Exam Format:Multiple-choice exam. 1st of 3 exams about 35 questions. Grades are not curved, but questions are dropped from the exam that have poor performance.Brief Introduction to Assignment 2:Writing will be similar to the paper we are turning in today, but the work for this assignment is different. If we drink alcohol, use any other drugs, other than medications that are prescribed to us, we are assigned to engage in a weekend of abstinence with no substance use.Tip: Insight and self-evaluation must be demonstrated in the write-up.Weekend of abstinence:Choose weekend with a social event planned that might involve substance use.Do not pick a weekend where substance use is unlikely.If people ask why you are not drinking/smoking/etc., the only explanation you should offer is “I don’t want anything, thanks.”Do not tell others you are not using as part of a class assignment.If you could not remain abstinent, your grade will not be affected.Not looking for “oh great weekend, I’m never going to use again…”Think about if you couldn’t remain abstinent, and talk about why.There are four weekends left in which we can remain abstinent before the assignment is due.Topics:Evolutionary perspective of what drives us at human beings, tie that into why we use substances and why we can become addicted.Reward/control pathway which maintains addictionAddiction susceptibility: genetic and environmental risk. Why some people can use substances all there live without developing problems, while some do. What are differences that contribute to addiction?Goals:Understand neurological basis for addiction and how it relates to evolutionUnderstand environment and genetics as risk and protective factors for addictionEvolutionary Perspective:The complexity of the “old brain” increased and a “new brain” that could reason developed over timeOld brainSurvival: cravings for food, sex sleep, etc.“Fight or flight”New brainExecutive functions, reason, creativity, etc.Applies these capacities to meet survival needs in ways that avoid getting us killedWhen survival is in play (e.g. sex, danger, stress), the old brain can override the newExtra notes:We have needed something to drive us. Something to tell us to hunt while we are hungry. Something to tell us to have sex, to procreate, to continue our lineage and advance as humans.Theory about back in those days: before Facebook and excel.. We had the old brain or a more simple brain.Old brain: time to eat, time to sleep, now time to do that. Basic needs to survival. The threats were different back then, tigers trying to kill us. Or people who wanted to steal our food.“Fight or flight”. Part of brain tells us whether to leave or stay or try to escape the situation. Now a days way more complex…We are able to do more things. New features or capabilities of what we can do as humans are contained in the new brain.Memories, complex skills, all in new brain.We still have old brain, new brain is developed more recently. Still drives tell us when to eat and sleep, but new brain helps us do these things that in a way that don’t get us killed, in a way that don’t interfere with functioning, etc. New brain helps tame the old brain.Those are 2 different aspects of the brain.What is important: When we have a need or survival issue at play like need for sleep or need for sex or food or eating, than the old brain has a tendency to override the new brain.We are not as able to preform those executive functions as well, old brain is faulting with the new brain.Proportion of old brain to new brain:Larger old brain than new brain in a fish, less evolved animal.We have a big new brain. This is more recent, and the new brain covers part of the old brain.Reward/Reinforcement Pathway:The “GO!” circuitry is a network of interconnected structures that promote survival (old brain)Includes a powerful system of reward and reinforcement, also called the mesolimbic dopaminergic reward pathwayThe prefrontal cortex (new brain) includes the “STOP!” systemWe can now look at brain activity, but using techniques to look at blood consumption in the brain. Which parts of brain are activated at different times. We can look at systems while they are working.Scientific support for some of these theories.We have a go system which relates to the old brain. Stop system relates to the new brain.Go system tells us we need something, this gives us a go to survive. It tells us go or use. We can think of go system that is telling us when to preform functions for survival. When we become addicted to substances that same system is telling us to use. Mostly it is in the back part of our brain. Inside of it is a system that is refereed to as the reward pathway.When you preform function that is necessary for survival, brain rewards us and it releases dopamine. Which sends pleasure signals to us. We get this reward, brain says oh that is good. Now that survival function is associated with a good feeling. So we are rewarded for surviving. We have incentive to repeat the same function. This is basic behavioral theory.So the go system mostly old brain.Stop system is mostly in the new brain or the prefrontal cortex.GO! and STOP! Systems map on to Old and New brain:GO!Triggers dopamine releaseStronger/more quickly repeated signals signify importanceReward things necessary for survivalWhen perform it will release dopamine, previously rewarded for preforming that action. Go system triggers the dopamine release. So brain signals when they are generated they are typically in strength, or how fast the brain is signaling and also you can measure how much signaling is going on. There is a lot of signaling going in to this part of the brain when survival function going on…STOP!Shuts down go system with situation is rectified or need it metStop releasing dopamineStop function: saying okay go system we have function, we need to stop. Without this, we would keep on preforming these actions that are necessary for survival. The stop system stops the release of dopamine.Brief Video on how these Go and Stop systems relate to addiction…For a person who does not suffer from an addition the GO! And STOP! Systems are interconnected at all times. (they are talking to each other)When someone develops an addiction, the go system “runs off on its own” and does not interact in a regulated way with the stop system.More on Reward/Reinforcement PathwayThe reward system is the part of the CNS most