De Luna Paolo, Mohamed Mustafar Mohamed Faiz Bin, Rainer Gregor
Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musée 5, Fribourg CH-1700, Switzerland.
Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Chemin du Musée 5, Fribourg CH-1700, Switzerland.
J Neurosci Methods. 2014 Sep 30;235:41-50. doi: 10.1016/j.jneumeth.2014.05.033. Epub 2014 Jun 28.
Tracking eye position is vital for behavioral and neurophysiological investigations in systems and cognitive neuroscience. Infrared camera systems which are now available can be used for eye tracking without the need to surgically implant magnetic search coils. These systems are generally employed using rigid head fixation in monkeys, which maintains the eye in a constant position and facilitates eye tracking.
We investigate the use of non-rigid head fixation using a helmet that constrains only general head orientation and allows some freedom of movement. We present a MATLAB software solution to gather and process eye position data, present visual stimuli, interact with various devices, provide experimenter feedback and store data for offline analysis.
Our software solution achieves excellent timing performance due to the use of data streaming, instead of the traditionally employed data storage mode for processing analog eye position data.
We present behavioral data from two monkeys, demonstrating that adequate performance levels can be achieved on a simple fixation paradigm and show how performance depends on parameters such as fixation window size. Our findings suggest that non-rigid head restraint can be employed for behavioral training and testing on a variety of gaze-dependent visual paradigms, reducing the need for rigid head restraint systems for some applications.
While developed for macaque monkey, our system of course can work equally well for applications in human eye tracking where head constraint is undesirable.
在系统与认知神经科学领域，追踪眼睛位置对于行为学和神经生理学研究至关重要。现有的红外摄像系统可用于眼睛追踪，无需通过手术植入磁性搜索线圈。这些系统通常在猴子身上采用刚性头部固定方式，这种方式能使眼睛保持在固定位置，便于进行眼睛追踪。
我们研究使用一种头盔进行非刚性头部固定，该头盔仅限制头部大致方向，允许一定程度的活动自由。我们提出了一种MATLAB软件解决方案，用于收集和处理眼睛位置数据、呈现视觉刺激、与各种设备交互、向实验者提供反馈并存储数据以供离线分析。
由于采用了数据流方式，而非传统的处理模拟眼睛位置数据时使用的数据存储模式，我们的软件解决方案实现了出色的定时性能。
我们展示了两只猴子的行为数据，表明在简单的注视范式下可达到足够的性能水平，并展示了性能如何取决于诸如注视窗口大小等参数。我们的研究结果表明，非刚性头部约束可用于各种基于注视的视觉范式的行为训练和测试，减少了某些应用中对刚性头部约束系统的需求。
虽然我们的系统是为猕猴开发的，但当然也同样适用于在不希望有头部约束的人类眼睛追踪应用中。
