Peggy Wright

Success in Twenty Questions depends on the questioner’s ability to keep clearly in mind all of the answers and mentally eliminating possible choices on the basis of these answers. The skill of the other player (in a two-person version) or group depends on the ability to come up with difficult-to-guess persons, places, or things. Special versions of the game can be played involving special interests—say, history or medicine—and limiting the answer to a person, place, or things taken from historical or medical sources.A devilishly clever form of Twenty Questions was first described by quantum physicist John Wheeler. The Wheeler version, called “Negative Twenty Questions,” is much more demanding in terms of working memory. Let me explain the game in terms of multiple players rather than the two-player version—which, if you decide to play that version, I’d suggest you play only with someone who is very smart.Unbeknownst to the questioner when he or she leaves the room, the other players purposely omit choosing a single person, place, or thing. So when the questioner returns and begins questioning, there is no definite person, place, or thing to be guessed. Instead the person questioned thinks of a person, place or thing consistent with the question asked. “Does it live in the ocean?” “No.” Each of the other players will do the same thing: after hearing the question, they will create a person, place, or thing of their own as long as it is consistent with previous questions and their answers. In this version of Twenty Questions, there is no agreed upon person, place, or thing to be guessed.As Wheeler explained the process to science writer John Horgan, “The word wasn’t in the room when I came in even though I thought it was. Not until you start asking a question do you get something. The situation cannot declare itself until you have asked your question. The asking of one question prevents and excludes the asking of another.”Wheeler applied this game of Negative Twenty Questions to quantum physics. “Every particle derives its function, its meaning, its very existence entirely—even in some context indirectly—from the elicited answers to yes-or-no questions.In this version of the game—a kind of test for communal working memory—all of the participants must remember each of the questions and the answers. During the course of the game these questions and answers must be maintained and shifted around in working memory. If even one question and response goes missing from working memory, the game falls apart. Didn’t I tell you it was devilishly clever?Prior to writing this sentence I brewed a pot of coffee. I didn’t have to consult any sources, bring anything in particular to consciousness, or concentrate very forcefully on what I was doing. After preparing hundreds, probably thousands, of pots of coffee, the whole process has become automated into procedural memory.If you drove your car today, your performance was pretty much automatic (unless you are in the process of learning to drive). If you are a veteran driver, you can do all kinds of things while driving that a novice driver can’t: listen to the radio, converse with a passenger or, if you dare, call to make a date on your cell phone. If I ask you how you can do these things and still drive, you can’t really put into words the steps leading up to your improved driving performance because it is based on procedural memory.Procedural memory (also known as skilled memory) doesn’t involve speech or words at all. Other examples include physical skills like skiing or riding a bike. After sufficient repetition of these activities the brain forms neuronal networks that spring into action whenever we are skiing or biking. After sufficient experience, these activities can be performed outside of conscious awareness. But even after we become skilled at these things, we can’t explain to anybody else how to do them because procedures rather than words are involved. This is why procedural memory is sometimes mistakenly called muscle memory, Actually, the memory resides in the brain and not in the muscles. But this doesn’t imply that our muscle movements play no part in how we establish memories.Psychologists have shown, for instance, that it is easier to establish a memory if we accompany an appropriate bodily movement of what we want to remember. For example, if you were requested to memorize and later recite a series of simple requests (pick up a pencil, open a jar, light a candle, etc.) your ability to remember the requests would be greatly improved, if at the time of memorization you actually carry out these actions using a pencil, a jar, and a candle. These movements establish the required motor-muscle program underlining the instruction.Getting back to the driving situation, if I ask you to teach me how to drive, you will have trouble doing that by verbal instruction alone because procedural memory doesn’t require consciousness and is a non-declarative memory. You cannot teach someone just by words; you have to convey to them the motor program. No one has ever learned by verbal instruction alone how to drive a car, ski, play a guitar, or any skilled action.Sometimes described as “knowing how” as opposed to “knowing that,” procedural memory is an acquired sense of how to carry out a complex pattern of behavior. I can instruct you how to make a cup of coffee starting with the selection and grinding of the coffee beans, but it is much easier for me to just make the coffee myself and serve it to you. The development of any skill or habit such as coffee making involves motor action involving automatic behavior. With sufficient practice, all of the necessary actions can be carried out without consciously thinking about them. As a result, once they’ve become automated, they are very difficult to teach to someone else.While procedural memory is a form of working memory, it is processed differently. The components of the action must be practiced frequently. But merely repeating a certain behavior does not guarantee the development of a skill: that perfect cup of coffee.As a first step of practice, the desired skill is broken down in its component parts accompanied by an understanding of how these parts come together. Unnecessary or ineffective actions are omitted, as the coffee-making procedural memory is established. As a key component, important steps are accentuated and the process is sped up and automated. These steps are 1) making an attempt (preparing the coffee), 2) analyzing the results (tasting), and 3) changing the procedure, if necessary, in order to obtain the desired result. With each rehearsal of the coffee-making protocol, a neural network is established outside of conscious awareness. Feedback (access to knowledge of the result), is the key to perfecting procedural memory: test the coffee yourself (internal feedback) and take into account the opinions of others (external feedback).Think of procedural memory not only as a form of working memory involving the muscular system. It also involves different parts of the brain, primarily a group of structures below the cortex called the basal ganglia, which includes such components as the stratum. As skills further develop, changes in the cortex also occur—the motor cortex, for instance, is linked to the learning of the new motor skill. Deep in my own brain is a cortical, as well as subcortical signature for my coffee-making ability. Elsewhere in my brain are the signatures for riding a bicycle, swimming, or dancing, and these involve different motor programs.The automated performances of procedural memory provide both promise and peril. Once something has been practiced and learned to the extent that conscious awareness isn’t necessary, reintroducing conscious awareness can prove an extreme liability. Once you have learned that new dance step, you better resist the temptation to further improve it by becoming aware of your feet movements, lest you segue from a “smooth operator” to a clumsy klutz.