The fMRI signal, slow cortical potential and consciousness

Trends Cogn Sci. 2009 Jul;13(7):302-9. doi: 10.1016/j.tics.2009.04.004. Epub 2009 Jun 15.


As functional magnetic resonance imaging (fMRI) has become a driving force in cognitive neuroscience, it is crucial to understand the neural basis of the fMRI signal. Here, we discuss a novel neurophysiological correlate of the fMRI signal, the slow cortical potential (SCP), which also seems to modulate the power of higher-frequency activity, the more established neurophysiological correlate of the fMRI signal. We further propose a hypothesis for the involvement of the SCP in the emergence of consciousness, and review existing data that lend support to our proposal. This hypothesis, unlike several previous theories of consciousness, is firmly rooted in physiology and as such is entirely amenable to empirical testing.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Brain Mapping
  • Cerebral Cortex / blood supply*
  • Cerebral Cortex / physiology*
  • Consciousness / physiology*
  • Electroencephalography / methods
  • Evoked Potentials / physiology*
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Magnetic Resonance Imaging* / methods
  • Models, Neurological
  • Oxygen / blood


  • Oxygen