Week 5 PSYC 1100: Biopsychology (ch.3)

Biopsychology

The exploration of the biological mechanisms that underlie behavior

Charles Darwin’s theory of evolution

“Organisms better suited for their environment will survive and reproduce, while those poorly suited for their environment will die off”

Characteristics/behaviors impacting survival and reproduction (evolution)

Those that help protect against predators, help keep offspring alive, and increases access to food

Charles Darwin

English naturalist who developed the theory of evolution by natural selection, published in his book “On the Origin of Species” in 1859

Why do certain genetic diseases (e.g. sickle cell anemia) still get passed down?

Because sickle cell anemia provides malaria resistance. So, there is still some evolutionary benefit to having it

Genetic variation

The variance of genetics between individuals

Chromosome

Long strand of genetic information known as DNA

Deoxyribonucleic acid (DNA)

Helix-shaped molecule made of nucleotide base pairs, provides

Gene

Sequence of DNA that controls physical characteristics known as traits (eye color, hair color, etc)

Allele

Specific variation of a gene. E.g. hair color has multiple alleles (black, brown, etc)

Genotype

Refers to the entire genetic sequence of an individual

Phenotype

Describes an individual’s observable characteristics

Dominant allele

Allele that is expressed even if only one is possessed (Aa or AA)

Recessive allele

Allele that is ONLY expressed if the person is homozygous for that allele (aa)

Heterozygous

Consisting of two different alleles (Aa)

Homozygous

Consisting of two identical alleles (AA/aa)

Mutation

A sudden, permanent change in a gene. Can come from DNA replication errors, raadiation, etc

Range of reaction (in genetics)

Asserts our genes set boundaries we operate in, and our environment interacts with the genes to determine where in the range we fall in

Genetic environmental correlation

Describes how our genes affect our environment, and our environment influences the expression of our genes

Epigenetics

Study of gene-environment interactions such as how the same genotype leads to different phenotypes

Parts of a neuron

Dendrite, cell body (soma), axon, myelin sheath, terminal buttons

Terminal buttons

A bulbous structure at the end of a neuron’s axon which releases neurotransmitters to transmit signals

Synapse

The space in between the terminal button of one neuron and the dendrite of another neuron

Parts of an action potential

Resting potential (-70mV), threshold of excitation, peak action potential, repolarization, hyperpolarization

Threshold of excitation

Level of change in the membrane that causes the neuron to become more active

Why are action potentials an “all-or-none” process?

Because the incoming signal is either sufficient to reach the threshold of excitation or not

Reuptake (in neurotransmission)

Involves moving a neurotransmitter from the synapse back into the axon terminal from which it was released (like a boomerang)== z

Neurotransmitter

Chemical messenger of the nervous system

Biological perspective of psychological disorders

Theorizes that psychological disorders like depression and schizophrenia are associate with malfunction of neurotransmitter systems

Role of acetylcholine

Muscle action and memory

Role of beta-endorphin

Pain and pleasure

Role of dopamine and serotonin

Mood, sleep, and learning

Role of norepinephrine

“Fight or flight” response. Constricts vessels and increases alertness

Psychotropic medication

Drugs that treat psychiatric symptoms through changing neurotransmitter action

Agonist

Drug that mimics or strengthens the effects of a neurotransmitter. E.g. dopamine agonist for Parkinson’s to increase dopamine

Antagonist

Drug that blocks or impedes the normal activity of a given neurotransmitter. E.g. antipsychotic drug to reduce dopamine

Function of somatic nervous system

Relays sensory and motor information to and from the CNS (conscious)

Function of autonomic nervous system

Controls our internal organs and glands (unconscious). Divides into the Sympathetic and Parasympathetic nervous systems

Function of sympathetic nervous system

Involved in stress-related activities and function (fight or flight)

Function of parasympathetic nervous system

Normal, day-to-day body processes like digestion (rest and digest)

Function of spinal cord

Delivers messages to and from the brain, and facilitates a “reflex arc”

Reflex arc

Process where certain reflexive actions are processed in the spinal cord and bypass the brain

What sides of the body are the left and right brain hemispheres responsible for?

The left hemisphere controls the right side of the body, and the left hemisphere controls the left side of the body

Lateralization

Concept that each hemisphere of the brain is associated with specialized functions

Corpus callosum

Brain structure connecting the left and right brain hemispheres

Three main categories of the brain

Forebrain (top), midbrain (middle), hindbrain (bottom)

Forebrain structures

Cerebral cortex, thalamus, hypothalamus, pituitary gland, limbic system

Cerebral cortex

Surface of the brain associated with complex mental capabilities, such as consciousness, emotion, and reasoning

Lobes of the cerebral cortex

Frontal love, temporal love, parietal lobe, occipital lobe

Function of the frontal lobe

Lobe of the cerebral cortex nvolved in executive functioning (planning, organization, attention), language

Divisions of the frontal lobe

Motor cortex, prefrontal cortex, Broca’s area

Function of motor cortex (division of frontal lobe)

Planning and coordinating movement, maintaining motor control

Function of prefrontal cortex (division of frontal lobe)

Responsible for higher-level cognitive functioning.

Brocca’s area (division of frontal lobe)

Region in the left hemisphere essential for language. Damage leads to difficulties producing language

Phineas Gage

Railroad foreman whose frontal lobe was impaled by an iron rod, causing unusual behaviors. Came from a loss of impulse control (frontal lobe damage)

Function of parietal lobe

Involved in processing various sensory and perceptual information. Contains the primary somatosensory cortex

Somatosensory cortex (part of parietal lobe)

Each of its regions (e.g. face, neck, jaw) processes sensory information from a different part of the body

Function of temporal lobe

Lobe of the cerebral cortex associated with hearing, memory, and some aspects of language

Auditory cortex (part of temporal lobe)

Strip of cortex in the temporal lobe responsible for processing auditory information

Wernicke’s area (part of temporal lobe)

Important for speech comprehension. Damage results in difficulty understanding language

Occipital lobe

Cerebral cortex lobe associated with visual processing, containing the primary visual cortex

Thalamus

The brain’s “wifi router,” as it relays senses (excluding smell) across the brain

Limbic system

Involved in mediating emotional response and memory, made up of the amygdala, hippocampus, and hypothalamus

Amygdala

Limbic system structure involved in emotion, tying emotional meaning to our memories, and processing fear

Hippocampus

Limbic system structure associated with learning and memory (particularly spatial memory)

Hypothalamus

Limbic system structure that regulates homeostatic processes (body temp, appetite, blood pressure)

Sections of the midbrain

Reticular formation, substantia nigra, ventral tegmental area (VTA)

Reticular formation

Midbrain section important in regulating sleep/wake cycle, arousal, alertness, and motor activity

Substantia nigra

Midbrain section where dopamine is produced; involved in movement control

Ventral tegmental area (VTA)

The VTA is a part of the midbrain where dopamine is produced; associated with mood, reward, and addiction

Parts of the midbrain

Medulla, pona, cerebellum

Medulla

Part of hindbrain that controls automated processes like breathing, blood pressure, and heart rate

Pons

Part of hindbrain that connects the brain and spinal cord; involved in regulating brain activity during sleep

Cerebellum

Part of hindbrain that controls balance, coordination, motor skills, and perhaps some types of memory

Computerized Tomography (CT) scan

Involves x-rays and creates an image through x-rays passing through varied densities within the brain. Can show brain tumors

Positron Emission Tomography (PET) scan

Individuals injected with a mildly radioactive substance have their brain blood flow measured. Can show activity in different parts of the brain

Magnetic resonance imaging (MRI)

Magnetic fields used to produce a piture of the tissue being damaged

Functional magnetic resonance imaging (fMRI)

MRI that shows changes in metabolic activity over time

Electroencephalography (EEG)

Involves recording the electrical activity of the brain via electrodes on the scalp. Can study precise timing of overall brain activities

Endocrine system

A series of glands that produce hormones tor regulate normal body functions

Pituitary gland

Master gland which controls the scretions of all other glands

Thyroid

Secretes thyroxine which regulates growth, metabolism, and appetite

Adrenal gland

Secretes hormones involved in the stress response

Gonad

Secretes sex hormones, which are important for successful reproduction and regulate sexual motivation and behavior

Pancreas

Secretes hormones that regulate blood sugar

Fraternal twins

Twins who develop from two different eggs fertilized by different sperm, so their genetic material varies the same as in non-twin siblings

Glial cell

Nervous system cell that provides physical and metabolic support to neurons

Neuroplasticity

Nervous system’s ability to change

Synaptic vesicle

Storage site for neurotransmitters

Gyri

Raised ridges or “bumps” on the surface of the cerebral cortex

Sulci

The shallow grooves or “furrows” that separate them