707 resultados para Halperín Donghi, Tulio


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Two experiments plus a pilot investigated the role of melodic structure on short-term memory for musical notation by musicians and nonmusicians. In the pilot experiment, visually similar melodies that had been rated as either "good" or "bad" were presented briefly, followed by a 15-sec retention interval and then recall. Musicians remembered good melodies better than they remembered bad ones: nonmusicians did not distinguish between them. In the second experiment, good, bad, and random melodies were briefly presented, followed by immediate recall. The advantage of musicians over nonmusicians decreased as the melody type progressed from good to bad to random. In the third experiment, musicians and nonmusicians divided the stimulus melodies into groups. For each melody, the consistency of grouping was correlated with memory performance in the first two experiments. Evidence was found for use of musical groupings by musicians and for use of a simple visual strategy by nonmusicians. The nature of these musical groupings and how they may be learned are considered. The relation of this work to other studies of comprehension of symbolic diagrams is also discussed.

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Investigated the organizing principles in memory for familiar songs in 2 experiments. It was hypothesized that individuals do not store and remember each song in isolation. Rather, there exists a rich system of relationships among tunes that can be revealed through similarity rating studies and memory tasks. One initial assumption was the division of relations among tunes into musical (e.g., tempo, rhythm) and nonmusical similarity. In Exp I, 20 undergraduates were asked to sort 60 familiar tunes into groups according to both musical and nonmusical criteria. Clustering analyses showed clear patterns of nonmusical similarity but few instances of musical similarity. Exp II, with 16 Ss, explored the psychological validity of the nonmusical relationships revealed in Exp I. A speeded verification task showed that songs similar to each other are confused more often than are distantly related songs. A free-recall task showed greater clustering for closely related songs than for distantly related ones. The relationship between these studies and studies of semantic memory is discussed. Also, the contribution of musical training and individual knowledge to the organization of the memory system is considered. (19 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)

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Two studies investigated the similarity of metronome settings to perceived and imagined familiar songs by subjects unselected for musical ability. In Study 1, mean tempo settings in the two tasks were about 100 beats per minute. Songs with slower perceived tempos tended to be faster in the imagery task and vice versa. In Study 2, subjects set fastest and slowest acceptable tempos for the same set of songs in the imagery mode. These settings were positively correlated with the preferred tempo for the song. Most subjects thought that there were limits on how fast or slow a song could be imagined. These results suggest that tempo is explicitly represented in auditory imagery.

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We previously observed that mental manipulation of the pitch level or temporal organization of melodies results in functional activation in the human intraparietal sulcus (IPS), a region also associated with visuospatial transformation and numerical calculation. Two outstanding questions about these musical transformations are whether pitch and time depend on separate or common processing in IPS, and whether IPS recruitment in melodic tasks varies depending upon the degree of transformation required (as it does in mental rotation). In the present study we sought to answer these questions by applying functional magnetic resonance imaging while musicians performed closely matched mental transposition (pitch transformation) and melody reversal (temporal transformation) tasks. A voxel-wise conjunction analysis showed that in individual subjects, both tasks activated overlapping regions in bilateral IPS, suggesting that a common neural substrate subserves both types of mental transformation. Varying the magnitude of mental pitch transposition resulted in variation of IPS BOLD signal in correlation with the musical key-distance of the transposition, but not with the pitch distance, indicating that the cognitive metric relevant for this type of operation is an abstract one, well described by music-theoretic concepts. These findings support a general role for the IPS in systematically transforming auditory stimulus representations in a nonspatial context. (C) 2013 Elsevier Inc. All rights reserved.

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Neuropsychological studies have suggested that imagery processes may be mediated by neuronal mechanisms similar to those used in perception. To test this hypothesis, and to explore the neural basis for song imagery, 12 normal subjects were scanned using the water bolus method to measure cerebral blood flow (CBF) during the performance of three tasks. In the control condition subjects saw pairs of words on each trial and judged which word was longer. In the perceptual condition subjects also viewed pairs of words, this time drawn from a familiar song; simultaneously they heard the corresponding song, and their task was to judge the change in pitch of the two cued words within the song. In the imagery condition, subjects performed precisely the same judgment as in the perceptual condition, but with no auditory input. Thus, to perform the imagery task correctly an internal auditory representation must be accessed. Paired-image subtraction of the resulting pattern of CBF, together with matched MRI for anatomical localization, revealed that both perceptual and imagery. tasks produced similar patterns of CBF changes, as compared to the control condition, in keeping with the hypothesis. More specifically, both perceiving and imagining songs are associated with bilateral neuronal activity in the secondary auditory cortices, suggesting that processes within these regions underlie the phenomenological impression of imagined sounds. Other CBF foci elicited in both tasks include areas in the left and right frontal lobes and in the left parietal lobe, as well as the supplementary motor area. This latter region implicates covert vocalization as one component of musical imagery. Direct comparison of imagery and perceptual tasks revealed CBF increases in the inferior frontal polar cortex and right thalamus. We speculate that this network of regions may be specifically associated with retrieval and/or generation of auditory information from memory.

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Most people intuitively understand what it means to “hear a tune in your head.” Converging evidence now indicates that auditory cortical areas can be recruited even in the absence of sound and that this corresponds to the phenomenological experience of imagining music. We discuss these findings as well as some methodological challenges. We also consider the role of core versus belt areas in musical imagery, the relation between auditory and motor systems during imagery of music performance, and practical implications of this research.

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Auditory imagery is more than just mental “replaying” of tunes in one’s head. I will review several studies that capture characteristics of complex and active imagery tasks, using both behavioral and neuroscience approaches. I use behavioral methods to capture people’s ability to make emotion judgments about both heard and imagined music in real time. My neuroimaging studies look at the neural correlates of encoding an imagined melody, anticipating an upcoming tune, and also imagining tunes backwards. Several studies show voxel-by-voxel correlates of neural activity with self-report of imagery vividness. These studies speak to the ways in which musical imagery allows us not just to remember music, but also how we use those memories to judge temporally changing aspects of the musical experience.

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The vocal imitation of pitch by singing requires one to plan laryngeal movements on the basis of anticipated target pitch events. This process may rely on auditory imagery, which has been shown to activate motor planning areas. As such, we hypothesized that poor-pitch singing, although not typically associated with deficient pitch perception, may be associated with deficient auditory imagery. Participants vocally imitated simple pitch sequences by singing, discriminated pitch pairs on the basis of pitch height, and completed an auditory imagery self-report questionnaire (the Bucknell Auditory Imagery Scale). The percentage of trials participants sung in tune correlated significantly with self-reports of vividness for auditory imagery, although not with the ability to control auditory imagery. Pitch discrimination was not predicted by auditory imagery scores. The results thus support a link between auditory imagery and vocal imitation.

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We examined aesthetic preference for reproductions of paintings among frontotemporal dementia (FTD) patients, in two sessions separated by 2 weeks. The artworks were in three different styles: representational, quasirepresentational, and abstract. Stability of preference for the paintings was equivalent to that shown by a matched group of Alzheimer's disease patients and a group of healthy controls drawn from an earlier study. We expected that preference for representational art would be affected by disruptions in language processes in the FTD group. However, this was not the case and the FTD patients, despite severe language processing deficits, performed similarly across all three art styles. These data show that FTD patients maintain a sense of aesthetic appraisal despite cognitive impairment and should be amenable to therapies and enrichment activities involving art.

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Mild encephalopathy with reversible splenial lesions has mainly been associated with influenza A and B virus infection. Patients present with neurologic symptoms 1 to 3 days after a prodromal illness and recover completely within a few days. Magnetic resonance imaging typically shows reversible lesions with reduced diffusion in the corpus callosum, predominantly in the splenium. We report on a 5-year old Caucasian boy who was referred with recurrent seizures and decreased level of consciousness after a 2-day prodromal fever and cough. Magnetic resonance imaging showed cytotoxic edema of the entire corpus callosum and the adjacent periventricular white matter with diffusion restriction and faint T(2)-hyperintensity. Parainfluenza virus type 1-3 infection was documented by direct immunofluorescence in the initial nasopharyngeal swab, but polymerase chain reaction for parainfluenza virus type 1-4 in the cerebrospinal fluid remained negative. This is-to our knowledge-the first description of mild encephalopathy with reversible splenial lesions in association with parainfluenza virus infection. The pathogenesis of mild encephalopathy with reversible splenial lesions, however, still remains unclear, and further studies investigating detailed mechanisms that lead to the typical brain lesions are warranted.

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WE INVESTIGATED HOW WELL STRUCTURAL FEATURES such as note density or the relative number of changes in the melodic contour could predict success in implicit and explicit memory for unfamiliar melodies. We also analyzed which features are more likely to elicit increasingly confident judgments of "old" in a recognition memory task. An automated analysis program computed structural aspects of melodies, both independent of any context, and also with reference to the other melodies in the testset and the parent corpus of pop music. A few features predicted success in both memory tasks, which points to a shared memory component. However, motivic complexity compared to a large corpus of pop music had different effects on explicit and implicit memory. We also found that just a few features are associated with different rates of "old" judgments, whether the items were old or new. Rarer motives relative to the testset predicted hits and rarer motives relative to the corpus predicted false alarms. This data-driven analysis provides further support for both shared and separable mechanisms in implicit and explicit memory retrieval, as well as the role of distinctiveness in true and false judgments of familiarity.

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BACKGROUND : Comparisons between younger and older stroke patients including comorbidities are limited. METHODS : Prospective data of consecutive patients with first ever acute ischemic stroke were compared between younger ( 45 years). RESULTS : Among 1004 patients, 137 (14 %) were

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Breslau, Univ., Diss., 4. Juni 1869

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Aim Geographical, climatic and soil factors are major drivers of plant beta diversity, but their importance for dryland plant communities is poorly known. The aim of this study was to: (1) characterize patterns of beta diversity in global drylands; (2) detect common environmental drivers of beta diversity; and (3) test for thresholds in environmental conditions driving potential shifts in plant species composition. Location Global. Methods Beta diversity was quantified in 224 dryland plant communities from 22 geographical regions on all continents except Antarctica using four complementary measures: the percentage of singletons (species occurring at only one site); Whittaker's beta diversity, β(W); a directional beta diversity metric based on the correlation in species occurrences among spatially contiguous sites, β(R2); and a multivariate abundance-based metric, β(MV). We used linear modelling to quantify the relationships between these metrics of beta diversity and geographical, climatic and soil variables. Results Soil fertility and variability in temperature and rainfall, and to a lesser extent latitude, were the most important environmental predictors of beta diversity. Metrics related to species identity percentage of singletons and β(W) were most sensitive to soil fertility, whereas those metrics related to environmental gradients and abundance (β(R2) and β(MV) were more associated with climate variability. Interactions among soil variables, climatic factors and plant cover were not important determinants of beta diversity. Sites receiving less than 178 mm of annual rainfall differed sharply in species composition from more mesic sites (> 200 mm). Main conclusions Soil fertility and variability in temperature and rainfall are the most important environmental predictors of variation in plant beta diversity in global drylands. Our results suggest that those sites annually receiving c. 178 mm of rainfall will be especially sensitive to future climate changes. These findings may help to define appropriate conservation strategies for mitigating effects of climate change on dryland vegetation.