Word recognition the integration of the different kinds of information occurs. The accuracy with which readers recognize words depends on the area of the retina that is stimulated. Reading in English selectively trains specific regions of the left hemiretina for processing this type of visual information, making this part of the visual field optimal for word recognition. As words drift from this optimal area, word recognition accuracy declines. Because of this training, effective neural organization develops in the corresponding left cerebral hemisphere. Eyes make brief, unnoticeable movements called saccades approximately three to four times per second. Saccades are separated by fixations, which
Letter frequency word variants when counting, such as "abstracts", "abstracted" and "abstracting" and not just the root word of "abstract". This system results in letters like "s" appearing much more frequently, such as when counting letters from lists of the most used English words on the Internet. A final variant is to count letters based on their frequency of use in actual texts, resulting in certain letter combinations like "th" becoming more common due to the frequent use of common words like "the". Absolute usage frequency measures like this are used when creating keyboard layouts or letter frequencies in old fashioned printing