Brain&Neuroscience (4)
What is cognitive neuroscience?
The study of brain structures and how that affects mental processes
What are the 2 main branches of the nervous system?
Central NS and Peripheral NS
What are the 2 main parts that make up the Central Nervous System?
Brain and spinal cord
What are the 2 main parts within the Peripheral Nervous system
Autonomic NS and Somatic NS
What are the 2 main parts of the Autonomic Nervous system?
Sympathetic NS and Parasympathetic NS
What part of your brain detects the threat?
Hypothalamus
Which branch of the peripheral nervous system is activated during fight or flight?
Autonomic NS
Which part of the Autonomic NS is activated before the physiological changes in fight or flight?
Sympathetic NS
Which part of the Autonomic NS is activated after the threat has passed in fight or flight?
Parasympathetic NS
What do the adrenal glands do in fight or flight?
release adrenaline into the bloodstream
What are sweaty palms, dilating pupils, increasing heart rate and shaking all examples of?
Physiological changes
What is the spinal cord responsible for? (2)
Reflexes, Relaying information between the brain and body
What is the Nervous system?
A complex network of nerves and cells that carry messages from the brain and spinal cord to various parts of the body
The brain is split into 2 hemispheres. The left hemisphere controls movement on which side of your body?
Right side
The brain is split into 2 hemispheres. The right hemisphere controls movement on which side of your body?
Left
What is the CNS responsible for?
- Recieve and interpret information from sense
- control actions& reactions
- decision making
- logic and personality
what is the PNS responsible for?
all nerves around your body sending messages to and from the CNS around your body
what does the somatic nervous system control? (+ example)
voluntary movements such as eating
what does the autonomic nervous system control?(+example)
Involuntary movements such as breathing
What are the 6 steps of fight or flight?
- the hypothalamus in your brain detects the threat
- Autonomic NS activates Sympathetic NS initiating fight or flight response
- adrenaline is released from tge adrenal glands into bloodstream
- physiological changes happen to the body, such as dilating pupils, mouth goes dry, increased heart&breathing rate, sweating, tense muscles.
- when the threat passes, autonomic ns activates parasympathetic ns
- body resumes rest and digest, body is returned to homeostasis
what is the James- Lange theory?
- event or stressor activates the hypothalamus.
- sympathetic division of ANS is activated and releases adrenaline
- Physiological changes occur caused by the adrenaline
- brain interprets physiological changes
- brain then establishes what emotion someone is feeling
A strenght of the James- Lange theory (PEA)
- Real life examples
- eg. tripping over
- face turns red before your brain registers it as embarrasment, adds validity as there are real-life applications
a weakness of James-Lange theory (PEA)
- some emotions have the same physiological changes as others
- eg fear and love both include heart rate increasing
- meaning that the emotion you feel cant be fully based on psychological changes, weakens validity
what is a sensory neuron and what does it do?
Sensory neurons carry messages from PNS to CNS and are activated by sensory input from the environment.
what is a relay neuron and what does it do?
Relay neurons pass info from Sensory neurons to Motor neurons
what are motor neurons and what do they do?
motor neurons carry messages from the CNS to effectors (muscles and glands). This allows voluntary and involuntary movements
what is the function of dendrites?
Dendrites recieve info from previous neurons and transfer it to the cell body.
what is the function of a nucleus in a neuron?
contains genetic material (dna)
what does the cell body do in a neuron?
protects the nucleus
what does the Myelin Sheath do?
protects the axon and speeds up transmission of electrical signal
what is the word for the electrical current passing through neurons?
action potential
what is the function of the axon in a neuron?
carries the action potential along the cell
what are the nodes of ranvier and what is their function?
they are gaps in the myelin sheath which speed up transmission of the action potential
what is the function of the axon terminal?
when the action potential reaches it, it releases chemical neurotransmitters to communicate with the next neuron
what is the synapse and roughly how wide is it?
the gap between 2 neurons, which is less than 40mm wide
explain the process of synaptic transmission
- the action potential arrives at the axon terminal of the pre-synaptic neuron
- this causes neurotransmitters to be released from the vesicles of the pre-synaptic neuron
- the neurotransmitters then diffuse across tge synapse/ synaptic cleft
- the neurotransmitters bind to the post synaptic receptor sites
- summation, which is when the number of exitatory and inhibitory neurotransmitters are added up to decide wether the next neuron will fire its own action potential
- neurotransmitters that dont bind to the post- synaptic receptor sites and are left in the synaptic cleft are either taken back in through the reuptake transporters or broken down by enzymes
what do inhibitory neurotransmitters do? (+example)
make it less likely that a neuron will fire it's action potential (eg. serotonin)
what do exitatory neurotransmitters do?(+example)
make it more likely that a neuron will fire its action potential eg. adrenaline
what is localisation?
the fact that specific parts of the brain are responsible for specific cognitive functions or behaviours
What is the frontal lobe responsible for?
decision making, personality, logical thinking
what is the motor cortex responsible for and where is it located?
its responsible for movement on the opposite side of the body and is located in the frontal lobe
what is broca's area responsible for and where is it located?
it's responsible for speech production, located in the frontal lobe
what is the temporal lobe responsible for?
processing auditory information
what is wernicke's area responsible for and where is it located?
it's responsible for speech understanding and is located in the left temporal lobe
what is meant by aphasia?
damage
what is the parietal lobe responsible for?
it interprets sensory info and where you are in relation to other things
what is the somatosensory cortex responsible for and where is it located?
its responsible for processing sensations, its located in the parietal lobe
what is the occipital lobe responsible for?
interpreting visual info
what is the cerebellum responsible for?
its responsible for balance&fine movements
what is the brainstem responsible for?
its responsible for linking the brain to the spinal cord
what is an engram?
a trace of learning created in your brain
what is the name for groups of neurons that fire together?
cell assemblies
what is Hebb's theory of learning?
Hebb stated that the brain is plastic meaning it can adapt and change
- first learning something new leaves an engram in the brain (if you dont think about or practice it again the engram fades away)
- if you think about or practice it again you strengthen the neuronal connections between the cell assemblies as the neurons fire together every time said thing is practiced, meaning their connections get stronger (fire together, wire together)
- this means the action becomes more intuitive
Hebb stated the brain is plastic. What does this mean?
the brain can adapt, grow and change as we learn new info, which can happen at any point in life
what is a weakness of hebb's theory?
reductionist, only focuses on biological aspect of learning doesn't take into account factors such as mental health which could affect learning - external validity
what are strengths of Hebb's theory?
evidence - pictures of engrams - internal validity
real life applications - schools encourage you to revise - external validity
what is the interpretive cortex responsible for and where is it located?
It's responsible for storing the personal meanings and detailed accounts of previous events in our memories. located in the temporal lobe
Outline penfield's study.
A- to investigate psychological experiences of patients when having their brains electrically stimulated
M - electrically stimulated the brains of conscious epileptic patients using the Montreal Procedure and asked them to report sensations
R - stimulation of occipital lobe made patients see colours and shadows
stimulation of somatosensory cortex made patients feel tingling sensations
stimulation of the motor cortex made patients experience jerky movements
stimulation of the interpretive cortex in the temporal lobe gave patients vivid memories and deja vu
C - his findings proved localisation of function and that the temporal libe had a role in memories
what are the weaknesses of penfield's study
lack of evidence- 40/520 participants experienced vivid memories or deja vu when having their interpretive cortex stimulated, cant be generalised, lacks external validity
cant be generalised - his sample was only epileptic patients meaning his results cant be generalised to neurotypical brains, lacks external validity
what are strengths of penfield's study?
scientific method - montreal procedure, same areas stimulated multiple times brought the same results, reliable and consistent findings = high internal validity
what is an episodic memory?
a memory of a personal event
what are semantic memories?
memories if knowledge and facts
what is a CT scan and what is it used for?
- Brain scanning technique
- similar to x-ray
- takes cross-sectional images of the brain from different angles and puts them tigether to create a 3d image
- black and white image, and images that look different ti the "normal" eg more black show damage
- used to diagnose strokes, tumours, cancers
strenght of a CT scan
higher quality images than an x-ray
weaknesses of a CT scan (2)
Used radiation therefore a health risk, doesn't provide info about brain activity
what is a PET scan and whats it used for?
- a person is injected with a radioactive tracer such as radioactive glucose
- person then performs a cognitive task
- person is then scanned, scanner shows radiation in the parts of the brain used
- can be used to diagnose conditions such as alhzimers and parkinson
strenght of a PET scan
shows brain activity and helps understand localisation of function
weaknesses of PET scan(2)
ethical issues as radioactive glucose could impact health, expansive
what is an fMRI scan and what is it used for?
measures change in blood oxygen levels while participant does a task
3d image of brain
helps understand which areas of the brain are responsibke fir which cognitive functions
strengths of fMRI scan
shows brain activity as the individual is completing a task
high spatial resolution
weaknesses of fMRI scan
5 sec delay between activity and image - low temporal resolution
Outline Tulving's Gold memory study
A - to find out wether episodic and semantic memories were found in different areas of the brain
M - used a PET scan to see what part of the brain was activated (used radioactive tracers instead of glucose)
• 6 ppts including him&his wife and he knew the other ppts
• asked them ti think of a childhood memory and a historical fact
• scanned to see which area if the brain used up the most radioactive gold
• detected using gamma rays
R - 3/6 ppts had a greater activity in their posterior cortex fir semantic memories and greater activity in their anterior cortex for episodic memories
C - different parts of LTM are localised in different parts of the brain
what is a strength of tulvings gold memory study? (PEA)
p - objective method
e - brain scans cant be faked
a - high internal validity
what are 2 weaknesses of tulving's gold memory study? (pea x2)
p- not enough evidence (3/6ppts)
e- (3/6ppts)
a- not generalisable to the whole population
p- limited application, not representative
e- all ppts in the same social circle
a- cant be generalised- lacks external validity