Why do we want Why do we get

Why do we “want”? Why do we get “addicted”? PSYCHOLOGY 320

First… Putting this in perspective What have we done thus far? What IS motivation? What does that mean? What kinds of things motivate behavior? How does the brain work? How did the lives and experiences of our forefathers influence our behavior? (i. e. Evolution/”Nature”) How does learning work? How we “associate” things in order to expect or predict outcome (i. e. Classical/Operant Conditioning/”Nurture”) How do “bad things” motivate us? (i. e. Negative Affect) How does “stress” motivate us? (And how is it connected to the same systems driven by “bad things”? ) How do “good things” motivate us? (i. e. Positive Affect) Peer Review

First… Putting this in perspective What have we asked thus far? How do internal/involuntary things motivate us? Hunger Thirst Sleep Arousal Sex To some degree: Development What are emotions and how do they drive us? Interoceptions Fear, Anxiety, and PTSD Anger, Aggression, Violence, and Murder and Psychopathy Sadness, Grief, Depression, and Suicide

First… Putting this in perspective Going forward What are emotions and how do they drive us? Want(ing), Like(ing), Addiction… Love, Bonding, Social Connection and Adhesion What is thought and how does it drive us? Why do we make mistakes? And why are people SO WRONG? ? ? !!! How does social life influence thought? What is society/culture and how does it drive us? What is religion and how does it drive us? What is _______ ? Just how much does “biology” drive us? Are we truly in control? What do we mean by “biology” anyway?

So… Want At this point, you should be able to tell me what system underlies “want” What is the name of the “pathway” What are some of the key brain regions What is the main neurotransmitter Are “want” and “reward” the same thing? Is “reward” and “reinforcement” the same thing? Not all reinforcements are rewards but all rewards are reinforcements

Why do we “want” things? Some thought questions for today… What kinds of things do we want? What makes us “want” them? Are “wanting” and “liking” the same thing? Do I always like things that I want? Do I always want things that I like? Are “wanting” and “needing” the same thing? How do we (generally) feel when we get what we want or need? How might evolution have influenced us to “want” and “like” things? Are rewards and reinforcements the same thing? How can studying addiction inform this topic? How does the brain drive wanting, liking, and the search for rewards?

So… Want/Reward/Reinforcement What brain circuit, region(s), and neurotransmitter drives reward?

Wants/Desires vs. Needs: a short aside Abraham Maslow’s theory of human motivation The Hierarchy of Needs

Wants/Desires vs. Needs a short aside Maslow argued that “wants” and “needs” were distinct Needs – survival Wants – desirable things but not necessary for survival

Wants/Desires vs. Needs a short aside Over the years… these lines have been blurred We often feel such an intense desire for things that do not ensure survival that we feel we need them Wants vs needs seem to be separated by subjectivity, or at best, semantics (and with semantics, comes culture and context) The fact that wants and needs are, to some degree, motivated by the same brain regions further complicates any rationale that they are, in fact, distinct. i. e. A shot of heroine induces a dopamine surge As does a breath of air or a bite of food (though not to the same degree) Another thing helping pull these together – when we get what we want or need, we often feel the same ways, “positive”. I. e. We have “positive affect”, or emotions with a “positive valence”

Positive Affect We talked before about Positive Affect and positive valence Pleasure, Euphoria Happiness, Joy Excitement Highly aroused happiness, pleasure, euphoria, etc Love, Infatuation We’ll get to that next week We also talked before about how these emotions/feelings are also driven by the mesolimbic pathway and nucleus accumbens (largely) Today, we’ll therefore move away from the emotional component of want and desire and focus on the neurobiology of the drive itself to continue the behavior

Addiction: a model of “want” What is addiction? Addictive Behaviors: compulsive actions that provide short term pleasure at the expense of more severe and long-term negative consequences. What types of things can we be addicted to? Most often, we talk about psychoactive drugs Why? This is an example of a xenobiotic that acts at the molecular level to alter behavior via the reward pathway This process most efficiently hijacks the otherwise adaptive system of the mesolimbic dopamine pathway which permits the organism to associate stimuli with outcomes linked with reward, reinforcement, and positive consequences.

Addiction Oversimplified graphic of dopamine in rewarding situations drawn on whiteboard Changes in “wanting” and “liking” over period of drug use drawn on whiteboard Sensitization and habituation drawn (again) on whiteboard Tolerance, Withdrawal, and Protein Changes drawn on whiteboard Up/down regulation redefined

Addiction: Changing the Brain proteins change over time as a result of behavior to, in effect, keep us at a balanced state – a “homeostatic”like state which is determined by our genes These regulatory changes can be overridden over longterm sustenance of this behavior, but never completely halted (generally speaking). Such changes in proteins coincide with the effects of the behavior itself (i. e. drug use) to induce neuroplasticity. Neuroplasticity: The brain’s potential to reorganize by creating new or altering existing pathways to adapt as needed. Can be “good” or “bad” I. e. – Grizzell et al. , 2014 Stress-induced plasticity Cotinine-induced plasticity Nicotine-induced plasticity

Addiction: Changing the Brain Some common forms of addiction-induced plasticity At the genetic level Epigenetics Genetic damage At the protein level Changes in dopamine receptor levels Changes in opioid receptor levels Changes in GABA receptor levels Changes in n. ACh. R levels And many others Changes in downstream protein factors

Addiction: Changing the Brain At the cellular level Changes synapse morphology Changes dendrite length Changes spine density Changes axon, soma, cell membrane At the simple network level Alters neurotransmitter release Changes nucleus accumbens Rewires and increases volume Including in cannabis use (Gilman et al. , 2014) Changes amygdala Rewires and increases volume Changes PFC, Hippocampus, and others

Addiction: Changing the Brain At the complex network level Alters PFC top-down control of behavior Alters amygdala-driven fear behavior Alters the reports of pleasure and reinforcement of a stimulus Recall our discussion on thirst and hunger… this is true following periods of deprivation – not just addiction Probably obvious and doesn’t need to be stated, but altogether, this alters the continuance of a behavior

Addiction as a model So what else can we derive from addiction As alluded to before in this class – many search for that “shortterm” euphoria to overcome prolonged or intense negative affect But not all drug use (or rather, not all of the reason for drug use) is for this short-term euphoric effect Negative reinforcement hypothesis Self-medication hypothesis Consider nicotine and the cotinine paper Another important thing to learn in all this is the power of associative conditioning Stimuli as predictors… Recovering addicts/alcoholics Physiological changes associated with cues but not the drug itself Yield positive and negative affect, depending on the stimulus

Addiction as a model: conclusion Not everything is the same… obviously Not all “drugs” are the same Not all “drug users” are the same But to see this system. . . This pathway. . . The way these things all interact in addiction. . . is to get a hyperbolic example of how “wants”, “needs”, “pleasure”, “fulfillment”, etc drive our behavior So long as you understand that this is a dynamic process meaning it is always changing, and not always identical in its complexity

Love and Pair Bonding We just cannot do love justice in this lecture… What is love? Why do we love? Why is it advantageous to love? Conceptually Evolutionarily Do other species “love”? Do other species form pair bonds? Do other species form monogamous pair bonds?

Love and Pair Bonding Prairie voles – the animal model of love Allowed us to better understand the roles of dopamine and oxytocin in pair bonding, romantic attraction, and what we call “love”. So what is love… biologically speaking?

Love: A chemical reaction First, let’s characterize love 3 types of “love” Lust Romantic Love Attachment Lust – drives mating Estrogen and testosterone Cortisol Infatuation/lust also coincides with decreased PFC activity

Love: A chemical reaction Romantic Love Monogamy Romantic love as a drug We’ll come back to this Attachment Long-term relationships Family Not always about “liking” Particularly driven by oxytocin and vasopressin Vasopressin is particularly important in male attachment

Love: A chemical reaction Good… but not great. . .

Love: A chemical reaction Helen Fisher f. MRI study – VTA and dopamine in romantic love Also has shown: Breakups are similar to addiction That is: when a reward is withheld, activity in the mesolimbic pathway drives that wanting behavior even more Adaptive in that it pushes you to seek out that rewarding consequence Nucleus accumbens core activity is increased when the “reward” of love is withheld following a breakup The “drives” of sex and romantic love Sex drive – you start the search Romantic love drive – you narrow it down

Love: A chemical reaction Love as a drug Helen Fisher: All the characteristics of addiction Love is a homeostatic imbalance Love is a “need”, an “urge”, a “drive” In love, you: Focus on the person Crave the person Obsess about them Distort your reality (recall the “illusion of knowledge” podcast and the reports of expected divorce in newlyweds) Willing to take risks to obtain this person The three main characteristics of addiction Tolerance – you constantly need more Withdrawals – you cannot be without them Relapse

Love: A chemical reaction Differences in the brain across love Love at first sight Devotion, prolonged love Largely dopamine driven Largely oxytocin driven Why do some people love instantly, frequently, etc. Simply put – individual differences in these reward regions and with the neurotransmission of: Dopamine Oxytocin Serotonin Vasopressin