INDEPENDENT COMPONENT ANALYSIS OF AUDITORY FMRI RESPONSES
Fabrizio Esposito, Elia Formisano, Erich Seifritz, Raffaele Elefante, Rainer Goebel, Francesco Di Salle · 2003
The basic principles used by the auditory cortex to decipher the sensory streams are less understood than those used by the visual cortex. Based on previous research on animals, functional Magnetic Resonance Imaging (fMRI) responses in the human auditory cortex to simple streams of colored acoustic noise are expected to follow both linear (sustained) and non-linear (transient) spatio-temporal patterns. Analysis employed in previous fMRI studies only allows the detection of linear responses. Here we present a data analysis strategy, that allows the detection and separation of both linear and non-linear responses. This strategy is based on the hierarchical combination of two “transposed” variants of the independent component analysis (ICA), operating in the space and in the time domain.