PSY 120 Module 3: Brain and Behavior

Nervous system

body’s electrochemical communication circuitry

complexity

the brain is very sophisticated, one cubic cm of brain contains over 50 million cells that work together

great integrator

the brain is pulling all types of information from the five sense systems together

adaptability

also known as plasticity, brain’s capacity to change

electrochemical transmission

how the brain is powered. electrical impulses and chemical messages power the nervous system (impulse travels down a nerve cell electrically, and then sends message to the next cell chemically)

central nervous system (CNS)

consists of the brain and spinal cord

peripheral nervous system (PNS)

nerves and everything else that connects CNS to the rest of the body

subdivisions of PNS

Autonomic and somatic

somatic system

sensory and motor nerves to control muscles

subdivisions of the autonomic system

parasympathetic and sympathetic system

autonomic system

internal organs, all involuntary functions

sympathetic system

activates internal organs during times of stress and arousal (controls fight or flight system)

parasympathetic system

reverses symptoms of flight/fight reactions (controls rest and digest system)

stress

the body and mind's automatic reaction to feeling threatened, pressured, or unable to cope with demands

neurons

nerve cells that handle info processing, conducts impulses (made up of cell body, dendrite, and axon)

cell body

the core section of the nerve cell that houses the nucleus and controls the cell's main metabolic activities

dendrite

receives impulses

axon

sends impulses, encased by myelin sheath

myelin sheath

a protective, fatty-protein layer that wraps around the axon of a neuron to insulate it and speed up electrical signals

glial cells

provides support and nutritional benefits to neurons

mirror neurons

activates from watching rather than doing, fires both when an individual performs an action and when they watch someone else perform that same action

all or nothing principle

a nerve cell or muscle fiber will fire completely or not at all when stimulated

resting potential

the stable, inactive electrical state of a neuron when it is not sending a signal

action potential

a brief, rapid reversal of electrical charge that travels down a neuron's axon to transmit a signal. It acts as a neural impulse or electrical spike

polarization

when a neuron has a negative charge (at rest)

synapse

junction/specialized cite between two neurons (includes gap/cleft)

synaptic vesicles

contrains neurotransmitters

neurotransmitters

chemicals containing the message —> released into gap

receptor sites

receives neurotransmitters

acetylcholine

affects movement, learning, memory, and REM sleep (an imbalance causes alzheimers)

dopamine

affects movement, learning, memory, and reinforcement (an imbalance causes schizophrenia and parkisons)

serotonin

affects mood, sleep, appetite, impulsitivity, aggression (an imbalance causes depression, anxiety, and eating disorders)

endorphins

provides relief from pain, feelings of pleasure, well being

How do drugs that impact behavior work?

they aim to balance neurotransmitters

Hindbrain

Contains some of most primitive parts of the brain, sits where spinal cord and brain merge. Acts as basic life-support system for body, vital automatic functions controlled here

Medulla

begins where spinal cord enters skull. Control vital automatic functions (heartbeat, breathing, BP, reflexes such as coughing, vomiting, sneezing)

pons

Bridge that connects cerebellum and brain stem and contains fibers involved in sleep and arousal

cerebellum

“little brain” in the hindbrain that controls complex motor movements

brain stem

Connects at spinal cord and extends upward. A primitive structure that includes much of the hindbrain (and also some of the midbrain)

midbrain

Lies deep within brain right atop the hindbrain. Relays physiological messages from hindbrain to the cognitive functions of the forebrain

substania nigra

group of neurons in the midbrain that release dopamine from their
terminal buttons. Dopamine is involved in physical and psychological disorders such as Parkinson's

reticular formation

Network of neurons and nerves involved in waking, sleeping, turning to noises. General alertness/consciousness

forebrain

The outer portion of the brain, including the cerebral cortex and the structures of the limbic system. Serves as seat of higher mental functioning.

limbic system

A system of structures thought to be involved in motivational and emotional behaviors (the amygdala) and memory (the hippocampus)

amygdala

linked to emotional an motivational behaviors such as fear, aggression, and defensive actions. Damage can lead to inability to recognize emotions such as sadness in facial expressions

hippocampus

important in formation of new memories

thalamus

Relay station in the forebrain; important gathering point for input from the senses; thought that info is probably combined in some way here

hypothalamus

forebrain structure; role in regulation of various motivational activities such as eating, drinking, and sexual behavior; release of hormones from the pituitary gland

cerebral cortex

he grayish matter full of fissures, folds, and crevices that covers the outside. Higher mental processes of language, memory, and thinkin

frontal lobe

largest in the cortex; planning and decision making, thinking, impulse control, certain kinds of memory, personality (Phineas Gage)

broca’s area

in left frontal lobe (posterior inferior frontal gyrus of the brain) plays an essential role in various speech and language functions

parietal lobe

Top middle portion of brain, contains somatosensory cortex, controls the sense of touch

somatosensory cortex

through which we experience the sensations of touch, temperature, and pain

temporal lobe

lie either side of the cortex; primary processor of auditory information from left and right ears; also contains areas related to speech and language perception (how one understands speech

Wernicke’s area

in the temporal lobe; language comprehension, can repeat a sentence but not understand any of the words. Becomes active when asked to perform tasks that require meaningful verbal processing (Understanding spoken language)

occiypiysl lobe

primary visual cortex (sight)

cerebral hemisphere

controls movement/receives visual info on/from opposite sides of the body

corpus colosum

nerve fibers; communication bridge between two lobes

left hemisphere

controls sensory and motor functions for the right side of the body; linear reasoning and language function

right hemisphere

controls left side of body; processing of visual and audiological stimuli, spatial manipulation, facial perception, and artistic ability

methods of gaining information about the brain

brain lesioning, electrical recording, brain imaging

endocrine system

network of glands and organs that make and release hormones directly into the blood to control many important body functions

hormones

the body's chemical messengers

collateral sprouting

the process where healthy, uninjured neurons grow new branches to reinnervate nearby target areas that lost their nerve supply due to injury or disease

substitution of function

a neuroplastic mechanism where uninjured brain regions or alternative behavioral strategies adapt to take over a lost ability

neurogenesis

the biological process by which new neurons are formed in the brain from neural stem cells and progenitor cells

genes

biochemical unit of heredity (coded instructions to carry out genetic traits)

chromosome

thread-like structures made of protein and a single molecule of DNA that carry genomic information from cell to cell

DNA

the hereditary molecule that carries genetic instructions for the development, functioning, growth, and reproduction of all living organisms and many viruses

behavioral genetics

attempts to determine how much of behavior is genetic vs environment

interactionist perspective

you cant measure nurture without nature (and vise versa)

False dichotomy within behavioral psychology

you HAVE to pick either nature or nurture (which is wrong due to interactionist perspective)

somewhat “heritable” things

intelligence, schizophrenia, sexual orientation, alcohol abuse, anxiety, depression, anti social behavior

evolutionary model of behavior

behavioral impulses and traits are passed down through genes, and the traits that aid in survival and reproduction will be passed down most often

caution of evolutionary model

many aspects of today’s environment were not present for most of evolution, therefore not all predisposed behavior may be adaptive in current environment (not all traits that aid in survival should be passed down)

evolutionary tradeoffs

many traits that help find a mate make it harder to live long enough to find a mate (peacock example)

percentages for the Clark and Hatfield study

Go on a date:

• men: 50%

• women: 50%

Go back to place:

• men: 69%

• women: 6%

Go in bed:

• men: 75%

• women: 0%

evolutionary psychology explanation of Clark and Hatfield study

males and females have different mating strategies (males are less careful, and females are more careful) due to parental investment

parental investment

sexes differ on amount of time they invest into their offspring which then dictates their mating strategies