Feature Coding in Human Auditory Cortex
I am particularly interested in auditory processing given the importance of sound for early infant learning and language development, and the frequency of atypical sound sensivities and language delays in neurodevelopmental disorders and as a consequence of premature birth or perinatal brain injury.
I currently co-direct an NIH funded study investigating “Auditory precursors of language delay in toddlers with autism spectrum disorders” at the Brain Development Imaging Lab.
Auditory fMRI
Investigating auditory processing in the human brain remains a challenge due to the small size of auditory cortex, substantial individual differences in anatomy, and limitations of the methods for neural measurement. Which precise features are encoded in auditory cortex and how tuning changes depending on task demands is unclear even in the adult brain. New methods for functional magnetic resonance imaging (fMRI) provide solutions to these limitations. I have used acquisition sequences that make less noise, improving the suitability of fMRI for auditory research; real-time adaptive fMRI that allows to prove differences in activity patterns of a high number of different natural sounds, and multivariate pattern analysis methods that are robust to individual differences in anatomy and exploit information in distributed neural networks. This makes it possible to assess which acoustic and abstracted features of simple and natural sounds are represented in human auditory cortex during perception and cognitive tasks, such as change detection and imagery, and how this changes over the course of brain development in young infants.
MVPA similarity matrix of frequency coding in auditory cortex. Left: expected similarity. Right: neural similarity matrix. See Linke et al., 2011.
Functional Connectivity
In addition to using auditory stimulation paradigms, I also use resting state fMRI to study how functional connectivity changes in the first year of life as an infant's auditory system matures; and how disruptions of connectivity and the organization of the auditory brain network in infants and children with perinatal brain injury or neurodevelopmental disorders relate to language development and social-behavioral symptom severity.
Using cloud computing and software developed in our lab, we won the first Human Brain Mapping (HBM 2013) Hackathon Challenge with our project analysing functional connectivity, tractography and gene expression data from the Human Connectome Project and Allen Brain Atlas to parcellate auditory cortex!
