biological approach

what is localisation of function?

the assosciation of certain brain regions with particular behaviours and functions.

what is the role of the hippocampus in memory?

information from the STM travels to the hippocampus, where specialised proteins strengthen the cortical synaptic connections and transfer the memory into the cortex for permanent storage in the LTM

what is hemispheric lateralisation?

the specialisation of one hemisphere of the brain over the other in the performance of certain functions.

what is contralateral organisation?

the phenomena where each brain hemisphere controls movement in the opposite side of the body

what is the role of the corpus callosum?

it is a bundle of nerve fibres in the middle of the brain that enables communication between the two hemispheres

what are the functions/roles of each of the hemispheres of the brain?

LEFT

• language

• logical reasoning

• verbal tasks

• broca’s area (production / articulation of speech)

• wernicke’s area (comprehension and production of meaningful speech)

• controls voluntary movement of right side

RIGHT

• visual - motor skills

• facial recognition

• creativity

• emotions

• controls voluntary movement of left side

Explain one reason why researchers and health professionals in fields like psychology, neuroscience, or medicine should understand which brain regions could be responsible for different localised functions. Refer to a specific example in your response.

An understanding of localisation of brain function can assist neurosurgeons when conducting procedures.  For example, it can help avoid damage to brain areas critical for specific functions when removing brain tumours.

what are the two types of neuroimaging and what do they show?

structural neuroimaging — static imaging that shows brain structure + anatomy.

functional neuroimaging — dynamic imaging that provides information about brain structure and activity.

what are the four types of brain scans?

• CT scan (computerised tomography)

• mRI scan (magnetic resonance imaging)

• PET scan (positron emission tomography)

• fMRI scan (functional magnetic resonance imaging)

describe how CT scans work, what they measure, and benefits + limitations

CT scans use xrays to scan the brain at different angles and compile cross-sectional images

measure brain structure

benefits:

• quick

• widely available (less expensive)

• can quickly identify structural damage

limitations:

• radiation exposure

• less detailed than mRI

describe how mRI scans work, what they measure, and benefits + limitations

mRI scans use magnetic fields and radio waves to produce detailed images of the brain

measure brain structure

benefits:

• high quality images

• no radiation

limitations:

• no info on brain activity

• cant be used with metal implants

describe how PET scans work, what they measure, and benefits + limitations

PET scans inject a radioactive tracer to record glucose metabolism and brain activity during cognitive tasks

measures brain activity

benefits:

• shows deep brain function

• can record brain activity over periods of time

• can identify inactive brain regions

limitations:

• invasive (radiation exposure)

• low resolution

• expensive

• correlational, not causal

describe how fMRI scans work, what they measure, and benefits + limitations

fMRI scans detect changes in oxygenated blood flow in response to neural activity, with images averaged across seconds

measure brain activity

benefits:

• non-invasive

• high resolution

• shows both structure and function

• brain activity in real time

limitations:

• expensive

• correlational, not causal

what is a neurotransmitter?

a chemical messenger that allows neurons to communicate with each other and with other cells in the body

what is a synapse?

 the site of transmission of electric nerve impulses between two neurons

how do neurotransmitters travel, and what role do they play in neural communication at a synapse?

At a synapse, neurotransmitters act as chemical messengers, relaying signals between neurons. They are released from the presynaptic neuron, cross the synaptic cleft, and bind to receptors on the postsynaptic neuron, influencing its activity. This process converts an electrical signal into a chemical signal and back again, enabling communication within the nervous system. 

name the three components of a synapse and outline their roles in communication between neurons

1. the axon terminal (presynaptic terminal)

2. the synaptic gap

3. dendrite (postsynaptic membrane)

The presynaptic terminal, typically at the end of an axon, releases neurotransmitters. These neurotransmitters travel across the synaptic cleft, a narrow gap, to reach the postsynaptic membrane, often on a dendrite. There, the neurotransmitters bind to receptors, initiating a signal in the postsynaptic neuron, either exciting or inhibiting its firing.

Distinguish between excitatory and inhibitory effects of a neurotransmitter with reference to glutamate and GABA.

Glutamate is the primary excitatory neurotransmitter, increasing the likelihood of an action potential, while GABA is the main inhibitory neurotransmitter, decreasing that likelihood. 

Outline the chemical neurotransmission process with reference to the lock and key model.

A neurotransmitter, the ‘key’ binds to a specific receptor, the ‘lock' on a neighboring neuron, triggering a response. This interaction either excites or inhibits the receiving neuron, influencing the transmission of nerve impulses.

what are agonists and antagonists?

agonists are chemicals that increase or mimic the effect of a neurotransmitter. they bind to receptors and activate them.

antagonists are chemicals that block or inhibit the effect of a neurotransmitter. they bind to receptors but dont activate them.

describe the process of neurotransmission

1. the presynaptic neuron fires an action potential that travels down the axon

2. once it reaches the axon terminal, vesicles containing neurotransmitters are prompted to to release

3. the neurotransmitters are released into the synaptic cleft, where they bind with the receptor site of the dendrite of the postsynaptic neuron

4. the signal is transmitted, either firing or inhibiting the action potential

5. leftover neurotransmitters in the synaptic cleft are either broken down by enzymes or reuptaken by the axon terminal

limitations of the neurotransmission theory

• reductionist theory — may be an oversimplification od complex human behaviour

• research can only be done indirectly and relies on fMRI technology (limitations of fMRI are therefore limitations of neurotransmission research)

what is neuroplasticity?

the brain’s ability to change its structure and function in response to environmental inputs.

what is a neural network?

a group of neurons that are connected and communicate with each other.

what is long term potentiation?

the strengthening of connections between neurons through repetition and practise.

what is neural pruning?

the weakening and eventual elimination of connections between neurons due to lack of use.

aloows the brain to become more efficient by removing unecessary or unused pathways.

what is a hormone?

chemical messengers that control / influence physiological processes in the brain and body and produe a slow, sustained response over a period of time.

where are hormones produced and released?

produced by glands in the endocrine system, and released into the bloodstream

what is the function of hormones?

they change the probability of a certain behaviour occuring by binding to the receptors of target cells and launching a sequence of changes.

what is stress?

a state of physiological and psychological arousal produced by an internal or external stressor/s.

what is a stressor and what are the types of stressors?

anything that causes stress

internal — originates WITHIN the individual

external — originates OUTSIDE the individual

what is a stress response and what are the types of stress responses?

reaction to a stressor, including both physiological and psychological changes

acute — suddenly produces a high arousal level for a relatively short amount of time

chronic — produces a high arousal level that persists for an extended period of time

what are the types of stress?

eustress — good stress creating a positive psychological response

distress — bad stress creating a negative psychological response

what are pheromones?

chemical communication within members of the same species

plays a role in the mating behaviour of animals

arguments for and against pheromones

FOR'

• present in other mammals

• humans also secrete scents, similarly to other animals

• some evidence that babies respond to pheromones during breastfeeding

AGAINST

• human mating behavious is impacted by coginitive + sociocultural factors

• poor evidence from studies — construct validity issues , cofounding variables, not replicable

• humans dont have a VNO or accessory olfactory bulb

what is epigenetics?

the study of changes in gene expression that occur without changes to the DNA sequence

what is the nature vs nurture debate?

a debate regarding the impact of genetics vs environment on the behaviour and characteristics of individuals.

what is the concordance rate?

a statistical measure used to determine the likelihood that two individuals will share a particular trait / characteristic

how do twin studies work?

researchers study the concordance rate of a behaviour in monozygotic twins, dizygotic twins, and siblings. if a behaviour is genetic, two more genetically similar indiviudals will exhibit the behaviour more commonly.

describe the two phase model of the fight-flight-freeze response

PHASE 1 — SAM

activation of the sympathetic nervous system

when a threat is percieved:

1. a signal is sent to the hypothalamus, activating the sympathetic nervous system

2. the sympathetic nervous system stimulates the adrenal medulla

3. the adrenal glands secrete adrenaline / noradrenaline

PHASE 2 — HPA AXIS

when the body can no longer maintain the intensity of the fight/flight response and adrenaline is depleted, cortisol is released to fill in

1. the hypothalamus activates the pituitary gland, which releases ACTH / cortisol

2. ACTH travels through the bloodstream to the adrenal glands, trigerring the release of corticosteroids.

nce the level of corticosteriods, the hypothalamus is signalled to turn off the stress response.

what causes a freeze state?

the simultaneous activation of both the sympathetic and parasympathetic NS, leaving the body in a state of both energy-conservation and mobilisation at the same time