Biopsychology

Question 1

Briefly outline the types of neuron

Answer 1

Motor- carries messages from CNS to muscles and glands

Sensory- carries messages from the PNS to the CNS

Relay- carries messages from sensory to motor neurons or other relay neurons

Question 2

Describe the structure of a neuron

Answer 2

Contains a cell body
Dendrites which carry nerve impulses towards the cell body
Axon covered in myelin sheath to speed up message
Terminal buttons that communicate with the next neuron in the chain

Question 3

Describe a sensory neuron

Answer 3

Found in receptors
Carry nerve impulses from the PNS to the CNS
Translated into sensations when they reach the brain
Some stop at the spinal cord for reflex actions

Long dendrites and short axons

Question 4

Describe a relay neuron

Answer 4

Most common
Only found in the CNS
Connect sensory neurons to motor or other relay neurons

Short dendrites and short axons

Question 5

Describe a motor neuron

Answer 5

Carry messages from CNS and control motor movements
When stimulated, release neurotransmitters that bind to receptors on muscle and trigger a reaction
Muscle relaxation = inhibition

Short dendrites and long axons

Question 6

Describe synaptic transmission

Answer 6

Nerve impulse travels down the axon of a pre-synaptic neuron

End of axon, neurotransmitters are released from vesicles within the pre-synaptic neuron

These diffuse across the synapse

Neurotransmitters bind to receptors on the post-synaptic neuron

Stimulates post-synaptic neuron to transmit a nerve impulse down its axon, to the next neuron

Neurotransmitters deactivate by being reabsorbed back or being broken down by enzymes

Question 7

Describe excitation and inhibition

Answer 7

Inhibitory neurotransmitters result in the neuron becoming negatively charged and less likely to fire- inhibitory synapse

Excitatory neurotransmitters ie dopamine, causes neuron to increase its positive charge and making it more likely to fire.

Question 8

Describe summation

Answer 8

After receiving inhibitory and excitatory at the same time,
Combined and added up

Question 9

Describe the peripheral nervous system

Answer 9

Transmits messages via millions of neurons to and from the CNS.
Relay nerve impulses from the CNS to the rest of the body and from body back to CNS.

Divided into

Somatic nervous system-
Voluntary actions,
Senses- carry motor and sensory info to and from CNS

Automatic nervous system-
Vital functions
Carries only motor info to and from the CNS

Question 10

Describe the somatic nervous system

Answer 10

Controls voluntary actions
Carries sensory and motor information from the senses to the CNS and back

Part of the peripheral nervous system

Question 11

Describe the sympathetic nervous system

Answer 11

Involved in responses that help us deal with emergencies
Fight or flight

Neurons preparing the body for rapid action,
Release stored energy
Pupils to dilate
Slows down digestion and urination

Question 12

Describe the automatic nervous system

Answer 12

Involuntary/ vital actions
Eg, breathing, increasing heart rate

Carries only motor information from senses to and from the CNS

Divided into;

Sympathetic nervous system
Parasympathetic nervous system

Question 13

Describe the parasympathetic nervous system

Answer 13

Returning the body to a rest state once the emergency has passes
Rest and digest

Slow heartbeat

Bodily processes inhibited by sympathetic are returned to normal

Question 14

Describe the fight or flight response

Answer 14

After acute stressor,
Hypothalamus directs the sympathetic branch of ANS to send neurotransmitters to the adrenal medulla

Releases adrenaline into the bloodstream
And noradrenaline

Triggers physiological reactions

Question 15

What is meant by localisation of function

Answer 15

Specific functions have specific locations within the brain

If a certain area is damaged, the associated function will also be affected

Question 16

State 7 parts of the brain and where they are

Answer 16

Auditory cortex,
Temporal lobe either side of the brain

Motor cortex,
Back of the frontal lobe

Somatosensory cortex,
Next to the motor cortex, at the front of the parietal lobe

Visual cortex,
In the occipital lobe at the back of the brain

Broca’s area,
Left frontal lobe

Wernicke’s area,
Small area in left temporal lobe

Question 17

Describe support for localisation of function

Answer 17

Supported by case study evidence,
Man who could only say Tan. Broca performed an autopsy, found a lesion in a region of his brain,
Concluded that his aphasia was caused by damage to the area that controlled speech.
Increases validity,
H Lacks external validity, based on one individual
Phineas gage

Brain scan research

Peterson et al demonstrated how W’s area was active during listening tasks and Broca’s was active during a reading task.
Tulving et al
Episodic and semantic memories recalled from different sides of the prefrontal cortex whilst procedural in the cerebellum
Demonstrates how specific brain regions are active

Question 18

Define hemispheric lateralisation

Answer 18

The idea that these two hemispheres of the brain are functionally different,
Certain mental processes and behaviours are mainly controlled by one hemisphere rather than the other

Question 19

What connects the two hemispheres

Answer 19

Corpus callosum
Bundle of fibres
Communication pathway do that they can exchange information

Question 20

Loosely describe the left hemisphere

Answer 20

Language processing
Strokes often lead to speech impediments in broca or wernicke area

Question 21

Loosely describe the right hemisphere

Answer 21

Facial recognition
Spatial relationships

Question 22

Evaluate hemispherical lateralisation

Answer 22

Supporting evidence
Fink
PET scans to identify active areas during a visual processing task
Ps asked to attend to elements of an image, right hem active
Finer detail, left hem active
Tasks such as visual processing are feature of connected brain

Plasticity
When damaged, brain can adapt to reorganize itself to recover the function
Turk et al,
Brain damage to left hemisphere developed capacity to speak in right hem
Undermines lateralisation, can be distributed

Animal research
Lashley
Removed 10-50% of cortex in rats and got them to learn a maze
Found that there were no important areas
Suggests higher cognitive processes like learning are distributed holistically
Reduces validity of theory, challenges

Lateralisation may be further complicated by age
Szflarski
Language became more lateralised to the left hem as children developed,
After 25, lateralisation decreased with each decade
Suggests lateralisation is a more complex process, unanswered questions
Challenges how stable it is throughout our lives.

Question 23

Describe research into split-brain studies

Answer 23

Sperry
11 split brain patients

Procedure:

Verbal recognition-
A visual image presented to LVF with a tachistoscope.
Ps asked to describe what they had seen.
Repeated on RVF

Touch recognition-
Ps hands screened
Asked to pick up object with right hand and asked to describe.
Repeated with left

Findings:

Verbal recognition-
When picture shown in RVF, patients would easily describe.
If on left, reported there was nothing there
Bc
Lacked language ability to describe it

Touch recognition-
Able to select matching object from a bag with left hand.
In each case patient couldn’t verbally describe but could understand what the object was using right hem and select corresponding object accordingly

Question 24

Evaluate research into split-brain studies

Answer 24

Supports lateralisation
Image flashed quickly to make sure info couldn’t pass to other hem
Ensures research measured what it intended to
Methodology is high,y standardised, reliable, internally valid

Flawed
Only 11 patients used who had history of epileptic seizures and had drug therapy- unique sample
Problematic
Undermines validity, confounding variables, weaken reliability

Question 25

State 4 methods of studying the brain

Answer 25

fMRI
EEG
ERP
Post mortem

Question 26

Describe functional magnetic resonance imaging

Answer 26

Detects changes in blood oxygenation and flow in the brain.
When area of the brain active, consumes more oxygen as the haemodynamic response)

Produces 3D images showing which part of the brain is involved in particular mental processes

Shows activity 1-4 seconds after an event occurs
Accurate within 1-2mm

Question 27

Evaluate fMRI

Answer 27

Less invasive,
Don’t use radiation or require insertion into the brain,
Risk free

Good spatial resolution
1-2mm
Allows R to investigate brain regions with greater accuracy

Expensive
Require trained operators
More difficult to organize, less attainable

Low temporal resolution
1-4 seconds , worse than others
Unable to predict with a high degree of accuracy the onset of brain activity

Question 28

Describe electroencephalogram

Answer 28

Places electrodes on Ps scalp to measure electrical activity in the brain
Records brainwave patterns generated from millions of neurons

Provides real time recording

Question 29

Describe Event-Rekated potentials

Answer 29

Uses a stimulus with the EEG to filter recordings leaving only event related potentials

Question 30

Evaluate EEG and ERP

Answer 30

Less invasive than other techniques like PET scans,
Don’t use radiation or inserted instruments

Cheaper methods in comparison to fMRI, more widely available.
Help to gather data leading to a greater understanding of sleeping and memory disorders

High temporal resolution
Takes readings every millisecond providing real time data.
Accurate measurements

Poor spatial resolution
Only detect activity in superficial regions of the brain
Unable to provide info on what is happening in deeper regions of the brain,
Limited technique in comparison to fMRI

Question 31

Evaluate post mortem

Answer 31

Provide a detailed examination of the structure of the brain that aren’t possible with scanning techniques
Access regions otherwise struggled
Useful for further research

Ethical issues
Consent and nether they provide it before death.
Many carried out on severe psychological deficits like HM who would be unable to provide fully informed consent

Causation
Deficits may not be liked to those found in the brain. Could’ve been result of other illness.
Other confounding variables,
Medication , length of time between death and exam, age of person at death

Question 32

Describe brain plasticity

Answer 32

Brains capacity to change or adapt because of experience and new learning

As we age, synaptic pruning occurs, rarely used synaptic connections are deleted, frequently used are strengthened

Question 33

Describe four methods of forming new synaptic connections

Answer 33

Axon sprouting-
Growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways

Denervation supersensitivity-
Axons that do similar job become aroused to a higher level to compensate. This can make the area over sensitive to pain

Recruitment of homologous areas-
Similar areas on opposite side of the brain carry out function

Neuronal unmasking-
Dormant neurons open connections to regions that are not normally activated,
Gives way to the development of new structures

Question 34

Evaluate plasticity

Answer 34

Evidence to support
Maguire et al
Used mri to scan London taxi drivers.
Had greater posterior hippocampus, correlated with the time they had been a taxi driver
Supports that the brain can adapt
Demonstrates structural changes

Evidence to support in animal studies
Huber and Wiesel
Kittens had eyes sewn up
Brains cortical responses analysed
Area with visual cortex not idle. It continued to process info from open info
Supports that brain can adapt as result of experience
Brain can reorganise neural connections

Doesn’t completely stop as we age