Prefrontal cortex

Can a study exclude the limbic system and adequately find how we process value?

gettingwell4 < 0 Detracted from science, Beliefs, Cerebrum, Limbic system, Lower brain ,

This 2014 human study was notable for defining away the limbic system and lower brain from consideration in processing positive and negative stimuli for value.

However, the researchers didn’t fully reveal their biases until the last paragraph of the supplementary material, where they were obligated to comment on a previous study that included the limbic system. Good for the reviewer if that was how the researchers became obligated to deal with the previous study.

It isn’t difficult to include the limbic system in studies of value. For example, the Teenagers value rewards more and are more sensitive to punishments than are adults study found:

  • Cerebral areas increased activity when the expected value of the reward increased.
  • Limbic system areas increased activity when the expected value of the reward decreased.

http://www.pnas.org/content/111/13/5000.full “Disentangling neural representations of value and salience in the human brain”

Why do researchers title their study the cortex vs. the limbic system or lower brain?

gettingwell4 2-3 stars Required further work, Brain development, Brainstem, Cerebrum, Limbic system, Lower brain, Stress ,

This 2012 review of 89 studies was ostensibly of the prefrontal cortex. The review title showed how researchers characterize their work as studying the cerebrum, even when they primarily deal with the limbic system and lower brains.

For example, the reviewer discussed rodent studies of the developing pup fetus regarding:

  • Sensory/motor – Paternal complex housing, maternal complex housing
  • Stress – Mild stress, bystander stress, moderate stress
  • Psychoactive drugs – Stimulants
  • Adult stimulants – Ethanol

The active brain areas of the rodent fetus are the brainstem and the limbic system, and those areas were primarily what was studied. The cerebrum of the developing pup is a tiny strip that has little cognitive function.

http://www.pnas.org/content/109/Supplement_2/17186.full “Experience and the developing prefrontal cortex”