While it has been suggested that music is processed by music-specific neural networks in the brain, this view has been broadened to show that music processing also encompasses generic cognitive functions, such as memory, attention, and executive processes. A study was published in 2009 which investigated the neural and cognitive mechanisms that underlie acquired amusia and contribute to its recovery. The study was performed on 53 stroke patients with a left or right hemisphere middle cerebral artery (MCA) infarction one week, three months, and six months after the stroke occurred. Amusic subjects were identified one week following their stroke, and over the course of the study, amusics and non-amusics were compared in both brain lesion location and their performances on neuropsychological tests.Results showed that there was no significant difference in the distribution of left and right hemisphere lesions between amusic and non-amusic groups, but that the amusic group had a significantly higher number of lesions to the frontal lobe and auditory cortex. Temporal lobe lesions were also observed in patients with amusia. Amusia is a common occurrence following an ischemic MCA stroke, as evidenced by the 60% of patients who were found to be amusic at the one-week post-stroke stage. While significant recovery takes place over time, amusia can persist for long periods of time. Test results suggest that acquired amusia and its recovery in the post-stroke stage are associated with a variety of cognitive functions, particularly attention, executive functioning and working memory. Neuroanatomy
Neurologically intact individuals appear to be born musical.
Cortical thickness and reduced white matter – in a recent study, voxel-based morphometry, an imaging technique used to explore structural differences in the brain, revealed a decrease in white matter concentration in the right inferior frontal gyrus of amusic individuals as compared to controls. Lack of extensive exposure to music could be a contributing factor to this white matter reduction. For example, amusic individuals may be less inclined to listen to music than others, which could ultimately cause reduced myelination of connections to the frontal areas of the brain. Involvement of the parahippocampal gyrus (responsible for the emotional reaction to music)

Treatment
Currently, no forms of treatment have proven effective in treating amusia. One study has shown tone differentiation techniques to have some success; however, future research on treatment of this disorder will be necessary to verify this technique as an appropriate treatment. History
In 1825, F. Gall mentioned a "musical organ" in a specific region of the human brain that could be spared or disrupted after a traumatic event resulting in brain damage. In 1865, Jean-Baptiste Bouillaud described the first series of cases that involved the loss of music abilities that were due to brain injury. In 1878, Grant Allen was the first to describe in the medical literature what would later be termed congenital amusia, calling it "note-deafness". Later, during the late nineteenth century, several influential neurologists studied language in an attempt to construct a theory of cognition. While not studied as thoroughly as language, music and visual processing were also studied.