Some people with aphasia have difficulty processing the written words that they see.
It is possible for a person with aphasia to look at one word, for example, “fork”, and think of a spoon or something else related to “fork”. Another kind of problem is to look at a written word and fail to recognize it in any meaningful way. For example, a person with aphasia could look at a written word like “fork” and not be able to think what it means. In these cases, it is helpful to add additional written information, gesture, or pictures, to help reading comprehension. Compare the following two statements: “Get the spoon” and “Get the spoon – the one for soup”. In the second statement there is additional information that may help trigger the correct meaning of the target, “spoon”. Even though the second statement is longer, it provides redundancy which helps comprehension.
Some people with aphasia have trouble recognizing the letters. Letters may look like strange squiggles; the individual letters themselves may have lost their connection to meaning. Again, additional information provided either through writing, gesture, speech, or pictures, can help the person understand the written word.
Other types of aphasia affect reading comprehension because verb forms and small “functor” words like prepositions and articles have lost their meaning. In this case, a person with aphasia would have more trouble understanding a sentence that is longer and more complex than a simpler sentence.
It is important to note that silent reading comprehension is different than being able to read out loud. Many people with aphasia can understand written words and sentences but be unable to read them out loud. We are used to teaching children to read by hearing them read out loud, and estimating their ability to read through how well they can do so. This is not the same in adults with aphasia who were able to read prior to their stroke or brain injury. It is important to test these two skills – silent reading comprehension and reading out loud – separately.