The 4th International Conference on Cognitive Neurodynamics ICCN2013

Analogies between cognitive and quantum phenomena: can we explain them?

Paavo Pylkkänen1,2

1 Department of Cognitive Neuroscience and Philosophy, University of Skövde, P.O. Box 408, SE-541 28 Skövde, Sweden. 2Department of Philosophy, History, Culture and Art Studies, P.O. Box 24, FI-00014 University of Helsinki, Finland.

E-mail: paavo.pylkkanen@his.se

In their forthcoming BBS target article “Can quantum probability provide a new direction for cognitive model-ing?”, Pothos and Busemeyer (PB) make a convincing case that there are empirical results concerning human decision making and judgement that can be elegantly accounted for by quantum probability (QP) theory, while classical (Bayesian) probability (CP) theory fails [1]. In particular, they point out that human judgement and preference often display order and context effects, viola-tions of the law of total probability and failures of com-positionality, and that in such cases QP - with features such as superposition and entanglement - provides a natural explanation of cognitive process. More generally, they suggest that QP is potentially relevant in any behav-ioral situation which involves uncertainty. Such success in modeling raises the question of how can it be that QP which was developed to account for quantum physical phenomena could possibly be able to account for cognitive phenomena. PB do not discuss this issue at great length, but suggest that the reason is because some cognitive phenomena are analogous to quantum phenomena. But this gives rise to a further question: why are these phenomena analogous to each other? Is it a mere coincidence or is there some deeper explanation? For example, might the neural processes underlying cognition be quantum-like in some way? PB remain agnostic about this issue, and thus we might call their program “weak quantum cognition” (somewhat analogously to the program of weak AI in artificial intel-ligence research).

There are various ways in which the neural pro-cesses underlying cognition could be quantum-like. The strongest possibility is that they literally involve subtle quantum effects (suggesting a program we might call “strong quantum cognition” or “quantum cognitive neuroscience”). A weaker possibility is to assume that the neural processes underlying cognition involve no subtle quantum effects, but can nevertheless give rise to quantum-like neural activity. Something like this is im-plied by Barros and Suppes when they suggest that clas-sical interference in the brain may lead to contextual processes [2]. They refer to experimental work according to which cortical oscillations may propagate in the cortex as if they were waves; and to simulations of the mamma-lian brain which show the presence of interference in the cortex. The idea that there are analogies between cogni-tive processes and quantum processes is an old one, going back to at least Niels Bohr, as PB indeed acknowledge. However, perhaps the clearest early ac-count of such analogies was given by David Bohm in his 1951 text-book Quantum theory. Bohm also speculated

about how the analogies might be given an explanation. Bohm’s analogies have been discussed in some detail by the author in [3]. In this paper I will consider the relevance of Bohm’s analogies and my previous discussion of them to current research on quantum cognition. In particular, I will consider the relation between quantum theory and classical physics and consider whether this might help us to understand the relationship between QP and CP mod-eling in cognitive science. Some connections to Aerts’ [4] idea of two modes of human thought will also be made. References [1] Pothos, M & Busemeyer J. R.: Can quantum proba-

bility provide a new direction for cognitive mo-deling?, forthcoming in Behavioral and Brain Sci-ence.

[2] Barros, J.A. & Suppes, P. Quantum mechanics, inter-

ference and the brain, Journal of Mathematical Psy-chology 53 (2009) 306-313.

[3] Pylkkänen, P. (2004) Can quantum analogies help us

to understand the process of thought?, in Being and Brain. At the Boundary between Science, Philosophy, Language and Arts, G. Globus, K. Pribram and G. Vitiello (eds.), pp. 167-197. Advances in Con-sciousness Research 58. Amsterdam: John Benja-mins.

[4] Aerts, D. Quantum structure in cognition, Journal of

Mathematical Psychology 53 (2009) 314-348.