Adaptive Optics Studies (with the Morgan Lab)
Single Cone Intrinsic Response
This project compares measurements of simultaneous lightness contrast across a variety of contextual conditions. The key manipuluation is that measurements obtained using real illuminated surfaces as stimuli are compared to measurements obtained using rendered computer graphics stimuli displayed on monitors. The broad goal is to understand the degree to which the graphics stimuli evoke the same performance as the real stimuli, and when there are deviations to understand what the critical differences between the graphics and real stimuli are.
This project studies the ability of human subjects to make discriminations between changes in the illumination of scenes, with the goal of using these and related measurements to understand the nature and properties of the visual system's representation of illumination and object surfaces. This project is collaborative with Anya Hurlbert's lab. A manuscript describing these data is in press (in Journal of Vision) as of March 2018.
This project studies how human subjects use object color and object material properties to identify and select objects. A manuscript describing Exp 1 has been submitted (January 2018).
Virtual World Psychophysics
Melanopsin Studies (with the Aguirre Lab)
Control Population Stimulus Nulling Experiment
This project studies the properties of melanopsin-directed spectral modulations, and asks how much cone contrast must be added to a nominally melanopsin-directed stimulus to minimize the visibility of that stimulus.
Perceptual Ratings of Light Flux, Cone-Directed and Melanopsin-Directed Light Pulses
This project records psychophysical ratings of light-flux, melanopsin and LMS directed stimuli. The goal is to determine if the different stimulus classes elicit different percepts. Data collected in this project have been published Spitschan, M., Bock, A. S., Ryan, J., Frazzetta, G., Briainard, D. H., Aguirre, G. K. (2017).
Quantifying light perception via perceptual and physiologic measures in response to melanopsin and cone stimulation in migraineurs with interictal photophobia and in headache-free control subjects
This project will determine if patients with light sensitivity due to migraine headache have increased sensitivity to cone stimulation, melanopsin stimulation, or both.
Comparison of monochromatic and silent-substitution evoked pupil responses
This project compares pupillary responses to monochromatic blue and red pulses and silent-substitution melanopsin- and cone-directed pulses.
Pupillometry measures of melanopsin contrast - maximum melanopsin and LMS contrast pulses
This project studies pupil responses to high-contrast melanopsin- and cone-directed pulses.
Comparison of monochromatic and silent-substitution melanopsin and LMS-directed evoked pupil responses
In this experiment, we are comparing pupil responses evoked by monochromatic blue and red light pulses to those evoked by silent substitution LMS-directed and melanopsin-directed stimuli.
MaxMelLMS Pupil (17 second protocol)
This project studies pupil responses to high-contrast melanopsin- and cone-directed pulses using a shortened stimulus protocol.
Max Mel MRI
This project studies evoked brain responses to high-contrast melanopsin- and cone-directed pulses using BOLD fMRI. Data collected in this project have been published Spitschan, M., Bock, A. S., Ryan, J., Frazzetta, G., Briainard, D. H., Aguirre, G. K. (2017).
This project studies evoked brain responses to melanopsin- and cone-directed pulses using BOLD fMRI at various contrast levels. Data collected in this project have been published Spitschan, M., Bock, A. S., Ryan, J., Frazzetta, G., Brainard, D. H., Aguirre, G. K. (2017).