Frequently however a pitter-patter of four sounds may be heard because the arm and leg are not precisely synchronized in their movements. Pulling to a standing position, cruising along furniture and finally walking alone complete the next chapter in mobility development. These stages in the development of mobility are also contributing to visual and auditory function. When crawling prone, one eye and one ear are utilized, as the arm and leg are advanced on that side. Creeping on hands and knees stimulates binocular vision coordinating two eyes to provide a clear single image in all directions and binaural hearing whereby sounds are localized from all areas.
Standing introduces the vertical dimension to vision and the tracking of eyes in all directions.
Language has been developing simultaneously from the reflex cry of the newborn through meaningful sounds to expressive vocalization and eventually spoken organized language. Recollection of deficiencies in any of these stages indicates some developmental neurological inadequacies which may still be manifested today if tested. In other instances however, these difficulties may not be recalled and a happy, healthy infancy may be reported. But now the children in these respective groups are promoted to Kindergarten. It is reported that they do not sit still, they talk when they should listen, they do not complete a task, they have difficulty learning letters or numbers.