Speech perception in amusia

Amusia is a disorder characterised by impaired pitch discrimination, which interferes with the perception of music and speech in laboratory conditions. However, people with amusia do not report problems with speech perception in everyday life. We hypothesise that amusics compensate for their deficit by focusing on durational information in speech, which provides cues to structural elements marked by pitch changes.

We will develop a behavioural and functional magnetic resonance imaging battery designed to test this compensatory hypothesis. Lexical stress perception, prosody perception, and speech-in-noise perception will be tested in three different conditions: with unaltered stimuli; with only pitch cues; and with only durational cues. We predict that people with amusia will be impaired only on the conditions containing only pitch cues. We further predict that the pattern of activation elicited when both pitch and duration cues are present will closely resemble the pattern when only durational cues are present, while pitch- and duration-tracking networks will be equally represented in control subjects.

The development of this testing paradigm would enable evaluation of pitch and duration processing during speech perception in a variety of populations.