Right-Hemispheric Disinhibition as a Neural Basis of Acquired Savantism and Foreign Accent Syndrome

A fundamental feature of the human brain is the substantial inhibition it normally experiences from different sources. One of the most important of these is callosal inhibition, most prominently manifested in the inhibition of the right hemisphere by the left one. Such inhibition may be especially prevalent during the preparation and execution of speech and other motor behavior, which preferentially activate the dopamine-rich left hemisphere of most humans. Release from left-hemispheric inhibition due to damage to the left hemisphere has been shown to lead to compensation by the right-hemisphere in speech, but paradoxical facilitation of the right hemisphere may also occur in many other instances. This review will discuss the basis for the left-hemispheric inhibition and show how disinhibition of the right hemisphere may underlie the emergence of previously latent prosodic and artistic/creative skills in two rare and enigmatic brain syndromes—acquired savantism and foreign accent syndrome.

Keywords:Foreign accent; Savantism; Acquired; Lateralization; Inhibition