Experiments in the GKAguirre Lab are usually preregistered. This page organizes links to these pre-registration documents by project. We initially made use of the open science foundation website for this purpose, but more recently simply commit documents to this repository, which accomplishes the same goal of establishing a date-and-time stamped record of our plans prior to embarking on an experiment.
It is apparently possible to tinker with the date/time stamp of an uploaded file on GitHub. We promise not to do this.
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. See:
- Spitschan M, Datta R, Stern AM, Brainard DH, Aguirre GK (2016) Human visual cortex responses to rapid cone and melanopsin-directed flicker. Journal of Neuroscience 36(5):1471 1482.
Pre-registrations:
- Control Popuation Stimulus Nulling Experiment Revision 2: https://osf.io/fxasd/ (Registered 12/9/2015)
- Control Population Stimulus Nulling Experiment - Subject Age 18 - 24: https://osf.io/ftxwy/ (Registered 12/14/2015)
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 iunder this preregistration are described in:
- Spitschan, M., Bock, A. S., Ryan, J., Frazzetta, G., Brainard, D. H., Aguirre, G. K. (2017). The human visual cortex response to melanopsin-directed stimulation is accompanied by a distinct perceptual experience. PNAS, 114(46), 1229112296, doi: 10.1073/pnas.1711522114.
Pre-registrations:
- Perceptual ratings of Light Flux, Cone-directed and Melanopsin-directed light pulses: https://osf.io/u8ggn/ (Registered 1/31/2017)
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 examined if patients with light sensitivity due to migraine headache have increased sensitivity to cone stimulation, melanopsin stimulation, or both.
- H McAdams, EA Kaiser, A Igdalova, EB Haggerty, B Cucchiara, DH Brainard, GK Aguirre (2020) Selective amplification of ipRGC signals accounts for interictal photophobia in migraine. PNAS
- EA Kaiser, H McAdams, A Igdalova, EB Haggerty, B Cucchiara, DH Brainard, GK Aguirre (2020) Enhanced reflexive eye closure is mediated by ipRGC signals and is specific to migraine with visual aura. bioRxiv
Pre-registrations:
- Exp 1: https://osf.io/5ry67/ (Registered: 4/17/2018)
- Addendum, addition of TBI subject population: https://osf.io/qtjyd/
- Addendum, power analysis of ongoing data collection: https://osf.io/kf253/
Data and supplementary materials:
This project investigates how changes in stimulation of melanopsin affects visual sensitivity.
Pre-registrations:
- Psychophysical investigation into the influence of melanopsin stimulation on senstivity to cone stimulation: https://osf.io/jd4qh/ (Registered: 10/5/2018)
- Sensitivity to L, M, S-cone-directed flicker on a pulsed melanopsin pedestal: https://osf.io/58gcf/ Registered: 02/05/2019
- Sensitivity to L,M,S-cone-directed flicker admixed on a pulsed melanopsin pedestal: https://osf.io/k38sy/ Registered: 5/7/2019
This project compares pupillary responses to monochromatic blue and red pulses and silent-substitution melanopsin- and cone-directed pulses. This work was presented in poster form but we judged the contrast of the silent substitution stimuli was not high enough for us to be confident about the results. The project was continued under "Comparison of monochromatic and silent-substitution melanopsin and LMS-directed evoked pupil responses" below.
Pre-registrations:
- Exp 1: https://osf.io/92zhb/ (Registered: 3/8/2016)
- Pupillometry measures of melanopsin contrast: https://osf.io/ev9zg/ (Registered: 8/8/2016)
This project studies pupil responses to high-contrast melanopsin- and cone-directed pulses. We did not pursue these measurements through to publication, but see pupillometry data collected along with fMRI measurements ("Max Mel fMRI" below) as well as "Comparison of monochromatic and silent-substitution melanopsin and LMS-directed evoked pupil responses".
Pre-registrations:
- Pupillometry measures of melanopsin contrast - Maximum melanopsin and LMS contrast pulses - Version 0: https://osf.io/jnu2s/ (Registered: 5/9/2016)
- Pupillometry measures of melanopsin contrast - Maximum melanopsin and LMS contrast pulses - Version 1: https://osf.io/xqcsw/ (Registered: 5/20/2016)
- Pupillometry measures of melanopsin contrast - Maximum melanopsin and LMS contrast pulses - Version 2: https://osf.io/sv6qk/ (Registered: 5/30/2016)
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. The work preregistered here is described in:
- McAdams, H., Igdalova, A., Spitschan, M., Brainard, D. H., Aguirre, G. K. (2018). Pulses of melanopsin-directed contrast produce highly reliable pupil responses that are insensitive to a change in background radiance. IOVS.
Pre-registrations:
- Exp 1: https://osf.io/k6qag/ (Registered: 8/8/2016)
- Addendum 1: https://osf.io/dydtb/ (Registered: 1/9/2017)
- Addendum 2: https://osf.io/hzk8b/ (Registered: 1/9/2017)
- Addendum 3: https://osf.io/76u9x/ (Registered: 1/31/2017)
This project studies pupil responses to high-contrast melanopsin- and cone-directed pulses using a shortened stimulus protocol. We did not pursue these measurements through to publication.
Pre-registrations:
- Exp 1: https://osf.io/8gbeh/ (Registered: 6/15/2016)
A comparison of pupil and perceptual responses to photoreceptor directed stimulation in trichromats and deuteranopes
This project involves making measurements of responses to photoreceptor directed stimulation in dueteranopes. The project has two main aims: 1) understand the extent to which deuteranopes behave similarly to trichromatic controls and 2) determine how responses change in deuteranopes as contrast is increased past 400% (the maximum contrast we are able to deliver to trichromatic observers).
Pre-registrations:
- https://osf.io/ptkvx/
- Initial upload: https://osf.io/tsqe9/
- First addendum: https://osf.io/zt8nw/
The initial experiments detailed in this pre-registration were completed in early 2020.
This project studies evoked brain responses to high-contrast melanopsin- and cone-directed pulses using BOLD fMRI. The work preregistered here is described in:
- Spitschan, M., Bock, A. S., Ryan, J., Frazzetta, G., Brainard, D. H., Aguirre, G. K. (2017). The human visual cortex response to melanopsin-directed stimulation is accompanied by a distinct perceptual experience. PNAS, 114(46), 1229112296, doi: 10.1073/pnas.1711522114.
Pre-registrations:
- Max Mel MRI: https://osf.io/swfr8/ (Registered: 3/24/2016)
- Addendum 1: https://osf.io/3mqjc/ (Registered: 3/24/2016)
- Addendum 2: https://osf.io/35dmt/ (Registered: 3/28/2016)
- MaxMelMR 400% LMS Pulses: https://osf.io/g76wt/ (Registered: 3/30/2016)
- Addendum 1: https://osf.io/gx2pa/ (Registered: 3/30/2016)
- MaxMelMR SplatterControlCRF: https://osf.io/25j37/ (Registered: 4/29/2016)
- Functional neuroimaging measures of melanopsin contrast — Rod control measurements: https://osf.io/pv3a4/ (Registered: 10/18/2016)
This project studies evoked brain responses to melanopsin- and cone-directed pulses using BOLD fMRI at various contrast levels. The work preregistered here is described in:
- Spitschan, M., Bock, A. S., Ryan, J., Frazzetta, G., Brainard, D. H., Aguirre, G. K. (2017). The human visual cortex response to melanopsin-directed stimulation is accompanied by a distinct perceptual experience. PNAS, 114(46), 1229112296, doi: 10.1073/pnas.1711522114.
Pre-registrations:
- MaxMel CRF: https://osf.io/qbgc2/ (Registered: 5/27/2016)
- Addendum 1: https://osf.io/sphg8/ (Registered: 5/30/2016)
- MaxLMS CRF: https://osf.io/sbnm8/ (Registered: 6/1/2016)
- Measuring the spatial extent of melanopsin-driven cortical signals: https://osf.io/3c9ev (Registered: 3/1/2019)
We have been collecting structural and functional MRI data from normally sighted subjects as part of a Human Connectome Project entitled Human Connectomes in Low Vision. We preregistered our protocol for retaining scanner acquisitions and subjects.
Pre-registration:
In this experiment, we aim to characterize the linear and nonlinear response properties of the cortical response to melanopsin stimulation. We are specifically intersted in the temporal responses of the melanopsin system, and the extent to which they differ from cone-mediated responses. After initial data collection in 2019, the project was put on hold.
Pre-registration:
Intra- and inter- subject variability in pattern reversal visual evoked potentials in a pediatric population determined by principal component analysis
The primary goal of this study is to establish intra- and inter-subject variability of prVEP in a pediatric control population using Principal Component Analysis (PCA).
Pre-registrations:
Cortical hyper-responsivity in migraine with visual aura: effects of temporal frequency and post-receptoral channel
This project compares visual discomfort and steady state visual evoked responses (ssVEP) elicited by LMS, L-M, and S directed stimuli flickering at a range of temporal frequencies in subjects with migraine with visual aura and headache free controls.
- Patterson Gentile CA, Aguirre GK (2020). A neural correlate of visual discomfort from flicker. JoV.
The main goals of this project:
- Evaluate the relationship between visual discomfort and neural activity in early cortex across a range of stimulus conditions
- Compare visual discomfort and early visual cortical response in migraine with visual aura subjects to headache free subjects.
Pre-registration:
POEM – Penn Online Evaluation of Migraine: An automated, web-based tool to classify subjects for migraine research
We developed an online, branching logic questionnaire and open-source analysis software to support the automated classification of headache symptoms based on the International Classification of Headache Disorders, 3rd edition (beta). This pre-registration document describes our effort to validate the tool against prior classifications made by a neurologist in a cohort of research subjects. The outcome of this project is described here:
- Kaiser, E.A., Igdalova A., Aguirre G.K., Cucchiara, B. (2019) A web-based, branching logic questionnaire for the automated classification of migraine. Cephalalgia. 39(10):1257-1266. doi: 10.1177/0333102419847749.
Pre-registration: