BIOPSYCHOLOGY

What is the nervous system?

specialized network of neurons that pass electrical messages around the body to elicit a response and protect from danger

two main functions of the nervous system

collect, process and respond to information in the environment and to co-ordinate the working of different organs and cells in the body

What makes up the CNS?

brain, brain stem, spinal cord

what is the brain?

The centre of all conscious awareness, divided into two hemispheres. outer later (cerebral cortex) is highly developed

What is the spinal cord?

extension of the brain, responsible for reflex actions. passes messages to and from the brain and connects nerves to the PNS

What is the PNS?

peripheral nervous system

Function of PNS

transmit messages via millions of neurons to and from the nervous system

What is the PNS divided into?

somatic nervous system and autonomic nervous system

What is the somatic nervous system?

governs muscle movement and recieves information from sensory receptors

What is the autonomic nervous system?

governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses. transmits information to and from internal bodily organs and operates involuntarily

What are the two divisions of the autonomic nervous system?

sympathetic and parasympathetic nervous system

What is the sympathetic nervous system?

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

What is the parasympathetic nervous system?

the division of the autonomic nervous system that calms the body, conserving its energy

function of endocrine system

works alongside the nervous system to control vital functions in the body through the action of hormones

What are glands?

organs that secrete hormones

What is the pituitary gland?

It is the master gland.

How do hormones work?

secreated into the blood and affect any cell in the body that has a receptor for that particular hormone

how many neurons are in a human?

100 billion, 80% located in the brain

what are the three types of neuron?

Sensory, relay and motor

function and structure of a sensory neuron

carry messages from the PNS to the CNS. have long dendrites and short axons and clump together in the PNS in ganglias

function and structure of relay neuron

connect sensory neurons to motor and other relay neurons, have short dendrites and axons and make up 97% of all neurons

function and structure of a motor neuron

connect the CNS to effectors such as muscles and glands. have short dendrites but long axons

4 main features of a neurons structure

cell body, dendrites, axons terminal buttons

What is the cell body of a neuron?

aka soma, includes a nucleus which contains the genetic material of the cell

What are dendrites?

branchlike structures that protrude from the cell body carry nerve impulses through the cell

What are axons?

Carry impulses away from the cell body

What are axons covered with and what is its function?

mylein sheath that protects the axon

what are gaps in the axon called and what is its function?

nodes of ranvier that speed up the transmission of the impulse

What are terminal buttons?

at the end of an axon, communicate with the next neuron in the chain across the synapse

how do neurons transmit signals?

neuron in a resting state is negatively charged compared to outside the cell. when a neuron is activated, the inside of the cell becomes positively charged for a split second causing an action potential to occur, creating an electrical impulse that travels down the axon towards the end of a neuron

What is a synapse?

Gap between neurons

How are signals between neurons transmitted?

Chemically across the synapse

what chemicals are passed across a synapse?

neurotransmitters

Where are neurotransmitters stored and released from?

synaptic vesicles

what are neurotransmitters taken up by in the next neuron?

postsynaptic receptor sites

give two examples of neurotransmitters

acetylcholine(ACh) and serotonin

What does acetylcholine do?

found where motor neuron meets a muscle, causing the muscles to contract

What does serotonin do?

Affects mood, hunger, sleep, and arousal

what effect can neurotransmitters have on the next neuron?

excitatory or inhibitory

What does an excitatory neurotransmitter do?

increases positive charge of postsynaptic neuron, making it more likely to fire

what does an inhibitory neurotransmitter do?

increases the negative charge of postsynaptic neuron, making it less likely to fire

Example of an excitatory neurotransmitter

adrenaline

Example of an inhibitory neurotransmitter

serotonin

What is summation?

the process of adding up postsynaptic potentials and responding to their net effect

what are the 4 main areas of the brain?

cerebrum, cerebellum, diencephalon, brain stem

What is localisation of function?

The theory that different areas of the brain are responsible for different behaviours, processes or activities.

what are the areas of the brain (localisation of function)?

motor area, somatosensory area, visual area, auditory area, language centers

what are the two language centers in the brain?

Broca's area and Wernicke's area

where is the motor area located in the brain?

At the back of the frontal lobe in both hemispheres

what is the function of the motor area?

controls voluntary movement in the opposite side of the body by sending signals to muscles in the body

Where is the somatosensory area located?

parietal lobe on both sides of the brain

what is the function of the somatosensory area?

Takes in the sensations of touch, pain, temperature, and proprioception

Where is the visual area located?

Occipital lobe in both hemispheres

what is the function of the visual area?

receives and processes visual information. contains different parts that process different types of observation

Where is the auditory area located?

Temporal lobe, both hemispheres.

what is the function of the auditory area?

Analyses speech based information. contains different parts that process different features of sound

Where is Broca's area located?

left frontal lobe

Function of Broca's area

speech production

How did Broca's study lead to the discovery of this area in the brain?

Patient Tan could understand and process speech but could only say, 'tan' due to damage to his left frontal lobe

Where is Wernicke's area located?

left temporal lobe

Function of Wernicke's area

language comprehension

How did Wernicke's study lead to the discovery of this area in the brain?

studies patients who could talk but not understand language due to damage in their left temporal lobe

what us aphasia?

when you lose some aspect of spoken language

what is lateralisation of function?

some mental processes in the brain are specialised to the right or left hemisphere

what does the left hemisphere of the brain control?

language, maths and logic

what does the right hemisphere of the brain control?

spatial abilities, face recognition, visual imagers, music

What is the corpus callosum?

a bundle of nerves that connects the two hemispheres

Who are split-brain patients?

Have disconnected hemispheres

-severed corpus callosum (cut to treat epilepsy)

What was the aim of Sperry's research?

to investigate what functions of the brain are lateralised

Outline 'Sperry's' Procedure.

an image/word was presented to the right visual field (processed by left hemisphere). at the same time the same/different image would be presented to the left visual field

Sperry's findings - describing what you see

image presented to right visual field, could describe. image presented to left visual field, couldn't describe. this is because there are no language centers in the right hemispheres

Sperry's findings - recognition by touch

in left visual field, could select matching object to the word shown with left hand

Sperry's findings - Composite words

one word presented to each visual field at the same time, individual would say word presented to right visual field and select the object presented to their left visual field

Sperry's findings - matching faces

when shown a picture of a face to the left visual field it was picked, face shown to the right visual field was ignored because right hemisphere is dominant in facial recognition

What is plasticity?

the brains ability to change and adapt as a result of experience and new learning

when does the brain grow the quickest?

at aged 2-3 the brain maxes at 15,000 synaptic connections

What is synaptic pruning?

as we grow older, weak neural connections are deleted while strong ones are strengthened, increasing the efficiency of our brains.

Outline Maguire et al (2000) taxi driver study.

found that London taxi drivers had significantly more grey matter in their posterior hippocampus, the part of the brain responsible for spatial and navigational skills

what is functional recovery?

The brains ability to recover after damage by moving the function of the damaged area to an undamaged area.

what are three types of functional recovery?

axonal sprouting, reformation of blood vessels, recruitment of similar areas on opposite hemispheres

what is neuronal unmasking?

the brains ability to reorganise itself by forming new synaptic connections close to the area of damage from inactive neural pathways.

who first discovered neuronal unmasking?

Wall (1977) who studied dormant synapses

What is axonal sprouting?

The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

What are the 4 ways of studying the brain?

fMRI, EEG, ERP, post-mortem

ways of studying the brains - fMRI

scans absorbed by deoxygenated blood in the brain. areas with high activity will require more blood so shows up on scans

ways of studying the brains - EEG

electrodes attached to scalp, measures electrical activity across the brain. used to diagnose unusual arrhythmic patterns of activity

ways of studying the brains - ERP's

an EEG but a stimulus is presented to an individual. researcher looks for a particular activity relating to the stimulus

ways of studying the brains - post mortem

comparing a patients brain with a healthy brain after death. differences found could have been cause for neurological issues that could have arisen in their lives

what is a biological rhythm?

Distinct patterns of changes in body activity that conform to cyclical time periods

what are the three types of biological rhythms?

Circadian, Infradian, Ultradian

What is a circadian rhythm?

A type of biological rhythm, subject to a 24-hour cycle, which regulates a number of body processes such as the sleep/wake cycle and changes in core body temperature.

what two things affects biological rhythms?

endogenous pacemakers (internal) and exogenous zeitgebers (external)

What are endogenous pacemakers?

Internal body clocks that regulate many of our biological rhythms.

What are exogenous zeitgebers?

external factors which may affect or adjust our biological rhythms

Siffre's cave study

Siffre lived in caves for long periods of time to test the internal body clock. found he would sleep in 25 hour cycles, suggesting the natural sleep/wake cycle may be longer than 24 hours

Outline Folkard et al's study

studied 12 people who lived in caves for 3 weeks. they went to bed when the clock said 11.45 and woke when it said 7.45. researchers gradually sped up the clock so a day only lasted 22 hours but only one ppt adjusted to the cycle

What does Folkard's study suggest?

circadian rhythm cannot be easily overridden by changed to the external environment.

What is an infradian rhythm?

a biological rhythm that takes more than a day

What is an ultradian rhythm?

A biological rhythm which occurs more than once a day.

what is an example of an infradian rhythm?

menstrual cycle