Anatomy of an eyeris Object
In eyeris: Flexible, Extensible, & Reproducible Pupillometry Preprocessing

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

📦 Key Components

When preprocessing .asc EyeLink files with eyeris, returned objects will be of the class eyeris, and will contain key components used throughout the package's backend.

The key components are:

file: the original file path of the source .asc file
timeseries: a list of data frames (1 df per identified recording block per file) which contains the following columns:
block: block number
time_orig: raw tracker time (ms)
time_secs: normalized tracker time, starting at 0 (seconds)
eye_x: eye position x-coordinate
eye_y: eye position y-coordinate
eye: which eye (Left or Right) the recorded data are sourced from
hz: tracker sampling rate (hz)
type: whether source data were recorded using the diameter or area method
pupil_raw: raw recorded pupil source data in arbitrary units (a.u.)

You'll notice that for each preprocessing step run, a new column will be added after the pupil_raw column; these new columns follow a structure where each subsequent step is appended to the previous columns name (i.e., pupil_raw_{previous steps}_{current_step}). To illustrate:

pupil_raw -> pupil_raw_deblink -> pupil_raw_deblink_detransient -> and so on...
events: a list of data frames containing trial event messages and timestamps
blinks: a list of data frames containing start/stop/durations for blinks
info: EyeLink EDF header data parsed into a data frame
latest: internal tracker used for assessing which steps have been run so far
confounds: a list of data frames containing confounding variables for each preprocessing step (see: 📊 summarize_confounds())
params: detailed list of steps run and parameters passed to each step
epoch_{name}: list of data frames for any given epoched timeseries

💡 Note: This vignette describes the structure of an `eyeris` object as returned by the main preprocessing pipeline. 1. Understanding these components will help you interpret results, debug issues, and extend the pipeline for your own research needs. 2. Furthermore, binocular data will have a `left` and `right` component to the `eyeris` object, which will contain the same components as the main `eyeris` object. 3. There is also a phantom `raw_binocular_object` component to the `eyeris` object, which contains the raw binocular data used internally to perform the binocular correlation analysis and plotting.

Now that we've explained what you can expect to see after running the eyeris glassbox() function, we'll demonstrate what the glassbox() wrapper is generally comprised of in terms of the steps and defaults that are implemented.

🧱 Building Blocks Under the Hood

While we strongly recommend against manually constructing the pipeline as will be shown below (given that using the glassbox() will provide maximum opportunities for reproducibility and reduction of accidental errors), more advanced users may want to see how the individual steps can be used like building blocks to iteratively test out parameters, switch steps around / remove steps (again, we strongly recommend against doing this unless you know what you're doing), etc.

The Default `glassbox()` Steps and Parameters, Deconstructed:

system.file("extdata", "memory.asc", package = "eyeris") |>
  eyeris::load_asc(block = "auto") |>
  eyeris::deblink(extend = 50) |>
  eyeris::detransient(n = 16) |>
  eyeris::interpolate() |>
  eyeris::lpfilt(wp = 4, ws = 8, rp = 1, rs = 35, plot_freqz = TRUE) |>
  # eyeris::downsample() |>  # optional (please read docs before enabling)
  # eyeris::bin() |>  # optional (please read docs before enabling)
  # eyeris::detrend() |>  # optional (please read docs before enabling)
  eyeris::zscore() |>
  eyeris::summarize_confounds()

💡 **For more detailed information on the implementation of functions within** **the `glassbox()` and thus how to create your own custom pipeline** **extensions that conform to the `eyeris` protocol, see the:** [🧩 Building your own Custom Pipeline Extensions vignette](custom-extensions.html).