(revised edtion from an old text)
INTRODUCTION: WHY METAPHORS ARE SO IMPORTANT IN SCIENCE.
There is a long tradition in our educational system, holding the idea that interpretation and creation of metaphors can be part of the Humanities curriculum –mainly literature-, but they have nothing to do with sciences. However, the evidence suggests that most of our best scientists –especially those disseminators who are able to convey big ideas to the non-scientific public- are specialists in the creation of metaphors. Metaphors are an excellent vehicle to communicate scientific ideas. Very complex theories, models and hypothesis had been popularized thanks to images and comparisons easy to understand for the average people. Let’s take the next example: the idea of the planet Earth as a complex system with different components working together in an extremely precise equilibrium, prompted James Lovelock to compare the whole planet with a living thing and to popularize it under the nickname of Gaia, a Greek goddess. After that, Gaia became a powerful metaphor in the hands of environmentalists, activists, politicians and the public opinion, generally speaking. Metaphors are easier to grasp; their educational purposes therefore are in high stem.
However an abuse of the metaphor can lead to misunderstandings that generate more problems than what they are trying to solve. Taking for example the theory of the “selfish gen” by Richard Dawkins: it created interpretations that were not on the mind of the biologist, supposing that human beings were selfish and evil because it was written in their genetic code or that genes had some kind of moral consciousness. On the other hand, metaphors are images that are not ahistorical. They explain an idea in a particular social and cultural context. They can be extremely expressive and cute for some circumstances, but lose all its power in a few years.
The abundant metaphors of the brain are typical examples of how fast a metaphor became old-fashioned because of technological shift. As Grah and Kuma suggested in American Scientist (March, 2015) it takes only a few decades or years to substitute one metaphor by another: in the fifties and sixties the philosopher John Searle explained how the brain was understood as some kind of phone calling-centre. Nowadays, due to new technology, we find this image inappropriate and out of date. Computers, Internet, holograms, the cloud, are now the available images for our brains, but we don’t know for how long.
THE BRAIN METAPHORS: AN EXAMPLE OF TBL LESSON
We decided in our secondary school to find all the possible metaphors we could guess for the brain and the mind (knowing that can be understood as two different concepts, we gave freedom of choice to decide for one or another). In order to get the maximum ideas and images, we had followed the TBL method provided by Robert Swartz. It mainly consists on giving our students a thinking map about how we could generate good metaphors and the graphic organizers that will help as conceptual scaffoldings in the elaboration of these images, and after that, apply some thinking routines that encourage the students to maximize their creativity.
First of all, students have to remember what a metaphor is, and we use for our topic one of the oldest images that is related to our brain: “the brain is like industrial slag”. The image refers to the external appearance of the brain, and maybe it works for the narrow knowledge that Egyptians had on this organ, but it is definitively not enough for our own culture. Therefore, new metaphors are needed, more useful and precise for the present. The lesson starts at this point with a challenge: “We are supposed to be writers in a magazine and disseminators of scientific information and we have to find a good image of the brain and mind that could be attractive for the readers of our magazine and stimulating for their imagination”.
How to create a good metaphor? We give the thinking map for every pair of students and we analyze every step, recommending if this should be useful in order to obtain a good image. But get a good metaphor about the brain implies some training and being aware of what has been done before our own work. We analyze some very ancient images and metaphors that were elaborated from Antiquity: the Egyptians thought about the brain as industrial slag, due to the external appearance of both objects. But Plato, for instance, was much more spiritual, and identified the soul as a winged chariot flying into the sky where two horses and a rider represents different features of our souls. We analyzed also two very well-known images from the 20th century: the mind as a computer (defended by cognitive psychologists) and the mind as a black box or a tabula rasa (defended by behavior psychologists and the philosophical empiricism). These are very well known metaphors explained in the curriculum of subjects like psychology or philosophy in high school degrees.
We help to motivate the creativity of the students showing typical pictures from these metaphors. Using the pictures, they are able to grasp much better all the possible similarities of the proposed metaphors, and they have to fill graphic organizers where more than three similarities were demanded. Brainstorming gives many similarities that were unthinkable for only a single person. These preliminary approaches prompt the students to check what they already know, how powerful can be these metaphors to understand the brain and mind, and attempt the creation of new images.
After that, students worked in pairs, trying to find the most attractive and recurrent images they can guess in order to explain scientific, psychological and philosophical characteristics of our brain. A brainstorming gives us the chance to listen to all the possible images for the brain that they were able to figure out. We hardly could write all of them in the blackboard, and some of them were as suggestive as a fridge, the sun, a nebulous, a plant, a fishnet, a starry night, a music box, a banana, a theatre, a train station, a piñata, a library, or a stock exchange. Some of them were so surprising and intriguing that the proper classmates were demanding more explanations in order to understand the real explicative power of the images. Some of them were abandoned by the same students, because they realize they were irrelevant or too conventional. Others, however, won more acceptation when they were discussed. We select some of the metaphors, and decided to extend only one of them widely -the fridge-, based on the fact that it could be original and effective.
Some TBL graphic organizers, to introduce the thinking skill (copyright, Robert Swartz, 1994)
A CHALLENGING METAPHOR: THE MIND AS A FRIDGE.
What kind of similitudes could we find between a fridge and our minds? That was the challenging question for the bold student who suggested this metaphor. For this new stage of the thinking skill the teacher gave them a graphic organizer where more than five similitudes were requested. After using again the same routine (work in pairs, think and share), the students were able to show a few of them.
In fact, some common characteristics were easy to guess. First of all, both of them are divided into some kind of shelves, racks or compartments. In fridges, different racks and drawers are designed and created in order to store different items, from bottles and cheese to eggs and lettuce. In our mind, different parts of the brain specialize in diverse skills like reasoning, communicating, or controlling our emotions. Even when fridges and brains have to be understood as a whole, each compartment has its own function. This characteristic fits very well with an innate approach to mind (like Plato and Descartes in the old days and current thinkers like Chomsky or Jerry Fodor), where mind frames are essential for the development of our knowledge, and the teacher encouraged the students to establish the relation with these theories that the students knew from the curricular content.
However, there is something equally essential: the items from the outer world. The students realized that an empty fridge has no use at all. The amount of food (and its preservation) in the fridge, and the acquisition of information is the feature that gives sense to both of them. It goes without saying that this characteristic postulates the metaphor very close to the ideas of empiricism, but if we take both features (shelves and food) as a whole, show us a constructivist approach, very close to the ideas of philosophers like Kant or psychologists like Jean Piaget or Howard Gardner.
Taking these two characteristics are attractive enough for the students in cognitive psychology, neuroscience or mind philosophy. However, we could deepen a little bit more the image of the mind as a fridge. Preservation is a characteristic in common, keep the information alive in the mind, cool and preserve the food from excessive heating in the fridge. Both devices, mind and fridge, need energy from an external power source, in terms of electricity, or organic supplies like glucose and considerable amounts of phosphorus or potassium. Even the basic structure of a fridge or our brains have a external similarity. Both devices are completely isolated from the surrounding environment, in order to avoid damages in the content (for instance, fresh food or keep our memories alive) and keep them working properly. Our skulls preserve our precious brains. The metallic box of the fridge accomplishes the same mission. The more features and characteristics you can identify, the better for the metaphor and its power of expression and persuasion.
The final result of the selected metaphor.
SOLVING MISLEADINGS, QUESTIONING AND ENRICHENING METAPHORS.
Working on metaphors has some disadvantages when you are talking about scientific concepts and abstract theories. For instance, when students were discussing about this topic, we can miss the typical dichotomy between soul, conscience and biological brain, that has been so important for some philosophical schools. For instance, it should be important to ask later if creating the metaphor of the fridge is supposing that the metaphor is suggesting a materialistic or a reductive vision of our brain. The teacher could ask more extensive question in order to solve this problem. But if we want to avoid any misunderstandings, it should be highly recommended to define very well the idea or concept that we want to represent in the metaphor. The first time that we applied this thinking skill on the brain, we include Plato’s winged chariot as a metaphor of the soul. But we realized that it would bring more problems if we wanted to focus the metaphors on the brain. Even using the world “mind” as some kind of reflection of the brain had its own problems, when there is not only one approach available for this concept.
As a result of all the process, students should be able to compare skillfully the explicative power of different metaphors. They realized, for instance, that taking the Egyptian image of the brain as industrial slag was based only on its external appearance and therefore it is not good enough for the present time. As the teacher remind them, the more features we will be able to compare, the better. And not only the first things that is coming up into the student’s minds.
 GRASH and GRUMMA, Metaphors of the brain, American Scientist, March 2015.