Description
- Abstract:
- A vast majority of visual system studies are conducted in the absence of eye movements and complex scenes. The purpose of simplifying these experiments is to reduce the number of variables that can influence our results; however, this means that most of our knowledge of visual function does not speak directly to how the visual system operates in normal, real-world, conditions that involve eye movements and complex images. Thus, the field of neuroscience has much to learn about the process of vision in experimental paradigms that mimic more naturalistic vision. Here I present research showing the effects of adding naturalness to experiments of primary visual cortical function in Macaque monkeys as well as perceptual ability of these animals, measured as contrast sensitivity. The main experimental paradigm showed that contrast sensitivity and neuronal responses in V1 are both affected by the inclusion of natural scene backgrounds and eye movements in a 2AFC detection task. These effects were spatial frequency-specific. Follow-up experiments determined that this spatial frequency-specificity was due to the visual contents of the natural scene background used in the study. The conclusion drawn from this research is that rapid-forming adaptation in V1 can occur within a 400ms fixation period, carry across a 7-degree saccadic eye movement, and affect neuronal responses and perceptual sensitivity to stimuli immediately following the saccade. Thus, in real-world vision, rapid adaptation effects are likely occurring during every fixation and then exerting influence on visual function at the following fixation. This novel finding has implications for the way visual neuronal function is studied in the lab setting, as well as the manner in which contrast sensitivity functions are viewed in clinical settings.
- Notes:
- Thesis (Ph.D. -- Brown University (2015)
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Citation
Niemeyer, James Edward,
"The effect of natural vision on perception and V1 neural activity"
(2015).
Neuroscience Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0T15211
