Data from: Fixational saccade inhibition and pupil dilation during self-paced limb movement preparation
Data files
Oct 08, 2025 version files 581.57 MB
-
Archive.zip
581.57 MB
-
README.md
1.76 KB
Abstract
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 signal covaried across individual limb movements with that of the fixational saccade rate signal. The pupil modulations, moreover, followed too shortly after the accompanying fixational saccade rate modulations to be caused by saccade-induced changes in visual input. Together, these observations suggest a joint neural factor influencing both fixational saccade rate and pupil size ahead of limb movements. We discuss possible interpretations of our findings, both specific ones that center on processes of motor planning or temporal expectation, and more general ones that are in terms effort.
Dataset DOI: 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 stamps of space bar presses, on the same mm time axis as derivative_cleaned.
All files are numpy files that can be opened in python using its numpy package, on the same mm time axis as derivative_cleaned.
Code/software
Any unzip utility is needed to unpack the archive. After that, python and its numpy package (any recent version) are needed to open the files. Entering this code in python will provide access to the raw data:
import numpy as np
data = np.load("path/to/file.npy", allow_pickle=True)
data
Human subjects data
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.
