Brain, Mind, Behavior General Info, Case Studies, Class

What are the central nervous system (CNS) components?

The brain and spinal cord.

What does the peripheral nervous system (PNS) include?

All nerve cells in the body that are not part of the CNS; includes the somatic and autonomic nervous systems.

What is the function of the somatic nervous system?

Involved in voluntary behavior.

What is the function of the autonomic nervous system?

Responsible for less voluntary actions, such as heart rate.

What are neurons?

Basic units of the nervous system; cells that receive, integrate, and transmit information.

What are the three functions of neurons?

Reception (taking in signals), Integration (assessing signals), Transmission (passing signals to other neurons).

What distinguishes sensory neurons?

They detect information from the physical world and pass it to the brain.

What are interneurons?

Relay stations that facilitate communication between sensory and motor neurons.

What are Motor Neurons?

Control movement by stimulating muscle cells

What is a reflex?

An automatic motor response.

What are the four regions of a neuron?

Dendrites, Cell body (soma), Axon, Terminal buttons.

What is the synapse?

The gap between the terminal buttons of a sending neuron and the dendrites of a receiving neuron, where chemical communication occurs.

What is an action potential?

The electrical signal that passes along the axon and causes the release of chemicals from the terminal buttons.

What is the resting membrane potential of a neuron?

Approx. -70 millivolts, indicating the neuron is not active.

Define excitatory signals

Signals that depolarize the cell membrane, increasing the likelihood that the neuron will fire.

What is the all-or-none principle?

When a neuron fires, it fires with the same potency each time; it either fires or it does not.

What is myelin sheath?

Fatty material made of glial cells that insulates some axons for faster movement of electrical impulses.

What role do neurotransmitters play?

They transmit signals from one neuron to another and influence emotion, thought, and behavior.

What is an agonist in relation to neurotransmitters?

A substance that enhances the actions of neurotransmitters.

What is the function of the thalamus?

The gateway to the brain; it organizes and relays incoming sensory information to the cortex.

What is the hippocampus associated with?

The formation of memories.

What is the role of the amygdala?

It processes emotional information and plays a vital role in learning to associate things with emotional responses.

Define heritability.

A statistical estimate of the extent to which variation in a trait within a population is due to genetics.

What distinguishes monozygotic from dizygotic twins?

Monozygotic twins are identical twins from one zygote, while dizygotic twins are fraternal twins from separate fertilized eggs.

What is phantom limb pain?

Pain felt in an amputated limb that no longer receives information from that limb.

What does the prefrontal cortex influence?

Attention, learning, decision making, problem solving, and personality.

Darwin’s Theory of Evolution

Species adapt overtime

Supported by mechanical processes

Provides a biological basis

Cole Blind Children Study

Purpose: Does blindness affect spontaneous control of negative emotions?

Findings: Does not effect emotional control but may heighten verbal responses over facial responses

Study on Identical Twins Reared Apart

Purpose: Explore influence of genetics vs. environment on traits, behaviors, abilities

Key Findings: Twins raised in different environments still had many similarities showing a biological/ genetic reasoning for this

Related to nature vs. Nurture

Imprinting

A phase-sensitive learning process where organisms recognize certain stimuli (e.g., parents or mates) during a critical period of development.

Temperament

Early biological based patterns of behavioral and emotional responses

Temperament Continued (Jerome Kagan)

• Definition: Biologically-based emotional and behavioral patterns present early in life.

• Key Types:

  • High-reactive: More anxious, shy, and cautious.

  • Low-reactive: Sociable, risk-taking, and open to novelty.

• Biological Basis: Neurochemicals (dopamine, serotonin) and brain regions (amygdala) influence temperament.

• Findings:

  • High-reactive infants → likely to become inhibited and socially anxious later.

  • Low-reactive infants → more likely to become uninhibited, confident, and sociable.

• Implications:

  • High-reactive: Suited to low-risk careers, less likely to engage in risky behaviors.

  • Low-reactive: More adaptable to social challenges, likely to take risks and seek out new experiences.

HPA axis (Hypo-Pituitary-Adrenal Axis)

Key Components:

1. Hypothalamus: Detects stress and releases CRH (Corticotropin-Releasing Hormone).

2. Pituitary Gland: Stimulated by CRH to release ACTH (Adrenocorticotropic Hormone).

3. Adrenal Glands: Release cortisol, the "stress hormone," in response to ACTH.

Stress Response, Fight or Flight

fMRI

Measures brain activity by blood oxygen level (more activity, more oxygen)

Assortative Mating and Income Inequality (When Harry Met Sally)

• Assortative mating: People increasingly marry those with similar education levels (e.g., college grads marrying college grads).

• Impact on inequality: More assortative mating has increased income inequality, particularly among the college-educated.

• 1960s vs. Now: In 1960, marriages had more mixed education levels. Now, education plays a key role in marriage, and more college grads marry each other.

• Consequences: This trend has contributed to a rise in the Gini coefficient (a measure of income inequality), but doesn’t fully explain extreme wealth disparities at the top.

The Genes of Left and Right

• Political attitudes have a genetic component: Research shows 40% of our political beliefs are influenced by genes, with 60% shaped by environment.

• Genetic studies: A 2014 study of 12,000 twins revealed that genes affect how we process information and perceive threats, influencing political views.

• Dopamine receptors: A 2015 study linked certain dopamine receptor genes to liberal vs. conservative stances, with liberal women more likely to have these genotypes.

Study of Twins may Suggest our Political Beliefs are Hardwired

• Genetic influence: Research shows genes account for up to 50% of why people lean liberal or conservative, or hold beliefs about authority and egalitarianism.

• Twin study: The study used data from identical and fraternal twins in the Minnesota Twin Registry (8,000 pairs, born 1936-1955), showing political ideology is partly inherited.

• Nature vs. Nurture

How does marijuana cause the munchies?

It heightens senses, making taste a more euphoric experience

Greely’s Experiment on Cognitive Enhancing Drugs

• Purpose: Henry Greely, a Stanford law professor, explored the ethical and legal implications of cognitive-enhancing drugs.

• Experiment: Greely's research focused on the use of nootropics (substances intended to improve cognitive function) to boost memory, focus, and intelligence.

• Findings: He suggested that such drugs could enhance mental performance, but raised concerns about fairness, social pressures, and potential long-term effects.

• Ethical concerns: The study highlighted the risks of inequality, where only certain groups (e.g., the wealthy) may benefit from cognitive enhancers, and the pressure to use them for competitive advantage in education and workplaces.

• Debate: Greely’s work sparked debates about autonomy (individual choice) versus social justice (impact on society). He emphasized that if cognitive enhancers became widespread, society might face significant ethical and legal challenges.

What is so unique about the brain?

It demands high modularity, yet it is very intertwined

What is brain plasticity?

The brain’s ability to adapt as life challenges it

Heredity

Transmission of characteristics from parents to offspring through genes

Heritability

• A statistical estimate of the extent to which variation in a trait within a population is due to genetics

  • Relevant to understanding the population as a whole, not an individual

  • Knowing the heritability of a trait does not indicate whether an indiv’s expression of that trait is due to genes or environment

Variation

The measure of the overall difference among a group of people for that particular trait

Choleric Temperament

Active, Reactive, Impatient

Sanguine Temperament

Optimistic, Social

Melancholic Temperament

Analytical, Quiet

Phlegmatic Temperament

Relaxed, Peaceful