been stated by some researchers that the recruitment and recovery of neurons in the left hemisphere opposed to the recruitment of similar neurons in the right hemisphere is superior for long-term recovery and continued rehabilitation. it is thought that, because the right hemisphere is not intended for full language function, using the right hemisphere as a mechanism of recovery is effectively a "dead-end" and can lead only to partial recovery. there is evidence to support that, among all types of therapies, one of the most important factors and best predictors for a successful outcome is the intensity of the therapy. by comparing the length and intensity of various methods of therapies, it was proven that intensity is a better predictor of recovery than the method of therapy used. prognosis in most individuals with expressive aphasia, the majority of recovery is seen within the first year following a stroke or injury. the majority of this improvement is seen in the first four weeks in therapy following a stroke and slows thereafter. however, this timeline will vary depending upon the type of stroke experienced by the patient. patients who experienced an ischemic stroke may recover in the days and weeks following the stroke, and then experience a plateau and gradual slowing of recovery. on the contrary, patients who experienced a hemorrhagic stroke experience a slower recovery in the first 4–8 weeks, followed by a faster recovery which eventually stabilizes. numerous factors impact the recovery process and outcomes. site and extent of lesion greatly impacts recovery. other factors that may affect prognosis are age, education, gender, and motivation. occupation, handedness, personality, and emotional state may also be associated with recovery outcomes. studies have also found that prognosis of expressive aphasia correlates strongly with the initial severity of impairment. however, it has been seen that continued recovery is possible years after a stroke with effective treatment. timing and intensity of treatment is another factor that impacts outcomes. research suggests that even in later stages of recovery, intervention is effective at improving function, as well as, preventing loss of function. unlike receptive aphasia, patients with expressive aphasia are aware of their errors in language production. this may further motivate a person with expressive aphasia to progress in treatment, which would affect treatment outcomes. on the other hand, awareness of impairment may lead to higher levels of frustration, depression, anxiety, or social withdrawal, which have been proven to negatively affect a person's chance of recovery. history expressive aphasia was first identified by the french neurologist paul broca. by examining the brains of deceased individuals having acquired expressive aphasia in life, he concluded that language ability is localized in the ventroposterior region of the frontal lobe. one of the most important aspects of paul broca's discovery was the observation that the loss of proper speech in expressive aphasia is due to the brain's loss of ability to produce language, as opposed to the mouth's loss of ability to produce words. the discoveries of paul broca were made during the same period of time as the german neurologist carl wernicke, who was also studying brains of aphasiacs post-mortem and identified the region now known as wernicke's area. discoveries of both men contributed to the concept of localization, which states that specific brain functions are all localized to a specific area of the brain. while both men made significant contributions to the field of aphasia, it was carl wernicke who realized the difference between patients with aphasia that could not produce language and those that could not comprehend language (the essential difference between expressive and receptive aphasia).