[LUM#3] Light and shadow of consciousness

[LUM Magazine] - Published on July 26, 2016 in Science-Society

What happens in our brains? It is still difficult to say. Among the mysteries that remain, there is one Holy Grail: the enigma of consciousness...

It has long been a complete mystery. Shrouded in its impenetrability, the brain was described from the outside. How do we behave? How do we speak? How does this data shed light on the mechanisms of the brain? In recent decades, technological advances, particularly in medical imaging, have begun to shed light on the inside of this black box. But the mystery remains...

An organ like any other?

"We have a pretty good understanding of how the liver and kidneys work; even though there is still much to learn, the basic concepts are there. We have a fairly good grasp of how the motor, vascular, and digestive systems function." "Fairly good," says Joël Bockaert, neurobiologist and founder of the Institute for Functional Genomics. Complete understanding often remains a shore that recedes as we approach it.

Understanding the brain? Wouldn't that mean, among other things, understanding how to create the immaterial with the material: consciousness and thought with nerve cells? Because the brain is indeed an organ. And as such, it is subject to metabolic and genetic determinants: "Autism and schizophrenia seem to have a strong genetic component," continues the neurobiologist.

But it is an organ of staggering complexity. The proof is that when it comes to repairing this subtle mechanism, we are very poor watchmakers... "Even today, when faced with virtually all brain diseases, we practitioners remain very helpless. We can relieve patients, but we cannot cure them," says Gina Devau.

Eternal impermanence

However, this neurobiologist specializing in Alzheimer's disease has some excellent news: "Your brain is aging well!" she says. It offers remarkable plasticity and incredible resilience. In the event of damage, it can reorganize itself to recover all or part of its lost faculties.

And for it to develop, all you need to do is keep it active. Because our brain structures deteriorate if we don't use them. "The brain changes and transforms itself constantly, throughout our entire lives. It is capable of creating new connections if it is stimulated," says Gina Devau. If there is one thing that characterizes our brain, it is its impermanence. Every second transforms it. So much so, according to scientists, that you will not be the same after reading this article...

But then, where does my identity come from? Far from the unconscious described intuitively by Freud, advances in science now allow us to imagine an unconscious that is perhaps more omnipresent than the father of psychoanalysis ever imagined. "This is an important discovery of recent decades: the brain functions largely unconsciously," says Joël Bockaert...

Who am I?

And scientists describe a brain that does not need us to perform the vast majority of the tasks it is responsible for. Managing physiological functions, breathing, controlling the heart, for example; juggling motor and sensory coordination, such as when riding a bike or playing the guitar: my brain performs these complex tasks on its own. That is, without me.

"It's an organ that functions extremely quickly: in the order of milliseconds. It's a process that escapes our consciousness, for which the basic tempo is more like a second," says Gina Devau. The same is true of speech: "When we speak, we do so at such speed that our words clearly don't have time to pass through the filter of consciousness," confirms Joël Bockaert. But then, who is this "I " that speaks? "I is another," said Rimbaud: poets, those inventors of the unknown, were the first to express this astonishment at the mystery of consciousness.

Consciousness is therefore only the tip of the iceberg, beneath which most decisions are made without our knowledge. What happens when it emerges? This fireworks display can be described, but not explained. "Everything lights up and synchronizes in the prefrontal cortex. This is the main seat of consciousness: it is what activates and manages most of the brain's functions," describes Joël Bockaert. This state, which allows us to focus our attention on a single, specific event, does not last. The brain then takes back control, like a discreet despot...

These traces that shape us

If there is one thing I rely on, it is undoubtedly my memory, that major pillar of identity building. "Our memories open a window onto the past, but also onto the future. They are what enable us to move forward," says Gina Devau.Itis our knowledge of places, past situations, and existing relationships that allows us to adapt in advance to what we project into the future. "There is no imagination without memory: the same regions of the brain are involved," explains Joël Bockaert.

We have some insight into how memory works. "When a memory is formed, the connections between certain neurons are strengthened to create a pattern , a particular shape." Networks are created, and they will either strengthen or disappear depending on whether or not they are used. Memories are therefore literally imprinted on us. They are physical traces: this begins to reduce the central mystery of "how can we create the immaterial with the material?"...and vice versa. As the American neurologist Antonio Damasio writes, Spinoza may well have been right: for the philosopher, "the body and the mind are one and the same thing, viewed from two different angles."

These physical traces that populate our memory are themselves subject to the law of impermanence. Because our memories are constantly changing. The patterns of the networks that compose them will evolve and rebuild themselves. Today, we have come to appreciate the fragility of memory. We know that it deceives us: the brain reconstructs memories, recoding them differently each time it brings them to consciousness, subjecting them to multiple factors that alter them.

The brain can be very deceiving.

Memory is therefore subject to emotions. Neurobiologist Isabelle Chaudieu works on post-traumatic stress disorder. Normally, our memory is formed during sleep, when the hippocampus redistributes memories to various areas of the brain where they will be stored long-term. In cases of extreme stress, the hippocampus is unable to do its job. "The prefrontal cortex, which is supposed to regulate emotions, becomes overloaded. It can no longer perform its role."

This is when a rapid response system takes over: it is called the subthalamic system. A state in which emotions take over the rational brain... "Controlling emotions is one of the major functions of the brain's higher systems. Almost all psychiatric disorders are linked to a fundamental imbalance in the prefrontal cortex," explains Isabelle Chaudieu.

But even when it is functioning perfectly, our brain routinely deceives us. This enchanting organ is a master in the art of creating illusions. Optical illusions, for example, are proof of this. "The brain erases, creates, reconstructs, recomposes, and invents shapes. It can even forge fictitious memories," summarizes Joël Bockaert.

An enchanting subject that will be long and arduous to capture under the eye of science. To understand it even a little, the road is long and will require the combined input of many disciplines, explains Gina Devau. "Clinical studies, behavioral studies, medical imaging, computer simulation, genetics... Each discipline provides a small window of insight. The picture is still too vast to be grasped at a single glance."

Keywords: LUM#3, LUM Magazine, Medicine, Neurology, Research, Health