Working Towards Mind Reading

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N400 Working towards mind reading

description

A sneak preview of my master thesis.

Transcript of Working Towards Mind Reading

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N400

Working towards mind reading

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Brain Computer Interfacing

Creating a direct link between your brain and a computer

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That sounds an awful lot like mind reading...

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Work towards mind reading

BCI

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Can a computer detect what I am thinking about?

Not directly (yet)

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What can we detect?

• Relaxation (alpha waves)• Imagined movement (ERD/ERS)• Recognition (P300)• Annoying flashing lights (SSVEP)• Priming (N400)• ...

Simple physiological responses

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• Discovered during a language study• Reading senseless sentences:

I drink coffee with cream and sugarI drink coffee with cream and socks

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ERP7 word sentences

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Priming

apple fruit juice

eatingtree

Newton healthy

pickingpearworm

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Priming

apple fruit juice

eatingtree

Newton healthy

pickingpearworm

Prime

Probe

Probe

Probe

Probe

Probe

Probe

Probe

Probe

Probe Probe

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ERP2 words

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How can we use this for mind reading?

1. Let the subject choose his own prime2. Don’t prime on a stimulus, but prime only by

thinking about the object3. Guess the prime by showing different probes

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Experimental setup

1. Give one of two possible physical objects to subject

2. Lo beep – close eyes and think about object3. Hi beep – open eyes4. Show a probe word that is related to one of

the two possible objects, record EEG5. Can the computer tell which object was

shown?

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ERPonly a probe word

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ERPonly a probe word

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Future researchbuilding a search tree

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Challenges

• When no result: problem in experiment, recording or data processing?Process of elimination

• More neuroscience than computer scienceRead up on neuroscience

• Ambiguous results: only works on some subjectsVerify results with statistics and control scenarios

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