Maya is seven years old and has a phobia of dogs. Her father is worried because she now refuses to walk to school or go to the local playground. He says, 'Maya used to love riding her scooter outside and playing tag with her friends, but now she insists on staying indoors to play video games and draw in her bedroom.'

A psychologist has suggested treating Maya's fear of dogs using systematic desensitisation. Explain how this procedure could be used to help Maya overcome her phobia.