1,721,051 research outputs found
Impaired filtering of distracter stimuli by TE neurons following V4 and TEO lesions in macaques
No full textDirecting attention to a behaviorally relevant visual stimulus can overcome the distracting effects of other nearby stimuli. Correspondingly, physiological studies indicate that attention serves to filter distracting stimuli from receptive fields (RFs) in several extrastriate areas. Moreover, a recent study demonstrated that lesions of extrastriate areas V4 and TEO produce impairments in attentional filtering. A critical remaining question concerns why lesions of ventral stream areas cause attentional filtering impairments. To address this question, we tested the effects of restricted area V4 and TEO lesions on both behavioral performance and the responses of downstream neurons in area TE. The lesions impaired behavioral discrimination thresholds and altered neuronal selectivity for target stimuli in the presence of distracters. With attention to the target, but in the absence of V4 and/or TEO inputs, TE neurons responded as though attentional inputs could no longer be used to filter distracters from their RFs. This presumably occurred because top-down attentional signals were no longer able to filter distracters from the RFs of the cells that provide TE with major input. Consistent with this interpretation, increasing the spatial separation between targets and distracters, such that they no longer fell within a typical V4 RF dimension, restored both behavioral performance and neuronal selectivity in the portion of TE RFs affected by the V4 lesion
Visual responses to targets and distracters by inferior temporal neurons after lesions of extrastriate areas V4 and TEO
No full textWhile lesions of visual areas V4 and TEO only modestly affect discrimination of isolated objects, they significantly impair the ability to selectively attend to an object surrounded by distracters.To test whether such deficits result from a loss of inputs to higher order areas, we recorded from area TE neurons after removing portions of V4 and TEO in a monkey. Responses to isolated targets in a lesion-affected visual quadrant were substantially preserved, indicating that TE still receives information even after removing a major source of input. Distracters increased or decreased the response to targets more in the lesion-affected than in the normal quadrant, supporting the idea that V4 and/orTEO are sites where top-down attentional inputs filter out distracting stimuli
A broadly tuned network for affective body language in the macaque brain.
No full textData and visual stimuli from the publication: *Taubert, J., Japee, S., Patterson, A., Wild, H., Goyal, S., Yu, D., Ungerleider, L. G. (accepted) A broadly tuned network for affective body language in the macaque brain
A broadly tuned network for affective body language in the macaque brain.
No full textData and visual stimuli from the publication: *Taubert, J., Japee, S., Patterson, A., Wild, H., Goyal, S., Yu, D., Ungerleider, L. G. (accepted) A broadly tuned network for affective body language in the macaque brain
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
A broadly tuned network for affective body language in the macaque brain.
No full textData and visual stimuli from the publication: *Taubert, J., Japee, S., Patterson, A., Wild, H., Goyal, S., Yu, D., Ungerleider, L. G. (accepted) A broadly tuned network for affective body language in the macaque brain
Variations on the Author
Get PDF“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
Get PDFWe 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
The representation of objects in the human occipital and temporal cortex
Get PDFRecently, we identified, using fMRI, three bilateral regions in the ventral temporal cortex that responded preferentially to faces, houses, and chairs [Ishai, A., Ungerleider, L. G., Martin, A., Schouten, J. L., & Haxby, J. V. (1999). Distributed representation of objects in the human ventral visual pathway. Proceedings of the National Academy of Sciences, U.S.A., 96, 9379--9384]. Here, we report differential patterns of activation, similar to those seen in the ventral temporal cortex, in bilateral regions of the ventral occipital cortex. We also found category-related responses in the dorsal occipital cortex and in the superior temporal sulcus. Moreover, rather than activating discrete, segregated areas, each category was associated with its own differential pattern of response across a broad expanse of cortex. The distributed patterns of response were similar across tasks (passive viewing, delayed matching) and presentation formats (photographs, line drawings). We propose that the representation of objects in the ventral visual pathway, including both occipital and temporal regions, is not restricted to small, highly selective patches of cortex but, instead, is a distributed representation of information about object form. Within this distributed system, the representation of faces appears to be less extensive as compared to the representations of nonface objects
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