Fixational saccade inhibition and pupil dilation during self-paced limb movement preparation

Fixational saccades are modulated in anticipation of several kinds of stimuli and motor actions, suggesting that they can form an overt marker of preparatory state. However, no existing work has studied fixational saccades ahead of spontaneous limb movements in the absence of sensory stimuli, in order to isolate motor preparation from other anticipatory processes (e.g., those related to stimulus processing). Here we examined fixational saccades while participants made self-paced hand and foot movements. We observed that fixational saccade rate steadily dropped prior to either kind of motor action, and recovered immediately after. To examine the relation between this fixational saccade rate signal and other known signals that precede volitional action, we analyzed how this signal related to anticipatory pupil size changes in the same dataset. Replicating previous work, we found steady pupil dilation ahead of limb movements, followed by rapid re-constriction. The amplitude of this pupil s..., , # Data from: Fixational saccade inhibition and pupil dilation during self-paced limb movement preparation

Dataset DOI: [10.5061/dryad.mcvdnckbv](10.5061/dryad.mcvdnckbv)

## Description of the data and file structure

These are eye tracking and key press records from an experiment during which human participants engaged in spontaneous key presses (spacebar or foot pedal).

### Files and variables

#### File: Archive.zip

**Description:** The archive contains, for each of 120 participants, 4 files for each of 2 experiment sessions. The file names are formatted like this:

\[participant number]M[session number]_[kind of data].npy

The [kind of data] string can be the following:

derivative_cleaned: time series data of preprocessed temporal derivative of pupil size, in mm / s on a time axis defined in mm.

foot: time stamps of foot presses, on the same mm time axis as derivative_cleaned.

saccades: time stamps of saccades, on the same mm time axis as derivative_cleaned.

space: time stamp..., We received explicit consent from our participants to publish the de-identified data in the public domain. The data contain no identifying features of the participants: just anonymized eye tracking and key press records.