Biopsychology AQA alevel psychology

What makes up the central nervous system?

brain and spinal cord

What makes up the peripheral nervous system?

somatic and autonomic nervous system

What makes up the autonomic nervous system?

sympathetic and parasympathetic branch

Role of the brain (CNS)

issues orders to muscles, glands, organs, interprets information from senses

Role of the spinal cord (CNS)

body and brain communication, info from brain to muscles and glands, relays and regulates information

Role of somatic nervous system

transmit and receive messages e.g. visual and auditory

Spinal nerves

sensory info into spinal cord, motor commands out

Cranial nerves

carry info out brain (e.g. vision, taste etc.)

Sensory neurons

relay info to CNS (e.g. senses)

Motor neurons

info from CNS to other areas to control actions

Role of autonomic nervous system

involuntary actions such as heart beating and digestion, transmit and receive, maintain homeostasis

Sympathetic branch

increases activity for fight or flight response

Parasympathetic branch

decreases activity to stop fight or flight response

Role of the endocrine system

produces and secretes hormones e.g. pituitary gland, adrenal glands, testes and ovaries

What is the outer part of the adrenal glands?

adrenal cortex

What is the inner part of the adrenal glands?

adrenal medulla

What does the adrenal cortex produce?

cortisol (stress hormone)

aldostrene (maintenance)

What does the adrenal medulla produce?

adrenaline and noradrenaline

Ovaries explanation

- plays a role in female reproduction and egg production

- oestrogen and progesterone (post ovulation)

Testes explanation

- produces testosterone

- develops male features e.g. facial hair, growth spurts

Hypothalamus signals to PG how much testosterone needs to be produced. Signal is sent to the testes to produce testosterone

Short term fight or flight response (sympathetic adrenal medullary pathway) SAM

Hypothalamus detects stress. Activates the autonomic nervous system (sympathetic branch). Adrenal medulla activated and produces adrenaline. Causes a physiological reaction. Parasympathetic branch later activated to reduce symptoms and produce noradrenaline.

Long term fight or flight response (hypothalamic pituitary pathway) HPA

Hypothalamus stimulates CRF release which targets the pituitary gland. Pituitary gland produces ACTH which travels to adrenal cortex. Adrenal cortex produces cortisol which is converted to glucose.

Role of neurons

receive and transmit information to other cells

Relay neurons

signals between parts of CNS, connects motor and sensory

- found in brain, visual system and spinal cord

Synaptic transmission

Travels down neuron to post-synaptic terminal. Chemicals released as synaptic vesicles into synaptic fluid in synaptic cleft. Post synaptic receptor sites receive message and convert into electrical impulse. Remainder in synapse is reabsorbed.

Excitation and inhibition

Specific ion channels, causes potential in dendrites

Excitatory = dopamine

Inhibitory = serotonin

What is brain localisation?

theory of different areas of the brain responsible for different behaviours

Phineas Gage

1848, explosive ignited on railway to cause an explosive to pass through left cheek and eye (through frontal lobe). Survived but caused him from being calm to become quick tempered

Pons, midbrain, medulla oblongata

responsible for regulating basic functions such as heart and lungs

Frontal lobe

thinking, planning, etc.

emotions, behaviour and personality

Temporal lobe

memory, language and understanding

Parietal lobe

sense of world/perception, spelling

Occipital lobe

vision

Broca's area

speech reproduction (not nouns and verbs), can cause Broca's aphasia

Wernicke's cortex

understanding language, inability or damage can cause anomia

Motor cortex

muscles signals, through brain stem and spine (voluntary movement)

Pre-frontal cortex (part of motor cortex)

sensory information prior to movement

Pre-motor cortex (part of motor cortex)

plans movement

Somatosensory cortex

bodily sensations and touch

Left hemisphere of the brain

- smaller details

Broca and Wernicke, language processing

Right hemisphere of the brain

- overall patterns

emotional recognition, spatial awareness

Amygdala

social, sexual behaviour

Thalamus

motor and sensory (cerebral cortex)

Hypothalamus

controls body systems (endocrine, homeostasis)

Hippocampus

short term memory

Cerebellum

movement, time, emotion, some learning and memory

Brain stem

information communicated between body and higher brain

Localisation of neurological disorders (brain localisation eval)

removal of areas of the frontal lobe (in severe cases of OCD and depression) controls behavioural aspects

- may have caused some aggressive behaviours

Brain plasticity definition

the ability for brain structure and neurological paths to change throughout your life

there is rapid growth in synaptic connections during infancy

How does brain trauma cause the brain to develop?

reorganises itself by forming new synaptic connections

- secondary neural pathways enables functions to occur in same way as before

Reforming blood vessels (brain plasticity)

occurs during brain plasticity

Increased brain stimulation (brain plasticity)

Takatsuru - if undamaged hemisphere is stimulated recovery from a stroke can be improved

Recruitment of homologous (brain plasticity)

areas on the opposite side of brain perform specific tasks. may cause functionality to shift back in time

Axonal sprouting (brain plasticity)

damaged with neighbouring neuron, may sprout connections to replace old ones

Denervation supersensitivity (brain plasticity)

axons that do a similar job become aroused to a higher level, over sensitivity may cause pain

Practical application (brain plasticity eval)

neurorehabiliation may be needed to maintain improvements, may require further intervention to completely successful

recovery tends to slow down after a few weeks

Medina (brain plasticity eval)

prolonged drug use means poorer cognitive functions and increased chance of dementia

- amputees may develop phantom limb syndrome sensation in missing limb due to reorganisation in somatosensory cortex

Age and plasticity (brain plasticity eval)

plasticity tends to reduce with age, better prosperity for reorganisation during childhood as consistent adaptation in brain

Synaptic pruning

disused connections deleted, used connections strengthened

Event related potentials

EEG statistical analysis, averaging technique, ERPS filtered out leaving responses relating to

Event related potentials strengths

describes precise roles of these cognitive processes

Event related potentials weaknesses

standardisation between different studies, background noise and extraneous variables may effect analysis of results

EEG (electroencephalogram)

electrodes attached to cap to record electrical impulses produced by brain activity (diagnoses certain conditions)

EEG strengths

invaluable for diagnoses such as epilepsy as easily detectable, high resolution, understanding stages of sleep

EEG weaknesses

cannot pinpoint exact source of neural activity or distinguish between activities

Post mortem examinations

analysis after death to examine linked abnormalities, may compare with neurological brain to assess extent

Post mortem examinations weaknesses

ethical issues, may be related to unrelated trauma or decay

Post mortem examinations strengths

understanding of key processes (Broca and Wernicke)

Functional magnetic resonance imaging (fMRI)

MRI technology used to measure brain activity

- detection of oxygen levels in brain, 3 dimensional images produced

Functional magnetic resonance imaging (fMRI) strengths

risk free, non-invasive, straightforward, high resolution

Functional magnetic resonance imaging (fMRI) weaknesses

expensive, can be unclear, may be difficult to tell what kind of brain activity is represented

What is a split brain?

a condition caused by removing the corpus collosum - it is cut to contain epilepsy into one hemisphere of the brain to reduce fits

What is hemispheric lateralisation/contra-lateralisation?

right hemisphere controls the left side, left hemisphere controls the right side

What are biological rhythms?

periods during of biological and physiological processes e.g. growth, temperature, appetite, menstrual cycle

Ultradian rhythms

shorter than 24 hours

What is REM sleep? (ultradian rhythms)

rapid eye movement

- characterised by being muscles being paralysed to not act out dreams, increased heart rate and brainwaves

What is stage 1 of sleep?

falling asleep, reaching a hypnogogic state, desynchronised brain waves

What is stage 2 of sleep?

light sleep, aware of surroundings, senses still activated, easily woken, sleep spindles (surge of electrical activity), k-complexes (electrical activity due to environmental stimuli) occur

What is stage 3/4 of sleep?

deep sleep, no senses, difficult to wake up, synchronised brain waves

How is brain activity measured?

electrical brain activity (EEG)

eye movement (EOG)

muscle movement (EMG)

Sleep cycle process

stage 1, stage 2, stage 3, stage 4, stage 3, stage 2, REM, stage 2, cycle repeats, occurs every 90 minutes

What is an infradian cycle?

longer than 24 hours e.g. menstrual cycle

Menstrual cycle as an infradian cycle

28 days, studies involve pheremones and synchronisation

4-5 before bleeding, 68% of females experiences change

may be controlled my exogenous zeitgebers

SAD as an infradian cycle

SAD (seasonal affective disorder), more melatonin is released during the day due to less light, causing more depressive symptoms

Exogenous zeitgebers

external environmental cues, such as light, dark, temperature, seasons

Endogenous pacemakers

internal body clock

Relationship between EPs and EZs

light receptors located in eye take in light

optic nerve to hypothalamus

SCN (internal body clock) to pineal gland

pineal gland secretes serotonin for as long as light is taken in

melatonin produced in dark hours

What are circadian rhythms?

every 24 hours such as sleep wake cycle

Shift work (disruption to bio-rhythms)

listed in the international classification of sleep disorders

sleep during the day can cause disruption to social activities, sunlight and noise

electric light changed society as we can now rely on electricity instead of natural light and dark patterns

average sleep time has decreased by 1.5hrs

body prepares us for sleep between 2am and 4am - accidents can occur during night shift work at these hours such as Chernobyl

Jetlag (disruption to bio-rhythms)

caused when there is a dislocation between our body clock and local zeitgebers

can cause extreme tiredness, depression, slowed mental and physical reactions

phase delay = delaying our cycle

phase advance = advance our cycle

frequently worse when travelling west to east