Brain network course patterns observed with fMRI during movie presentation

Objective: Previous functional magnetic resonance imaging (fMRI) studies mostly used abstracted paradigms to investigate different aspects of human brain function and pathological alterations of brain function in neuropsychiatric diseases. Though, the application of those particular tasks underlie several restrictions, subjects have to be compliant and without relevant cognitive impairment. Therefore, we decided to investigate human brain function in more natural conditions in subjects which freely viewed a film.

Material and Methods: We investigated N=6 healthy subjects (age 20–65 years), fMRI was acquired on a 3 Tesla Trio® Scanner (Siemens, Erlangen, Germany). The subjects freely viewed a 45min film of the Carmen Opera during fMRI acquisition. We selected the film Carmen because it includes particularly expressive scenes and music. In the initial analysis, spatiotemporal activity patterns in one brain were identified with independent component analysis (ICA). In the following intersubject correlation analysis, these patterns were used to model common brain activation, using first eigenvariate of temporal courses. Common time courses (first eigenvariates) were used as input regressors for the reanalysis of single subject fMRIs using standard SPM (statistical parametric mapping) first level procedure after which we made also second level analysis using SPM.

Fig.1

Results: ICA provided a number of brain network patterns activated during our paradigm. Common time courses from primary visual and acoustic activations induced activation in higher level cortical networks beyond primary sensory brain areas. Figure 1 shows an example of the difference between the single subject acoustical independent component (A) and a common acoustical timecourse activation (B) applied to the same subject.

Conclusion: The simple experimental design of this study gives us the possibility to include groups of subjects not compliant to follow abstract fMRI paradigms requiring also a higher level of concentration over a longer time. It may be particularly useful in the examination of children as well as in patients with specific neuropsychiatric diseases. It would be of special interest to find differences in functional connectivity between sensory and higher brain processing networks in such groups.