Behavioral and electrophysiological correlates of memory binding deficits in patients at different risk levels for Alzheimer’s disease

Pietto M, Parra MA, Trujillo N, Flores F, García AM, Bustin J, Richly P, Manes F, Lopera F, Ibáñez A, Baez S.
behavioural-and-electro
 
Behavioral and Electrophysiological Correlates of Memory Binding Deficits in Patients at Different Risk Levels for Alzheimer’s Disease
Abstract.
Deficits in visual short-term memory (VSTM) binding have been proposed as an early and specific marker for Alzheimer’s disease (AD). However, no studies have explored the neural correlates of this domain in clinical categories involving prodromal stages with different risk levels of conversion to AD. We assessed underlying electrophysiological modulations in patients with mild cognitive impairment (MCI), patients in the MCI stages of familial AD carrying the mutation E280A of the presenilin-1 gene (MCI-FAD), and healthy controls. Moreover, we compared the behavioral performance and neural correlates of both patient groups. Participants completed a change-detection VSTM task assessing recognition of changes between shapes or shape-color bindings, presented in two consecutive arrays (i.e., study and test) while event related potentials (ERPs) were recorded. Changes always occurred in the test array and consisted of new features replacing studied features (shape only) or features swapping across items (shape-color binding). Both MCI and MCI-FAD patients performed worse than controls in the shape-color binding condition. Early electrophysiological activity (100–250 ms) was significantly reduced in both clinical groups, particularly over fronto-central and parieto-occipital regions. However, shape-
color binding performance and their reduced neural correlates were similar between MCI and MCI-FAD. Our results support the validity of the VSTM binding test and their neural correlates in the early detection of AD and highlight the importance of studies comparing samples at different risk for AD conversion. The combined analysis of behavioral and ERP data gleaned with the VSTM binding task can offer a valuable memory biomarker for AD.
Keywords: Electroencephalogram (EEG), event related potentials (ERPs), familial Alzheimer’s disease, memory binding, mild cognitive impairment, short-term memory
 
J Alzheimers Dis. 2016
 

The social context network model in psychiatric and neurological diseases

Baez S, García AM, Ibáñez A.
Curr Top Behav Neurosci2016, In press. 
 
social-context
 
¿Como hacemos las personas para usar la información contextual y la experiencia a fines de anticipar los significados sociales de las interacciones? En este trabajamos mostramos como esta habilidad depende de una red fronto-temporo-insular y puede ser entendida a través del llamado Social Context Network Model (SCNM). Luego revelamos como el SCNM puede ser útil para la comprensión de los déficits de cognición social en múltiples patológicas psiquiátricas y neurológicas.
Para acceder al Link, por favor haga CLICK AQUÍ

Bilingualism and cognitive reserve: A critical overview a plea methodological innovations

Calvo N, García AM, Manoiloff L, Ibáñez A.
Front Aging Neurosci. 2016 Jan 12;7:249
bilingualism-and-cognitive

 

Un conjunto de estudios muy influyentes sugiere que el bilingüismo conferiría una protección cognitiva ante los síntomas de Alzheimer. Sin embargo, la evidencia es inconsistente y contradictoria. En este trabajo identificamos las causas de las discrepancias y enumeramos medidas metodológicas que podrían esclarecer la cuestión.

Para acceder al Link, por favor haga CLICK AQUÍ

Hands typing what hands do: Action-semantic integration dynamics throughout written verb production

García AM, Ibáñez A.
 Cognition. 2016 Apr;149:56-66.
hands-typing

 

En este estudio, exploramos la relación entre el significado de las palabras y los circuitos motores durante la escritura al teclado. El principal hallazgo fue que los verbos que aluden a acciones corporales (y acciones manuales, en particular) requieren mayor tiempo de planificación que los verbos abstractos. Estos resultados confirman que los circuitos motores se activan de acuerdo al significado de las palabras que procesamos.
Para acceder al Link, por favor haga CLICK AQUÍ

The impact of bilingualism on working memory: A null effect of the whole may noy be so on the parts

Calvo N, Ibáñez A, García AM.
Front Psychol. 2016 Feb 25;7:26
the-impact-of-biling
En esta revisión se describen las dificultades actuales que se presentan a la hora de diagnosticar ACV perinatales durante el período neonata como disparador para desarrollar al ACV isquémico presuntamente perinatal como entidad individual y su utilidad como modelo de estudio de la enfermedad vascular prenatal y neonatal.
Para acceder al Link, por favor haga CLICK AQUÍ

The overt pronoun constraint across three dialects of spanish

Gelormini-Lezama C, Huepe D, Herrera E, Melloni M, Manes F, García AM, Ibáñez A.

J Psycholinguist Res. 2016 Apr 9.

overt-pronom

 

 

En este trabajo los autores investigan la interpretación de pronombres en Buenos Aires, Santiago de Chile y Barranquilla. Los resultados muestran que los hablantes nativos de español interpretan el pronombre explícito contrariando las predicciones de la teoría chomskyana, lo cual informa tanto a las teorías de adquisición del lenguaje como a las teorías de procesamiento lingüístico.

 

Para acceder al Link, por favor haga CLICK AQUÍ

Brain network organization and social executive performance in frototemporal dementia

Sedeño L, Couto B, García-Cordero I, Melloni M, Baez S, Morales Sepúlveda JP, Fraiman D, Huepe D, Hurtado E, Matallana D, Kuljis R, Torralva T, Chialvo D, Sigman M, Piguet O, Manes F, Ibanez A.
J Int Neuropsychol Soc. 2016 Feb;22(2):250-62.
brain-network

En este estudio mostramos, mediante técnicas avanzadas para el estudio de la red cerebral, que la conectividad funcional de las áreas de atrofia (redes fronto-temporo-insulares) de la variante conductual de la demencia frontotemporal (VcDFT) se encuentra selectivamente afectada en comparación a un grupo de controles sanos. Además, esta afectación es específica de la VcDFT ya que estos pacientes también se diferencian de pacientes con accidentes cerebro-vasculares en regiones fronto-insulares. Por último, la alteración de la conectividad de las áreas de atrofia en VcDFT se asocia con déficits característicos de esta enfermedad en procesos cognitivos de alto nivel como las funciones ejecutivas y la cognición social.

Para acceder al Link, por favor haga CLICK AQUÍ

Integration of intention and outcome for moral judgment in frototemporal dementia: Brain structural signatures.

Baez S, Kanske P, Matallana D, Reyes P, Slaschevsky A, Matus C, Vigliecca NS, Torralva T, Manes F, Ibañez A.
integration-of-intention
INTEGRATION OF INTENTION AND OUTCOME FOR MORAL JUDGMENT IN FRONTOTEMPORAL DEMENTIA: BRAIN STRUCTURAL SIGNATURES.
Neurodegenerative Diseases, 2016. 

 

Background: Moral judgment has been proposed to rely on a distributed brain network. This function is impaired in behavioral variant frontotemporal dementia (bvFTD), a condition involving damage to some regions of this network. However, no studies have investigated moral judgment in bvFTD via structural neuroimaging. Methods: We compared the performance of 21 bvFTD patients and 19 controls on a moral judgment task involving scenarios that discriminate between the contributions of intentions and oucomes. Voxel-based morphometry was used to assess (a) the atrophy pattern in bvFTD patients, (b) associations between gray matter (GM) volume and moral judgments, and (c) structural differences between bvFTD subgroups (patients with relatively preserved moral judgment and patients with severer moral judgment impairments). Results: Patients judged attempted harm as more permissible and accidental harm as less permissible than controls. The groups’ performance on accidental harm was associated with GM volume in the precuneus. In controls, it was also associated with the ventromedial prefrontal cortex (VMPFC). Also, both groups’ performance on attempted harm was associated with GM volume in the temporoparietal junction. Patients exhibiting worse performance displayed smaller GM volumes in the precuneus and temporal pole. Conclusions: Results suggest that moral judgment abnormalities in bvFTD are associated with impaired integration of intentions and outcomes, which depends on an extended brain network. In bvFTD, moral judgment seems to critically depend on areas beyond the VMPFC.

Orbitofrontal and limbic signatures of empathic concern and intentional harm in the behavioral variant frototemporal

Baez S, Morales JP, Slachevsky A, Torralva T, Matus C, Manes F, Ibanez A.
orbitofrontal
ORBITOFRONTAL AND LIMBIC SIGNATURES OF EMPATHIC CONCERN AND INTENTIONAL HARM IN THE BEHAVIORAL VARIANT FRONTOTEMPORAL DEMENTIA
Cortex. 2015 Nov 24;75:20-32.

Perceiving and evaluating intentional harms in an interpersonal context engages both cognitive and emotional domains. This process involves inference of intentions, moral judgment, and, crucially, empathy towards others’ suffering. This latter skill is notably impaired in behavioral variant frontotemporal dementia (bvFTD). However, the relationship between regional brain atrophy in bvFTD and deficits in the above-mentioned abilities is not well understood. The present study investigated how gray matter (GM) atrophy in bvFTD patients correlates with the perception and evaluation of harmful actions (attribution of intentionality, evaluation of harmful behavior, empathic concern, and moraljudgment). First, we compared the behavioral performance of 26 bvFTD patients and 23 healthy controls on an experimental task (ET) indexing intentionality, empathy, and moral cognition during evaluation of harmful actions. Second, we compared GM volume in patients and controls using voxel-based morphometry (VBM). Third, we examined brain regions where atrophy might be associated with specific impairments in the patient group.

 

 

The cerebellum and embodied semantics: evidence from a case of genetic ataxia due to STUB1 mutations

García AM, Abrevaya S, Kozono G, García-Cordero I, Córdoba M, Kauffman M, Pautassi R, Muñoz E, Sedeño L, Ibáñez A.

J Med Genet. 2016 Nov 3. pii: jmedgenet-2016-104148. doi: 10.1136/jmedgenet-2016-104148.

cerebelum

Reportamos un caso de ataxia genética con una mutación nueva y mostramos que la atrofia del cerebelo y su afectación de la conectividad funcional se asocian con déficits selectivos en verbos de acción. El patrón de atrofia coincidió con los sitios de expresión del gen afectado (STUB1). Así, brindamos la primera evidencia de relación entre genética, atrofia cerebelosa y redes involucradas en el lenguaje de acción.

 

Para acceder al link hacer CLICK AQUÍ