From Brain Waves to Game Design: A Study on Analyzing and Manipulating Player Interest Levels

Abstract

Traditional single player first person shooter (FPS) games adopt a generally linear level design. Players are not given much choice as to where to go next, and thus it is paramount that the designer is able to keep the player interested throughout the whole level. It is widely accepted that in order to keep the player's interest, it is important to offer the player a varied gaming experience by presenting high interest and low interest encounters in an alternating fashion. However, while there are general theories and rules of thumb as to how this can be done, there is little formal knowledge about how exactly high or low interest levels can be achieved. Our goal is to create a better understanding on how to design encounters that affect interest levels in linear FPS games. Specifically, how exactly a player's interest levels can be raised intentionally. To accomplish this, we developed a method for measuring and comparing player interest levels based on electroencephalogram (EEG) data measured using a “Neurosky Mindset” unit, which is a commercially available EEG device. We measured player EEG data for the first 4 levels of the FPS game “Call of Duty: Modern Warfare 2” and calculated player interest levels for the entire length of gameplay. By referring to recorded gameplay videos, we were able to associate each increase in interest levels for each player to a specific point in game. From this data, we found and isolated points in each level where most players showed a rise in interest levels, and discovered that certain patterns existed between these situations. These findings led to another study where we further analyzed these situations and found out what factors caused most players to show a rise in interest levels. We were able to divide these factors into 6 different categories called Triggers: “Anticipation”, “Concentration”, “Surprise”, “Frustration”, “Overwhelm” and “Fear”. As these triggers represent mutually exclusive elements that affect a player's interest levels, we found that in most situations where many test subjects showed a rise in interest levels, more than one trigger is present, a phenomenon we call Stacking. While our study is still ongoing, we believe that by using these triggers as guidelines, game designers will be able to intentionally plan and control the player's interest level for FPS games with a certain level of guarantee.