Daniel Ts'o

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Electrophysiological and brain imaging studies have shown that different populations of neurons contribute to perceptual decision making. Perceptual judgment is a complicated process that has several subprocesses, including the final step of a discrete choice among available possibilities. Using the psychophysical paradigm of difference scaling combined(More)
PURPOSE To characterize the properties of stimulus-evoked retinal intrinsic signals and determine the underlying origins. METHODS Seven adult cats were anesthetized and paralyzed to maximize imaging stability. The retina was stimulated with a liquid crystal display (LCD) integrated into a modified fundus camera (Topcon, Tokyo, Japan). The LCD presented(More)
PURPOSE To elucidate the anatomic origins of stimulus-evoked intrinsic optical signals in the mammalian retina by using selective pharmacologic blockade of specific retinal layers. METHODS Four adult cats were used to investigate the stimulus-evoked intrinsic signals. The retinas were visually stimulated with a liquid crystal display (LCD) integrated into(More)
In the early stages of some retinal diseases, such as glaucoma, loss of retinal activity may be difficult to detect with current clinical instruments. Because current instruments require unattainable levels of patient cooperation, high sensitivity and specificity are difficult to attain. We have devised a new retinal imaging system that detects intrinsic(More)
We have adapted intrinsic signal optical imaging of neural activity to the noninvasive functional imaging of the retina. Results to date demonstrate the feasibility and potential of this new method of functional assessment of the retina. In response to visual stimuli, we have imaged reflectance changes in the retina that are robust and spatially colocalized(More)
PURPOSE To examine the extent to which neurovascular coupling contributes to stimulus-evoked intrinsic signals in the retina. METHODS The retinas of five adult cats were examined in vivo. Animals were anesthetized and paralyzed for imaging stability. The retinas were imaged through a modified fundus camera capable of presenting patterned visual stimuli(More)
Optical imaging of the retina is a novel means for imaging retinal function in humans and mammals, based on changes of retinal reflectance due to visual stimulation. The signal is noisy, weak, approximately 0.3-0.6% of total reflectance, and complex, making extraction of the signal is correspondingly difficult. We used an extension of principal component(More)
Independent component analysis (ICA) is a statistical technique that estimates a set of sources mixed by an unknown mixing matrix using only a set of observations. For this purpose, the only assumption is that the sources are statistically independent. In many applications, some information about the nature of the unknown signals is available. In this paper(More)
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