psych exam two

genes contain…

instructions for making proteins

blueprint of the brain

highly conserved across evolution, but small differences in blueprints can have big effects

genotype

the sequence of letters of your genome - mostly inherited from your parents

phenotype

a measurable trait - height, weight, how high you can jump, etc.

genes + phenotype + environment

our environment has a large impact on whether a given genotype affects our behavior - our environment changes phenotypes not by changing the genes themselves, but by changing when and how they act

epigenetics

the study of how your behaviors and environment can cause changes that affect the way your genes work - changes are reversible and do not change the dna sequence, but changes how your body reads a dna sequence

heritability

how much of a phenotype is inherited, presumably due to genetic factors

twin studies

monozygotic twins are found to have more heritable phenotypes than dizygotic twins

are desired behavioral traits heritable?

no - this would be eugenics: the study of how to arrange reproduction within a human population to increase the occurrence of desirable heritable traits

why can we not make accurate predictions about a phenotype based on genotype?

the environment can change or be manipulated to alter the phenotype - in heritability if you know the phenotype in a specific environment you might have a decent guess at the genotypes, but it does not mean that if you know the genotypes, you can guess what the phenotypes are

which neurotransmitter is important in making predictions, particularly if the outcome is surprising?

dopamine producing regions (like the ventral tegmental area) send axons all over the brain simultaneously

what is learning?

process of predicting - a relatively permanent change in behavior due to experience

nonassociative learning

simple learning to reduce (habituation) or increase (sensitization) the amount of responding we do to stimuli that innately drives a response

• learning about one thing that is linked with nothing

• occurs in response to a single stimulus, without reinforcement

associative learning

linking up stimuli and experiences because something that was previously neutral predicts something important (good or bad)

habituation

reducing your responses to something that repeats in your environment and doesn’t predict anything

• nonassociative learning

• decrease in an innate response to a frequently repeated stimulus

sensitization

increasing your responses to something that repeats in your environment and is potentially noxious

• nonassociative learning

• increased reaction to a stimulus after repeated exposure

classical conditioning

learning key association (provoking responses/actions) measure responses to the cue to measure the strength of learning

• one learns to link two or more stimuli and anticipate events

unconditioned stimulus (US or UCS)

something that innately valuable

• a stimulus that leads to an automatic response

• example: food

conditioned stimulus (UR or UCR)

response you have innately to something valuable

• not learned but is natural

• example: salvation

conditioned stimulus

a learned substitute stimulus that triggers the same response as an unconditioned stimulus

• bell —> meant receiving food

conditioned response

a learned response to a previously neutral stimulus

• bell —> means food —> results in salvation

are classical condition responses voluntary or involuntary

involuntary

acquisition

the initial learning of the US-CS link in classical conditioning

• first stages of learning

• a response is established

extinction

active learning process where the CR is weakened in response to the CS if it is frequently presented in the absence of the US

• the gradual weakening of a conditioned response

• behavior decreases or disappears

spontaneous recovery

the reemergence of a conditioned behavior after it was supposedly extinct

• unexpected

• quickly returns after a period of rest

blocking

less is learned about the relationship between a stimulus and an outcome if pairings are conducted in the presence of a second stimulus that has previously been established as a reliable predictor of that outcome

• no need to learn about a second predictive stimulus

garcia effect

some associations are evolutionary advantaged

latent inhibition

trouble learning that the cue predicts anything at all

• when you already have an association with the cue

operant conditioning - instrumental conditioning

a voluntary action triggers an outcome

• a cue in the environment triggers an action

• an action triggers an outcome

classical vs operant conditioning

classical: certain responses to conditioned stimulus paired with unconditioned (involuntary)

operant: reinforcements or punishments (voluntary-reveals our motivation)

phineas gage

an iron bar went through his skull and changed his personality

• likeable —> rude

• led to believing parts of the brain are responsible for certain things

hemispatial neglect

reduced awareness of stimuli on one side of space, even though there may be no sensory loss

• damage to brains cerebral cortex on one side

H.M and his stories suggestion about the brain

removed his hippocampus to relieve severe epilepsy - after surgery he had no change in personality, seizures disappeared, IQ improved, lost most of memories and could not learn anything new, still retained information and could do tasks

• still had short term memory

• showed the differences between short term and long term memory

frontal lobe

cognitive functions - complex thought & map of the body’s muscles

• control of voluntary movement or activity

• socially appropriate choices

parietal lobe

processes information from senses

spatial awareness; map of the body’s skin surface

• temperature

• taste

• touch

• vision

• smell

occipital lobe

primarily responsible for vision

temporal lobe

processes memories and integrating them with the sensation of taste, sound, sight, touch, and smell

• hearing; object memory

central nervous system

protected by bony structures (skull and vertebrae) and layers of soft protective tissue (meninges) between the bone and the nervous tissue

• spinal cord

• brain

peripheral nervous system

nerves connecting the CNS to the rest of the body

somatic peripheral nervous system

voluntary muscle movement

• go here

• do this

autonomic peripheral nervous system

involuntary movement

• heartbeat

• pupil

• hormones

somatic pns responsibilities

communicating information about our environment via sensory fibers up to the central nervous system which make an assessment of our environment and communicates a set of actions both voluntary and involuntary which are executed via motor fibers

• our actions, in turn, expose us to new information

sympathetic nervous system

• fight or flight

• increase function of systems needed to do the thing right now

• decrease function of systems that can wait for better times

parasympathetic nervous system

• relaxed

• dangers is gone

• calm and safe

key components of the endocrine system

affects the function of a lot of systems more slowly (minutes, hours, or longer) via hormones

• ex. adrenal glands and stress

operation of endocrine glands when stressed

1. brain including hypothalamus, detects stressor

2. hypothalamus directs pituitary to release a hormone into the bloodstream that increases the function of adrenal glands

3. adrenal glands release more cortisol into the bloodstream

4. cortisol changes the way multiple systems work, including the brain

5. brain eventually detects elevated cortisols, tells hypothalamus “that’s enough maybe?”

the brain - rodents vs primates

CNS follows the same plan across a variety of animal species

• same topological pattern of connection between brain regions

• different size

• different amount of complexity of cortex

insular lobe

taste; awareness of internal organs

hippocampus

memories of time and place; spatial navigation

amygdala

emotional associations

basal ganglia

planning and executing movement

thalamus

sensory pathways to and from cortex

hypothalamus

master controller of the brain and body; regulation of bodily homeostasis (stability or equilibrium)

tegmentum

eye and head orienting

ventral tegmental area

reward pathway for subcortical motor system

substantia nigra

regulates basal ganglia subcortical motor system

pons

regulation of breathing; relays sensations to the cortex and subcortex

medulla oblongata

vital survival functions including breathing and heart rate; critical reflexes such as coughing and swallowing

reticular formation

arousal and attentiveness; sleep and wakefulness

forebrain (neocortex)

• occipital lobe

• temporal lobe

• parietal lobe

• frontal lobe

• insular lobe

forebrain (subcortex)

• hippocampus

• amygdala

• basal ganglia

• thalamus

• hypothalamus

midbrain

• tegmentum

• ventral tegmental area

• substantia nigra

hindbrain

• pons

• medulla oblongata

• reticular formation

neuroplasticity

brains ability to reorganize itself by forming new neural connections

• allows neurons to. compensate for injury and disease

• used to help patients recover after stroke, TBI, and brain-split surgery

what part of the brain may have contributed to HM’s difficulties?

temporal lobe communication with hippocampus are important for long term memory storage - part of it was removed

aphasia

a stroke in either of two regions of the brain which can impair spoken communication

wernickes aphasia symptoms

• saying many words that don’t make sense

• unable to understand the meaning of words

• able to speak well in long sentences but they don’t make sense

• using the wrong words or nonsense words

• unable to understand written words

• trouble writing

• frustration

what area of the brain is disrupted in hemispatial neglect

comes from parietal lobe damage on one side

somatotopic map in the somatosensory cortex

the border of the parietal lobe, next to the frontal lobe

proprioception

sense of where/how the body is moving

how does the frontal lobe execute our intentions?

controls movement - motor cortex is in the front lobe right next to the somatosensory cortex in the parietal lobe

brocas aphasia

can’t speak fluently but can understand

• difficulty forming complete sentences

• leaving out words like is or the

• saying something that doesn’t resemble a sentence

• using words close to what you intend but not right (saying car when you mean truck)

• trouble understanding sentences

• making mistakes in following directions like “left, right, under, after”

prefrontal cortex functions

• focusing one's attention

• predicting the consequences of one's actions

• anticipating events in the environment

• impulse control

• managing emotional reactions

insular lobe

monitors information from the interior of the body

• hunger

• thirst

• nausea

• pain

• gas

subcortical regions

ancient and powerful structures supporting memory, emotions, and motivation

limbic system

the major subcortical forebrain structures - between the cortex and the brainstem

place cells

individual neurons in the hippocampus selectively fire to represent a particular area in the world

episodic memories

formed in the hippocampus - what happened to us, when, and where

loss of amygdala

lack of fear - can diminish the ability of both strong good and bad things to affect our decisions and memories

thyroid gland

regulates energy metabolism

pancreas

regulates blood sugar levels

ovary

secretes female sex hormones

pituitary gland

master gland that controls other glands throughout the body

parathyroid glands

regulate calcium levels in bones and blood

adrenal glands

involved in fight-or-flight response

testis

secretes male sex hormones

motivation and habit formation

occurs in the limbic system in the basal ganglia

thalamus

a relay between cortical and subcortical regions

major dopamine centers

centers in the midbrain

• ventral tegmental

• substantia nigra

dopamine

teaches us about how to get more of things we like (by increasing motivation and action initiation)

main function of neurons

• receive signals

• integrate signals

• transmit signals

dendrites

• projections from neuron

• highly branched

• equipped in additional protrusions called spines

• 10,000 synapses per neuron

• receive signals from other via synapses

axon

• single projection from the soma/cell body

• little branching

• protected by myelin sheath

• passes electrical signal down its length

• sends/transmits signal to next neuron in a pathway vai synapse at axon terminal

myelin sheath

part of glia - prevents dissipitation through the axon membrane

oligodendrocytes

myelin sheath within central nervous system

schwann cells

myelin sheath in the peripheral nervous system

neurons tend to be organized

different layers get different mixes of inputs, from different regions, and send to different outputs

glia

hold the nervous system together “glue”

action potential

how electrical signals are transmitted from one neuron to another

• a temporary shift (from negative to positive) in the neuron’s membrane potential caused by ions suddenly flowing in (sodium Na+) and out (potassium K+) of the neuron

neurotransmitters

a release of chemical messengers in chemical transmission

• carry information from the pre-synaptic (sending) neuron to the post-synaptic (receiving) cell

• released by exocytosis stimulated by depolarization of the plasma membrane by action potential