Scientists Model Words as Entangled Quantum States in our Minds

February 18, 2009 By Lisa Zyga, feature
Researchers have modeled the human mental lexicon as consisting of words that cannot be separated from other words, which may explain why words have many associations, a feature which helps us communicate. Credit: by surrealmuse.

( -- When you hear the word “planet,” do you automatically think of the word’s literal definition, or of other words, such as “Earth,” “space,” “Mars,” etc.? Especially when used in sentences, words tend to conjure up similar words automatically. Further, human beings’ ability to draw associations and inferences between words may explain why we’re generally able to communicate complex ideas with each other quite clearly using a limited number of words.

Research has shown that words are stored in our memories not as isolated entities but as part of a network of related words. This explains why seeing or hearing a word activates words related to it through prior experiences. In trying to understand these connections, scientists visualize a map of links among words called the mental lexicon that shows how words in a vocabulary are interconnected through other words.

However, it’s not clear just how this word association network works. For instance, does word association spread like a wave through a fixed network, weakening with conceptual distance, as suggested by the “Spreading Activation” model? Or does a word activate every other associated word simultaneously, as suggested in a model called “Spooky Activation at a Distance”?

Although these two explanations appear to be mutually exclusive, a recent study reveals a connection between the explanations by making one novel assumption: that words can become entangled in the human mental lexicon. In the study, researchers from the Queensland University of Technology (QUT) in Australia and the University of South Florida in the US have investigated the quantum nature of word associations and presented a simplified quantum model of a mental lexicon.

Classical vs. Quantum Correlations

The researchers begin by explaining the difference between classical correlations (in the Spreading Activation model) and quantum correlations (in the Spooky Activation at a Distance model). Specifically, no pre-existing elements or hidden variables exist in quantum correlations as they do in classical correlations. For example, a classical correlation would be a scenario in which someone writes the same number on two pieces of paper, and sends them to two distant ends of the Universe. When received, both papers have the same number, but this correlation is due to a pre-existing action.

On the other hand, the quantum analogue of this scenario is much stranger. At one end of the Universe, someone writes a number on a blank piece of paper. At the other end of the Universe, another individual discovers that the same number is written on another piece of paper. Called quantum entanglement, this scenario doesn’t occur in everyday life, but it has been observed at the quantum scale and is referred to as “non-locality.”

Non-Separable Entities

In this study, the researchers ask if quantum entanglement might exist for systems beyond modern physics, such as word correlations.

“We take the position that quantum entanglement in modern physics is a physical manifestation of something more general called ‘non-separability,’” coauthor Peter Bruza of QUT told “We view quantum theory as an abstract framework for developing models of non-separability in a variety of domains including cognition. Note that, even though we are using quantum theory to model the non-separability of words in human memory, we make no claim that this corresponds to a physical manifestation of entanglement in the brain.”

In the researchers’ word entanglement model, each associated word can either be recalled or not recalled. An entangled state would occur when two associated words (e.g. “Earth” and “space”) are either both recalled or both not recalled in relation to a cue word (e.g. “planet”). Intuitively, this makes sense: when visualizing Earth, it’s hard to not also visualize the surrounding space. In this example, Earth and space make up a non-separable entity.

Word Recall Probability

Next, the researchers suggest that the probability of a word being activated in memory lies somewhere between Spreading Activation (in which words are individually recalled based on individually calculated conceptual distance) and Spooky Activation at a Distance (in which the cue word simultaneously activates the entire associative structure). Most likely, Spreading Activation underestimates the strength of activation, while Spooky Activation at a Distance overestimates the strength of activation.

“Even though both the Spreading Activation and Spooky-Activation-at-a-Distance models are based on an underlying network, both models are still fundamentally reductive in nature and assume that words are separate, distinct entities in human memory,” Bruza explained. On the other hand, the quantum-based model doesn’t assume that words are separate entities.

In the new model, associative word recall probability depends on how strongly connected the associated words are to each other. For instance, “Earth” and “space” are entangled in the context of “planet,” but “Earth” and “gas giant” may not be entangled (though “Jupiter” and “gas giant” may be). Words that are entangled with many other words have a greater probability of being recalled, while words that are entangled with few or no other words have a smaller recall probability. While the idea of word entanglement may sound odd, Bruza explained that it may be just one example of a strange concept.

“We think it is odd that entanglement occurs at all,” he said. “As a phenomenon, it suggests that the world is not the separable and reducible place that we have always taken it to be. If entanglement is found in other types of (non-physical) systems, it will suggest that the quantum formalism is modeling non-separability per se, and this will indicate that quantum theory could provide a whole new approach to the study of complex systems, i.e. non-separable and irreducible systems.”

The Future of Quantum Cognition

The researchers explain that their model is overly simplified, and it would be very difficult to extrapolate to a more realistic model due to the vastness of the human mental lexicon. However, experiments involving memory tests might be able to distinguish between the predictions of the three different models. Currently, researchers are performing an empirical analysis using the University of South Florida’s “Free Association Norms,” a database of word association norms which involves data from more than 6,000 participants producing nearly three-quarters of a million responses to 5,019 stimulus words. Eventually, all this analysis of semantic models may have applications for future technology, Bruza explained.

“Current information processing technology is very efficient at processing symbols, but is largely clueless as to what they mean,” he said. “Our position is that, in order for such technology to better align with humans, it needs to process ‘meanings’ like those we harbor. As our information environment becomes more complex, we will need technology that can draw context-sensitive associations like the ones we would draw, but increasingly don’t as we lack the cognitive resources to do so. Therefore, such the ‘meanings’ processed by such technology should be motivated from a socio-cognitive perspective.”

This kind of research is an example of an emerging field called “quantum cognition,” the aim of which is to use quantum theory to develop radically new models of a variety of cognitive phenomena ranging from human memory to decision making. Although speculative, this research is gaining momentum. For instance, later this year, the highly regarded Journal of Mathematical Psychology will publish a special issue of quantum models of cognition. In addition, quantum cognition is a prominent theme within the Quantum Interaction Symposia, which provide a forum for a growing body of researchers applying quantum theory to non-quantum domains.

More information: Bruza, Peter; Kitto, Kristy; Nelson Douglas; McEvoy, Cathy. “Extracting Spooky-activation-at-a-distance from Considerations of Entanglement.” To appear in Proceedings of the Third Quantum Interaction Symposium, Lecture Notes in Artificial Intelligence, vol 5494, Springer, 2009. Available at arXiv:0901.4375v1.

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2 / 5 (8) Feb 18, 2009
By AWT these "Entangled Quantum States" should be of mechanical nature, they really exists inside of our brain like standing waves of electrochemical activity and neural network density/impedance. If we see some phrase and/or combination of words together, it becomes hardwired into our brain like association for faster and effective usage.
1 / 5 (1) Feb 18, 2009
"this correlation is due to a pre-existing action [...] quantum analogue of this scenario is much stranger"

Uh...? Last I checked Quantum Entanglement requires "pre-existing action" to occur.

The continued analogy seems to suggest when something happens, the result is "magically" duplicated.
3.3 / 5 (3) Feb 18, 2009
At one end of the Universe, someone writes a number on a blank piece of paper. At the other end of the Universe, another individual discovers that the same number is written on another piece of paper.

This description is completely wrong. Entangled states have to come from a single source.

We view quantum theory as an abstract framework for developing models of non-separability in a variety of domains including cognition.

This whole theory is pure speculation, physorg usually picks marginal science for it's editorials, probably no serious scientist will take the offer.
2.3 / 5 (3) Feb 18, 2009
..this whole theory is pure speculation...
It's easy to say - but which experience of yours contradicts this view, really? For me such research is rather selfevident.
4.8 / 5 (47) Feb 18, 2009
Why use such a mangled anology? Lame.
1.6 / 5 (7) Feb 18, 2009
Face it people god is on the earth asking you to join him.
5 / 5 (3) Feb 18, 2009
For something to behave "like" quantum entanglement, it must disobey classical physics, because quantum entanglement is inconsistent with classical physics. Yet these researchers claim there is a classical analog of quantum entanglement. Therefore these researchers are wrong.
2 / 5 (4) Feb 18, 2009
Try to consider this toy.
1.7 / 5 (6) Feb 18, 2009
...these researchers claim there is a classical analog of quantum entanglement..
AWT predicts many classical analogies of quantum phenomena. Some of them were already published here at physorg. You should simply learn a bit more about physics.

3.4 / 5 (5) Feb 19, 2009
..this whole theory is pure speculation...
It's easy to say - but which experience of yours contradicts this view, really? For me such research is rather selfevident.

Science is not about what feels good or sounds reasonable, science is about what is backed by experiment.

It is irresponsible to publish a theory for without a single backing piece of evidence because many lay people who trust scientists may be mislead.

This article is a perfect example of taking advantage of a fashionable buzzword to sell useless and confusing theory. What's even worse from the explanation of quantum entanglement they give it seems the authors don't even know what they are talking about.

AWT predicts many classical analogies of quantum phenomena.

If AWT explains so much it should be easy to come up with some quantitative predictions which can verified by experiment or even by data already in literature, try to predict electron mass or other masses, derive one of physical constants from the other ones, explain why dark matter makes up the percent it makes up, come up with explanation for quantum of action, calculate pioneer effect, anything, there are countless places where modern physics can be improved.

If you manage to make some valid predictions AWT will be promoted to a regular scientific theory and many people will learn about it, not to mention prizes and funding for yourself, OTOH if you can't predict anything new it means AWT only *seems* to explain things and you are fooling yourself and wasting time.
not rated yet Feb 19, 2009
This sort of reminds me of the holographic memory theory...
3 / 5 (2) Feb 19, 2009
..if AWT explains so much it should be easy to come up with some quantitative predictions..
Say it to string theorists first (especially before 40 years, when string theory has appeared)...;-)

The qualitative predictions are predictions as well. For example, order of Venus phases or stellar parallax are qualitative predictions of heliocentric model.

Technically, you even cannot compute anything from heliocentric model explicitly, because it assumes mass of planets and validity of gravitational law, which were tested just by heliocentric model.
2.3 / 5 (3) Feb 19, 2009
..this sort of reminds me of the holographic memory theory...
..or quantum mind theory of Hameroff-Penrose, in particular.


For Penrose, consciousness has a non-algorithmic ingredient. At the quantum level, different alternatives can coexist. A single quantum state could in principle consist of a large number of different, simultaneous activities.

By AWT the neural net inside of brain doesn't use quantum phenomena on it's fundamental level (at least I don't see any direct evidence for it). Instead of this, waves of electrochemical activity between individual neurons appears like quantum waves of boson condensate on background of ion motion confined to cellular membranes, mediated by London cohesion interactions, i.e. by similar way, like the motion of ions inside of ball lightning, for example.
3 / 5 (4) Feb 19, 2009
..if you can't predict anything new it means AWT only *seems* to explain things...
Explanation isn't prediction. For example, from AWT follows the dispersion and superluminal speed of gravitational waves (in analogy to surface (light) and underwater waves) and it explains, why we cannot detect them. The same is valid for hidden dimension, Lorentz symmetry violation and other quite common phenomena - scientists simply didn't realize, where to look for them.

Deeper insight could save us a lota money, indeed. But I don't think, science can reflect new things from outside, especially if it could cut investments into new research. Science is salary machine for people involved, only very gradual changes can occur here.
5 / 5 (1) Feb 19, 2009
A fun book about cognitive science is "I am a strange loop" by Douglas Hofstadter.
If you are interested in how thinking actually works take a read through the book. Not to say he is right, of course, I'm just saying it is very interesting.
5 / 5 (1) Feb 22, 2009
It's interesting to note how the psychological basis of thought is generally capable of being grouped into to two basic directions, overall.

As in -the wiring of the people who fear the unknown and exist via labeling and writing in stone..and the others who can shift with the breeze and end up getting to more places and faster-in discovery.

One is filled with a kind of wonder and joy of life and discovery always shifting toward the new........ the other finds joy in life via permanence, sedimentation, and labeling.

I ceased making apologies and easing the fear of the sedimental types-- long ago. Not worth the effort. They will still take a bite out of you regardless of your position or behaviour toward them.

May as well kick them in the teeth while they do it, for they won't change until it fails to work for them.
not rated yet Feb 22, 2009
I didn't even bother to read the story -- I took one glance at the headline and knew the user comments would be the best part. How did I know that the first post would start with the words "By AWT"? Thanks for not disappointing me, guys. ;-)
not rated yet Feb 23, 2009
But Damon surely a totally irrelevant post about AWT should have been unexpected when the article is about explaining poorly understood phenomena with a badly misunderstood botch of upside down quantum theory since there is NO evidence for quantum processes in nerves in the first place.

Not to say that Dr. Penrose if full of it(remember he was brought up by Alexa and had nothing to do with the dubious speculation masquerading as research in the article). Penrose may be right. He is after all a brilliant and competent mathematical-physicist who makes my brain hurt. I actually hope he is right about there being quantum processes in the human brain. Its just that there is no evidence for it so far and his hypothesis about micro-tubules seemed pretty questionable even when he first proposed it. Maybe in the future.

1 / 5 (1) Feb 23, 2009
..its just that there is no evidence for it so far and his hypothesis...
Of course not, here are much closer evidence. The neural waves are spreading like solitons around neural network and here's a firm experimental evidence for it (although it doesn't involve micro-tubules). In addition, the behavior of neural membranes corresponds the specific state of matter, which exists for example in supercritical fluids and it introduces the non-linear energy wave spreading. Existence of solitons correspond the wave packets of elementary particles by AWT.

The phrase "by AWT" means, it's not commonly accepted fact, but my hypothesis. I'm using it for distinction of peer-reviewed research and private speculations to make it clear for every reader.
1 / 5 (1) Feb 23, 2009
...people who fear the unknown and exist via labeling and writing in stone..and the others who can shift with the breeze and end up getting to more places ...
AWT explain the existence of such dualities wery well, for example by using of water surface analogy. Energy spreads more intensivelly at water surface, just because it's formed by combination of two phases. The formation of phase interface therefore accelerates the evolution. After all, this is why we have sexual dimorphism, system of two (or more) political parties, bosons and fermions and so on.

The rest is completelly matter of probability. Just because such dual system spreads energy better, it's more atemporal and stable so we have a nonzero probability, we will remain inside it during evolution.
Feb 23, 2009
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Apr 05, 2009
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