Untwisting amusia What behavior, brain waves and genetic underpinnings reveal about perception in congenital amusia

Congenital amusia is an innate disorder that negatively affects pitch and rhythm perception. For a long time, amusia was seen as a music-specific disorder but it has been shown that speech perception is also affected by it. This disorder is not caused by hearing loss, brain damage or an insufficient exposure to music in childhood and about 1.5% to 4% of the general population are said to be affected. Furthermore, it is assumed that amusia has a hereditary component.
This thesis uses various experimental methods to explore how different areas of perception are affected by congenital amusia.
First, the diagnosis of amusia is investigated in chapter 2 via a large-scale behavioral study that compares data that were collected online and in the laboratory. In chapters 3 and 4 speech perception is investigated: In chapter 3 vowel perception is investigated by means of a behavioral and an electroencephalography study. In chapter 4 word stress perception is investigated by the same means. In chapter 5 a dizygotic twin pair, of whom one twin is amusic and the other is not, is assessed. We conducted a large battery of tests assessing the performance of the twins in music, pitch perception and memory, language perception and spatial processing.
All in all, the goal of this thesis was to untangle certain aspects of auditory perception in congenital amusia by investigating its cognitive, neural and genetic underpinnings. While some questions have received answers, many new questions arose.