These are the capacities of our brain that allow us to interact with our environment: they allow us to perceive, concentrate, acquire knowledge, reason, adapt and interact with others.

In our lives, we all process a great deal of information. We do a whole lot of activities with our mind (we see, we memorize, we move, we talk, etc.). Human cognition is our "thinking apparatus". This cognition has different roles (memorizing, speaking, moving, etc.): these are the cognitive functions, that is to say the different major roles of our cognition. This cognition has the function of perceiving, paying attention, memorizing, reasoning, producing movements, expressing oneself.

The main signs of loss of focus are: : Memory loss : Difficulty performing familiar tasks : Language disorders : Disorientation in time and space : Difficulties with abstract notions : Misplace things : Mood and behavior changes : Personality changes : Loss of interest

The risk factors are now well established: • low level of education; • Cardiovascular risk factors: untreated high blood pressure, stroke, high cholesterol, diabetes, overweight, obesity; • female sex; • environmental factors (tobacco, alcohol, pollution, certain drugs, etc.) • sleep disorders; Some less frequently cited risk factors are increasingly documented: • chronic inflammation of the body (recurrent and persistent increase in white blood cells) is linked to a narrowing of the areas of the brain involved in Alzheimer's disease; • a history of head trauma with loss of consciousness of more than 5 minutes would favor an early onset of symptoms of the disease due to weakening of the brain; • Mood disorders such as chronic stress or depression are also linked to Alzheimer's disease. In addition, an unbalanced diet, lack of physical activity and stimulating intellectual activity could also be associated with an increased risk of Alzheimer's disease.

Acetylcholine deficiency is increasingly recognized as a co-factor. • Acetylcholine is a chemical found in the brain. It is believed to be important for learning and memory. • The level of acetylcholine in a person with Alzheimer's disease is lower than that of a person without. • By increasing the concentration of acetylcholine, it is possible to temporarily soothe or stabilize the symptoms of Alzheimer's disease.