AP psychology U1

heredity definition

the predisposed characteristics that influence an individual’s physical, behavioural and mental traits and processes inherited from parents through genes.

environment definition

the external factors that an individual experiences, such as a person’s family, friend groups, school and other societal factors

how does evolution affect behaviour in terms of genes?

it focuses on natural selection, the passing down of genes, and how many of our behaviours and mental processes actually come from our ancestors 

eugenics definition

improving the genetic quality of the human population by promoting the reproduction of individuals with desirable traits and discouraging reproduction among those with traits deemed undesirable 

heritability definition

the mathematical measure to estimate how much variation there is in a population related to its genes (populations, not individuals)

range of heritability 

0 to 1

for example, what does it mean when the heritability is 0.7

70% of gene variations in a population is caused by genetics 

30% is due to the environment 

epigenetic definition

study of how the environment and a person’s behaviours affect their genes and how they work

plasticity definition

when the brain changes and builds new neural pathways in response of a persons’ experiences

central nervous system is made up of…

brain and spinal cord

central nervous system function

controlling and processing all body functions

brain function (5)

1. processing sensory information

2. thinking 

3. controlling motor functions 

4. emotions 

5. regulating bodily functions 

peripheral nervous system is made up of…

nerves branching out from the spinal cord and brain 

peripheral nervous system function

connects CNS to the body cells

afferent neurons

sensory neurons

send signals from the sensory receptors to the CNS

Approaches brain 

efferent neurons

motor neurons

signals from CNS to spinal cord to the PNS

Exits brain

somatic nervous system controls…

voluntary muscle movement

autonomic nervous system

controls involuntary functions (crucial for survival)

sympathetic division

(fight or flight response)

increases heart rate, dilates eyes, decreases breathing, slows down digestion 

parasympathetic division

(rest and digest)

increases digestion, slows down heart rate, increases breathing, saves and stores energy

what is the reflex arc?

the neural pathway that tells the body to respond to the stimulus without thinking / process the information 

what is the path of neural signals in a reflex arc?

sensory neurons (afferent) → interneurons → motor neurons (efferent)

what is a interneuron

neurons within the CNS that communciate internally and connect afferent to efferent neurons to transport signals to muscles to make them react

nociceptors

pain receptors

glial cells function (7)

1. provide support for neurons

2. supporting the whole nervous system

3. insulates neurons

4. speed up signal transmission

5. facilitate communication between neurons

6. transport nutrients

7. removing waste products

where do we find glial cells?

axon of neurons

how does a neuron work

1. the cells have a resting negative cell membrane potential. it is more negatively charged on the inside due to more negative ions 

2. dendrites receive action potential which begins depolarisation across the axon, where positive ions (Na+) flow into the neurons, causing the inside of the cells to be more positive. this disturbance in the membrane potential causes electrical signal to pass along the axon 

3. the myelin sheaths and nodes of ravelin speeds up the travel of action potential / electrical signal 

4. when the signal reaches the axon terminal, neurotransmitters are released into the synapse, which diffuse across it to attach to receptors on the post-synaptic receptors on the adjacent neurons 

5. action potential starts in the other neuron

what happens to a neuron after depolarization

1. After depolarization, repolarization occurs when positive ions rush out of the cell, so the membrane potential is returned to its normal negative resting potential

2. The neuron goes through the absolute refractory phase, where it cannot fire an action potential temporarily

when are electrical synapses used

sending quick and immediate messages

excitatory neurotransmitters

Increases likelihood for neuron to start depolarization and fire an action potential

inhibitory neurotransmitters

increases hyperpolarization which decreases the likelihood that the neuron will send an action potential

serotonin

manages arousal, sleep, pain sensitivity, mood and hunger

dopamine

Manages movement, emotions, learning, attention and reward

GABA (Gamma-Aminobutyric acid)

Inhibitory neurotransmitter → sleep, movement, slow down nervous system

Glutamate

Excitatory neurotransmitter → long term memory and learning (counterpart to GABA)

Norepinephrine

increases heart rate, BP, alertness, (FOF response) (a lack thereof is implicated in depression)

Endorphins

pain control, impacts pain tolerance

Acetylcholine

Muscle action, learning, memory

substance P

transmits pain from sensory nerves to CNS

hyperpolarization

when the insides of the neuron becomes more negative, moving it further away from the threshold for it to fire an action potential

what happens to neurotransmitters when it binds to the receptors

it unbinds and either break down or is reabsorbed 

soma

neuron cell body which allows for the neuron to function

dendrite 

receive chemical information from neighbouring neurons through receptor sites

axon fibre

carries signals away from the soma and towards the axon terminal

Schwann cell

wraps around the axon and produces the myelin sheath

myelin sheath

covers and protects the axon from damage and increases how fast the action potential can travel down the axon

nodes of ranvier

gaps between myelin sheath — promotes the continuing action potential

multiple sclerosis

1. myelin sheath is damaged, resulting in the disruption in the transmission of electrical signals

2. symptoms: muscle fatigue, weakness…

myasthenia gravis

1. autoimune disorder, affects the comuniaiton between nerves and muscles

2. antibodies block or destroy acetylcholine receptors, preventing muscle contraction and leading to muscle weakness and fatigue

Agonist drugs

• increase effect of neurotransmitter through

  • mimicking the neurotransmitters by binding to the receptors

  • increasing production of NT

  • or blocking reuptake → more neurotransmitters in the synapse since they are not reabsorbed

antagonists drugs

• decreases effect of neurotransmitter

  • block neurotransmitters from being released from the PreST

  • block post-synaptic receptors

stimulants

• excite and promote neural activity

• give individual energy

• reduce apetite

• awakeness, irritability

depressants

• reduce neural activity

• drowsy, muscle relaxation, reduced breathing, death

hallucinogens

• reduce motivation, lead to panic

• hallucinate

opioids

pain relief

addictive depressants

constant use of drugs causes…

a person to develop a higher tolerance, more drugs need to be consumed to achieve the same effect → addiction, withdrawal symptoms

adrenaline

response to high emotional situations, forms memories, expands air passages, redistribute blood (FOF response)

leptin

regulate energy balance, inhibit hungers

gherkin

hunger, release of growth hormones

melatonin

(produced by pineal gland) regulates sleep-wake cycle

oxytocin

(hypothalamus, released by pituitary gland) love hormones, promotes feelings of affection and emotional bonding

brain stem consists of

mid brain

pons 

medula oblongata 

medula function 

controls autonomic function  

pons function

connects different parts of the nervous system, maintains sleep and dreaming

cerebellum function

controls muscle movement, balance, procedural learning 

procedural learning meaning

a type of long-term memory that involves learning how to perform tasks or actions through repetition and practice often without conscious awareness

reticular activating system (anatomy + function)

a bundle of nerves that runs through the brain stem 

1. regulating consciousness and arousal / awareness

2. filter incoming sensory information and highlights important ones 

brain’s reward centre function

feel satisfaction and pleasure

use neurotransmitters to feel rewarded (especially dopamine)

limbic system consists of

and where is it found?

thalamus, hypothalamus, hippocampus, amygdala

between the cerebral cortex and the brain stem

thalamus

receives sensory information, excepts for smell, then sends the information to the right part of the brain to be interpreted 

limbic system function

emotion, memory, learning, motivation

hypothalamus

maintains homeostasis, hunger, thirst, body temperature, sexual behaviours 

regulates endocrine system by signalling the pituitary gland 

pituitary gland 

(the master gland)

releases hormones that affect growth metabolism, and other glands throughout the body 

hippocampus

forms new long term memories, especially explicit memories

(does not store memories)

amygdala

involved in emotions, especially fear and aggression

what are the lobes of the cerebral cortex

1. frontal lobe

2. parietal lobe 

3. temporal lobe

4. occipital lobe

corpus callosum

a thick band of neurons that connects the left and right hemispheres and allows them to communicate with each other

occipital lobe location and function

processes visual information

temporal lobe location and function

process sounds, helps with language and comprehension

Wernicke’s area

responsible for language and comprehension

Wernicke’s aphasia

where the individual’s Wernicke’s area is damaged, having difficulty comprehending spoken language  

association areas 

regions that help the brain organise and make sense of information 

somatosensory cortex

processes touch, pressure, pain, from the body, get a sense of where your body is 

contralateral organisation

each hemisphere controls the opposite side of the body

parietal lobes

• processes sensory information like touch, temperature, and pain

• spatial awareness, navigation, and coordinating body movements

frontal lobes

responsible for higher level thinking and executive functions 

what are the two main areas of the frontal lobe and where are they located?

• prefrontal cortex 

• motor cortex

prefrontal cortex is involved in…

• judgment 

• planning 

• foresight 

• attention 

• complex thought

• emotional regulation

motor cortex is involved in…

• voluntary muscle movement 

broca’s area function and location

Broca’s aphasia 

difficulty in producing speech when the Broca’s area is damaged 

cortical specialisation

lesion studies

where researchers destroy certain parts of the brain to gain insight into their functions

autopsy

examining a dead body to understand the cause of death

EEG (electroencephalogram)

measures electrical activity in the brain by placing electrodes on an individual’s scalp 

FMRI (functional magnetic resonance imaging)

shows which areas of the brain is active by measuring changes in blood flow