optman 2014-05-09 22:56 0 票支持; 0 票反对
开始时间: 05/11/2015 持续时间: 6 weeks
大学或机构: Duke University(杜克大学)
课程评论: 1 个评论
Knowing where things are is effortless. But “under the hood,” your brain devotes a tremendous amount of computational power to figuring out even the simplest of details about the world around you and your position in it. Recognizing your mother, finding your phone, going to the grocery store, playing the banjo – these require careful sleuthing and coordination across different sensory and motor domains. This course traces the brain’s detective work to create this sense of space and argues that the brain’s spatial focus permeates our cognitive abilities, affecting the way we think and remember.
The material in this course overlaps with that normally covered in classes on perception or systems neuroscience.
Seeing: from the brain’s molecular light switches to a world in depth
This unit explains what light is, and how it is detected by photoreceptors in the eye. It includes a history of vision research dating back to ancient Greece, and describes the role of the astronomer Kepler in deducing how the image of the visual scene is formed on the eye. How the two-dimensional projection of the visual scene onto the surface of the retina is interpreted by the brain as a three-dimensional world is explored through examples from various artists such as Magritte and Escher.2. Somatosensory
This unit introduces the brain mechanisms responsible for sensory processing of vision and touch, with an emphasis on the formation of sensory maps in the visual and somatosensory pathways of the brain. The implications of these maps and other neural response properties for perception of spatial location are explored, with an emphasis on object motion and contours. Experiments using electrical stimulation in sensory maps to probe their connection to perception are discussed.
Sherlock ear: how your brain finds sounds
This unit turns to a sensory system for which spatial location must be inferred from indirect measurements. For vision and touch, the sensory receptors are able to measure spatial location in kind: objects at different locations activated different sensory receptors. For hearing, the brain must compare and contrast the sounds arriving at each ear to make inferences about the location of origin. This unit discusses the how this works, from the nature of sound itself to the interpretation of location-dependent sound attributes by the brain.
5. Brain meters for space
Moving with maps and meters
This unit introduces the concept of a “meter” for spatial signals in the brain. More commonly but somewhat obscurely referred to as rate coding, this kind of representation involves neural response rates that scale in proportion to spatial location – a meter whose level indicates position. This kind of code is used in movements, the sense of body position, and in the early stages of the auditory pathway.
6. Reference frames
Defining space: reference frames
Spatial locations are measured with respect to reference positions, but these reference positions differ depending on the type of sensory input. The eyes measure locations with respect to the eyes, and the ears measure locations with respect to the ears. This unit discusses some illusions related to this issue and describes brain mechanisms for translating between different reference frames. Synthesizing a sense of space across time as the body and its sense organs move through the environment requires integrating memories of the sensory input at different times and positions.
Going places: Balance, flow, steps and shortcuts
This unit shifts focus in two ways: (a) it involves space on a larger scale such as traveling from one place to another, and (b) it involves a sense of one’s own position in the environment as opposed to the position of objects or events in that scene. The role of the sense of balance and one’s own movements are incorporated. Animal species that navigate long distances and how they do this are described.8. Space and memory
optman 2014-05-09 22:56 0 票支持; 0 票反对