Biopsychology

what is the Somatic nervous system

responsible for:

• voluntary muscle movements

• reflex actions

• processing sensory information

What is the peripheral nervous system

Transmits Info to and from CNS

• breaks into somatic and autonomic

what is the Autonomic nervous system

• controls vital functions in the body - all involuntary processes.

• made up of two sub branches - parasympathetic and sympathetic

what is the parasympathetic nervous system for

• homeostasis (rest and digest) contracted pupils, stimulates digestive system, slow heart beat

what is the sympathetic nervous system responsible for

• fight or flight response - increased heart rate, dilated pupils, relaxed bladder

what are the 3 major glands in the brain

• Hypothalamus - centre of brain - maintains homeostasis, body temp and heart rate

• Pineal gland - controls circadian rhythms - Melatonin

• pituitary gland - master gland directs a lot of hormone activity - ACTH

what are the two glands in the neck

• thyroid - regulates metabolism - T3 and T4

• Thymus - production of white blood cells

what are the four glands near the bladder

• pancreas - aids digestion - insulin, glucagon, gastrin

• Adrenal gland - essential for survival - adrenaline

• testes - maintain health of reproductive system - testosterone

• Ovaries - primary reproductive organ - oestrogen, progesterone

what is the motor cortex

• frontal lobe

• involuntary movements

• loss of movement if damaged

what is the somatosensory cortex

• parietal lobe

• sensations ( sight, taste, touch)

• no sensations if damaged

what is the visual cortex

• occipital lobe

• processes visual information

• damage would result in opposite field of vision

what is the primary auditory cortex

• temporal lobe

• processes speech based information

• damage can result in hearing loss

what is Broca’s area

• frontal lobe

• speech production

• damage can cause loss of speech (Broca’s aphasia)

what is Wernicke’s area

• temporal lobe

• speech comprehension

• damage could lead to Wernicke’s aphasia

positive evaluations for localisation of function

P - supporting evidence from brain scans and case studies

E - Tulving - different types of LTM, Peterson Wernicke’s area and Broca’s area

E - Phineas Gage - pole through head

L - show evidence on how the brain is localised

Negative evaluations of localisation of function

P - Lashely’s research suggests that cognitive functions work more holistically

E - found that no one area of a rats cortex was responsible for memory

E - learning seemed to require every part of the cortex

L - higher cog processes not localised

P - language may not just be localised to Broca’s and Wernicke’s area

E - Dick and Tremblay - 2% modern researches think language completely controlled by these areas

E - scans such as FMRIs shows language is distributed more holistically

L - contradicts localisation of function

What are hormones

• chemical messenger produced by glands that travels through the bloodstream to affect target organs and influence behavior, mood, or bodily functions

what are Neurotransmitters

• released by nerve terminal

• has immediate effect

• direct effect on next neuron

how does a signal travel through a neuron

what does a neuron contain

• dendrites - receive signals

• cell body - contain nucleus

• nucleus - where genetic material is contained

• Axon - carries impulses to the axon terminals

• Myelin sheath - protects axon so impulses can travel faster made up of Schwann cells

• Axon terminals - contains neurotransmitter

what is a motor neuron

• carries impulses from the CNS to the effectors (muscles and glands)

• short dendrites and long axons

what is a relay neuron

• carries impulses from sensory neurons to motor neurons

• have short dendrites and short axons

what is a sensory neuron

• carries signals from PNS to CNS

• have long dendrites and short axons

• translated into sensations

what is the process of synaptic transmission

1. action potential travels down the axon of the pre-synaptic neuron

2. Vesicles release neurotransmitter into synaptic cleft

3. neurotransmitters are received by post synaptic receptors

4. excess neurotransmitters are taken up by the pre-synaptic neuron reuptake pump

5. enzymes are released into cleft to break down remaining neurotransmitters

what is an excitatory neurotransmitter

positively charged neurotransmitters that make a neuron more likely to fire (dopamine)

what is an inhibitory neuron

negatively charges neurotransmitter that make a neuron less likely to fire (serotonin)

what is action potentials

when the cell is positively charged action potentials occur

what is summation

whether or not a neuron fires another action potential based on the overall charge of neurotransmitters

what is the left hemisphere dominant in

language and speech

what is the right hemisphere dominant in

visual and motor tasks and facial recognition

what was the aim and method of Sperry’s split brain research

• to investigate to what extent the brain is lateralised

11 epileptic patients who has there corpus callosum severed where given 4 tasks

1. describe what you see - shown a picture of an object in both fields

2. recognition by touch - shown object and had to select matching object from grab bag

3. two words shown simulationsly which had to be written down and spoken

4. matching faces - matching face from a series of faces

what were the findings of sperry’s research

1. describing what you see - patient could only describe when item in right visual field

2. recognition by touch - were able to pick out items with left hand

3. composite words - patient would be able to say word in right visual field and draw word in left visual field

4. matching faces - left visual field was most accurate

positive evaluations for hemispheric lateralisation

P - Sperry’s research

E - method

E - showed how left and right hemispheres carried out different tasks more effectively

L - suggests certain functions are lateralised

Negative evaluations for hemispheric lateralisation

P - Sperry’s research lacks generalisability

E - only 11 participants took part in all variations

E - behaviour was compared to neurotypical control and found it was a major confounding variable

L - results may be due to epilepsy rather than split brain

P - language centres not always in left hemisphere

E - left handed may have language control centres in either hemisphere

E - leading to neurosurgeons finding which hemisphere is dominant in language to minimise cog effects

L - however results would just be opposite

what is synaptic pruning

where the brain deletes rarely used connections and strengthens frequently used connections

study’s supporting synaptic pruning

Maguire et al - black cab drivers had increased volume of grey matter in area of brain when studying for exam

Draganski - brain scans on medical students before and after exams - showed changes to partial cortex and posterior hippocampus

infomation about the infant brain

peak synaptic connections at 2-3 - 15000

as get older connections half

what are the three types of functional recovery

Axonal sprouting - growth of new nerve endings which connect to undamaged nerves

Denervation super sensitivity - remaining neurons become more sensitive to compensate

recruitment of homologous areas - areas in other hemisphere that are not damaged work harder

Positive evaluations of plasticity and functional recovery

P - has practical applications in helping brain injury recovery

E - forms of physical therapy now used to maintain improvements in functioning

E - these types of therapy used with stroke patients to practice using effected parts of the body

L - helps patients suffering from brain injuries such as strokes

Negative evaluations of plasticity and functional recovery

P - plasticity can have negative effects such as

E - prolonged drug use can lead to poorer cognitive function as well as increased risk of dementia

E - also 60-80% of amputees develop false limb syndrome. thought to be caused by issues in the somatosensory cortex

L - suggests that brains ability to adapt to damage is not always beneficial

P - idea that plasticity slows with age is also questionable

E - Bezzola et al - showed how 40 hours of golf training produced changes in neural representation of movement in participants aged 40 - 60

E - scans found that there was more efficient neural representations after training

L - shows neural plasticity does continue throughout life span

what is an FMRI and is positives and negatives

FMRIS detected changes in blood flow to regions of the brain and show 3d images of active areas

+ non invasive, high spatial resolution, objective method

- costly compared to other techniques, poor temporal resolution, doesn’t directly measure neural activity

what is an Post-mortem and is positives and negatives

analysis of a persons brain after death

+ allows for examination in greater detail, allowed for areas to be discovered - Broca’s

- need consent before death, only retrospective data, age and drug use can effect brain structure

what is an EEG and is positives and negatives

measures electrical activity via electrodes using a skull cap

+ high temporal resolution, cheap

- generalised signal from thousands of neurons hard to pinpoint, doesn’t detect deep brain activity

what is an ERP and is positives and negatives

ERPs are EEGs with extraneous brain activity filtered out

+ cheap, non-invasive, high temporal resolution

- difficult to eliminate all extraneous activity,

what are Biological rhythms

controlled by endogenous pacemakers (internal clocks) and exogenous zeitgebers (external cues) circadian rhythms are biological rhythms which occur around 24 hours

what was Siffre’s cave study

• Siffre spend 2 months in a cave away from natural light

• Body clock extended due to lack of external cues - sleep wake cycle was around 25 hours and thought it was a month earlier when he emerged

What was Aschoff and Wevers study

• participants spent 4 weeks in a world war 2 bunker without natural light

• All displayed normal circadian rhythms of 24-25 hours

What was Folkard et als study

• 12 people in a cave for 3 weeks and following a clock for sleep wake

• researchers sped up clock so that day only 22 hours

• 1 comfortably adjusted

Positive evaluations for circadian rhythms

P - Better understanding of consequences of disruption

E - E.G. night shift experience period of reduced concentration around 6am - leading to accidents

E - research has also pointed to a link between shift work and bad health - 3 times more likely to develop heat disease

L - real world app of how to be most efficient

negative evaluations of circadian rhythms

P - research is difficult to generalise

E - Aschoff and Weaver - small samples potential for variation of cycles

E - Czeisler found individual differences in cycle 13-65 hours

L - difficult to use as research only shows averages

P - Poor control in studies

E - Siffre’s study exposer to artificial lights was not controlled

E - Czeisler found that dim lighting could adjust between 22 - 28 hours

L - results may lack validity as sleep cycle may vary more

What is the Suprachiasmic nucleus

A tiny bundle of nerves, that is the main endogenous pacemaker

• plays crucial role in sleep/wake cycle as it receives info from the optic chasuim on light and adjusts accordingly when dark it secretes serotonin

What was Ralph et al’s study on

bred mutant hamsters with a 20 hour sleep cycle then transferred the SCN cells to a normal hamster it then also had a 20 hour sleep cycle

what was Morgan’s study

removed hamsters SCN and found that there circadian rhythm disappeared when it was replaced it came back