What does "Neural Correlates of Consciousness" mean?

This idea comes from a perspective that consciousness arises with brain processes.  This goes against the philosophy of mind-body dualism, which attempts to explain the mind and body as separate somethings.


The neural correlates of consciousness are those neuronal mechanisms, processes, and activities that are correlated with certain conscious experiences, such as seeing a color or feeling an emotion.  According to this view, every phenomenal mental state has a corresponding brain state.


The brain is a complex and interconnected system, with many processes running in parallel.  So, when looking for correlations with consciousness, we look for the minimal amount of neuronal activity associated with various aspects of consciousness.  Gathering empirical data is crucial for study of this nature, because it does not rely on philosophical or theoretical arguments.


Today, there are incredible methods and techniques for gathering information about the brain (while the person is still alive!) that are quite recent developments.  These brain scanning techniques can observe a person's brain as they have thoughts and experiences. There are several major types of brain scanning techniques:

Computed Tomography (CT) uses X-Rays that pass through the brain and

form an image that is measured on the other side. 
Dense tissues appear darker than less-dense tissues.

Positron Emission Computed Tomography (PECT) is similar to CT, but radiolabeled compounds that can be tracked are first injected into the brain of the subject.  When X-Rays are passed through the brain, the labeled compounds can be identified and tracked.  This can show blood flow, metabolic activity, and other processes.

Magnetic Resonance Imaging (MRI) amplifies the activity of certain protons in the
 brain.  The resulting image is created by measuring the time it takes for the protons to return to their original state.  The strength of the image depends on the density of the material.










Functional Magnetic Resonance Imaging (fMRI) is similar to MRI, but is used to study brain activity while the brain undergoes specific processes or tasks.
 














Professor Christopher Koch's Glossary of Terms:  This is a useful glossary of terms relating to the study of the neural correlates of consciousness.

Next time, we will take a look at some actual brain processes that have been correlated with conscious experiences.