Now showing items 1-20 of 20

    • Abnormal subcortical activity in congenital mirror movement disorder with RAD51 mutation 

      Demirayak, Pınar; Onat, Onur Emre; Gevrekci, A. Ö.; Gülsüner, S.; Uysal, H.; Bilgen, R.; Doerschner, Katja; Özçelik, Tayfun; Boyacı, Hüseyin (Turkish Society of Radiology, 2018)
      PURPOSE Congenital mirror movement disorder (CMMD) is characterized by unintended, nonsuppressible, homologous mirroring activity contralateral to the movement on the intended side of the body. In healthy controls, unilateral ...
    • Attention modulates neuronal correlates of interhemispheric integration and global motion perception 

      Akin, B.; Ozdem, C.; Eroglu, S.; Keskin, D. T.; Fang, F.; Doerschner, Katja; Kersten, D.; Boyacı, Hüseyin (Association for Research in Vision and Ophthalmology Inc., 2014)
      In early retinotopic areas of the human visual system, information from the left and right visual hemifields (VHFs) is processed contralaterally in two hemispheres. Despite this segregation, we have the perceptual experience ...
    • Attention-dependent representation of a size illusion in human V1 

      Fang, F.; Boyacı, Hüseyin; Kersten, D.; Murray, S.O. (Cell Press, 2008)
      One of the most fundamental properties of human primary visual cortex (V1) is its retinotopic organization, which makes it an ideal candidate for encoding spatial properties, such as size, of objects. However, three-dimensional ...
    • Border ownership selectivity in human early visual cortex and its modulation by attention 

      Fang, F.; Boyacı, Hüseyin; Kersten, D. (Society for Neuroscience, 2009)
      Natural images are usually cluttered because objects occlude one another. A critical aspect of recognizing these visual objects is to identify the borders between image regions that belong to different objects. However, ...
    • Color vision in humans and computers 

      Boyacı, Hüseyin; Akarun L. (IEEE, 2008)
      Humans and many other species rely on color for object recognition. What are the biological underpinnings of color vision and how can we computationally model human color perception? In this study we briefly summarize ...
    • Context-dependent lightness affects perceived contrast 

      Pamir, Zahide; Boyacı, Hüseyin (Elsevier Ltd, 2016)
      Perceived contrast of a grating varies with its background (or mean) luminance: of the two gratings with the same photometric contrast the one on higher luminance background appears to have higher contrast. Does perceived ...
    • Contrast affects fMRI activity in middle temporal cortex related to center-surround interaction in motion perception 

      Türkozer, Halide B.; Pamir, Zahide; Boyacı, Hüseyin (Frontiers Research Foundation, 2016)
      As the size of a high contrast drifting Gabor patch increases, perceiving its direction of motion becomes harder. However, the same behavioral effect is not observed for a low contrast Gabor patch. Neuronal mechanisms ...
    • Distinct patterns of surround modulation in V1 and hMT+ 

      Er, Görkem; Pamir, Zahide; Boyacı, Hüseyin (Academic Press Inc., 2020)
      Modulation of a neuron’s responses by the stimuli presented outside of its classical receptive field is ubiquitous in the visual system. This “surround modulation” mechanism is believed to be critical for efficient processing ...
    • Effect of contiguity and figure-ground organization on the area rule of lightness 

      Boyacı, Hüseyin; Şimşek, M. K.; Subaşı, Ece (Association for Research in Vision and Ophthalmology, 2014)
      In a simple two-dimensional (2D) display composed of two uniform surfaces with different luminances, the lightness of the darker surface varies as a function of its relative area while its luminance is held constant ...
    • Estimating the glossiness transfer function induced by illumination change and testing its transitivity 

      Doerschner, K.; Boyacı, Hüseyin; Maloney, Laurence T. (Association for Research in Vision and Ophthalmology, 2010)
      The light reflected from a glossy surface depends on the reflectance properties of that surface as well as the flow of light in the scene, the light field. We asked four observers to compare the glossiness of pairs of ...
    • Homozygous LAMC3 mutation links to structural and functional changes in visual attention networks 

      Ürgen, Buse M.; Topaç, Yasemin; Üstün, F. Seyhun; Demirayak, Pınar; Oğuz, Kader K.; Kansu, T.; Saygı, S.; Özçelik, Tayfun; Boyacı, Hüseyin; Doerschner, Katja (Elsevier, 2019)
      The occipital lobe contains a substantial part of the neural machinery involved in visual perception. Mutations in the LAMC3 gene have recently been shown to cause complex bilateral occipital cortical gyration abnormalities. ...
    • Identification of a novel missense mutation in RAD51 in a large family with congenital mirror movements 

      Onat, Onur Emre; Gülsüner, Süleyman; Bilgen, R.; Dal, G. M.; Bilguvar, K.; Boyacı, Hüseyin; Doerschner, Katja; Uysal, H.; Günel, M.; Özçelik, Tayfun (American Society of Human Genetics, 2012-11)
      Congenital mirror movements (CMM) are a rare and heterogeneous group of disorders characterized by involuntary contralateral movements of mainly the upper extremities during intentional movements on the opposite side. ...
    • Integrated assessment of visual perception abnormalities in psychotic disorders and relationship with clinical characteristics 

      Türközer, H. B.; Hasoğlu, T.; Chen, Y.; Norris, L. A.; Brown, M.; Delaney-Busch, N.; Kale, E. H.; Pamir, Zahide; Boyacı, Hüseyin; Kuperberg, G.; Lewandowski, K. E.; Topçuoğlu, V.; Öngür, D. (Cambridge University Press, 2019)
      Background-The visual system is recognized as an important site of pathology and dysfunction in schizophrenia. In this study, we evaluated different visual perceptual functions in patients with psychotic disorders using a ...
    • Nesne tanımada bağlam ve anlambilimsel sınıflandırmanın önemi: Bilgisayarla görme ve insanda görme alanlarındaki çalışmalar 

      Aksoy, Selim; Boyacı, Hüseyin; Gökçay, D. (IEEE, 2008-04)
      Sahne sınıflandırması ve nesne tanıma, bilgisayarla görme alanında fok uzun yıllardır üzerinde çalışılan temel problemlerdir. Bilgisayarlara kazandırılmaya çalışılan, sahnelerin ve içerdikleri nesnelerin otomatik olarak ...
    • Recessive LAMC3 mutations cause malformations of occipital cortical development 

      Barak, T.; Kwan, K. Y.; Louvi, A.; Demirbilek, V.; Saygi, S.; Tüysüz, B.; Choi, M.; Boyacı, Hüseyin; Doerschner, Katja; Zhu, Y.; Kaymakçalan, H.; Yilmaz, S.; Bakircioglu, M.; Çağlayan, A. O.; Öztürk, A.K.; Yasuno, K.; Brunken W. J.; Atalar, Ergin; Yalçnkaya, C.; Dinçer, A.; Bronen, R. A.; Mane, S.; Özçelik, Tayfun; Lifton, R. P.; Šestan, N.; Bilgüvar, K.; Günel, M. (Nature Publishing Group, 2011)
      The biological basis for regional and inter-species differences in cerebral cortical morphology is poorly understood. We focused on consanguineous Turkish families with a single affected member with complex bilateral ...
    • Size aftereffect is non-local 

      Altan, Ecem; Boyacı, Hüseyin (Elsevier, 2020)
      It is well known that prolonged exposure to a certain size stimulus alters the perceived size of a subsequently presented stimulus at the same location. How the rest of the visual space is affected by this size adaptation, ...
    • Statistical analysis methods for the fMRI data 

      Behroozi, M.; Daliri, M.R.; Boyacı, Hüseyin (2011)
      Functional magnetic resonance imaging (fMRI) is a safe and non-invasive way to assess brain functions by using signal changes associated with brain activity. The technique has become a ubiquitous tool in basic, clinical ...
    • Strongly correlated models of high-temperature superconductivity 

      Boyacı, Hüseyin (Bilkent University, 1999)
      Son zamanlarda nanometrc büyüklüğündeki örneklerle ya|)dan tek ek'ktron ta.^ınma deneyleri, üstün iletkenlerin büyüklüklerinin alt sının ile ilgili soruyu yeniden gündeme getirmiştir, iler ne kadar, belirsiz tanecik ...
    • Superconductivity in ultrasmall metallic particles 

      Boyacı, Hüseyin; Gedik, Zafer; Kulik, Igor O. (Springer, 2000)
      Recent single electron transport experiments in nanometer size samples renewed the question about the lower limits of the size of superconductors, and the crossover from superconducting to normal state. In order to give ...
    • Supercurrents and persistent currents in strongly correlated electron systems 

      Boyacı, Hüseyin (Bilkent University, 1995)
      The lull understanding· ol’the solution Гог the 1-tl Hubbard model is of interest in its own right, and may provide clues to the understanding of higher dimensioned systiMiis. We have found tin? exact solution of tlie ...