Below is an excerpt from the introduction chapter in Such Stuff as Dreams: The Psychology of Fiction by Keith Oatley:
Representation of models in the brain
In 1996 a group of researchers led by Giacomo Rizzolatti made a discovery that set the world of neuroscience abuzz. It was of neurons that fired either when a monkey saw a particular intended action – picking up a small piece of food – or when the monkey itself performed the same action. The researchers called these mirror neurons. They provided evidence for a principle that had long been considered in the psychology of perception, called analysis by synthesis. The idea was that when we perceive some human – produced action, we do so by being able to synthesize the same action ourselves. The importance for reading and understanding of stories is that, perhaps, when we understand an action as we read about it in a novel, our understanding depends on making a version of the action ourselves, inwardly.
One cannot directly record the activity of mirror neurons in human participants; it would be totally inappropriate to implant electrodes in people’s brains. So, to study this possibility in humans, researchers have created what computer people call work-arounds. One work-around is to use functional Magnetic Resonance Imaging (fMRI), with which it has been found that when participants observed or read phrases relating to foot, hand, or mouth actions, there was activation of the regions of the brain that are used in making these same actions: A different kind of work-around has been to use a method called transcranial magnetic stimulation. Here, parts of the brain known to be directly responsible for initiating actions are stimulated briefly and gently (from outside the skulls of humans). For instance, the researchers stimulated the part of the brain responsible for making hand movements and when they did so they could record electrical activity of the muscles of the hand. They did the same for foot movements. What would happen now, the researchers asked, if the human participants were stimulated in this way and at the same time were asked to listen to a brief sentence that concerned making either a movement of the hand such as “He played the piano” or of the foot such as “He kicked the ball?” They found that when participants listened to sentences concerning hand movements, the electrical activity recorded in the hand muscles in response to the transcranial stimulation was reduced. This reduction did not occur when participants listened to sentences about foot movements or sentences that did not indicate movement. Similarly, when listening to sentences about foot movements, the stimulation-elicited electrical activity in the foot muscles was reduced as compared to the activity that occurred when listening to sentences about the hand or to sentences that were not about movement. The explanation of the reduction of electrical activity in the hand or foot muscles in response to the stimulation was that the parts of the brain concerned with initiating hand or foot movements were already occupied with understanding the sentences that concerned those movements.
Putting this another way, what these researchers found was that when we understand a sentence, as well as activation of the areas of the brain concerned with hearing and language there is also activation in the areas concerned with making the same actions ourselves.
The researchers interpret their findings in terms of mirror neurons. Recognition of an action in the imagination when we hear or read about it involves brain systems responsible for initiating that action.
In recent experiments, Nicole Speer and her colleagues had participants read whole short stories while they were in an fMRI scanner. When readers were engaged in a story, the researchers found that, at the points in which the story said a protagonist undertook an action, activation of the brain occurred in the part which the reader himself or herself would use to undertake the action. So, when the story-protagonist pulled a light cord, a region in the frontal lobes of the reader’s brain associated with grasping things was activated. When the protagonist “went through the front door into the kitchen, ”there was increased activity in a region that is activated when the reader views spatial scenes. The writer gives the cues, and the reader imagines a door, or imagines entering a room and seeing what it might be like. As I do, in this book, the researchers in this study describe reading as a process of simulation, based in experience, and involving being able to think of possible futures. These experiments indicate that, based on their experience, readers construct an active mental model of what is going on in the story, and can also imagine what might happen next.