Using Electroencephalography Measurements and High-quality Video Recording for Analyzing Visual Perception of Media Content

Summary

We present detection, acquisition, and analysis of eyeblink rates while watching media content.

Abstract

This article explores a method to detect differences in visual perception in humans. The method used is based on the psychological (or "cognitive") function of eyeblinks. Participants' eyeblinks are detected and acquired while watching videos specifically created for the investigation. The detection and acquisition of eyeblinks are carried out with the help of a 20-channel electroencephalographic (EEG) wireless device. The international 10-20 system for electrode placement is followed. A high-definition (HD) video camera is used to record participants' facial expressions, for contrast purposes. Instead of using pre-existing media content, purpose-made video content has been created following specific criteria of interest for this investigation, with stimuli enabling researchers to manage the precise parameters of interest. Otherwise, results could be contaminated with uncontrolled variables. The synchronization of the presentation of video stimuli with EEG recordings needs to be done in milliseconds. Analysis of collected data is performed with robust software for working with big matrices. Statistically significant differences in eyeblink rate related to media professionalization and editing style are found with the reported experimental procedures.

Introduction

The Purpose of This Method

This method proposes a dual protocol for detecting eyeblinks. The aim is to analyze viewers' visual perception of media content, specifically created for this investigation, by using EEG recordings and HD video recording systems.

The Rationale Behind the Development and/or Use of This Method

Each eyeblink hides visual flow for 150-400 ms^1,2. Blinking has physiological^3,4,5

Protocol

All methods described here have been approved by the Ethics Commission for Research with Animals and Humans (CEEAH) of the Universitat Autònoma de Barcelona.

1. Creation and Presentation of the Visual Stimuli

1. Create the video stimuli according to the desired goals.
   1. Decide which variables are of interest for the video stimuli.
      NOTE: For example, in the present investigation, the main variable of interest is the editing style.
      1. Decide the duration, the content, and the style of the video based on the interest of the experiment. To determine all of these variables, consider how many videos the ....

Results

Using the procedure presented here, the eyeblink rate of 40 participants while watching three different video movies was analyzed. For a comparative analysis on media professionalization, half of the participants were media professionals. They were selected based on the criterion of a minimum 6 years of job experience in making decisions related to media editing and audio-visual cuts. For a comparative analysis on editing styles, the three video stimuli were created with exactly the same .......

Discussion

A method for analyzing visual perception of media content with purpose-made video creation is described here. Many other studies attempt to analyze the perception of media content in narrative contexts with pre-existing films. The present method proposes to create visual content with a narrative construction following the criteria of interest, and is based on the suggestion that eyeblink rate is connected to the viewer's attention⁹. For that reason, the study detects participants' eyeblinks while .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
EEG Device	Neurolectrics	Enobio 20 EEG/EMG system
Ag/AgCl Electrodes	Neuroelectrics	[NE022b] GelTrode
Recording EEG software	Neuroelectrics	NicOffline software
HD-video camera	Sony Corporation	Sony HDR-GW55VE
Syringe	Monoject	Monoject 412, curved tip syringe, 50/box
Saline electrode EMG gel	Signa-Gel	X32-204: Signa Gel
Visual Stimuli Presentation Software	Paradigm Stimulus Presentation	Perception Research System Incorporated
EEG software analysis	Centre National de la Recherche Scientifique and Montreal Neurological Institute	Brainstorm3
EEG software analysis	The MathWorks Inc.	MATLAB 2013b
TV for video presentation	Panasonic Corporation	PanasonicTH- 42PZ70EA  - 50"
PC for presenting stimuli	MacBook Air	Year 2013, running Mac OSX Mountain Lion
PC for recording stimuli	MacBook	Year 2009 running Windows 7	With a bootcamp partition of the disk for providing Windows OS
Statistical Analysis	Systat Software Inc.	Sigmaplot 11.0