1,721,545 research outputs found
Autism, Asperger syndrome and brain mechanisms for the attribution of mental states to animated shapes.
No full textExamined brain mechanisms associated with attribution of mental states to animated shapes among 10 adults with autism or Asperger syndrome (mean age 33 yrs) and 10 normal subjects (Ss [mean age 25 yrs]). Ss were PET scanned while watching animated sequences. The animations depicted 2 triangles moving about on a screen in 3 different conditions: moving randomly, moving in a goal-directed fashion, and moving interactively with implied intentions. The last condition frequently elicited descriptions in terms of mental states that viewers attributed to the triangles (mentalizing). The autism group gave fewer and less accurate descriptions of these latter animations, but equally accurate descriptions of the other animations compared with controls. While viewing animations that elicited mentalizing, in contrast to randomly moving shapes, the normal Ss showed increased activation in a previously identified mentalizing network (medial prefrontal cortex, superior temporal sulcus at the temporo-parietal junction and temporal poles). The autism group showed less activation than the normal group in all these regions. Results suggest a physiological cause for the mentalizing dysfunction in autism: a bottleneck in the interaction between higher- and lower-order perceptual processes. (PsycINFO Database Record (c) 2003 APA, all rights reserved
The effect of adult-acquired hippocampal damage on memory retrieval: an fMRI study.
No full textBilateral hippocampal pathology typically results in significant memory problems. Despite apparently similar structural damage, patients with such lesions can differ in the pattern of impairment and preservation of memory functions. Previously, an fMRI study of a developmental amnesic patient whose anoxic hippocampal damage was incurred perinatally revealed his residual hippocampal tissue to be active during memory retrieval. This hippocampal activity was apparent during the retrieval of personal and general facts relative to a control task. In this study, we used a similar fMRI paradigm to investigate whether residual hippocampal activation was present also in patient VC with adult-acquired anoxic hippocampal pathology. VC's performance and reaction times on the experimental personal and general fact tasks were comparable to age-matched control subjects. However, in contrast to the elderly control sample and the previous developmental amnesic patient, his residual hippocampal tissue did not show activation changes during the experimental tasks. This finding indicates that patient VC's successful retrieval of personal and general facts was achieved without a significant hippocampal contribution. It further suggests that the hippocampal activation observed in the elderly controls and previous developmental amnesic patient was not necessary for successful task performance. The reason for this difference in hippocampal responsivity between VC and the developmental amnesic patient remains to be determined. We speculate that it may relate to the age at which hippocampal damage occurred reflecting plasticity within the developing brain, or to cognitive differences between VC, the developmental amnesic patient, and the control subjects
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Different brain circuits underlie motor and perceptual representations of temporal intervals
Full text linkIn everyday life, temporal information is used for both perception and action, but whether these two functions reflect the operation of similar or different neural circuits is unclear. We used functional magnetic resonance imaging to investigate the neural correlates of processing temporal information when either a motor or a perceptual representation is used. Participants viewed two identical sequences of visual stimuli and used the information differently to perform either a temporal reproduction or a temporal estimation task. By comparing brain activity evoked by these tasks and control conditions, we explored commonalities and differences in brain areas involved in reproduction and estimation of temporal intervals. The basal ganglia and the cerebellum were commonly active in both temporal tasks, consistent with suggestions that perception and production of time are subserved by the same mechanisms. However, only in the reproduction task was activity observed in a wider cortical network including the right pre-SMA, left middle frontal gyrus, left premotor cortex, with a more reliable activity in the right inferior parietal cortex, left fusiform gyrus, and the right extrastriate visual area V5/MT. Our findings point to a role for the parietal cortex as an interface between sensory and motor processes and suggest that it may be a key node in translation of temporal information into action. Furthermore, we discuss the potential importance of the extrastriate cortex in processing visual time in the context of recent findings
The social brain: allowing humans to boldly go where no other species has been
No full textThe biological basis of complex human social interaction and communication has been illuminated
through a coming together of various methods and disciplines. Among these are comparative studies
of other species, studies of disorders of social cognition and developmental psychology. The use of neuroimaging
and computational models has given weight to speculations about the evolution of social
behaviour and culture in human societies. We highlight some networks of the social brain relevant to
two-person interactions and consider the social signals between interacting partners that activate
these networks.Wemake a case for distinguishing between signals that automatically trigger interaction
and cooperation and ostensive signals that are used deliberately.We suggest that this ostensive signalling
is needed for ‘closing the loop’ in two-person interactions, where the partners each know that they have
the intention to communicate. The use of deliberate social signals can serve to increase reputation and
trust and facilitates teaching. This is likely to be a critical factor in the steep cultural ascent ofmankind
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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