PSYC: Biopsych

Evolutionary history; 3 stages of brain evolution

• Reptilian

  • Brainstem, cerebellum

  • Basic life requirements: breathing, temp regulation, motor processes

  • Reactive & reflexive → avoid hazard

• Mammalian or paleomammalian

  • Limbic system

  • “Common denominator” of all animals

  • Maternal care; audio-vocal communication, play

    • Audio-vocal communication maintains maternal-offspring contact

    • Most mammal infants voice a separation cry if separated from their mothers

  • Memory, emotion, social behavior → approach social rewards

• Human or neomammalian

  • Massive cerebral cortex

  • More influenced by socio-cultural processes

  • Abstract thought, language, cooperative planning, empathy → higher order thinking

    • E.g. calculus, government institutions

    • Species with larger brains play & explore more (more approach behaviors)

• [ * ] How does the order of the development of the brain impact our thoughts & behaviors today?

  • Instincts that don’t serve much purpose in a modern environment that remain

The stress response

• Amygdala “sounds alarm” → hypothalamus controls → sympathetic (and therefore autonomic) nervous system → adrenal glands release epinephrine & cortisol

• Many negative consequences for prolonged stress

  • Persistent epinephrine can damage blood vessels & arteries → high blood pressure

  • High cortisol levels → increased build up of fat tissue

  • [ * ] The body is adaptive; if there are negative consequences to stress, why do we feel stress?

    • Stress is required to prompt action; in the past was a tool to help us survive

• Fight or flight: heightens our attention to threat

  • Epinephrine improves breathing, stimulate the heart, & raise a dropping blood pressure

  • Cortisol helps control blood sugar levels, regulate metabolism, help reduce inflammation, & assist with memory formulation

  • [ * ] Freeze or fawn

    • Alternate responses

      • Freeze = no response, “frozen in fear”

      • Fawn = typically seen in confrontational situations such as satisfying a robber by giving them your money

Neuropsych

• Neuropsychologist: someone that emphasizes understanding the relationship between the physical brain & behavior

  • First came to be in 1930s

    • Compare; medical textbooks date back to 400-1500 BC

  • Clinical neuropsychologist: injuries & illnesses in brain impact behaviors

• Anatomy & physiology

  • Basic function

    • Neurotransmitters released (epinephrine, cortisol, serotonin) if electrical charge is strong enough (threshold = action potential) → transported to dendrite of next neuron across synapse

    • Sensory (afferent) neurons: carry neural impulses from sensory receptors to CNS

    • Motor (efferent) neurons: carry neural impulses from CNS to muscles to cause movement

    • Interneurons: located in CNS; between sensory & motor neurons

      • Considered “middle man”; help transmit signals back & forth

  • fMRIs

    • When neurons activate, there is change in blood flow; this change is mapped onto brain to see which parts of the brain are activated

    • Observe and compare

Addiction & the brain

• About dopamine…

• Commonly associated with addiction…but chemicals are present in a variety neurological & behavioral processes → don’t mean only one thing

  • Misuse of the term “addiction”

  • “Moral panic”; is tech addictive? Are video games/social media addictive?

• Neurological perspective

  • Dopamine about learning that rewards feel good → perform actions that led to them again

    • Basically, anything fun = release of dopamine

    • [ ! ] Some illicit drugs (e.g. methamphetamine) cause massive releases of dopamine

      • Immense overstimulation of brain’s motivation centers fosters psychological addiction

  • → Dopamine activation does not equal addiction

• E.g. video game addictions

  • Many factors (social, psychological, health, family, game factors)

Interpreting outcomes

• “Bad >> good”

  • Feel fear & helplessness stronger than excitement or joy

  • Bad info carries more weight than good info

• Loss aversion

  • Examples in economic context

    • E.g. investing solely in safe products with little to no interest as as time passes inflation reduces/eliminates your purchasing power

    • E.g. not selling stock below the price you paid because you don’t want to take a loss

    • E.g. selling a stock because it is greater than the price you paid just to lock in the profits

  • Social experience doesn’t change this

    • E.g professional traders from the Chicago Board of Trade (CBOT) exhibit even more loss aversion that non-professional student subjects

  • Risk aversion: general desire to minimize uncertainty

    • Based on expected outcomes

    • [ * ] However, people are more likely to be okay with taking a risk if it gives them an opportunity to avoid a loss

    • [ * ] If there’s a known outcome, most with rather go with that compared to the unknown but likely better outcome