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Puzzles and the Brain

Mixed research on puzzles and riddles.

I recently Googled relevant psychology, neuroscience, aging, and education websites to get a sense of the kind of research being conducted on the relationship between puzzles and general brain functioning. I found an astronomical number of sites. I then looked up sources that I considered to be scientifically reliable ones. Much of the research in this domain turns out to be ambiguous, and certainly not as optimistic as it is claimed to be by the media.

For example, a study published in Brain and Cognition (Volume 46, 2001, pp. 95-179) showed that the elderly performed significantly poorer on the Towers of Hanoi puzzle than younger subjects. The puzzle — in case you are not familiar with it — consists of three pegs requiring solvers to move the concentric disks placed on the left peg in order from the smallest on top to the largest on the bottom to the right peg, so that at no point in the movement of the disks can a larger one rest on top of a smaller one. The direction of movement is not restricted.

Another study examining crosswords and aging published in the Journal of Experimental Psychology (Volume 128 [2]. 1999, pp. 131-164) found no evidence to suggest that crossword puzzle experience reduces age-related decline in cognition. However, in other work, one of the researchers, E. J. Meinze, found evidence to suggest that a high level of experience with crosswords in older subjects does seem to partially attenuate the negative effects of age on memory and perceptual speed tasks (Psychology of Aging, Volume 15 [2], 2000, pp. 297-312).

So, does doing crosswords, Sudoku, logic puzzles, visual conundrums, and the like diminish the ravaging effects on mental skills by the process of aging? Does puzzle-solving enhance cognition generally?

I became interested in these questions after working with brain-damaged children in Italy in the mid-1980s (with results published in my book Cervello, lingua, ed educazione [Brain, Language, and Education], 1988). Here's what I did.

If a child was assessed as having a weak visual symbol memory, impairing how she or he spelled words or read them, I would prepare appropriate puzzle material, such as jumbled letters that the child would unscramble to construct words. If the word were "tiger," I would give the child the jumbled form "gerti" and a picture of a tiger. What surprised me was how quickly the children improved in their writing and reading skills.

However, I had no real explanation for the improvement. We know so little about the connection between brain activities and learning processes that the outcomes I was able to produce may indicate nothing more than a "co-occurrence" between an input and a brain activity, not a "correlation" between the two.

Nevertheless, from that experience, it is my cautious opinion that puzzles are beneficial to brain activity and I will attempt to explain here why I believe this is so.

Consider a simple riddle such as: "What is yours yet others use more than you do?" The riddle stumps many people because it cannot be "thought out" through straightforward "logic." The solver has to think outside the puzzle content itself and use knowledge of language, experience, and other "external mental activities" to solve it. The answer is: "Your name." Once the answer is understood, memory for it remains much more permanent because it is unexpected.

The psychologists Sternberg and Davidson argued, as far back as 1982 (Psychology Today, Volume 16, pp. 37-44), that solving puzzles entails the ability to compare hidden information in a puzzle with information already in memory, and, more importantly, the ability to combine the information to form novel information and ideas. The thinking involved in solving puzzles can thus be characterized as a blend of imaginative association and memory. It is this blend, I would claim, that leads us to literally see the pattern or twist that a puzzle conceals. It is a kind of "clairvoyance" that typically provokes an "aha!" effect.

I should mention that some of the research I came across suggests that culture is a factor in how puzzles affect brain functioning. I'm not sure what to make of this line of research. Even though people speak different languages, puzzles seem to rise above culture-specific modes of understanding the world. The classic case-in-point is the following puzzle:

A traveler comes to a riverbank with a wolf, a goat, and a head of cabbage. He finds a boat there that can hold himself and one other. How does he get his animals and cabbage across safely? He cannot leave the goat alone with the wolf, for the wolf would eat the goat; and he cannot leave the goat alone with the cabbage, for the goat would eat it.

The traveler starts by bringing the goat across. He leaves the animal there and goes back. On the original side, he picks up the wolf (he could also pick up the cabbage), goes across, leaves the wolf on the other side, and goes back with the goat. On the original side, he leaves the goat, picks up the cabbage and goes across. He leaves the cabbage safely with the wolf and goes back to pick up the goat on the original side for his last trip across.

Now, this version comes down to us from the pen of Alcuin (c. 735-804), the English scholar, theologian, and adviser to Charlemagne. But the same puzzle is found across the world in different linguistic and cultural guises — that is, the details may change, but the structure remains the same, involving curious situations with people such as cannibals, jealous husbands, etc. All this suggests that the puzzle is culture-independent. It is part of a common human imagination. Puzzles seem to tap into a universal part of brain functioning, even though they may appear in different cultural forms. The great British puzzles Henry E. Dudeney (1857-1930) once put it as follows:

The curious propensity for propounding puzzles is not peculiar to any race or any period of history. It is simply innate, though it is always showing itself in different forms; whether the individual be a Sphinx of Egypt, a Samson of Hebrew lore, an Indian fakir, a Chinese philosopher, a mahatma of Tibet, or a European mathematician makes little difference (The Canterbury Puzzles and Other Curious Problems, 1958, p. 12).

There is little doubt in my mind that puzzles are beneficial, ambiguous empirical findings aside. I saw this with my own eyes within my own family.

I once suggested to an ailing relative, who suffered from a serious brain-degenerative disease, to engage in crosswords and Sudoku. He had never done puzzles in his life. His doctor immediately saw a significant slowing down of the degeneration. The relative eventually died of the disease, but I am convinced that his newly-found passion for puzzles delayed his eventual loss of consciousness.

I will return to the topic of puzzle-solving in a future post. But I would really like to get your own ideas on the theme of this one, especially if you also have anecdotal evidence such as the one I mention here or else are a researcher in the field.

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