Eye saccades align optic flow with retinal specializations during object pursuit in freely moving ferrets
Data files
Jan 21, 2025 version files 101.46 MB
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dataset_configs.tar.xz
101.42 MB
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multiview_files.tar.xz
30.21 KB
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README.md
4.19 KB
Abstract
During prey pursuit, how eye-rotations, such as saccades, enable continuous tracking of erratically moving targets while simultaneously enabling an animal to navigate through the environment is unknown. To better understand this, we measured head and eye rotations in freely running ferrets during pursuit behavior. By also tracking the target and all environmental features we reconstructed the animal’s visual fields and their relationship to retinal structures. In the reconstructed visual fields, the target position clustered on and around the high acuity retinal area location, the area centralis, and surprisingly this cluster was not significantly shifted by digital removal of either eye saccades, exclusively elicited when the ferrets made turns, or head rotations which were tightly synchronized with the saccades. Here we show that, while the saccades did not fixate the moving target with the area centralis, they instead aligned the area centralis with the intended direction of travel. This also aligned the area centralis with features of the optic flow pattern, such as flow direction and focus of expansion, used for navigation by many species. While saccades initially rotated the eyes in the same direction as the head turn, saccades were followed by eye rotations countering the ongoing head rotation, which reduced image blur and limited information loss across the visual field during head-turns. As we measured the same head and eye rotational relationship in freely moving tree shrews, rats and mice, we suggest that these saccades and counter-rotations are a generalized mechanism enabling mammals to navigate complex environments during pursuit.
README: Eye saccades in freely moving ferrets - open source data
Summary
The archives in this repository contain the data required to reproduce the results of the connected Current Biology manuscript "Eye saccades align optic flow with retinal specializations during object pursuit in freely moving ferrets". They allow reproduction of all major findings.
We include kinetic data (positions and orientations) of head, eyes and environmental features for all experiments used in the publication.
Description of data
datasets_config
Contains csv files head, eyes and targets for all datasets (fXXX) and variants ("sacfrozen" for frozen eye position during saccades etc.).
Data is organized in folders following the scheme
dataset_variant
Datasets
*dataset*s used in the publication are named f005-f008 and f010. Datasets are named consecutively, including attempts that where interrupted early or had technical issues. Datasets f001-f004 and f009 have been discarded for these reasons.
Variants
variant*s denote various simulated variations of the raw data (without any "_*variant"):
- sacfrozen "freezes" the eye movements during saccades, replacing them with a linear interpolation with artificial noise.
- eyedelta_... have the timing of the eye traces (and consequently saccades) shifted by minus (_m0p05) or plus (_p0p05) 50 ms.
- SacAmpShift_... modifies the amplitude of the saccade by by scale factors of 0.5, 0.75, 1.25 or 1.5. This variant has been studied, but not included in the final main manuscript.
See methods section of main publication for details on the changes.
Files
Each folder contains the following files:
- frametimes.csv containing timing information with columns
- t: time in seconds
- frn: frame index of the tracking, i.e. data row in other csv files
- trajectory_[x].csv containing kinetic information for object [x] with columns
- px: x position of object
- py: y position of object
- pz: z position of object
- rx: x quaternion coefficient of object
- ry: y quaternion coefficient of object
- rz: z quaternion coefficient of object
- rw: w quaternion coefficient of object
- trajectory_[x].csv containing kinetic information for object [x] with columns
- px: x position of object
- py: y position of object
- pz: z position of object
- rx: x quaternion coefficient of object
- ry: y quaternion coefficient of object
- rz: z quaternion coefficient of object
- rw: w quaternion coefficient of object
- ball.[mtl,obj] is the wavefront file of a ball in the size of a table tennis ball used for rendering the target in Multiview
- rectangles/rectangle_[nnn]_[mmm].csv containing positions of rectangle objects of walls and boxes
- px: x position of object
- py: y position of object
- pz: z position of object
- rx: x quaternion coefficient of object
- ry: y quaternion coefficient of object
- rz: z quaternion coefficient of object
- rw: w quaternion coefficient of object
- rectangles/rectangle_[nnn]_[mmm].obj containing shape of rectangle objects of walls and boxes in wavefront format.
multiview_files
Contains configuration files to rund datasets with Multiview software:
Multiview -s [config].multiview
Data is organized in the following naming scheme
dataset_variant.multiview
Each file contains proprietary scripting code for Multiview to perform the necessary action to generate flow data in OpenEXR format, where the first channel contains x flow, the second channel contains y flow and the third channel contains movement speed towards or away from the viewer.
Note that folder paths may need to be adjusted in the script files to suit the local file system of the user.
export_frames.py is a Python script called by Mutiview for saving the frames and does not need to be directly interacted with.
Code/Software
Multiview is required to generate optic flow fields. It can be obtained as open source at
Methods
- Simultaneous tracking of eye and head position of ferrets chasing a target.
- Analysis of gaze direction and reconstruction of visual fields