Pupil Frequency-Tagging Method (PFTM) Equiluminance Testing

Ye L, Mahony B, W., Wang X, Daye P, Wang W, Cavanagh P, Pouget P, & Andolina IM (2023) “Assessing perceptual chromatic equiluminance using a reflexive pupillary response” bioRχiv, 2023.10.19.563116 https://doi.org/10.1101/2023.10.19.563116

Perceptual equiluminance testing using pupillometry (Pupil Frequency Tagging Method) + minimum (heterochromatic) flicker and minimum motion measurements. These experiments depend on the Opticka experimental framework and PTB to be installed to function. The GUIs allow you to modify most options and then run the task. For the

There are three different tasks:

• EquiLum.mlapp — GUI to run the PFTM equiluminant task.
• EquiFlicker.mlapp — GUI to run the minimum flicker task.
• Equimotion.mlapp — GUI to run the minimum motion task.

And some analysis tools:

• pupilPower.m — class to load eyelink files & perform PFTM analysis from pupil data.
• pupilPowerReport.rpt — MATLAB report generator setup, pass in a YAML list of eyelink files to automate analysis across all subjects and generate a PDF report.
• `runEquiMotionPlot.m`` — a function to replot the psychometric curve fits from the EquiMotion task.

Equimotion "Yellow"

For equimotion we developed a procedural (GLSL) shader version of Cavanagh's composite yellow grating which blends red and green on alternating pixel lines to blend-to-yellow. In testing we confirmed that this is spectrally identical to mixing the R and G channels per-pixel as measured with the SpectroCal:

Analysis

pupilPower.m loads a single EDF file generated by EquiLum.mlapp and parses it and plots the results:

There are many options to modify the analysis, see the class properties for more details...