Im asking about the soul, is the soul dependent of functions of body?
Yes and no. Firstly, the body is more dependent on the soul than the soul is on the body since it is the soul that animates and gives life to the body. The lower powers of the soul such as the sensory and vegetative powers depend on the body or various organs of the body for their operations. Accordingly, the acts of the sensory and vegetative powers of the soul are acts of the composite being, i.e., the soul and body together. The acts of the higher rational and spiritual powers of the human soul, i.e., the intellect and will, are acts that operate or function independently of the body or any bodily organ. However, in this life on earth, the intellect depends for its knowledge on the sense powers of the soul which powers act through the body because in this life we receive knowledge through the senses so Aristotle stated that our intellects are like a clean slate when we are born into the world.
When human beings die here on earth their souls live on and leave the body but they still have their spiritual powers of intellect and will by which they have knowledge and can make acts of will such as love. As the Church teaches, when we die we face the immediate judgement of God whereby we either go to heaven, purgatory, or hell. The souls in heaven see and know God through their intellect and love him with their will and they are eternally happy. The souls in purgatory are undergoing purification and the souls in hell are eternally miserable.
A baby soul can have spiritual life without a body and a brain full mature, in case that the baby die until the body is ready to work.