Oculomatic : High speed, reliable, and accurate open-source eye tracking for humans and non-human primates

Abstract

Background Video-based noninvasive eye trackers are an extremely useful tool for many areas of research. Many open-source eye trackers are available but current open-source systems are not designed to track eye movements with the temporal resolution required to investigate the mechanisms of oculomotor behavior. Commercial systems are available but employ closed source hardware and software and are relatively expensive, limiting wide-spread use. New Method Here we present Oculomatic, an open-source software and modular hardware solution to eye tracking for use in humans and non-human primates. Results Oculomatic features high temporal resolution (up to 600Hz), real-time eye tracking with high spatial accuracy (< 0.5°), and low system latency (∼ 1.8ms, 0.32ms STD) at a relatively low-cost. Comparison with Existing Method(s) Oculomatic compares favorably to our exciting scleral search-coil system while being fully non invasive. Conclusions We propose that Oculomatic can support a wide range of research into the properties and neural mechanisms of oculomotor behavior.

Multiple timescales of normalized value coding underlie adaptive choice behavior

“…Visual stimuli were generated using a liquid-crystal display (240 Hz) placed 67 cm in front of the animal. Monkeys' eye movements were monitored using the Oculomatic video-based system 56 . Monkey H’s eye movements were also recorded using a scleral search coil, with horizontal and vertical eye position sampled at 600 Hz using a quadrature phase detector (Riverbend Electronics).…”

Back to Pupillometry: How Cortical Network State Fluctuations Tracked by Pupil Dynamics Could Explain Neural Signal Variability in Human Cognitive Neuroscience

“…The recording of pupillometry is achieved noninvasively by camera-based, infrared eyetrackers. Commercial alternatives are matched by open-source systems, which in some cases include their own analysis software ( Zimmermann et al, 2016 ) making them particularly user friendly and adaptable to the desired experimental paradigm. Usually, the pupil area or diameter is reported in arbitrary units.…”

MAD saccade: statistically robust saccade threshold estimation via the median absolute deviation

“…On the other hand, peak velocities cannot be reliably recovered under low-frequency sampling regimes (Mack et al, 2017), suggesting that the effect of outliers may be more prevalent at higher sampling rates. Future studies could ascertain the performance of robust and non-robust thresholding using different experimental equipment, including both commercially available and open-source systems (Zimmermann et al, 2016). Additionally, robust estimation may be beneficial in non-human animal models, for which head-free eye-tracking is challenging.…”