PSYC 340 1st Edition Lecture 21Outline of Last LectureWhat you missed last class (04.14.15)I. Discriminative stimuli (SD) A. Tells you whether or not response outcome relationship is in effect B. Introduces opportunity for additional forms of learning 1. Setting the occasion to respond 2. Pavlovian conditioning a. Ex: stimulus can be associated with outcome: b. By introducing SD, introduce the animal may learn Pavolvian relationship where tone signals the outcome C. Avoidance paradigm 1. Tone  shock a. If an animal respond during a tone, it can turn off tone and turn off shock (avoidance-learning) b. S-S relationship (Pavolvian relation) as a result of Pavlovian relation, they’re not going to like tone; tone will elicit conditioned emotional response (negative affective state; fear) c. Versus previous example: tone will elicit emotional response but it’s something that it likes; positive affective state II. Two-Factor Theory A. The underlying mechanisms 1. Pavlovian conditioning of a drive/motivation system 2. Instrumental reinforcement by a change in conditioned drive state 1. First factor is Pavlovian conditioned emotional response/feeling; second factor involves instrumental factor/learning that drives a. What turns off shock is reinforced B. Examples of conditioned emotional states: 1. Phobic behavior2. Evidence conditioning can occur without awareness3. Notion at work 4. Acting like emotional magnet, your instrumental behavior solves emotional problem; working towards things you like and get away from things you don’t like.C. Application to Avoidance Behavior 1. Murphy Zajone2. A potential paradox3. Instrumental behavior tries to maximize those things that elicit positive emotional stateThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.4. Two factor theory gets us out of paradoxa. According to two factor theory, Sole reason animal responds is that it will terminate fear-eliciting signalA. Two factor theory of avoidance learning1. Conditioning of fear to the signal2. Subject learns to escape from the fear-eliciting stimulus3. A novel test (Kamin)A. A more detailed Pavlovian analysis1. Stimulus associated with making the R may act as a conditioned inhibitor2. Phobic Behaviora. Avoidance response is preventing exposure to fear eliciting signal;don’t have to face things eliciting fear response because they’re avoiding itII. Clinical implicationsA. Flooding1. Have o slowly desensitize them without flooding; do it in way they can’t use their avoidance responseB. Extinction of conditioned fear with and without medication (Barlow)1. Behavioral therapy alone2. Behavioral therapy + drug therapy3. Drug therapy alone4. If you look at immediate treatment of all three everything was workinga. When you came back 6 months later, behavior therapy alone had lasting affect; drug alone there was nothing, drug is temporary fix; behavior therapy and rugs therapy too showed no lasting effect, getting drug eliminated treatment of behavior therapyCurrent LectureNeural Basis of Drug Addiction I. Drugs and Reward Learning A. Modes of drug action 1. Drugs usurp control neurobiological mechanisms that facilitate reward learning a. Understanding reward learning  understanding drug addiction 2. Typically impact neurotransmitters a. Methamphetamine emulates this neurotransmitter (dopamine) i. Dopamine agonist b. Cocaine – impedes reuptake of dopamine i. Allows the dopamine to remain active in the synapse longer c. Heroin, morphine – opiate receptor agonist d. Nicotine – asteocoline (sp?) receptorse. GABA – inhibitory transmitter (keeps brain calm)i. Alcohol impact GABAB. Sites of action 1. Nucleus accumbens (NA) a. It’s a reward center – made to help you learn: i. “This is where you can get yummy cheesecake” but also ii. “This is where you can get DRUGS”2. Glutamate input (cortex) 3. Dopamine input (ventral tegmental area [VTA]) a. Projects up from the midbrain to the NAb. Like a teaching signal – it’s like the midbrain saying “you should really like this stuff!” c. Dopamine afferents from the VTA go through the NA and attach tothe dendrites; NA also gets cortical afferents from the cortex (immediate cues from your environment)d. VTA is going to say, “something really good just happened! Code that sensory stimulus from the Cortical afferents) e. When is the VTA activated? B. Dopamine activity within the VTA (Schultz) 1. Reward prediction error a. Activity in the VTA is predicted by a Rescorla-Wagner-like rule i. When something unexpected (and good) happens 2. Schultz shows us with his experiments that this is true a. Measured neural activity of dopamine in the VTAb. More activity following an unexpected reward c. Reward predicted (by a signal) – more neural activity following thesignal CS after learning that CS = R i. US (reward) no longer produces an increase in neural activity d. Negative prediction – predict the reward, but there is no rewardi. Hole/dip in neural activity where the R should be, but there is an increase in neural activity where the CS is ii. R-W would say that this is would form inhibition 3. Dopamine response = reward occurred – reward predicted a. Really just like the R-W: (lambda-Vt) C. Drugs of abuse artificially drive dopamine activity 1. Act like Trojan horses a. Light up neural activity in NA artificially i. Brain things, “Wow! Something really reward must have just occurred.” - But the reward is not really that good - Drugs are bad, kids. b. Substitute for the natural reward; makes you want the drug i. Cues are now going to drive the drug-seeking behavior 2. Difference between how these drugs make us feel and how we are addicted to itProblems of relapse I. Opponent process theory and drug addiction A. Remember talking about caffeine and stuff for the first test? Yeah, that. 1. Keep talking more so a can counteract bigger B B. Evidence (Stewart) 1. Made rats barpress for opiates [morphine] a. Barpress = morphine; got to like morphine; barpressed for asmuch morphine as possible2. Then, put them on extinction a. Barpress = no morphine b. Responding starts to go down (naturally) 3. What would happen to the OPT if we gave them a bit of naloxone (opiateantagonist) or morphine during extinction a. Naloxone is going to make you feel worse – block all that