Mes: junio 2015

Recent advances in neuroscience have provided new insights into the understanding of heart-brain interaction and communication. Cardiac information to the brain relies on two pathways, terminating in the insular (IC) and anterior cingulate (ACC) cortices, along with the somatosensory cortex (S1-S2). Interoception relying on these neuroanatomical pathways has been shown to modulate social cognition. We report the case study of C.S., a patient with an «external heart » (an extracorporeal left-univentricular cardiac assist device, LVAD). The patient was assessed with neural/behavioral measures of cardiac interoception complemented by neuropsychological and social cognition measures. The patient’s performance on the interoception task (heartbeat detection) seemed to be guided by signals from the artificial LVAD, which provides a somatosensory beat, rather than by his endogenous heart. Cortical activity (heart-evoked potential, HEP) decreased in comparison to normal volunteers, particularly during interoceptive states. The patient accurately performed several cognitive tasks, expect for empathy, theory of mind and decision-making. This evidence suggests an imbalance in the patient’s cardiac interoceptive pathways that enhances sensation driven by the artificial pump over that from the cardiac vagal-ICC-ACC pathway. A patient with two hearts, one endogenous and one artificial, presents a unique opportunity to explore models of interoception and heart-brain interaction

Objectives: To assess brain functional connectivity and variability in adults with attention deficit/hyperactivity disorder (ADHD) or euthymic bipolar disorder (BD) relative to a control (CT) group.

Methods: Electroencephalography (EEG) was measured in 35 participants (BD = 11; ADHD = 9; CT = 15) during an eyes-closed 10-min rest period, and connectivity and graph theory metrics were computed. A coefficient of variation (CV) computed also the connectivity’s temporal variability of EEG. Multivariate associations between functional connectivity and clinical and neuropsychological profiles were evaluated.

Results: An enhancement of functional connectivity was observed in the ADHD (fronto-occipital connections) and BD (diffuse connections) groups. However, compared with CTs, intrinsic variability (CV) was enhanced in the ADHD group and reduced in the BD group. Graph theory metrics confirmed the existence of several abnormal network features in both affected groups. Significant associations of connectivity with symptoms were also observed. In the ADHD group, temporal variability of functional connections was associated with executive function and memory deficits. Depression, hyperactivity and impulsivity levels in the ADHD group were associated with abnormal intrinsic connectivity. In the BD group, levels of anxiety and depression were related to abnormal frontotemporal connectivity.

Conclusions: In the ADHD group, we found that intrinsic variability was associated with deficits in cognitive performance and that connectivity abnormalities were related to ADHD symptomatology. The BD group exhibited less intrinsic variability and more diffuse long-range brain connections, and those abnormalities were related to interindividual differences in depression and anxiety. These preliminary results are relevant for neurocognitive models of abnormal brain connectivity in both disorders.

Durante muchos años, el deterioro cognitivo se ha establecido como un síntoma bien conocido de la esclerosis múltiple. Además, sabemos que está presente incluso al principio de la enfermedad. En este estudio de casos y controles, decidimos evaluar si hay un deterioro de las funciones cognitivas, incluso antes de la aparición en aquellos pacientes que eventualmente sufren de esclerosis múltiple. Se evaluó el desempeño de la escuela en general, y en particular el rendimiento escolar en matemáticas y lenguaje en un grupo de pacientes que más tarde desarrollarían la enfermedad y comparamos nuestros resultados con un grupo control. Se encontró que el rendimiento escolar era más pobre en los sujetos que iban a sufrir esclerosis múltiple. Paralelamente, encontramos que cuanto más tardío fuera el comienzo del primer síntoma, mejor eran las calificaciones. La prueba de un déficit cognitivo premórbido por un método de evaluación indirecta validado nos permitió comprobar la existencia de un compromiso neurológico, incluso antes de un diagnóstico clínico o la realización de la primera resonancia magnética en pacientes que luego sufrirían de esclerosis múltiple.

The ´interpreter advantage hypothesis´ posits that task-specific cognitive skills developed by professional interpreters (PIs) generalize to more efficient linguistic and executive abilities in non-interpreting tasks. This paper reviews relevant studies in order to establish preliminary data patterns and outline new research questions. Though not entirely consistent, the evidence suggests that interpreting expertise enhances aspects of semantic processing, working memory, and cognitive flexibility. The data also gives rise to new related queries: Are linguistic and executive enhancements in PIs independent from each other? Are all the superior skills of PIs cumulatively enhanced by the double influence of bilingualism and interpreting experience? And how soon after the onset of formal training do these advantages appear? Tentative answers to these questions are also implied in the evidence considered.

Disentangling interoception: insights from focal strokes affecting the perception of external and internal milieus. Autores Couto B, Adolfi F, Sedeño L, Salles A, Canales-Johnson A, Alvarez-Abut P, Garcia-Cordero I, Pietto M, Bekinschtein T, Sigman M, Manes F, Ibanez A. Año 2015 Journal  Couto B, Adolfi F, Sedeño L, Salles A, Canales-Johnson A, Alvarez-Abut P, Garcia-Cordero I, … Leer más

Social cognition impairments are pervasive in the frontotemporal dementias (FTD). These deficits would be triggered by (a) basic emotion and face recognition processes as well as by (b) higher level social cognition (e.g., theory of mind, ToM). Both emotional processing and social cognition impairments have been previously reported in the behavioral variant of FTD (bvFTD) and also in other versions of FTDs, including primary progressive aphasia. However, no neuroanatomic comparison between different FTD variants has been performed. We report selective behavioral impairments of face recognition, emotion recognition, and ToM in patients with bvFTD and progressive non-fluent aphasia (PNFA) when compared to controls. Voxel-based morphometry (VBM) shows a classical impairment of mainly orbitofrontal (OFC), anterior cingulate (ACC), insula and lateral temporal cortices in patients. Comparative analysis of regional gray matter related to social cognition deficits (VBM) reveals a differential pattern of fronto-insulo-temporal atrophy in bvFTD and an insulo-temporal involvement in PNFA group. Results suggest that in spite of similar social cognition impairments reported in bvFTD and PNFA, the former represents an inherent ToM affectation whereas in the PNFA these deficits could be related to more basic processes of face and emotion recognition. These results are interpreted in the frame of the fronto-insulo-temporal social context network model (SCNM).

The roles of interoceptive sensitivity and metacognitive interoception in panic. Autores Yoris A, Esteves S, Couto B, Melloni M, Kichic R, Cetkovich M, Favaloro R, Moser J, Manes F, Ibanez A, Sedeño L. Año 2015 Journal  Yoris A, Esteves S, Couto B, Melloni M, Kichic R, Cetkovich M, Favaloro R, Moser J, Manes F, Ibanez A, Sedeño … Leer más

Impairments in negative emotion recognition and empathy for pain in Huntington’s disease families. Autores Báez S, Herrera E, Gershanik O, García A, Bocanegra Y, Kargieman L, Manes F, Ibanez A. Año 2015 Journal  Báez S, Herrera E, Gershanik O, García A, Bocanegra Y, Kargieman L, Manes F, Ibanez A. Volumen Abstract   Otra información    

Acute loss of consciousness. Autores Bekinschtein T, Gleichgerrcht E, Manes F. Año 2015 Journal Bekinschtein T, Gleichgerrcht E, Manes F. Volumen 127:195-204. Abstract Otra información  

In cognitive neuroscience, the reissue of the notion of emergence and downward causation has been used as an interlevel model of mind-brain interactions from different perspectives. Within this perspective, intentionality has been interpreted as global to local determination (downward causation) on the neurophysiological level. Consciousness would act as the large-scale, global activity of the system that governs or constrains local interactions of neurons. This argument seems to solve several difficulties with regard to descriptions of consciousness on a neurophysiological and mental level. Nevertheless, the inconsistencies of this argument are shown, and a contextual and pragmatic explanation of the downward causation of consciousness is given.