By Dr. Laura Mondino
I would like to dispel a myth that we often hearduring the course of our personal growth process (or read in “certain” books) from those who know very little about how the brain works. At least compared to someone who has studied the brain for years in university classrooms and maybe has even handled it in the operating rooms or research centres.
Negation is a typical function of human language, and is considered a pragmatic universal need for the communicative necessities to which it responds. However, it is often said that we first need to represent the meaning of a word in order to then negate it.
Several studies have supported the fact that it is not true that the brain does not understand negations, including the most recent one carried out by the researchers of the Center for Neuroscience and Cognitive System (CNCS) in Rovereto and of the Institut des Sciences Cognitives “Marc Jeannerod” of the CNRS in Lyon.
NEGATION AND THE BRAIN
Imagine reading the sentence “There are no eagles in the sky”. You are then shown two pictures: an eagle in its nest and an eagle in the sky. If you were asked which picture you associated to the sentence you just read, you would immediately indicate that of the eagle in the sky and only after would you correct yourself.
Starting from this evidence, neuroscientists, language experts and psychologists have postulated that in order to process the meaning of a negation, it is first necessary to understand the affirmation.
However, in the example of the eagle, there is a practical conditioning: the brain chooses the cognitively more economic way. The sentence “There are no eagles in the sky” leaves many possibilities open. Indeed the eagles could be in their nest, on a tree or flying low over water.
Our brain thus prefers to memorise the only impossible case, an eagle in the sky, rather than the numerous possible ones. What happens though if there is no practical conditioning? Is it still true that understanding negations occurs in two stages?
In order to answer this question, the three researchers showed the subjects involved in the study sentences related to actions which imply movement of the hand, in a positive and negative version, for example “now I’m writing” and “I’m not writing”.
THE ROVERETO EXPERIMENT
The study involved 30 people, all Italian and right-handed. Each subject was shown a series of state verbs and action verbs on a computer screen preceded by a context adverb “now” or “not”. To monitor brain activity during the experiment, the part of the motor cortex associated to the movement of the forearm and the right hand was stimulated with Transcranial Magnetic Stimulation.
The researchers observed that the electric pulses reaching the hand when the subjects read positive actions are more intense than the ones evoked by negative actions, which are even weaker than those measured with verbs of state.
This difference of intensity already exists during the initial stages when the sentence appears on the screen.
The processing of the negations, therefore, occurs differently than that of the affirmations from the early stages, without needing to pass through the processing of the positive meaning.
The experiment has clarified the operation of a fundamental logic mechanism, negation, showing how the brain is more efficient than we think.
Processing negations probably contributes to defining the difference between human cognition and non-human cognition.
If our cognitive system did not recognise negation, this very statement, like an infinite number of others, would be incomprehensible to humans. And as a consequence not even positive statements.