Prepare EEG Events and the IA File
Prepare synchronized EEGLAB events and a tab-delimited text interest-area file for deterministic mapping.
Last updated: 2026-10-07
Inspect a representative dataset
Before opening EyeSort, check the continuous event stream:
unique(string({EEG.event.type}))
fieldnames(EEG.event)
Record the exact trial, condition, item, fixation, and saccade event names. Inspect a fixation and saccade to confirm the X-position fields are numeric or convertible to numeric values.
Condition and item trigger values must yield the same numeric keys used in the IA file. For example, S211 and IA value 211 can match; do not use nonnumeric condition/item keys.
Build the tab-delimited IA file
Use one row per condition–item stimulus. A minimal header might be:
condition trigcondition trigitem Beginning PreTarget Target Ending
trigcondition and trigitem are numeric matching keys. condition is descriptive text used in readable labels and BDF bins. Each named region cell contains the literal text displayed in that region, including intentional spaces.
Keep region names and order consistent across relevant rows. The number entered in Step 2 must equal the number of named region columns.
Measure text geometry
Record the horizontal X coordinate of the first character and the rendered width of one character. EyeSort computes each region width as:
character count × pixels per character
It then advances from the sentence offset. Use the actual font, size, display scaling, and resolution from data collection. A proportional font or multiline display falls outside the verified 1.0 mapping model.
Preserve reproducible inputs
Archive the IA file, stimulus-display measurements, trigger dictionary, and one representative synchronized dataset. After Step 2, save the text-IA configuration and export the parsed-region table as a QC record.