So how exactly does the limbic brain ‘take over’ or ‘hijack’ the cortex? As you can see in Fig. 1. there are three distinct brain areas that make up the reward circuit and influence addictive behavior. These are;
- The Ventral tegmental area (VTA)
- The Nucleus Accumbens (NA)
- The Prefrontal cortex (PFC)
Fig 1. The brain’s dopamine pathway (or reward circuit)
The reward circuit begins in the VTA which manufactures a neurotransmitter called dopamine.3 Dopamine gets released from the VTA whenever we anticipate or actually experience something useful for our survival. So whenever we are in the presence of a reward like food or sex, lots of dopamine gets fired off from the VTA and works its way up to the Nucleus accumbens. Whenever a big shot of dopamine hits your Nucleus accumbens you will experience a feeling of reward, like something important is happening that you should take notice of. Dopamine evolved for this reason. It helps us to notice rewards and then move towards them. Without it we wouldn’t notice anything that was necessary for our survival and we would die.