The central nervous system is based around stimuli, a stimulus is a change in the organsims environment. The central nervous system is made up of the brain and the spinal chord. The CNS is connected to the body by the peripheral system and the PNS consists of ensory neurons that carry impulses from receptors and motor neurons that carry impulses from the CNS to effectors.
Alexander pavlov inducted a study about the way the human and animal mind works at a young age and how enviromental chnages can effect and train the mind to different things.
He conducted his study using a bell and a piece of meat and he noticed when he presented the meat to a dog it salavated. pavlov then produced the meat with the ringing of a bell and he repteated this a number of times. he then took the meat away from the dog and rang the bell but the dog continued to salavte there fore asscociating the bell with the meat.
the way this works scientifically is by using the primary stimulus which is the meat and associating it with a secondary stimulus to create a response from either of those things which is salvation.
4.2 Feral child
feral children are basically children who are born with humans but after birth are brought up by animals, this is extremely rare these days but some cases still exist. these children have been isloated away from the outside world so they lack the normal process of growing up and learning. Theories show that if someone does not learn certain basic skills such as speech or eyesight then past a certain point it will be almost impossible to learn that skill. This is why feral children are unable to learn how to speak like us because they have been isolated for too long. this isolation doesnt always have to be accidental it could be deliberate.