The goal of this project is to characterize the neural substrate underlying differences between perception of the central and peripheral parts of the visual field. Important visual functions, such as reading, require central vision and clinical conditions, such as macular degeneration selectively affect this part of the visual field, conferring significant disability. We will focus our investigation on the perception of boundaries between different textures. These boundaries are used in order to parse images into distinct regions and objects and perception of these boundaries differs between central and peripheral vision. These differences are likely to result from the manner in which information is processed in different parts of the visual field and the way in which information is transmitted through the visual system, via the anatomical connections between different regions of the visual system. To study these differences, we will measure properties of the visual system in healthy human participants, using a combination of methods. We will use behavioral measurements to characterize the perception of texture boundaries in different parts of the visual system. We will use functional magnetic resonance imaging (fMRI) to measure activity in different regions of the visual system and detect activity related to the presence of texture boundaries. We will use diffusion-weighted MRI to characterize the anatomical connections between different parts of the visual system. Finally, we will combine the information from the anatomical measurements and the functional measurements and analyze the way in which information about different parts of the visual field is segregated and shared between parts of the visual system. Understanding the neural representation of different parts of the visual field in texture perception will benefit the development of novel treatments for patients with visual impairments affecting parts of the visual field, such as macular degeneration and disorders in which visual acuity in central vision is affected, such as amblyopia.
The goal of this project is to understand brain activity and neural connectivity underlying differences in perception between different parts of the visual field. Understanding these differences is important in order to better treat clinical conditions in which different parts of the visual field are affected, such as macular degeneration (selectively affects central vision) and retinitis pigmentosa (selectively affects peripheral vision). Moreover, the methods developed may be used in order to measure the disruption of connections between different parts of the brain in other disorders.
|Rokem, Ariel; Takemura, Hiromasa; Bock, Andrew S et al. (2017) The visual white matter: The application of diffusion MRI and fiber tractography to vision science. J Vis 17:4|
|Tian, Qiyuan; Rokem, Ariel; Folkerth, Rebecca D et al. (2016) Q-space truncation and sampling in diffusion spectrum imaging. Magn Reson Med 76:1750-1763|
|Takemura, Hiromasa; Rokem, Ariel; Winawer, Jonathan et al. (2016) A Major Human White Matter Pathway Between Dorsal and Ventral Visual Cortex. Cereb Cortex 26:2205-2214|
|Rokem, Ariel; Yeatman, Jason D; Pestilli, Franco et al. (2015) Evaluating the accuracy of diffusion MRI models in white matter. PLoS One 10:e0123272|
|Ajina, Sara; Pestilli, Franco; Rokem, Ariel et al. (2015) Human blindsight is mediated by an intact geniculo-extrastriate pathway. Elife 4:|
|Yeatman, Jason D; Weiner, Kevin S; Pestilli, Franco et al. (2014) The vertical occipital fasciculus: a century of controversy resolved by in vivo measurements. Proc Natl Acad Sci U S A 111:E5214-23|
|Pestilli, Franco; Yeatman, Jason D; Rokem, Ariel et al. (2014) Evaluation and statistical inference for human connectomes. Nat Methods 11:1058-63|
|Kay, Kendrick N; Winawer, Jonathan; Rokem, Ariel et al. (2013) A two-stage cascade model of BOLD responses in human visual cortex. PLoS Comput Biol 9:e1003079|