Abstract
We present a model of the early stages of processing in the visual cortex, in particular V1 and MT, to investigate the potential role of end-stopped V1 neurons in solving the aperture problem. A hierarchical network is used in which the incoming motion signals provided by complex V1 neurons and end-stopped V1 neurons proceed to MT neurons at the next stage. MT neurons are categorized into two types based on their function: integration and segmentation. The role of integration neurons is to propagate unambiguous motion signals arriving from those V1 neurons that emphasize object terminators (e.g. corners). Segmentation neurons detect the discontinuities in the input stimulus to control the activity of integration neurons. Although the activity of the complex V1 neurons at the terminators of the object accurately represents the direction of the motion, their level of activity is less than the activity of the neurons along the edges. Therefore, a model incorporating end-stopped neurons is essential to suppress ambiguous motion signals along the edges of the stimulus. It is shown that the unambiguous motion signals at terminators propagate over the rest of the object to achieve an accurate representation of motion.
Highlights
Visual information processing in the cortex begins in the primary visual cortex (V1) of the occipital lobe, which receives its input from the retina via the dorsal lateral geniculate nucleus (LGN) [1]
The initial motion signals are generated by neurons with receptive field properties similar to those found in V1
The outputs from these neurons are processed by a model that replicates the receptive field characteristics of middle temporal visual area (MT) neurons
Summary
Visual information processing in the cortex begins in the primary visual cortex (V1) of the occipital lobe, which receives its input from the retina via the dorsal lateral geniculate nucleus (LGN) [1]. Information from V1 is sent to higher brain regions through two cortical pathways: the dorsal and ventral pathways [1]. The main role of the dorsal pathway is to determine the spatial location and motion of stimuli, while the ventral pathway is specialized for processing form and color information. Processing of motion information starts in V1 but the receptive fields of the neurons in this area are very small, with diameters in the central visual field of less than one degree. Due to these small receptive fields, the neurons can only measure local motion.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
