Visual target modulation of functional connectivity networks revealed by self-organizing group ICA

Hum Brain Mapp. 2008 Dec;29(12):1450-61. doi: 10.1002/hbm.20479.


We applied a data-driven analysis based on self-organizing group independent component analysis (sogICA) to fMRI data from a three-stimulus visual oddball task. SogICA is particularly suited to the investigation of the underlying functional connectivity and does not rely on a predefined model of the experiment, which overcomes some of the limitations of hypothesis-driven analysis. Unlike most previous applications of ICA in functional imaging, our approach allows the analysis of the data at the group level, which is of particular interest in high order cognitive studies. SogICA is based on the hierarchical clustering of spatially similar independent components, derived from single subject decompositions. We identified four main clusters of components, centered on the posterior cingulate, bilateral insula, bilateral prefrontal cortex, and right posterior parietal and prefrontal cortex, consistently across all participants. Post hoc comparison of time courses revealed that insula, prefrontal cortex and right fronto-parietal components showed higher activity for targets than for distractors. Activation for distractors was higher in the posterior cingulate cortex, where deactivation was observed for targets. While our results conform to previous neuroimaging studies, they also complement conventional results by showing functional connectivity networks with unique contributions to the task that were consistent across subjects. SogICA can thus be used to probe functional networks of active cognitive tasks at the group-level and can provide additional insights to generate new hypotheses for further study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping / methods*
  • Cerebral Cortex / anatomy & histology
  • Cerebral Cortex / physiology*
  • Cognition / physiology*
  • Female
  • Gyrus Cinguli / anatomy & histology
  • Gyrus Cinguli / physiology
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging / methods*
  • Male
  • Nerve Net / anatomy & histology
  • Nerve Net / physiology*
  • Neural Pathways / anatomy & histology
  • Neural Pathways / physiology
  • Neuropsychological Tests
  • Parietal Lobe / anatomy & histology
  • Parietal Lobe / physiology
  • Photic Stimulation
  • Prefrontal Cortex / anatomy & histology
  • Prefrontal Cortex / physiology
  • Psychomotor Performance / physiology*
  • Young Adult