Distribution and prognostic relevance of tumor-infiltrating lymphocytes (TILs) and PD-1/PD-L1 immune checkpoints in human brain metastases

Simple cells in primary visual cortex were famously found to respond to low-level image components such as edges. Sparse coding and independent component analysis (ICA) emerged as the standard computational models for si
Simple cells in primary visual cortex were famously found to respond to low-level image components such as edges. Sparse coding and independent component analysis (ICA) emerged as the standard computational models for simple cell coding because they linked their receptive fields to the statistics of visual stimuli. However, a salient feature of image statistics, occlusions of image components, is not considered by these models. Here we ask if occlusions have an effect on the predicted shapes of simple cell receptive fields. We use a comparative approach to answer this question and investigate two models for simple cells: a standard linear model and an occlusive model. For both models we simultaneously estimate optimal receptive fields, sparsity and stimulus noise. The two models are identical except for their component superposition assumption. We find the image encoding and receptive fields predicted by the models to differ significantly. While both models predict many Gabor-like fields, the occlusive model predicts a much sparser encoding and high percentages of ‘globular’ receptive fields. This relatively new center-surround type of simple cell response is observed since reverse correlation is used in experimental studies. While high percentages of ‘globular’ fields can be obtained using specific choices of sparsity and overcompleteness in linear sparse coding, no or only low proportions are reported in the vast majority of studies on linear models (including all ICA models). Likewise, for the here investigated linear model and optimal sparsity, only low proportions of ‘globular’ fields are observed. In comparison, the occlusive model robustly infers high proportions and can match the experimentally observed high proportions of ‘globular’ fields well. Our computational study, therefore, suggests that ‘globular’ fields may be evidence for an optimal encoding of visual occlusions in primary visual cortex.
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Metadaten
Author:Patrick Nikolaus Harter, Simon Bernatz, Alexander Scholz, Pia Susan Zeiner, Jenny Zinke, Makoto Kiyose, Stella Blasel, Rudi Beschorner, Christian Alexander Senft, Benjamin Bender, Michael Wilfried Ronellenfitsch, Harriet Wikman, Markus Glatzel, Matthias Meinhardt, Tareq A. Juratli, Joachim Peter Steinbach, Karl H. Plate, Jörg Wischhusen, Benjamin Weide, Michel Guy André Mittelbronn
URN:urn:nbn:de:hebis:30:3-415115
DOI:http://dx.doi.org/10.18632/oncotarget.5696
ISSN:1949-2553
Pubmed Id:http://www.ncbi.nlm.nih.gov/pubmed?term=26517811
Parent Title (English):Oncotarget
Document Type:Article
Language:English
Date of Publication (online):2015/10/16
Date of first Publication:2015/10/16
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2016/09/29
Tag:PD-1; PD-L1; brain metastases; tumor-infiltrating lymphocytes
Volume:6
Issue:38
Pagenumber:14
First Page:40836
Last Page:40849
Note:
Licensed under a Creative Commons Attribution 3.0 License.
HeBIS PPN:399894136
Institutes:Medizin
Dewey Decimal Classification:610 Medizin und Gesundheit
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 3.0

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