Optimizing Fixation Filters for Eye-Tracking on Small Screens

The study of consumer responses to advertising has recently expanded to include the use of eye-tracking to track the gaze of consumers. The calibration and validation of eye-gaze have typically been measured on large screens in static, controlled settings. However, little is known about how precise gaze localizations and eye fixations are on smaller screens, such as smartphones, and in moving feed-based conditions, such as those found on social media websites. We tested the precision of eye-tracking fixation detection algorithms relative to raw gaze mapping in natural scrolling conditions. Our results demonstrate that default fixation detection algorithms normally employed by hardware providers exhibit suboptimal performance on mobile phones. In this paper, we provide a detailed account of how different parameters in eye-tracking software can affect the validity and reliability of critical metrics, such as Percent Seen and Total Fixation Duration. We provide recommendations for producing improved eye-tracking metrics for content on small screens, such as smartphones, and vertically moving environments, such as a social media feed. The adjustments to the fixation detection algorithm we propose improves the accuracy of Percent Seen by 19% compared to a leading eye-tracking provider’s default fixation filter settings. The methodological approach provided in this paper could additionally serve as a framework for assessing the validity of applied neuroscience methods and metrics beyond mobile eye-tracking.

Immunohistochemistry as an Important Technique in Experimental and Clinical Practices

Immunohistochemistry (IHC) is a well-known technique in the field of biological and medical sciences. This technique is based on the principle of antigenantibody interaction and is used for identification of cellular or tissue constituents, i.e., an antigen by using a specific antibody. The binding of an antibody to an antigen is confirmed either by labelled primary antibody itself or by using secondary labelling method such as fluorescence labelled antibody. Such interactions give information about the cellular process occurring inside the cell. In last few years, huge amount of data have been generated using IHC. Furthermore, adequate knowledge of this technique is required for the optimum result and its reproducibility. The detailed information about the tissue section, antigen retrieval (AR), increased sensitivity of the detection systems and proper standardization are the key points for this technique. This protocol will address overview of the technique, tissue preparation, microtome, antigen retrieval, antibodies and antigen fixation, detection methods, background reduction and trouble shootings.

Measuring the Spatial Noise of a Low-Cost Eye Tracker to Enhance Fixation Detection

The present study evaluates the quality of gaze data produced by a low-cost eye tracker (The Eye Tribe©, The Eye Tribe, Copenhagen, Denmark) in order to verify its suitability for the performance of scientific research. An integrated methodological framework, based on artificial eye measurements and human eye tracking data, is proposed towards the implementation of the experimental process. The obtained results are used to remove the modeled noise through manual filtering and when detecting samples (fixations). The outcomes aim to serve as a robust reference for the verification of the validity of low-cost solutions, as well as a guide for the selection of appropriate fixation parameters towards the analysis of experimental data based on the used low-cost device. The results show higher deviation values for the real test persons in comparison to the artificial eyes, but these are still acceptable to be used in a scientific setting.