Their thinking may, therefore, becomes intuitive rather than conscious. They appear to be extreme visual thinkers and have great difficulty with concepts and ideas that they cannot visualize. They often have trouble reading words known as “content words” –for example “of”, “it”, “which” and “than” because they are unable to visualize these words. They also find phonics difficult and learn by remembering the look of words rather than the sound. The brain of an autistic person is crammed full of images which are being manipulated, rotated, flipped and broken down all the time. This can cause emotional or mental problems and autistic pupils are prone to obsessive disorders.