psychology unit 3 AOS1

controlled experiment

the effect of the independent variable on the dependent variable is tested while aiming to control all other variables.

qualitative data

non-numerical data

quantitative data

numerical data

subjective data

open to interpretation

• can be qualitative

objective data

not open to interpretation

• can be quantitative

central nervous system

consists of the brain and spinal cord; processes and coordinates responses to sensory stimuli. Integrates and coordinates all incoming sensory info and initiates outgoing motor messages to be sent to the body, either conscious commands or involuntary responses.

brain

a complex structure that receives and processes sensory stimuli from the body and coordinates responses. communicates with body via spinal cord

Spinal cord

a dense bundle of nerves that carry sensory information from the body o the brain, and motor info from the brain to the body.

roles of the spinal cord

1. carry incoming sensory info from the PNS to the brain for processing

2.carry motor info initiated in the brain towards the PNS

spinal reflexes

a quick response important for your survival.

• occurs in pain response

• occurs by intercepting interneurons in spinal cord

• faster reaction time to help survival

spinal reflex process

1.Sensory receptors detect danger which transmit sensory info via sensory neurons to spinal cord.

2.interneuron in the spinal cord immediately relays sensory neural signal from a sensory neuron to a motor neuron as a motor neural signal, initiating an automatic and unconscious motor response.

3.motor info transmitted via motor neurons to skeletal muscles (carry out this unconscious motor response to the dangerous or harmful sensory stimulus).

4.The sensory info continues to travel via afferent tracts in the spinal cord to the brain. Brain independently registers the sensation that triggered the spinal reflex.

Peripheral NS

involves all the nerves outside the CNS that carry messages between the CNS and muscles, organs and glands throughout the body

somatic NS

carries sensory (afferent) info to the CNS. And carries motor (efferent) info from the CNS to the body

Autonomic NS

controls the body's internal environment in an autonomous or self regulating manor. Performing most of its functions without conscious awareness and responsible for basic functions like digestion, respiration, HR

Sympathetic NS

a subdivision of the ANS that increases our arousal, regulating the body for a quick response to deal with a situation (increases HR)

parasympathetic NS

subdivision of the ANS that controls the body's internal environment in a self regulating way, it returns the body to a calm state after a threatening or stressful situation (decreasing HR) (much slower at returning the body because adrenalin takes longer to be removed)

Functions of the parasympathetic NS

1. maintain a balanced internal state, including regulating energy levels and saliva
2. counterbalancing the energising function of the sympathetic NS by lowering arousal and restoring the body to a calm state after a threat has passed

Nervous system subgroups

enteric NS goes under autonomic NS

Unconscious responses

1. dangerous / harmful stimulus detected by sensory receptors

2. sensory info sent along afferent neurons to spinal cord

3. interneuron relays sensory info from afferent neuron to efferent neuron as motor info (initiates automatic + unconscious response

4. motor info sent along efferent neurons to effector muscle i carries out unconscious motor response to the sensory stimulus.

5. into sent to brain so that it registers the sensation + can store in long-term memory to not happen again

conscious responses

1. Sensory stimulus comes into contact with sensory receptors that detect sensation from environment

2. sensory info transmitted via afferent neurons to brain via spinal cord

3. brain processes sensory info + interprets environmental sensation (where decision is male) + coordinates + initiates conscious motor response

4. Motor info transmitted via efferent neurons to effector muscle

5. effector/skeletal muscle carries out conscious motor response to sensory stimulus

3 functions of the NS

1. input
2. processing
3. output

Neaurons

an individual nerve cell that is specialised to receive, process, and transmit info within the NS

neural transmission

• an electrochemical impulse that occurs when a neuron is activated or fires and nerves communicate together

• action potential initiated the axon towards axon terminals

• communication within neuron uses energy

neurotransmitter

a chemical produced by neurons that carries messages to other neurons or cells within the NS, including muscles, organs and glands

Synapse

the point of communication between 2 neurons or between a neuron and a target cell such as a muscle gland

synaptic vesicle

a membrane bound shear filled with neurotransmitter molecules

synaptic gap

the space between the axon terminal of the presynaptic neurone and the membrane of the post synaptic neuron

receptor site

a membrane protein on the dendrites of a neuron that receives and detects specific neurotransmitters

excitatory effect

the increased likelihood that the post synaptic neuron will fire an action potential or neural impulse

Glutamate

• important role in learning + memory

• effects of glutamate form + strengthen synaptic connections between neurons that are repeatedly activated during learning

• enables synaptic plasticity

• thought + movement

eg. reading forms memories, glutamate released to associate concept in brain

inhibitory effect

decreases the likelihood that the post synaptic neuron will fire an action potential or neural impulse

GABA

• inhibitory neurotransmitter that supresses and slows down the neural activity

• role in regulating postsynaptic activation in neural pathways

• prevents over excitation of neurons

  reduces anxiety

• prevents seizures - by inhibiting uncontrolled firing of action potentials

• CALMING

Neuromodulators

• effect on multiple postsynaptic neurons

• released slower and more diffusely compared to neurotransmitters.

• alter responsiveness to neurotransmitter signals

• broad and long-lasting effects.

• modify the efficiency of synaptic transfer.

dopamine

• has both excitatory and inhibitory effects based on receptor types.

• motor movement, pleasure, motivation, and reward-based learning.

• Dopamine also influences thirst, hunger (time to eat + motivation for food), and cravings, affecting appetite control and behavior.

• Dopamine levels decreases below baseline in reward pathway sensation of hunger → increase Good seeking eating behaviour + dopamine Increases in reward pathway when eating → pleasure experienced + reinforcing pattern of brain activity and behaviour

reward pathway

a group of structures in the brain that are activated by rewarding or reinforcing stimuli

serotonin

• neurotransmitter that acts as neurmodulator

• mood, sleep, and bowel function.

• starts in the brain stem and travels through the brain, regulating activity.

• regulate sleep-wake cycles and alertness.

• Low serotonin can lead to mood disorders like depression + anxiety.

long-term potentiation

relatively permanent strengthening of the synaptic connections as a result of repeated activation of a neural pathway. long lasting

Long term depression

the relatively permanent weakening of synaptic connections as a result of repeated low level activation. long lasting

Sprouting (LTP)

involves the growth if axon and dendrite fibbers at the synapse, changing the physical structure and appearance of the neuron.

rerouting (LTP and LTD)

the formation of new connections between neurons to establish alternative neural pathway

pruning (LTD)

the removal of excess neurons and synaptic connections to increase the efficiency of neural transmission

stressor

is any event that causes stress or is perceived as a threat and a challenge to our ability to cope

stress

a state of mental, emotional, and psychological tension, resulting from a stressor

psychological response to stress

fear
excitement
thoughts

physical responses to stress

increased HR
increased muscle tension

internal stressor

a cause of stress that originates within an individual, it can be either psychological or biological

external stressor

a source of stress that originates outside of an individual. including environmental events and social or cultural stressor such as temperature, planning events, loss of relationship

acute stress

• sudden threat

• short term

• beneficial(helps deal more effectively with the challenge)

chronic stress

stress that lasts for a long period of time. can supress your immune system, upset digestion and reproductive system

fight flight freeze response

an autonomic biological response to a perceived stressor that increases our chance of survival in our environment

role of cortisol in chronic stress

• stressed = adrenaline released (increase heart rate)

• prolonged stress = cortisol released (stay alert longer)

• too much cortisol for a long time can weaken our immune system, making us more likely to get sick and feel anxious or depressed.

General Adaption System (GAS)

Stage 1: Alarm Reaction (GAS)

• initial awareness of stressor

• response to immediate threat

shock (GAS)

-    drop in arousal/resistance which lowers ability to cope with stressor

-    muscle tone, body temperature and blood sugar levels decrease

• acute stress

counter shock (GAS)

-    compensates for acute stress = sympathetic NS activated to release adrenaline + cortisol and  triggering fight, fight freeze response

-    biological responses = increased muscle tension, heart rate, temperature + glucose

-    arousal levels rise above normal

Stage 2: resistance (GAS)

-    occurs when stressor persists over time + body adapts to ongoing presence cortisol increased to repair damage + maximise resources (at peak)

-    increased glucose, fat + protein levels to provide energy and aid repair

-    cortisol suppresses immune system when cortisol released over prolonged time

-    physiological signs of wear + tear occur (cold symptoms, lethargy and headaches)

Stage 3: Exhaustion (GAS)

-  depleted energy levels + bodily resources

- prolonged exposure to stress leads to exhaustion excess cortisol impairs immune system + gut function

-    symptoms = weakness, susceptibility to illness, sleep disturbances, irritability, fatigue, anxiety/depression

-    coping with stressor becomes challenging + managing extra stressors is difficult

strengths and limitations of GAS

Strengths:

-    outlines a predictable physiological response pattern in distinct stages therefore measurable in individuals

-    acknowledges link between chronic stress + illness

-    offers objective insights into biological processes of the stress response

Limitations:

-    developed from rat studies, limits its applicability to humans

-    only emphasizes biological aspects a neglecting psychological factor (emotion + cognition)

-    assumes constant response to all stressors therefore overlooking subjective nature of stress responses that vary among individuals + situations

Transactional model of stress and coping

Appraisal

the process of categorising an event on the basis of its perceived significance and how it may effect our wellbeing

primary appraisal

• whether a situation or event is significant and stressful or not.

• then further categorised into irrelevant, benign, threat, harm/loss, challenge.

• if stressful, something must be done to manage

irrelevant

the situation has no implications for the individuals wellbeing and nothing is gained or lost.

benign

the outcome of a situation is perfervid as positive, maintains or enhances wellbeing, invovles pleasurable emotions

threat

anticipated harm or loss in the future because of the event, fear/anxiety

harm/loss

damage to the individual that has already occurred

challenge

perceived to have potential for personal growth or gain

secondary appraisal

• considering available recourses and coping strategies to decide the best ways of dealing with the stressor.

 

strengths and weaknesses of Transactional model of stress and coping

strengths:

-  tracks individual subjective stress responses

-  considers cognitive/psychological processes within stress responses, unlike biological models

-    created using data from human subjects

-    explains variation in responses to the same stressor

-    offers coping strategies for dealing with stressors

Limitations:

-    primary and secondary appraisal stages may occur at same time, challenging their chronological order

-    individuals may not understand the source of stress, in primary appraisal

-    lacks biological processes, despite stress having both biological + psychological factors

Gut brain axis

• Connection between brain and gut (bidirectional)

enteric NS

• Controls digestion.

• Regulates muscle contractions, gastric acid, and interacts with the immune system.

• communicates to the brain through the vagus nerve.

Vagus nerve

• Connects the brain stem to the colon.

• Controls mood, immune response, digestion, and heart rate.

• Facilitates communication between the brain and gut

Gut microbiota

• Microorganisms residing in the gut.

• Digest food, provide nutrition for body, and influence neurotransmitter production.

• Imbalance leads to dysbiosis     (changes in types + functions of microbiota, loss of beneficial microbiota) or symbiosis (balance of microbiota).

• Influence depression + anxiety and cognitive decline.

relationship between stress, Gut microbiota and NS functions

• high levels of stress + increased cortisol levels = changes to gut microbiota associated with anxiety and depression

• healthy gut microbiome linked with less stress

• healthy diet = more diverse gut microbiome (symbiosis) = leads to decrease in anxiety and depression

• gut microbiota involved in production of serotonin, linked with whether or not levels of depression and anxiety are present

coping

all the things we do to mange and reduce the stress we experience. an attempt to manage the demands of the stressor

coping strategy

method used to reduce the stress produced by the stressor

coping flexibility

the ability to modify our coping strategies to adapt and meet the demands of the different stressful situations.

content specific effectiveness

• matches or is appropriate to the stressor

• meets specific demands to stressor

approach stratagies

• confronting stressor directly

• to reduce or eliminate stressor

• focused towards stress via engagement with stressor

eg. advice seeking, talking through problems with family and friends, making plans on getting control on issue, accountability/responsibility for problem

avoidance strategies

• avoiding stressor

• dealing with it indirectly

• shift focus from stressor

eg. distractions, denial, procrastination, substance use or abuse

emotion focused coping strategies

• target emotional components of stressor

• indirectly dealing

eg. meditation, distraction, denial, wishful thinking

problem focused coping strategies

• directly targeting source of stressor

• aim to reduce in practical way

eg. seeking info/advice, taking action, time management

cortisol function

-    boosts metabolism

-    reduces inflammation

-     increases energy levels + blood glucose levels

-    heightens alertness + brain glucose use

-    enhances tissue repair

-    modifies energy in digestion (function)