The work carried out in this doctoral thesis investigated the representation of
statistical sound properties in human auditory cortex. It addressed four key aspects in
auditory neuroscience: the representation of different analysis time windows in
auditory cortex; mechanisms for the analysis and segregation of auditory objects;
information-theoretic constraints on pitch sequence processing; and the analysis of
local and global pitch patterns. The majority of the studies employed a parametric
design in which the statistical properties of a single acoustic parameter were altered
along a continuum, while keeping other sound properties fixed.
The thesis is divided into four parts. Part I (Chapter 1) examines principles of
anatomical and functional organisation that constrain the problems addressed. Part II
(Chapter 2) introduces approaches to digital stimulus design, principles of functional
magnetic resonance imaging (fMRI), and the analysis of fMRI data. Part III (Chapters
3-6) reports five experimental studies. Study 1 controlled the spectrotemporal
correlation in complex acoustic spectra and showed that activity in auditory
association cortex increases as a function of spectrotemporal correlation. Study 2
demonstrated a functional hierarchy of the representation of auditory object
boundaries and object salience. Studies 3 and 4 investigated cortical mechanisms for
encoding entropy in pitch sequences and showed that the planum temporale acts as a
computational hub, requiring more computational resources for sequences with high
entropy than for those with high redundancy. Study 5 provided evidence for a
hierarchical organisation of local and global pitch pattern processing in neurologically
normal participants. Finally, Part IV (Chapter 7) concludes with a general discussion
of the results and future perspectives