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Search Results: 1 - 10 of 359 matches for " Facundo Manes "
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Assessment of Global Fatigue in Multiple Sclerosis: A Spanish Language Version of the CGI and PGI Fatigue Scales  [PDF]
Steven D. Targum, Pablo Richly, Vladimiro Sinay, Daniel Goldberg-Zimring, Facundo Manes
Neuroscience & Medicine (NM) , 2013, DOI: 10.4236/nm.2013.43022
Abstract:

Background: Fatigue is often identified as weakness following muscular exertion in patients with multiple sclerosis (MS) but may be associated with other physical, cognitive and emotional symptoms. Objective: To develop a Spanish language global impression of fatigue scales to evaluate symptoms of fatigue distinct from a particular disease. Methods: 50 ambulatory patients with MS attending a clinical institute in Argentina consented to participate in this reliability study. The Spanish language version of the Clinical and Patient Global Impressions of Fatigue (CGI-S-F and PGI-S-F) instruments were administered with the Massachusetts General Hospital cognitive and physical functioning questionnaire (MGH-CPFQ). Results: The CGI-S-F and PGI-S-F scores were well correlated with each other (p < 0.00005). The mean CGI-S for fatigue was 2.28 ± 1.07 (SD) and PGI-S for fatigue was 2.30 ± 1.16 (p = ns) reflecting borderline to mild perception of fatigue. The total MGH-CPFQ was 16.68 ± 4.32. Both CGI-S-F and PGI-S-F measures were correlated with the MGH-CPFQ: CGI-Severity (r = 0.632; p

Comparing the Neuropsychiatric Profile of Patients with Alzheimer Disease Who Present Spared versus Impaired Executive Functioning
Ezequiel Gleichgerrcht,Anabel Chade,Teresa Torralva,María Roca,Facundo Manes
Current Gerontology and Geriatrics Research , 2011, DOI: 10.1155/2011/514059
Abstract: Background. A “dysexecutive” group of patients with Alzheimer disease (AD) has been previously identified, and these patients have been found to present higher frequency of psychiatric symptoms and more pronounced functional impact. This study aimed at evaluating the frequency of neuropsychiatric symptoms in patients with early AD who present with impaired executive functioning. Methods. Thirty patients with early AD diagnosis were divided into a spared (SEF) and an impaired (IEF) executive functioning group according to their performance scores on neuropsychological tests. Their closest relatives or caregivers completed the Cambridge behavioral inventory (CBI), which assesses behavioral symptoms grouped into 13 categories. Results. A significant difference was exclusively found between SEF and IEF in terms of the frequency of stereotypies and repetitive motor behavior (=60.5, =.024). Conclusions. The presence of stereotypies could be associated with a dysexecutive profile in AD patients. These results shed light on the role of frontal circuitry in the expression of motor symptoms in AD and prompt for further research that will contribute to the differential diagnosis both of different subtypes of AD and other types of dementia.
Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects
Pia Aravena,Esteban Hurtado,Rodrigo Riveros,Juan Felipe Cardona,Facundo Manes,Agustín Ibá?ez
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011751
Abstract: Behavioral studies have provided evidence for an action–sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes.
Contextual blending of ingroup/outgroup face stimuli and word valence: LPP modulation and convergence of measures
Esteban Hurtado, Andrés Haye, Ramiro González, Facundo Manes, Agustiń Ibá?ez
BMC Neuroscience , 2009, DOI: 10.1186/1471-2202-10-69
Abstract: Results showed that, during an IAT, indigenous participants with greater behavioral ingroup bias displayed a frontal LPP that was modulated in terms of complex contextual associations involving ethnic group and valence. The LPP was lateralized to the right for negative valence stimuli and to the left for positive valence stimuli. This valence lateralization was influenced by the combination of valence and membership type relevant to compatibility with prejudice toward a minority. Behavioral data from the IAT and an explicit attitudes questionnaire were used to clarify this finding and showed that ingroup bias plays an important role. Both ingroup favoritism and indigenous/non-indigenous differences were consistently present in the data.Our results suggest that frontal LPP is elicited by contextual blending of evaluative judgments of in-/outgroup information and positive vs. negative valence association and confirm recent research relating in-/outgroup ERP modulation and frontal LPP. LPP modulation may cohere with implicit measures of attitudes. The convergence of measures that were observed supports the idea that racial and valence evaluations are strongly influenced by context. This result adds to a growing set of evidence concerning contextual sensitivity of different measures of prejudice.Prejudice, as understood in this work, is a complex phenomenon that represents an attitude or set of attitudes displayed by an individual or individuals that can be understood and measured in different ways and that can be affected by factors that are internal (e.g., individual bias) and external (e.g., context) to the subjects who show it. It is possible to discuss aspects of the phenomenon of prejudice at various levels of description. In an attempt to consider the phenomenon of prejudice at the level of its possible relationship to cerebral event related potentials, we developed an experiment in which several measures in addition to EEG are taken in subjects undergoing proces
Functional Imaging Reveals Movement Preparatory Activity in the Vegetative State
Tristan Andres Bekinschtein,Facundo Francisco Manes,Mirta Villarreal,Adrian Mark Owen,Valeria Della-Maggiore
Frontiers in Human Neuroscience , 2011, DOI: 10.3389/fnhum.2011.00005
Abstract: The vegetative state (VS) is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect signs of purposeful behavior in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI) to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Our results may reflect residual voluntary processing in these two patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness.
The relationship between executive functions and fluid intelligence in schizophrenia
María Roca,Facundo Manes,Diana Bruno,Agustín Ibá?ez,Teresa Torralva
Frontiers in Behavioral Neuroscience , 2014, DOI: 10.3389/fnbeh.2014.00046
Abstract: An enduring question is unity vs. separability of executive deficits resulting from impaired frontal lobe function. In previous studies, we have asked how executive deficits link to a conventional measure of fluid intelligence, obtained either by standard tests of novel problem-solving, or by averaging performance in a battery of novel tasks. For some classical executive tasks, such as the Wisconsin Card Sorting Test (WCST), Verbal Fluency, and Trail Making Test B (TMTB), frontal deficits are entirely explained by fluid intelligence. However, on a second set of executive tasks, including tests of multitasking and decision making, deficits exceed those predicted by fluid intelligence loss. In this paper we discuss how these results shed light on the diverse clinical phenomenology observed in frontal dysfunction, and present new data on a group of 15 schizophrenic patients and 14 controls. Subjects were assessed with a range of executive tests and with a general cognitive battery used to derive a measure of fluid intelligence. Group performance was compared and fluid intelligence was introduced as a covariate. In line with our previous results, significant patient-control differences in classical executive tests were removed when fluid intelligence was introduced as a covariate. However, for tests of multitasking and decision making, deficits remained. We relate our findings to those of previous factor analytic studies describing a single principal component, which accounts for much of the variance of schizophrenic patients' cognitive performance. We propose that this general factor reflects low fluid intelligence capacity, which accounts for much but not all cognitive impairment in this patient group. Partialling out the general effects of fluid intelligence, we propose, may clarify the role of additional, more specific cognitive impairments in conditions such as schizophrenia.
Early Neural Markers of Implicit Attitudes: N170 Modulated by Intergroup and Evaluative Contexts in IAT
Agustín Ibá?ez,Ezequiel Gleichgerrcht,Esteban Hurtado,Ramiro González,Andrés Haye,Facundo F. Manes
Frontiers in Human Neuroscience , 2010, DOI: 10.3389/fnhum.2010.00188
Abstract: The Implicit Association Test (IAT) is the most popular measure to evaluate implicit attitudes. Nevertheless, its neural correlates are not yet fully understood. We examined event related potentials (ERPs) in response to face- and word processing while indigenous and non-indigenous participants performed an IAT displaying faces (ingroup and outgroup members) and words (positive and negative valence) as targets of category judgments. The N170 component was modulated by valence of words and by ingroup/outgroup face categorization. Contextual effects (face–words implicitly associated in the task) had an influence on the N170 amplitude modulation. On the one hand, in face categorization, right N170 showed differences according to the association between social categories of faces and affective valence of words. On the other, in word categorization, left N170 presented a similar modulation when the task implied a negative-valence associated with ingroup faces. Only indigenous participants showed a significant IAT effect and N170 differences. Our results demonstrate an early ERP blending of stimuli processing with both intergroup and evaluative contexts, suggesting an integration of contextual information related to intergroup attitudes during the early stages of word and face processing. To our knowledge, this is the first report of early ERPs during an ethnicity IAT, opening a new branch of exchange between social neuroscience and social psychology of attitudes.
Facial and semantic emotional interference: A pilot study on the behavioral and cortical responses to the dual valence association task
Agustín Ibá?ez, Esteban Hurtado, Rodrigo Riveros, Hugo Urquina, Juan F Cardona, Agustín Petroni, Alejandro Lobos-Infante, Joaquin Barutta, Sandra Baez, Facundo Manes
Behavioral and Brain Functions , 2011, DOI: 10.1186/1744-9081-7-8
Abstract: Behavioural measures and Event Related Potentials were recorded while participants performed the DVAT.Behavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT.Results suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.Integrating information about emotional valence from face expressions and semantic information is an essential aspect of social interactions. In particular, the integration of emotional cues in a highly associative context (e.g., face to face communication) is critical for understanding complex social cues. For example, to understand an irony, one benefits from integrating semantic information with facial clues that orient the listener to the opposite meaning. Language modulates the information presented in facial expressions [1], and in turn, emotion modulates semantic understanding [2]. In certain situations, the incompatibility of emotional cues regarding semantic information in an associative context requires cognitive processes in order to solve this conflict. In cognitive sciences, several paradigms are considered robust indexes of the degree of conflict, such as Simon effect, or interference between routes of divergent/convergent emotional information, such as Emotional Stroop effect. Conflict tasks, also known as interference tasks, present to the subject two or more tasks to be performed simultaneously. Each task requires the implementation of a limited number of maneuvers, which produces interference or conflict when one task is incongruent with another one.Here we present behavioural and neural correlates of an interference task, triggered by incongruent emotional discrimination, in a similar vein than
Tracking the Cognitive, Social, and Neuroanatomical Profile in Early Neurodegeneration: Type III Cockayne Syndrome
Sandra Baez,Blas Couto,Eduar Herrera,Yamile Bocanegra,Natalia Trujillo-Orrego,Lucia Madrigal-Zapata,Juan Felipe Cardona,Facundo Manes,Agustin Ibanez,Andres Villegas
Frontiers in Aging Neuroscience , 2013, DOI: 10.3389/fnagi.2013.00080
Abstract: Cockayne syndrome (CS) is an autosomal recessive disease associated with premature aging, progressive multiorgan degeneration, and nervous system abnormalities including cerebral and cerebellar atrophy, brain calcifications, and white matter abnormalities. Although several clinical descriptions of CS patients have reported developmental delay and cognitive impairment with relative preservation of social skills, no previous studies have carried out a comprehensive neuropsychological and social cognition assessment. Furthermore, no previous research in individuals with CS has examined the relationship between brain atrophy and performance on neuropsychological and social cognition tests. This study describes the case of an atypical late-onset type III CS patient who exceeds the mean life expectancy of individuals with this pathology. The patient and a group of healthy controls underwent a comprehensive assessment that included multiple neuropsychological and social cognition (emotion recognition, theory of mind, and empathy) tasks. In addition, we compared the pattern of atrophy in the patient to controls and to its concordance with ERCC8 gene expression in a healthy brain. The results showed memory, language, and executive deficits that contrast with the relative preservation of social cognition skills. The cognitive profile of the patient was consistent with his pattern of global cerebral and cerebellar loss of gray matter volume (frontal structures, bilateral cerebellum, basal ganglia, temporal lobe, and occipito-temporal/occipito-parietal regions), which in turn was anatomically consistent with the ERCC8 gene expression level in a healthy donor’s brain. The study of exceptional cases, such as the one described here, is fundamental to elucidating the processes that affect the brain in premature aging diseases, and such studies provide an important source of information for understanding the problems associated with normal and pathological aging.
Moduli spaces for families of rational maps on P^1
Michelle Manes
Mathematics , 2009,
Abstract: Let phi: P^1 --> P^1 be a rational map defined over a field K. We construct the moduli space M_d(N) parameterizing conjugacy classes of degree-d maps with a point of formal period N and present an algebraic proof that M_2(N) is geometrically irreducible for N>1. Restricting ourselves to maps phi of arbitrary degree d >= 2 such that the composition h^{-1} phi h = phi for some nontrivial h in PGL_2, we show that the moduli space parameterizing these maps with a point of formal period N is geometrically reducible for infinitely many N.
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