bci brain wrestling game
TRANSCRIPT
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
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?