of lesion, overall health status, and motivation. each individual reacts differently to treatment intensity and is able to tolerate treatment at different times post-stroke. intensity of treatment after a stroke should be dependent on the person's motivation, stamina, and tolerance for therapy. outcomes if the symptoms of aphasia last longer than two or three months after a stroke, a complete recovery is unlikely. however, it is important to note that some people continue to improve over a period of years and even decades. improvement is a slow process that usually involves both helping the individual and family understand the nature of aphasia and learning compensatory strategies for communicating. after a traumatic brain injury (tbi) or cerebrovascular accident (cva), the brain undergoes several healing and re-organization processes, which may result in improved language function. this is referred to as spontaneous recovery. spontaneous recovery is the natural recovery the brain makes without treatment, and the brain begins to reorganize and change in order to recover. there are several factors that contribute to a person's chance of recovery caused by stroke, including stroke size and location. age, sex, and education have not been found to be very predictive. there is also research pointing to damage in the left hemisphere healing more effectively than the right. specific to aphasia, spontaneous recovery varies among affected people and may not look the same in everyone, making it difficult to predict recovery. though some cases of wernicke's aphasia have shown greater improvements than more mild forms of aphasia, people with wernicke's aphasia may not reach as high a level of speech abilities as those with mild forms of aphasia. history the first recorded case of aphasia is from an egyptian papyrus, the edwin smith papyrus, which details speech problems in a person with a traumatic brain injury to the temporal lobe. during the second half of the 19th century, aphasia was a major focus for scientists and philosophers who were working in the beginning stages of the field of psychology. in medical research, speechlessness was described as an incorrect prognosis, and there was no assumption that underlying language complications existed. broca and his colleagues were some of the first to write about aphasia, but wernicke was the first credited to have written extensively about aphasia being a disorder that contained comprehension difficulties. despite claims of who reported on aphasia first, it was f.j. gall that gave the first full description of aphasia after studying wounds to the brain, as well as his observation of speech difficulties resulting from vascular lesions. a recent book on the entire history of aphasia is available (reference: tesak, j. & code, c. (2008) milestones in the history of aphasia: theories and protagonists. hove, east sussex: psychology press). etymology aphasia is from greek a- ("without", negative prefix) + phásis (φάσις, "speech"). the word aphasia comes from the word ἀφασία aphasia, in ancient greek, which means "speechlessness", derived from ἄφατος aphatos, "speechless" from ἀ- a-, "not, un" and φημί phemi, "i speak". neuroimaging methods magnetic resonance imaging (mri) and functional magnetic resonance imaging (fmri) are the most common neuroimaging tools used in identifying aphasia and studying the extent of damage in the loss of language abilities. this is done by doing mri scans and locating the extent of lesions or damage within brain tissue, particularly within areas of the left frontal and temporal regions- where a lot of language related areas lie. in fmri studies a language related task is often completed and then the bold image is analyzed. if there are lower than normal bold responses that indicate a lessening of blood flow to the affected area and can show quantitatively that the cognitive task is not being completed. there are limitations to the use of fmri in aphasic patients particularly. because a high percentage of aphasic patients develop it because of stroke there can be infarcts present which is the total loss of blood flow. this can be due to the thinning of blood vessels or the complete blockage of it. this is important in fmri as it relies on the bold response (the oxygen levels of the blood vessels), and this can create a false hyporesponse upon fmri study. due to the limitations of fmri such as a lower spatial resolution, it can show that some areas of the brain are not active during a task when they in reality are. additionally, with stroke being the cause of many cases of aphasia the extent of damage to brain tissue can be difficult to quantify therefore the effects of stroke brain damage on the functionality of the patient can vary. neural substrates of aphasia subtypes mri is often used to predict or confirm the subtype of aphasia present. researchers compared 3 subtypes of aphasia- nonfluent-variant primary progressive aphasia (nfppa), logopenic-variant primary progressive aphasia (lvppa), and semantic-variant primary progressive aphasia (svppa), with primary progressive aphasia (ppa) and alzheimer’s disease. this was done by analyzing the mris of patients with each of the subsets of ppa. images which compare subtypes of aphasia as well as for finding the extent of lesions are generated by overlapping images of different participant's brains (if applicable) and isolating areas of lesions or damage using third party software such as mricron. mri has also been used to study the relationship between the type of aphasia developed and the age of the person with aphasia. it was found that patients with fluent aphasia are on average older than people with non-fluent aphasia. it was also found that among patients with lesions confined to the anterior portion of the brain an unexpected portion of them presented with fluent aphasia and were remarkably older than those with non-fluent aphasia. this effect was not found when the posterior portion of the brain was studied. associated conditions in a study on the features associated with different disease trajectories in alzheimer's disease (ad)-related primary progressive aphasia (ppa), it was found that metabolic patterns via pet spm analysis can help predict progression of total loss of speech and functional autonomy in ad and ppa patients. this was done by comparing an mri or ct image of the brain and presence of a radioactive biomarker with normal levels in patients without alzheimer’s disease. apraxia is another disorder often correlated with aphasia. this is due to a subset of apraxia which affects speech. specifically, this subset affects the movement of muscles associated with speech production, apraxia and aphasia are often correlated due to the proximity of neural substrates associated with each of the disorders. researchers concluded that there were 2 areas of lesion overlap between patients with apraxia and aphasia, the anterior temporal lobe and the left inferior parietal lobe. treatment and neuroimaging evidence for positive treatment outcomes can also be quantified using neuroimaging tools. the use of fmri and an automatic classifier can help predict language recovery outcomes in stroke patients with 86% accuracy when coupled with age and language test scores. the stimuli tested were sentences both correct and incorrect and the subject had to press a button whenever the sentence was incorrect. the fmri data collected focused on responses in regions of interest identified by healthy subjects. recovery from aphasia can also be quantified using diffusion tensor imaging. the accurate fasciculus (af) connects the right and left superior temporal lobe, premotor regions/posterior inferior frontal gyrus. and the primary motor cortex. in a study which enrolled patients in a speech therapy program, an increase in af fibers and volume was found in patients after 6-weeks in the program which correlated with long-term improvement in those patients. the results of the experiment are pictured in figure 2. this implies that dti can be used to quantify the improvement in patients after speech and language treatment programs are applied. conclusion neuroimaging tools serve as a useful method for determining disorder progression, quantification of cortical damage, aphasia subtype, treatment effectiveness, and differentiating diagnosis with correlated disorders. utilization of neuroimaging tools is necessary for the progression of knowledge of aphasia and its subtypes. further research research is currently being done using functional magnetic resonance imaging (fmri) to witness the difference in how language is processed in normal brains vs aphasic brains. this will help researchers to understand exactly what the brain must go through in order to recover from traumatic brain injury (tbi) and how different areas of the brain respond after such an injury. another intriguing approach being tested is that of drug therapy. research is in progress that will hopefully uncover whether or not certain drugs might be used in addition to speech-language therapy in order to facilitate recovery of proper language function. it's possible that the best treatment for aphasia might involve combining drug treatment with therapy, instead of relying on one over the other. one other method being researched as a potential therapeutic combination with speech-language therapy is brain stimulation. one particular method, transcranial magnetic stimulation (tms), alters brain activity in whatever area it happens to stimulate, which has recently led scientists to wonder if this shift in brain function caused by tms might help people re-learn languages. the research being put into aphasia has only just begun. researchers appear to have multiple ideas on how aphasia could be more effectively treated in the future.