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Understanding facial emotions is fundamental to interact in social environments and modify behavior accordingly. Neurodegenerative processes can progressively transform affective responses and affect social competence. This exploratory study examined the neurocognitive correlates of face recognition, in individuals with two mild cognitive impairment (MCI) etiologies (prodromal to dementia - MCI, or consequent to Parkinson's disease - PD-MCI). Performance on the identification and memorization of neutral and emotional facial expressions was assessed in 31 individuals with MCI, 26 with PD-MCI, and 30 healthy controls (HC). Individuals with MCI exhibited selective impairment in recognizing faces expressing fear, along with difficulties in remembering both neutral and emotional faces. Conversely, individuals with PD-MCI showed no differences compared with the HC in either emotion recognition or memory. In MCI, no significant association emerged between the memory for facial expressions and cognitive difficulties. In PD-MCI, regression analyses showed significant associations with higher-level cognitive functions in the emotional memory task, suggesting the presence of compensatory mechanisms. In a subset of participants, voxel-based morphometry revealed that the performance on emotional tasks correlated with regional changes in gray matter volume. The performance in the matching of negative expressions was predicted by volumetric changes in brain areas engaged in face and emotional processing, in particular increased volume in thalamic nuclei and atrophy in the right parietal cortex. Future studies should leverage on neuroimaging data to determine whether differences in emotional recognition are mediated by pathology-specific atrophic patterns.
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Disfunción Cognitiva , Emociones , Expresión Facial , Reconocimiento Facial , Imagen por Resonancia Magnética , Humanos , Disfunción Cognitiva/fisiopatología , Disfunción Cognitiva/diagnóstico por imagen , Masculino , Femenino , Anciano , Reconocimiento Facial/fisiología , Emociones/fisiología , Persona de Mediana Edad , Enfermedad de Parkinson/fisiopatología , Enfermedad de Parkinson/diagnóstico por imagen , Reconocimiento en Psicología/fisiología , Pruebas Neuropsicológicas , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatologíaRESUMEN
The present work investigates whether financial abilities can be associated with numerical abilities and with general cognitive abilities. We compared performance on numerical and financial tests, and on tests routinely used to measure general cognitive performance, in healthy controls and in a group of people with heterogeneous pathological conditions including mild cognitive impairment, amyotrophic lateral sclerosis, traumatic brain injury, and schizophrenia. Patients showed lower performances in both numerical and financial abilities compared to controls. Numerical and financial skills were positively correlated in both groups, but they correlated poorly with measures of general cognitive functioning. Crucially, only basic financial tasks -such as counting currencies- but not advanced ones -like financial judgments- were associated with numerical or general cognitive functioning in logistic regression analyses. Conversely, advanced financial abilities, but not basic ones, were associated with abstract reasoning. At a qualitative analysis, we found that deficits in numerical and financial abilities might double dissociate. Similarly, we observed double dissociations between difficulties in financial abilities and cognitive deficits. In conclusion, financial abilities may be independent of numerical skills, and financial deficits are not always related to the presence of cognitive difficulties. These findings are important for both clinical and legal practice.
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We report the reading performance of an Italian speaker with egocentric Neglect Dyslexia on sentences with Negative Concord structures, which contain a linguistic cue to the presence of a preceding negative marker and compare it to sentences with no such cue. As predicted, the frequency of reading the whole sentence, including the initial negative marker non, was higher in Negative Concord structures than in sentences which also started with non, but crucially, lacked the medially positioned linguistic cue to the presence of non. These data support the claim that the presence of linguistic cues to sentence structure modulates attention during reading in Neglect Dyslexia.
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Dislexia , Lateralidad Funcional , Humanos , Lingüística , Señales (Psicología) , AtenciónRESUMEN
Our ability to calculate implies more than the sole retrieval of the correct solution. Essential processes for simple calculation are related to the spreading of activation through arithmetic memory networks. There is behavioral and electrophysiological evidence for these mechanisms. Their brain location is, however, still uncertain. Here, we measured magnetoencephalographic brain activity during the verification of simple multiplication problems. Following the operands, the solutions to verify could be preactivated correct solutions, preactivated table-related incorrect solutions, or unrelated incorrect solutions. Brain source estimation, based on these event-related fields, revealed 3 main brain networks involved in simple calculation: 1) bilateral inferior frontal areas mainly activated in response to correct, matching solutions; 2) a left-lateralized frontoparietal network activated in response to incorrect table-related solutions; and (3) a strikingly similar frontoparietal network in the opposite hemisphere activated in response to unrelated solutions. Directional functional connectivity analyses revealed a bidirectional causal loop between left parietal and frontal areas for table-related solutions, with frontal areas explaining the resolution of arithmetic competition behaviorally. Hence, this study isolated at least 3 neurofunctional networks orchestrated between hemispheres during calculation.
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Mapeo Encefálico/métodos , Lóbulo Frontal/fisiología , Magnetoencefalografía/métodos , Conceptos Matemáticos , Lóbulo Parietal/fisiología , Solución de Problemas/fisiología , Adulto , Cognición/fisiología , Femenino , Lóbulo Frontal/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Lóbulo Parietal/diagnóstico por imagen , Distribución Aleatoria , Adulto JovenRESUMEN
Patients with mild cognitive impairment (MCI) might experience difficulties in numerical and financial abilities of daily living that compromise their autonomy. The aim of the present work was to examine whether specific tests of the standard neuropsychological assessment could be used to predict these deficits in the clinical practice. Thirty-four MCI patients underwent a comprehensive clinical and neuropsychological examination including (1) a complete assessment of financial abilities and (2) a traditional neuropsychological assessment including measures of language, memory, executive functioning, reasoning, attention, and visuospatial abilities. The neuropsychological tests were used as predictors of the performance in everyday financial tasks using logistic regression analysis. Deficits in financial tasks including calculating percentages, using financial concepts and applying financial judgments were significantly predicted by tests of executive functions, language and short-term memory, while deficits in frequently encountered financial tasks activities such as item purchase and reading numbers could not be predicted by standard neuropsychological evaluations. Contingency tables on performance above/below clinical cut-offs evidenced some cases of financial deficits in the absence of cognitive deficits and, vice versa, some patients with cognitive decline did not show financial impairments. These results suggest that while some cognitive functions might be crucial for taking financial decisions, an ad hoc test of financial capacity is essential to make overall inferences about the everyday financial autonomy of MCI patients. This has potential implications for clinical and legal decisions that directly impact the individuals and their families.
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Trastornos del Conocimiento , Disfunción Cognitiva , Actividades Cotidianas , Disfunción Cognitiva/diagnóstico , Función Ejecutiva , Humanos , Pruebas NeuropsicológicasRESUMEN
Specific impairments in numerical functions may cause severe problems in everyday life that cannot be inferred from the available scales evaluating instrumental activities of daily living. The Numerical Activities of Daily living (NADL) is a battery designed to assess the patient's performance in everyday activities involving numbers (Informal Test) and in more scholastic capacities (Formal Test). A downside of this battery is its duration (45 min). The aim of the present study is to build a shorter version of NADL to make it more suitable for clinical and research purposes. The shortening procedure involved only the Formal test, and followed two steps: (i) a correlation of subtests with the general scores, and (ii) an item-analysis within the subtests previously showing higher correlations. Correlations between NADL-Short and NADL original version, and the new cut-offs were calculated. Lastly, the relationship between NADL-Short and other brief cognitive screening tests used in the clinical practice was evaluated in neurological patients and healthy controls. The NADL-Short includes the original Informal Test and the shortened Formal Test. It is a quick and easy clinical tool (15 min) to assess numerical abilities applied to informal and formal situations. It correlates highly with the original battery (Kendall's tau greater than 0.6 across tasks) and the cut-offs correctly identify impaired performance (accuracy of 95% or above). Correlation analysis showed a low positive correlation between NADL-Short and other brief cognitive scales. These findings suggest that it is appropriate to use specific tools to make inferences about a person's numerical abilities.
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Actividades Cotidianas , Humanos , Pruebas NeuropsicológicasRESUMEN
People with Parkinson's disease (PD) experience functional limitations early in the progression of the disease, showing, among other cognitive deficits, difficulties in mathematical abilities. The neural correlates of such abilities have been scarcely investigated in PD, and it is not known whether patients may exhibit difficulties only in formal numerical tasks (e.g., mental multiplications), or also in everyday activities involving numbers (i.e., informal numerical abilities such as time estimates). The present study investigated formal and informal numerical abilities in PD patients and explored their relationship with cortical and subcortical brain volume. We examined patients with PD and mild cognitive impairment (PD-MCI) and age-matched healthy controls (HCs) using the numerical activities of daily living (NADL) battery, assessing both scholastic numerical abilities (formal test), and the ability to use numbers in everyday life (informal test). We compared NADL performances in both groups. Within the PD group, we investigated the association between NADL and cortical and subcortical volumes using multiple linear regressions. The correlation with other cognitive tests was also explored. PD-MCI performed worse than HC in the formal NADL test. In PD-MCI patients, brain-behavior correlations showed two distinct patterns: cortical volumes correlated positively, while striatal volumes correlated negatively with NADL formal tasks. Both formal and informal tests correlated with measures of cognitive functioning. Our results suggest specific impairments in formal numerical abilities in PD-MCI, but not in everyday activities. While cortical atrophy is associated with worse performance, the negative correlations with subcortical regions suggest that their activation may reflect potential compensatory mechanisms.
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Disfunción Cognitiva , Enfermedad de Parkinson , Actividades Cotidianas/psicología , Disfunción Cognitiva/fisiopatología , Humanos , Conceptos Matemáticos , Pruebas Neuropsicológicas , Enfermedad de Parkinson/psicologíaRESUMEN
It has been proposed that at least two distinct processes are engaged during task-switching: reconfiguration of the currently relevant task-set and interference resolution arising from the competing task-set. Whereas in healthy individuals the two are difficult to disentangle, their disruption is thought to cause different impairments in brain-damaged patients. Yet, the observed deficits are inconsistent across studies and do not allow drawing conclusions regarding their independence. Forty-one brain tumor patients were tested on a task-switching paradigm. We compared their performance between switch and repeat trials (switch cost) to assess rule reconfiguration, and between trials requiring the same response (congruent) and a different response for the two tasks (incongruent) to assess interference control. In line with previous studies, we found the greatest proportion of errors on incongruent trials, suggesting an interference control impairment. However, a closer look at the distribution of errors between two task rules revealed a rule perseveration impairment: Patients with high error rate on incongruent trials often applied only one task rule throughout the task and less frequently switched to the alternative one. Multivariate lesion-symptom mapping analysis unveiled the relationship between lesions localized in left orbitofrontal and posterior subcortical regions and perseveration scores, measured as absolute difference in accuracy between two task rules. This finding points to a more severe task-setting impairment, not reflected as a mere switching deficit, but instead as a difficulty in creating multiple stable task representations, in line with recent accounts of OFC functions suggesting its critical role in representing task states.
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Lesiones Encefálicas , Neoplasias Encefálicas , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico por imagen , Humanos , Desempeño Psicomotor , Tiempo de ReacciónRESUMEN
Alström syndrome (OMIM#203800) is an ultra-rare autosomal recessive monogenic disease presenting pathogenic variants in ALMS1 (chromosome 2p13). It is characterized by early onset of blindness, hearing loss and systemic comorbidities, with delayed development without cognitive impairment. We aimed to investigate the cognitive functions and describe new pathogenic variants in Alström syndrome patients. Nineteen patients (13 adults, 6 children) underwent a thorough clinical, genetic, laboratory, instrumental, and neurocognitive assessment. Six new pathogenic variants in ALMS1 including the first described in exon 6 were identified. Four patients displayed a "mild phenotype" characterized by slow disease onset or absence of complications, including childhood obesity and association with at least one pathogenic variant in exon 5 or 6. At neurocognitive testing, a significant proportion of patients had deficits in three neurocognitive domains: similarities, phonological memory, and apraxia. In particular, 53% of patients showed difficulties in the auditory working memory test. We found ideomotor and buccofacial apraxia in 74% of patients. "Mild phenotype" patients performed better on auditory working memory and ideomotor apraxia test than "typical phenotype" ones (91.9 + 16.3% vs. 41.7 + 34.5% of correct answers, Z = 64.5, p < .01 and 92.5 + 9.6 vs. 61.7 + 26.3, Z = 61, p < .05, respectively). Deficits in auditory working memory, ideomotor, and buccofacial apraxia were found in these patients and fewer neuropsychological deficits were found in the "mild" phenotype group. Furthermore, in the "mild" phenotype group, it was found that all pathogenic variants are localized before exon 8.
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Síndrome de Alstrom/genética , Síndrome de Alstrom/patología , Proteínas de Ciclo Celular/genética , Análisis Mutacional de ADN/métodos , Mutación , Fenotipo , Análisis de Secuencia de ADN/métodos , Adolescente , Adulto , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Adulto JovenRESUMEN
OBJECTIVE: In the present study, we explored numerical problems in individuals with aphasia. We investigate whether numerical deficits, usually accompanying aphasia, can be observed on number comprehension tasks that do not necessarily require an oral response. METHOD: Individuals with aphasia were classified into anterior, posterior, and global subgroups according to the lesion type. To investigate numerical cognition, we used a relatively recent tool, the Numerical Activities of Daily Living (NADL). RESULTS: The results showed that individuals with aphasia have problems with tasks of basic number comprehension as well as in most NADL. In the formal part of the NADL, anterior aphasic patients made comparatively more errors than the posterior aphasic patients. Global aphasic patients presented an invariably poor performance on almost all tasks. CONCLUSION: The results provide insight into how numerical deficits may impair an individual with aphasia in activities of daily living. This study is a preliminary attempt to start the validation process of the NADL for the Greek population.
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Actividades Cotidianas , Afasia , Afasia/etiología , Cognición , Comprensión , Humanos , Matemática , Pruebas NeuropsicológicasRESUMEN
Financial capacity is the ability to manage money and finances according to a person's values and self-interests. In Italy, the first instrument specifically designed to assess financial capacity has recently been developed: the Numerical Activities of Daily Living - Financial (NADL-F). The aims of this study are (1) to prepare a shorter version of NADL-F and (2) to examine the relationship between the new short version and a measure of general cognitive functioning of comparable length, the MMSE. After an item analysis performed on NADL-F, the items presenting a higher internal consistency were selected. The resulting NADL-F Short is a reliable, easy to use, and quick to administer tool for assessing financial capacity both in clinical and legal practice. Correlation analysis showed a low positive correlation between four NADL-F Short tasks and the MMSE, for the healthy participants group. For the patient group, instead, a low-moderate correlation was found for all the NADL-F Short tasks, except one. Many participants scoring high in the MMSE (both healthy controls and neurological patients) showed low NADL-F Short scores. These findings suggest that it is not correct to use generic tools like the MMSE to make inferences on a person's financial capacity.
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Actividades Cotidianas , Cognición , Humanos , Italia , Pruebas Neuropsicológicas , Reproducibilidad de los ResultadosRESUMEN
Resting-state functional magnetic resonance imaging (rs-fMRI) has the potential to shed light on the pathophysiological mechanisms of Huntington's disease (HD), paving the way to new therapeutic interventions. A systematic literature review was conducted in three online databases according to PRISMA guidelines, using keywords for HD, functional connectivity, and rs-fMRI. We included studies investigating connectivity in presymptomatic (pre-HD) and manifest HD gene carriers compared to healthy controls, implementing seed-based connectivity, independent component analysis, regional property, and graph analysis approaches. Visual network showed reduced connectivity in manifest HD, while network/areas underpinning motor functions were consistently altered in both manifest HD and pre-HD, showing disease stage-dependent changes. Cognitive networks underlying executive and attentional functions showed divergent anterior-posterior alterations, possibly reflecting compensatory mechanisms. The involvement of these networks in pre-HD is still unclear. In conclusion, aberrant connectivity of the sensory-motor network is observed in the early stage of HD while, as pathology spreads, other networks might be affected, such as the visual and executive/attentional networks. Moreover, sensory-motor and executive networks exhibit hyper- and hypo-connectivity patterns following different spatiotemporal trajectories. These findings could potentially help to implement future huntingtin-lowering interventions.
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Corteza Cerebral/fisiopatología , Conectoma , Enfermedad de Huntington/fisiopatología , Red Nerviosa/fisiopatología , Síntomas Prodrómicos , Corteza Cerebral/diagnóstico por imagen , Humanos , Enfermedad de Huntington/diagnóstico por imagen , Red Nerviosa/diagnóstico por imagenRESUMEN
OBJECTIVE: This study explored mental rotation (MR) performance in patients with myotonic dystrophy 1 (DM1), an inherited neuromuscular disorder dominated by muscular symptoms, including muscle weakness and myotonia. The aim of the study was twofold: to gain new insights into the neurocognitive mechanisms of MR and to better clarify the cognitive profile of DM1 patients. To address these aims, we used MR tasks involving kinds of stimuli that varied for the extent to which they emphasized motor simulation and activation of body representations (body parts) versus visuospatial imagery (abstract objects). We hypothesized that, if peripheral sensorimotor feedback system plays a pivotal role in modulating MR performance, then DM1 patients would exhibit more difficulties in mentally rotating hand stimuli than abstract objects. METHOD: Twenty-four DM1 patients and twenty-four age- and education-matched control subjects were enrolled in the study and were required to perform two computerized MR tasks involving pictures of hands and abstract objects. RESULTS: The analysis of accuracy showed that patients had impaired MR performance when the angular disparities between the stimuli were higher. Notably, as compared to controls, patients showed slower responses when the stimuli were hands, whereas no significant differences when stimuli were objects. CONCLUSION: The findings are coherent with the embodied cognition view, indicating a tight relation between body- and motor-related processes and MR. They suggest that peripheral, muscular, abnormalities in DM1 lead to alterations in manipulation of motor representations, which in turn affect MR, especially when body parts are to mentally rotate.
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Distrofia Miotónica/psicología , Desempeño Psicomotor/fisiología , Rotación , Adulto , Estudios de Casos y Controles , Cognición/fisiología , Femenino , Mano/fisiología , Humanos , Masculino , Persona de Mediana Edad , Pruebas NeuropsicológicasRESUMEN
Cognitive impairment is frequent in progressive supranuclear palsy (PSP) and less common in multiple system atrophy (MSA), but characteristics and progression compared with Parkinson's disease (PD) need to be properly defined. We evaluated 35 PSP with Richardson's syndrome (PSP-RS), 30 MSA as well as 65 age-, sex-, and education-matched PD with an extensive clinical and neuropsychological assessment, allowing Level II cognitive diagnosis. Eighteen PSP, 12 MSA and 30 PD had a second evaluation between 12 and 18 months (mean 15 months) after the first assessment. PSP performance at Montreal Cognitive Assessment (MoCA), verbal fluencies (phonemic and semantic tasks), Stroop test (Error and Time), Digit Span Sequencing (DSS), incomplete letters of Visual Object and Space Perception (VOSP) and Benton's Judgment of Line Orientation (JLO) performance were significantly poorer at baseline compared to PD and MSA. Executive, language and visuospatial abilities declined longitudinally in PSP, but not in PD and MSA. After 1.5 year, 16% of PSP converted to dementia. Our study provides evidence that cognitive progression is more severe and rapid in PSP-RS than PD and MSA. Further, we observed that MoCA, verbal fluency (particularly semantic), DSS and Benton's JLO are valuable tests to detect cognitive progression in PSP-RS and may be proposed as possible biomarker to assess efficacy of disease modification strategies.
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Disfunción Cognitiva/fisiopatología , Demencia/fisiopatología , Progresión de la Enfermedad , Atrofia de Múltiples Sistemas/fisiopatología , Enfermedad de Parkinson/fisiopatología , Parálisis Supranuclear Progresiva/fisiopatología , Anciano , Disfunción Cognitiva/etiología , Demencia/etiología , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Atrofia de Múltiples Sistemas/complicaciones , Enfermedad de Parkinson/complicaciones , Parálisis Supranuclear Progresiva/complicacionesRESUMEN
BACKGROUND: Pediatric patients with circumscribed cerebellar pilocytic astrocytoma (PA) tumors generally perform within the normal range on neuropsychological tests after a complete tumor resection. The outcome in academically relevant abilities such as mathematics, which in adults involve some cerebellar functions, is however much less understood. The aim of this study is to retrospectively investigate the neuroplasticity of mathematical skills and associated cognitive functions following cerebellar resection of PA in pediatric patients. METHODS: Twenty-two children (mean age = 11.2 + 1.8), including 11 PA patients (females = 6) and 11 healthy controls (females = 6), were administered a battery of mathematical (MaT) and neuropsychological tests. Single-case statistical analyses were carried out (Crawford's t) as well as between-group comparisons (Wilcoxon test). Spearman correlations between MaT and neuropsychological tests were calculated. RESULTS: Thirty-six percent of the patients showed difficulties in some mathematical tasks, 50% of them within a broader cognitive deficit. Verbal working memory was associated with MaT performance both in patients and controls while, crucially, visuospatial memory, and visual-motor integration were associated with MaT in patients only. Among patients, MaT correlated negatively with tumor size and positively with the interval surgery test. CONCLUSIONS: The results evince an overall recovery of mathematical abilities despite PA in the majority of patients. This functional reestablishment is supported by visuospatial and visuomotor integration functions that contribute to set up emerging mathematical skills in these patients. Higher levels of compensation are found in more developed tumors as compared to smaller ones.
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Astrocitoma/cirugía , Neoplasias Cerebelosas/cirugía , Trastornos del Conocimiento/epidemiología , Cognición , Matemática , Complicaciones Posoperatorias/epidemiología , Rendimiento Académico , Adolescente , Adulto , Niño , Trastornos del Conocimiento/etiología , Femenino , Humanos , Masculino , Memoria a Corto Plazo , Pruebas Neuropsicológicas , Complicaciones Posoperatorias/etiologíaRESUMEN
Financial capacity is the ability to manage one's own finances according to self-interests. Failure in financial decisions and lack of independence when dealing with money can affect people's quality of life and are associated with neuropsychological deficits or clinical conditions such as mild cognitive impairment or Alzheimer's disease. Despite the importance of evaluating financial capacity in the assessment of patients with neuropsychological and psychiatric disorders, only a few tools have been developed. In the present article, the authors introduce the Numerical Activities of Daily Living - Financial (NADL-F) test, a new test to assess financial capacity in clinical populations. The NADL-F is relatively short, yet it encompasses the most common activities involving financial capacities. The NADL-F proved to have satisfactory psychometric properties and overall good validity for measuring financial abilities. Associations with performance on basic neuropsychological tests were investigated, in particular focusing on mathematical abilities as cognitive correlates of financial capacity. Results indicate that the NADL-F could be a useful tool to guide treatments for the enhancement of financial capacities. By sharing all materials and procedures, the authors hope to promote the development of further versions of the NADL-F in different languages, taking into account the necessary adjustments related to different socio-cultural contexts.
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Actividades Cotidianas/psicología , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Administración Financiera , Matemática , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Psicometría , Encuestas y CuestionariosRESUMEN
It is widely accepted that different number-related tasks, including solving simple addition and subtraction, may induce attentional shifts on the so-called mental number line, which represents larger numbers on the right and smaller numbers on the left. Recently, it has been shown that different number-related tasks also employ spatial attention shifts along with general cognitive processes. Here we investigated for the first time whether number line estimation and complex mental arithmetic recruit a common mechanism in healthy adults. Participants' performance in two-digit mental additions and subtractions using visual stimuli was compared with their performance in a mental bisection task using auditory numerical intervals. Results showed significant correlations between participants' performance in number line bisection and that in two-digit mental arithmetic operations, especially in additions, providing a first proof of a shared cognitive mechanism (or multiple shared cognitive mechanisms) between auditory number bisection and complex mental calculation.
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Cognición/fisiología , Matemática , Procesos Mentales/fisiología , Estimulación Acústica , Adulto , Atención/fisiología , Femenino , Humanos , Masculino , Memoria a Corto Plazo/fisiología , Estimulación Luminosa , Solución de Problemas , Percepción Visual/fisiología , Adulto JovenRESUMEN
Recent studies by Bastiaanse and colleagues found that time reference is selectively impaired in people with nonfluent agrammatic aphasia, with reference to the past being more difficult to process than reference to the present or to the future. To account for this dissociation, they formulated the PAst DIscourse LInking Hypothesis (PADILIH), which posits that past reference is more demanding than present/future reference because it involves discourse linking. There is some evidence that this hypothesis can be applied to people with fluent aphasia as well. However, the existing evidence for the PADILIH is contradictory, and most of it has been provided by employing a test that predominantly taps retrieval processes, leaving largely unexplored the underlying ability to encode time reference-related prephonological features. Within a cross-linguistic approach, this study tests the PADILIH by means of a sentence completion task that 'equally' taps encoding and retrieval abilities. This study also investigates if the PADILIH's scope can be extended to fluent aphasia. Greek- and Italian-speaking individuals with aphasia participated in the study. The Greek group consisted of both individuals with nonfluent agrammatic aphasia and individuals with fluent aphasia, who also presented signs of agrammatism. The Italian group consisted of individuals with agrammatic nonfluent aphasia only. The two Greek subgroups performed similarly. Neither language group of participants with aphasia exhibited a pattern of performance consistent with the predictions of the PADILIH. However, a double dissociation observed within the Greek group suggests a hypothesis that may reconcile the present results with the PADILIH.
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Afasia de Broca/diagnóstico , Lenguaje , Lingüística , Anciano , Anciano de 80 o más Años , Femenino , Grecia , Humanos , Italia , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Factores de TiempoRESUMEN
Although parietal areas of the left hemisphere are known to be involved in simple mental calculation, the possible role of the homologue areas of the right hemisphere in mental complex calculation remains debated. In the present study, we tested the causal role of the posterior parietal cortex of both hemispheres in two-digit mental addition and subtraction by means of neuronavigated repetitive TMS (rTMS), investigating possible hemispheric asymmetries in specific parietal areas. In particular, we performed two rTMS experiments, which differed only for the target sites stimulated, on independent samples of participants. rTMS was delivered over the horizontal and ventral portions of the intraparietal sulcus (HIPS and VIPS, respectively) of each hemisphere in Experiment 1, and over the angular and supramarginal gyri (ANG and SMG, respectively) of each hemisphere in Experiment 2. First, we found that each cerebral area of the posterior parietal cortex is involved to some degree in the two-digit addition and subtraction. Second, in Experiment 1, we found a stronger pattern of hemispheric asymmetry for the involvement of HIPS in addition compared to subtraction. In particular, results showed a greater involvement of the right HIPS than the left one for addition. Moreover, we found less asymmetry for the VIPS. Taken together, these results suggest that two-digit mental addition is more strongly associated with the use of a spatial mapping compared to subtraction. In support of this view, in Experiment 2, a greater role of left and right ANG was found for addition needed in verbal processing of numbers and in visuospatial attention processes, respectively. We also revealed a greater involvement of the bilateral SMG in two-digit mental subtraction, in response to greater working memory load required to solve this latter operation compared to addition.
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Cognición/fisiología , Lóbulo Parietal/fisiología , Estimulación Magnética Transcraneal/métodos , Adulto , Mapeo Encefálico/métodos , Femenino , Humanos , Masculino , Conceptos MatemáticosRESUMEN
Although activation of dorsal premotor cortex (PMd) has been consistently observed in the neuroimaging studies of mental rotation, the functional meaning of PMd activation is still unclear and multiple alternative explanations have been suggested. The present study used repetitive transcranial magnetic stimulation (rTMS) to investigate the role of PMd in mental rotation. Two tasks were used, involving mental rotation of hands and abstract objects, with either matching (same stimuli) or mirror stimuli. Compared to sham stimulation, TMS over right and left PMd regions significantly affected accuracy in the object task, specifically for the same stimuli. Furthermore, response times were longer following right PMd stimulation in both the object and the hand tasks, but again, selectively for the same stimuli. The effect of rotational angle on response times and accuracies was greater for the same stimuli. Moreover TMS over PMd impaired the performance accuracy selectively in these stimuli, mainly in a task that included abstract objects. For these reasons, the present findings indicate a contribution of PMd to mental rotation.