1. Schrödinger's Cat: Research on the Radical Subjective Solution of the Measurement Problem.
Dick Bierman & Stephen Whitmarsh, University of Amsterdam
Presented at QuantumMind, Salzburg, july 15-21, 2007

2. NO !!!!

3. If the measurement is affecting the ‘measured’ it is extremely important to precisely define what constitutes a measurement

4. Measurement
Def1: A measurement is something what you do with a measurement device….
Usable in the daily practice of physics
But incorrect: a problem!
(von Neumann)

5. The Measurement Problem ‘solutions’
Many World solution (Everett)
Deterministic solution (Bohm)
Non linear Schrodinger equation (GRW)
Objective Reduction (Penrose)
Radical subjective solution (Wigner, Stapp)

6. Note that the radical solution is associated with Schrödinger’s Cat.
…. The reduction of the state vector is a physical event which occurs only when there is an interaction between the physical measuring apparatus and the psyche of some observer…..
from Hall, J., Kim, C., McElroy, and Shimony, A. (1977). Wave-packet reduction as a medium of communication. Foundations of Physics 7 (1977),
Note that the radical solution is associated with Schrödinger’s Cat.

7. Hall et al experiment

8. Assumptions
Consciousness of first observer collapses the state before second observation.
2. Final Observer (brain) is sensitive for difference collapsed and non collapsed state
3. Final Observer can report this

9. Weaknesses in Hall
Assumption 1 is violated: Delay between first and second observation too short
Assumption 3 is inconsistent: The dependent variable is a conscious verbal report, too late!

10. Improvements in replications
HALL et al 1977
Delay few microseconds
Dependent variable: conscious verbal report
Amsterdam
Delay 1000 msecs
Dependent variable: brain signals before final observer is conscious p

11. Amsterdam original set-up

12. Amsterdam original set-up
Dependent variable: brainwaves of final observer
Pseudorandom switch between conditions Pre-observed - not pre-observed

13. Analysis procedure Predetermined: we only analyze peak amplitudes.
We also apply non-parametric statistics (because of non normality of the distribution of data)

14. Results pooled over condition

15. Results split for condition (preobserved and not-preobserved)

16. Study 1-RESULTS peak analysis
What
Peak
Preobs-Obs(MuV)
T (df=29)
Prob.
binomial
N20
1.002
2.12
0.043
0.20
P40
0.903
2.64
0.013
0.016
N100
0.350
0.66
0.52 1
P200
-0.09
-0.18
0.86
N300
-0.04
-0.08
0.93
P350
-0.54
-1.17
0.25
0.36
N400
0.098
0.80
P100
-0.16
-0.67
0.50
N160
-0.152
-0.84
0.41
0.58
N200
-0.956
-3.93
0.0005
0.005

17. Control analysis
Split data randomly rather than according to Exp. Condition and repeat analysis.
Effectsizes are on the average an order of magnitude smaller and statistically non significant

18. Conclusions study 1 Copenhagen interpretation supported
Bohr
Copenhagen interpretation supported
God plays dice
And …Consciousness stands outside of quantum physics (dualism) or must be considered a ‘hidden variable’ with non local aspects
But wait a minute: Strong claims need strong evidence….. So study 2!

19. Visual pre-observation for
Replication set up
Alpha source
GM detector
Count down clock
EEG amplifiers
Trigger-in
delay
Audio-beep
Final Observer
Visual pre-observation for
~ 50% of the events
Computer
Pre Observer

20. 4 clusters of electrodes
Results averaged over 4 conditions (classical-quantum, preobserved- not preobserved)
4 clusters of electrodes

22. No pre-observation effect
But…………

23. An effect of source of events (Quantum vs Classic)

24. Was the (pre) Observation ‘Conscious’
It was less specific than in experiment 1

25. Study 3 More information to pre-observer
- I.e. was the source quantum or classic
Control of ‘decay-times’ distribution in all conditions.

26. Preliminary Results study 3

27. Review

28. Amsterdam 1

29. Amsterdam 2

30. Amsterdam 3

31. Conclusion
The support for the idea that ‘consciousness collapses the statevector’ has evaporated.
Initial results due to differences in decay time distribution?
However it could be that the assumptions underlying this approach are invalid.
The measurement problem is more alive than ever.

32. Thanks for your attention