Brain WrestlingCOGS160

Jimmy Nonno: Software debugging/developmentJoanne Shin: Hardware implementation

Melissa Wedeen: Neuroscience & HCI design

● Brain Wrestling is similar to arm wrestling ○ Difference: no physical contact between "arm" and

player ○ Controlled by "meditation" and "attention" levels

measured by NeuroSky Mindset

Objective: Create an Interactive Mind-Controlled Game

Hardware/Mechanical ● Goal: Integrate Arduino and Mindset

○ Move Servo with Mindset● How does a microcontroller work?

○ Upload Program, no need for computer○ Compact, mobile game

● Challenge: ○ Mindset communicates via Bluetooth, Arduino does

not have Bluetooth Capability○ Integrate Bluetooth module & Arduino

● Mechanical Constraints○ Acrylic "arm" and housing ○ Win/Lose LEDs taken out ○ Servo Torque specs

http://www.youtube.com/watch?v=UYWNZoQiZjs

Software● Code written in the Arduino Language

○ C/C++ Functions● Template Code

○ Reads in data from headset and assigns it to a variable

○ Lights up LEDs based on values of Meditation and Attention

● Data Values ○ Raw wave value○ Brainwaves

■ Delta, Theta, Alpha, Beta, and Gamma○ Attention and Meditation

eSense Values● Attention and Meditation

○ Attention - How well the user is focusing■ Stare at a single point on the screen

○ Meditation - How relaxed the user is■ Try to relax, close eyes

● NeuroSky's Algorithms○ Calculating eSense

■ Headset amplifies raw brainwave signal■ Removes ambient noise and muscle movement■ Algorithm applied to remaining signal

○ Values aren't actually numbers, but ranges of activity

eSense RangeseSense Range Interpretation

1 - 20 Strongly lowered levels

20-40 Reduced levels

40-60 Neutral level

60-80 Slightly Elevated

80-100 Elevated

LED Bar and PositionMeditation/Attention Number of LEDs ON Servo Motor Step

1 - 9 1 +25 Degrees

10 - 19 2 +20 Degrees

20 - 29 3 +15 Degrees

30 - 39 4 +10 Degrees

40 - 49 5 +5 Degrees

50 - 59 6 0 Degrees

60 - 69 7 -5 Degrees

70 - 79 8 -10 Degrees

80 - 89 9 -15 Degrees

90 - 99 10 -20 Degrees

100 10 -25 Degrees

Neuroscience● Focus: High beta and gamma, low alpha● Meditation: High alpha● Used code provided by Neurosky

How to make game more difficult?Rejected Ideas:

● Increasingly difficult visual searches○ But we wanted users to focus on the brain wrestling

● Distracting stimuli - sudden sounds, flashes○ However, user may focus on distracting stimuli○ May make user experience unpleasant

Increasing Difficulty● Attention-switch costs would make game

more difficult○ Switch between meditation and attention

● Meditation is more difficult than focus, especially because user has eyes open during game.

Divided into different modes/levels:● Training - Computer does not "fight back"● Focus - "easy" mode, attention● Zen - "intermediate" mode, meditation● Challenge - switch between Focus and Zen

Design - "Arm" shape● Considered making the "arm" look like an

actual arm○ Phantom limb/Mirror neuron theory○ User would be able to relate to the arm, and make

the experience more natural○ However, the housing would not fit, so it would not

look like a real hand anyway.● So, we decided to make it a brain

○ Potential users liked that idea more○ More "iconic" for our "brain wrestling" game

Design - Info/Status Display● LED lights denote different modes

○ LED light lights up for the mode that the user is playing on (e.g. LED next to Train lights up)

○ Different colors make mode easy to discriminate○ Placement - close to the "brain" at the top, in user's

realm of vision● Status bar provides a more accurate visual

feedback system for user○ Status bar fills up from right to left in same direction

that user pushes arm.● Arrow points from right to left - English-

speakers read left to right.

Looking Forward● User testing/characterization

■ Timing & Difficulty■ Different user groups

● Anticipated results ■ We think that people with ADHD will find the

game more difficult when they are off medication● Potential application:

○ Neurofeedback for children diagnosed with ADHD ● Player vs. Player

Discussion● Questions?