Furthermore, they provide a simple interpretation of gender-related categorical effects and are supported by studies assessing the importance of prior experience in the cortical representation of objects On the other hand, inborn models maintain that category-specific semantic disorders reflect the disruption of innate brain networks, which are shaped by natural selection to allow rapid identification of objects that are very relevant for survival. From the empirical point of view, these models are mainly supported by observations of blind subjects, which suggest that visual experience is not necessary for the emergence of category-specificity in the ventral stream of visual processing. The weight of the data supporting experience-dependent and inborn models is thoroughly discussed, stressing the fact observations made in blind subjects are still the subject of intense debate. It is concluded that at the present state of knowledge it is not possible to choose between experience-dependent and inborn models of conceptual representations.

Neural underpinnings for model-oriented therapy of aphasic word production

Model-oriented therapies of aphasic word production have been shown to be effective, with item-specific therapy effects being larger than generalisation effects for untrained items. However, it remains unclear whether semantic versus phonological therapy lead to differential effects, depending on type of lexical impairment. Functional imaging studies revealed that mainly left-hemisphere, perisylvian brain areas were involved in successful therapy-induced recovery of aphasic word production. However, the neural underpinnings for model-oriented therapy effects have not received much attention yet.We aimed at identifying brain areas indicating (1) general therapy effects using a naming task measured by functional magnetic resonance imaging (fMRI) in 14 patients before and after a 4-week naming therapy, which comprised increasing semantic and phonological cueing-hierarchies. We also intended to reveal differential effects (2) of training versus generalisation, (3) of therapy methods, and (4) of type of impairment as assessed by the connectionist Dell model.Training effects were stronger than generalisation effects, even though both were significant. Furthermore, significant impairment-specific therapy effects were observed for patients with phonological disorders (P-patients). (1) Left inferior frontal gyrus, pars opercularis (IFGoper), was a positive predictor of therapy gains while the right caudate was a negative predictor. Moreover, less activation decrease due to therapy in left-hemisphere temporo-parietal language areas was positively correlated with therapy gains. (2) Naming of trained compared to untrained words yielded less activation decrease in left superior temporal gyrus (STG) and precuneus, bilateral thalamus, and right caudate due to therapy. (3) Differential therapy effects could be detected in the right superior parietal lobule for the semantic method, and in regions involving bilateral anterior and mid cingulate, right precuneus, and left middle/superior frontal gyrus for the phonological method. (4) Impairment-specific changes of activation were found for P-patients in left IFGoper. Patients with semantic disorders (S-patients) relied on right frontal areas involving IFG, pars triangularis. After therapy, they revealed less activation decrease in areas involving left STG, caudate, paracentral lobule, and right rolandic operculum.Regarding naming performance, the present study corroborates previous findings on training and generalisation effects and reveals differential therapy effects for P-patients. Moreover, brain imaging results confirm a predominance of (1) general effects in the left brain hemisphere. (2) Brain regions related to visual strategy, monitoring/feedback, and articulatory patterns were characteristic for the familiar trained items. (3) Distinct regions associated with strategies, monitoring capacities, and linguistic information indicate the specific therapeutic influence on word retrieval. (4) While P-patients relied more on preserved phonological functions in the left hemisphere, S-patients revealed right-sided compensation of semantic processing as well as increased strategic efforts in both hemispheres.

Semantic Disorders and Adaptation Problems in Children in Residential Care

This research analyses the semantic disorders and the level of personal, social and school adaptation in children in residential care between 6 and 18 years of age. The research is carried out in the Residential Childcare Homes of Extremadura (Spain). The study shows that there are important difficulties affecting the semantic organisation of the children’s narrative and conversational discourse, lexical recuperation problems in spontaneous language, and scarce ability to store or represent the semantic meanings of words. Similarly, with respect to the children’s degree of personal, social and school adaptation, we conclude that there is a relationship between the level of semantic dominion and the degree of adaptation. The scarce semantic competence leads to a bad adaptation of the children to their environment and to behavioral and emotional disorders. In this work, a proposal is made for activities aimed at improving children’s semantic competence, and the need to set up socio-educational intervention programmes to encourage the development of linguistic skills in minors in care is stressed.

Preliminary study on apraxia of Alzheimer’s disease patients

Objective To understand the capacity of application, and discuss the types as well as the mechanism of these dysfunctions. Methods A battery of neuropsychological tests including tool naming, tool naming by function, using of transitive tools, novel task test and naming photographs (living and inanimate) were applied in this study.20 AD patients and 20 healthy controls were enrolled in the study. Results The AD patients performed worse than the controls on the tool naming, tool naming by function, application of transitive tool, novel task test, naming tasks of living and inanimate pictures. The results represented significance in all of the tests (t=-6.54, -5.94, -4.16, -4.81, -2.17, -2.08; P<0.05). There were significant correlations between the performances in application the tasks and the ADAS-cog, MMSE and ADL scores (P<0.05). Conclusion The findings indicate that AD patients have apraxia, mainly impairment in ideomotor apraxia and ideational apraxia. Additionally, the patients have significantly decreased performance in ideational apraxia. The result suggests that AD patients’ apraxia might result from the semantic processing disorder. Key words: Alzheimer’s disease; Apraxia; Neuropsychological tests

Clinical diagnostic criteria and classification controversies in frontotemporal lobar degeneration

Frontotemporal lobar degeneration (FTLD) can manifest as a spectrum of clinical syndromes, ranging from behavioural impairment to language or motor dysfunction. Recently, revised diagnostic criteria have been proposed for the behavioural and progressive aphasia syndromes associated with frontotemporal degeneration. The present review will summarize these diagnostic guidelines and highlight some lingering controversies in the classification of FTLD clinical syndromes. We will discuss common tools and methods used to identify the insidious changes of behavioural variant frontotemporal dementia (bvFTD), the value of new, patient-based tasks of orbitofrontal function, and the issue of a benign or ‘phenocopy’ variant of bvFTD. With regard to primary progressive aphasia (PPA), we will discuss the scope of the semantic disorder in semantic-variant PPA, the nature of the speech disorder in non-fluent, agrammatic PPA, and the preliminary utility of a logopenic PPA classification.

Re-Evaluation of Attractor Neural Network Model to Explain Double Dissociation in Semantic Memory Disorder

Structure of semantic memory was investigated in the way of neural network simulations in detail. In the literature, it is well-known that brain damaged patients often showed category specific disorder in various cognitive neuropsychological tasks like picture naming, categorisation, identification tasks and so on. In order to describe semantic memory disorder of brain damaged patients, the attractor neural network model originally proposed Hinton and Shallice (1991) was employed and was tried to re-evaluate the model performance. Especially, in order to answer the question about organization of semantic memory, how our semantic memories are organized, computer simulations were conducted. After the model learned data set (Tyler, Moss, Durrant-Peatfield, & Levy, 2000), units in hidden and cleanup layers were removed and observed its performances. The results showed category specificity. This model could also explain the double dissociation phenomena. In spite of the simplicity of its architecture, the attractor neural network might be considered to mimic human behavior in the meaning of semantic memory organization and its disorder. Although this model could explain various phenomenon in cognitive neuropsychology, it might become obvious that this model had one limitation to explain human behavior. As far as investigation in this study, asymmetry in category specificity between animate and inanimate objects might not be explained on this model without any additional assumptions. Therefore, further studies must be required to improve our understanding for semantic memory organisation.

Factors in action-object semantic disorder for Chinese-speaking persons with or without Alzheimer's disease

The present study aimed to elucidate the nature of action-object semantic impairment, as revealed in a category fluency task and a picture naming task completed by Chinese-speaking persons with or without Alzheimer's disease (AD). Also, the predictive power of semantic variables on the severity of dementia was addressed. Speech samples were collected from twenty AD persons, twenty control seniors and twenty control adults in Taiwan. Each participant individually completed two tasks: a category fluency task and a picture naming task. Results of the category fluency task indicated that the content of information in Chinese-speaking AD participants was seriously deteriorated, thus producing significantly smaller number of semantic-lexical items. Category Effect was only significant for healthy controls in the semantic fluency task; no significant Category Effect was found in AD participants. Additionally, results of Multiple regression analyses demonstrated that action fluency, action naming and frequency of pictures could reliably predict the severity of dementia. Findings in the present study helped characterize the nature of semantic disorders in Chinese-speaking AD participants and contributed to the predictive power of semantic variables and of pictorial variables on the severity of dementia. ► We elucidated the nature of semantic impairment in a category fluency task. ► We examined the semantic category effects in a picture naming task. ► Our findings shed light on the predictive power of semantic variables on the severity of AD. ► Our findings are of theoretical and clinical implications for AD persons.

Selective impairment of living things and musical instruments on a verbal ‘Semantic Knowledge Questionnaire’ in a case of apperceptive visual agnosia

Semantic memory was investigated in a patient (MR) affected by a severe apperceptive visual agnosia, due to an ischemic cerebral lesion, bilaterally affecting the infero-mesial parts of the temporo-occipital cortices. The study was made by means of a Semantic Knowledge Questionnaire (Laiacona, Barbarotto, Trivelli, & Capitani, 1993), which takes separately into account four categories of living beings (animals, fruits, vegetables and body parts) and of artefacts (furniture, tools, vehicles and musical instruments), does not require a visual analysis and allows to distinguish errors concerning super-ordinate categorization, perceptual features and functional/encyclopedic knowledge. When the total number of errors obtained on all the categories of living and non-living beings was considered, a non-significant trend toward a higher number of errors in living stimuli was observed. This difference, however, became significant when body parts and musical instruments were excluded from the analysis. Furthermore, the number of errors obtained on the musical instruments was similar to that obtained on the living categories of animals, fruits and vegetables and significantly higher of that obtained in the other artefact categories. This difference was still significant when familiarity, frequency of use and prototypicality of each stimulus entered into a logistic regression analysis. On the other hand, a separate analysis of errors obtained on questions exploring super-ordinate categorization, perceptual features and functional/encyclopedic attributes showed that the differences between living and non-living stimuli and between musical instruments and other artefact categories were mainly due to errors obtained on questions exploring perceptual features.All these data are at variance with the ‘domains of knowledge’ hypothesis’, which assumes that the breakdown of different categories of living and non-living things respects the distinction between biological entities and artefacts and support the models assuming that ‘category-specific semantic disorders’ are the by-product of the differential weighting that visual-perceptual and functional (or action-related) attributes have in the construction of different biological and artefacts categories.

Refractory semantic access dysphasia resulting from resection of a left frontal glioma

The existence of semantic access disorders is now well established, however the precise cognitive and anatomical underpinnings are still debated. Here we describe the case of a patient that became aphasic after the resection of a left frontal glioma. Detailed lesion reconstruction indicates that the lesion was mostly restricted to the left dorsal and ventral prefrontal cortices and the underlying white matter, but sparing temporal lobes. Critically, the patient showed all the signs of refractory semantic access dysphasia, supporting the association between this syndrome and damage to left prefrontal areas likely to subserve retrieval and selection mechanisms for verbal material.

NEUROLINGUISTICS PERSPECTIVE ON LEXICAL PERCEPTION AND SEMANTIC DISORDER OF AUTISM SPECTRUM DISORDER

Autism patients get suffer from language disorder that can be identified from the late of speaking, the problems in processing linguistic information and understanding the speech meaning. This triggers to the learning problems that is worsened by attention disorder. The language acquisition is also affected by the limited vocabularies, starting from lexical perception up to vocabularies that are parts of semantic acquisition. In neurolinguistics perspective, complexity of language disorder for the spectrum autism can be explained based on the perceptual information management and the domination of his brain hemisphere. Linguistic information is processed in monoprocessing due to different hemisphere domination that happens after the process of brain lateralizes that ends up to the base of different lexicon perceptual system and the semantic acquisition for spectrum autism so that his expressive language skill reaches far beyond his receptive language. This strengthen the argumentation that language pathology is based on the relation between brain and linguistic mechanism.&lt;br /&gt;Keywords: Neurolinguistics, Lexical Perception, Semantic Disorder, Autism Spectrum Disorder&lt;br /&gt;&lt;br /&gt;

Agnosias: recognition disorders in patients with brain tumors

Two main varieties of recognition disorders are distinguished in neuropsychology: agnosias and semantic disorders. The term agnosias is generally used to denote recognition defects limited to a single perceptual modality (which is itself apparently intact), whereas the term semantic disorders is used to denote recognition defects involving all the sensory modalities in a roughly similar manner. Brain tumors can be one of the aetiologies underlying agnosias and semantic disorders. However, due to the heterogeneity and the rarity of recognition disorders, their investigation can be useful only to suggest or exclude the oncological nature of a brain lesion, but not to systematically monitor the clinical outcome in tumor patients. Furthermore, the relevance of recognition disorders as a hint toward a diagnosis of brain tumor varies according to the type of agnosia and of semantic disorder and the localization of the underlying brain pathology. The hypothesis that a variety of agnosia (or of semantic disorder) may be due to a neoplastic lesion can, therefore, be advanced if it is consistent with our knowledge about the usual localization and the growing patterns of different types of brain tumors.

Does the left superior longitudinal fascicle subserve language semantics? A brain electrostimulation study

Recent diffusion tensor imaging (DTI) tractography studies indicate that the supramarginal gyrus (SMG) represents a relay between frontal and temporal language sites. Some authors postulate that pathways connecting SMG to the posterior temporal lobe, i.e., the posterior part of the superior longitudinal fascicle (SLF) subserve semantic aspects of language. However, DTI provides only anatomic but not functional data. Therefore, it is impossible to conclude. Interestingly, intra-operative electrical mapping of cortical and subcortical language structures during tumor surgery is recognized as a reliable technique in functional neuroanatomy research. We mapped the underlying white matter of the SMG, especially the SLF, in 11 patients who underwent awake surgery for a glioma involving the left inferior parietal lobule. Using direct electrostimulation, we investigated the exact role of the SLF in language. Our findings indicate that the white matter under the inferior parietal lobule is highly involved in the dorsal phonological system. First, the SMG, connected to the ventral premotor cortex by horizontal fibers of the SLF, subserves articulatory processing, as demonstrated by dysarthria elicited by stimulation. Second, long arcuate fibers, found deeper in the white matter, subserve phonological processing, as supported by phonemic paraphasia induced by electrostimulation. Third, the most important result is that no semantic disturbances were elicited by stimulating the SLF, including its posterior part. Furthermore, no semantic disorders occurred postoperatively. Subcortical brain mapping by direct electrical stimulation does not provide arguments for a possible role of the left SLF in language semantic processing.

Atypical semantic knowledge and autobiographical memory disorder in a young adult with Downs syndrome

A study of lexical semantic knowledge and autobiographical memory is described in PQ, a 22-year-old male with Downs syndrome. Performance is compared with younger typically developing verbal mental age controls. PQ's lexical stores contained a normal number of items, however, he was impaired at naming both pictures and item descriptions. PQ's own descriptions of items contained a normal volume of information, but the pattern of information differed from normal as he produced less ‘sensory’ and more ‘thematic’ and ‘functional’ information. PQ has an autobiographical memory deficit. His ability to recall ‘specific’ memories was significantly impoverished. It is suggested that both PQ's naming difficulties and his autobiographical memory disorder may reflect atypical knowledge specification with absence of distinctive featural knowledge and increased conceptual overlap and looser networks pervasive across both semantic and autobiographical memory systems.

Validation de la batterie rapide de dénomination (BARD) chez 382 témoins et 1004 patients d’une consultation mémoire

The Rapid BAttery of Denomination (BARD) is a short 10-item naming test derived from the 60-item Boston Naming Test. It is easily performed in less than 15 seconds by normal controls independently of age, gender and education (Croisile, 2005,2007,2008). Our aim was to evaluate the BARD in various conditions seen in a memory clinic. The BARD was used in 382 normal subjects (165 men and 217 women, aged from 20 to 97 years) and 1004 patients attending a memory clinic. Three groups of 505 patients with Alzheimer's disease (AD) were compared: mild patients (n=402), moderate patients (n=84) and moderately severe patients (n=19). The BARD was also used in 499 patients with a Mini Mental Status (MMSE)>or=20: 173 patients with amnestic Mild Cognitive Impairment (aMCI), 56 patients with frontotemporal dementia (FTD), 41 patients with Lewy Body dementia (LBD), 36 patients with nonfluent primary progressive aphasia (NFPPA), 27 patients with semantic dementia (SD), 16 patients with posterior cortical atrophy (PCA), 150 patients with anxiety or depression (ADD). The performance of the patients was not affected by age, gender or education. aMCI had a score of 9.97+/-0.18, ADD a score of 9.97+/-0.2. A mild anomia was observed in three groups: mild AD (9.78+/-0.5), FTD (9.79+/-0.65) et LBD (9.98+/-0.16). A more pronounced anomia was present in moderate AD (9.10+/-1.06), moderately severe AD (8.05+/-1.27), PCA (8.12+/-3.28) and NFPPA (8.44+/-1.61). The anomia was severe in SD (5.85+/-2.46). The 10 items were perfectly named by 98 % of ADD, 96.53 % of aMCI, 82.09 % of mild AD, 87.5 % of FTD patients, 97.56 % of LBD patients, 68.75 % of PCA patients, but only 45.24 % moderate AD, 5.26 % of moderately severe AD, 27.78 % of NFPPA, and 3.7 % of SD. In the patients with MMS>or=20, Anova showed that the BARD scores of the ADD, aMCI, mild AD, FTD and LBD groups were significantly greater than the BARD scores of NFPPA, SD and PCA. PCA and NFPPA groups did not differ for BARD scores whereas they were significantly better than SD. A ROC curve comparing the 822 mild anomic patients (AD, FTD, LBD, aMCI, ADD) with the 79 more anomic patients (NFPPA, SD, PCA) showed that for a BARD score of 10, sensitivity was 72.2 %, specificity was 89.2 %, and 87.7 % of the patients were correctly classified. The BARD is a quick and useful tool for identifying naming disorders in a memory clinic. In patients with MMSE>or=20, making one error at the BARD is highly abnormal and significantly characteristic of cognitive disorders: the more frequent the errors are, the more probable is the presence of a visual agnosia (PCA), an aphasia (NFPPA), or a semantic disorder (SD).

Personal experience and arithmetic meaning in semantic dementia

Arithmetic skills are generally claimed to be preserved in semantic dementia (SD), suggesting functional independence of arithmetic knowledge from other aspects of semantic memory. However, in a recent case series analysis we showed that arithmetic performance in SD is not entirely normal. The finding of a direct association between severity of patients' semantic disorder and arithmetic impairment pointed to a closer relationship between semantic memory and arithmetic knowledge than previously acknowledged. The present study aimed to determine whether arithmetic performance in SD is subject to the same influences as has been found in other semantic domains, namely an autobiographical effect. SD patients were assessed on their ability to perform arithmetic in personally relevant compared to non-personal contexts. Patients who were regular, current followers of the television game show Countdown performed better on a simplified version of the show's number game compared to a conventional written calculation task, whereas patients with no experience of Countdown demonstrated the opposite pattern. SD patients showed better knowledge of multiplication table 'facts' when these were embedded in a situation relevant to their daily lives compared to a non-personal arithmetic task. They also performed better on a written calculation task when problems were presented as a monetary transaction compared to a standard arithmetic problem. A reference group of patients with Alzheimer's disease (AD) showed the reverse pattern. The findings provide convincing evidence that autobiographical relevance influences SD patients' arithmetic performance. Moreover, they challenge current views on conceptual number knowledge as a unitary, abstract competence.