Posts Tagged ‘ACC’

VENs: the Key to Consciousness?

July 28, 2012

VENs stands for Von Economo Neurons. Constantin von Economo was the neuroscientist who discovered these neurons.1 VENs are quite distinctive in appearance. They are at least 50 per cent and sometimes up to 200 percent larger that typical neurons. They have a long spindly cell body with a single projection at each end and very few branches. They are quite rare. They make up just about one per cent of the neurons in two small areas of the brain: the anterior cingulate cortex (ACC) and the fronto-insular (FI) cortex. The ACC and FI are heavily involved in many of the more advanced aspects of cognition and feeling. They make up a social monitoring network that keeps track of social cues so that we can react appropriately.

The ACC and FI keep a subconscious tally of what is going on around us and direct attention to the most important events as well as monitoring sensations from the body to detect any changes. Both these brain regions are active when we recognize our reflection in a mirror. This suggests that these parts of the brain underlie our sense of self. It is a key component of consciousness providing a sense of self identify and a sense of the identity of others. They provide the sense of how we feel.

The notion is that VENs provide a fast relay system, a kind of social superhighway that allows the gist of a situation to move quickly through the brain, enabling us to react intuitively. This is a crucial survival skill in social species such as our own. VENs are also found in social mammals.

People with fronto-temporal dementia lose large numbers of VENs in the ACC and FI early in the disease. The main symptom of the diseases is a complete loss of social awareness, empathy, and self-control.

According to one study2 people with autism fall into two groups. One group consists of those who have too few VENs, so they might not have the necessary wiring to process social cues. The other group consists of those who have far too many VENs. Having too many VENS might make emotional systems fire intensely, causing people with autism to feel overwhelmed.

Another study3 found that people with schizophrenia who committed suicide had significantly more VENs in their ACC than schizophrenics who died of other causes, The notion is that the over-abundance of VENs might create an overactive emotional system that leaves them prone to negative self-assessment and feelings of guilt and hopelessness.

Bud Craig, a neuroanatomist at Barrow Neurological Institute has pointed out that the bigger the brain, the more energy it takes to run, so it is crucial that it operates as efficiently as possible. He said, “Evolution produced an energy calculation system that incorporated not just the sensory inputs from the brain. And the fact that we are constantly updating this picture of “how I feel now” has an interesting and very useful by-product: we have a concept that there is an “I” to do the feeling. Evolution produced a very efficient moment-by-moment calculation of energy utilization that had an epiphenomenon, a by-product that provided a subjective representation of my feelings.”4

The author of the New Scientist article concludes “If he’s right—and there is a long way to go before we can be sure—it raises a very humbling possibility: that far from being the pinnacle of brain evolution, consciousness might been a big, and very successful accident.”5

Although I am excited by the possibility that the neurological basis of consciousness has been found, I am disturbed by their reductionist conclusions. Most of us assume that there is a neural basis for consciousness. But the finding of this neural basis does not prove that consciousness is an epiphenomenon (not real). The next post will provide evidence regard the reality and purpose of consciousness.

1Williams, C. (2012). The Conscious Connection. New Scientist, 21 July, 33-35.

3PloS One, vol 6, pe20936).

4Op cit.p. 35


© Douglas Griffith and, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and with appropriate and specific direction to the original content.