Every now and then we happen to try one of the sensations perhaps more frightening from the everyday life: risk falling for the stairs for having “taken badly” the measures. This phenomenon reveals us surprisingly so much on how the brain and the human mind: in every moment the brain generates forecast Based on our senses regarding where our body will soon be in space, and regulates all the muscles accordingly. When the reality (the step is not there) denies the forecast that has been created in our head (there is still a step) a forecasting error which activates specific motor circuits, those of balance and emotional ones. This misadventure is “the price to pay” to have a nervous system that does everything for anticipate the futuresometimes wrong.
The brain prepares the steps before the eyes see the steps
The brain It is essentially one predictive machine. His main work is to predict the near future, because this can so Increase survival chances of the body, preparing for what will come. In addition, i visual signals they use between 80 and 120 milliseconds to reach the cerebral cortexand this means that our sensations (for example what we see), when we notice it, are already, in a sense, part of the past. In practice, when we see a step, the information “there is a step” reaches the brain with a little delay.
To make up for all this, the brain creates forecast on the physical world that they simulate in advance the outcome of our actions. This is also the case for our steps, at every step. If you think about it, it is thanks to this mechanism that we succeed in walk on irregular land Or go up the stairs: seeing the step before interacting, the brain prepare All the muscle set -up necessary to make the body is ready to climb it.
How do we build the “map” of the staircase in the head?
The information that comes to us from the outside world is constantly analyzed and processed to allow us to react in a congruous way. For example, parietal cortex, hippocampus And cerebellum They integrate vision, proprioception (the perception of one’s body in space) and short -term memory. All external sensory data and those relating to the movement of our body become one space-motor map that we continue to always use, even in the dark or unconsciously: We automatically go down the steps Until an unexpected feedback denies the mental map that we have created. When the forecasts are disregarded, a “is createdforecasting error“That the brain integrates, changing its model, that is, by changing the map.
The risks of the “automatic pilot”
The problem lies precisely in this automatism. It is normal to think of something else while we make the stairs. On the other hand, it is one of our strengths can automatically be able to carry out some motor duties to dedicate us cognitively to other things and most of the time it is a superpower that works. Other times, however, some external elements ends up for “surprise us”, Putting our space-motor models in crisis. It happens, for example, when we stumble On a step: the mental map remembered that the step was lower and the brain had prepared the leg for a lesser height, and here we find ourselves cursing face on the ground. Other times, however, perhaps going down the stairs of a place that we frequently attend, the most frequent mental maps (like the stairs of our condominium) appear in our head precisely because of the autopilot: The number of house steps is applied to the number of steps of the shopping center in which we are, and the brain is preparing to make the extra step that, in reality, it does not exist!
