Brain And Neuroscience Flashcards
ANS
What controls
Autonomous nervous system
Involuntary actions, eg neurons
Divisions of ANS
Sympathetic
- state of physiological arousal
Fight or flight
Parasympathetic
-. Rest and digestFight or flight response
Sympathetic division of ANS releases adrenaline
-
Fight or flight response- increase blood pressures ect so that body ahs more energy for fight or flight
-
Parasympathetic division takes over once threat has passed.
Changes in body in Sympathetic division
Increased heart rate Increased breathing rate Dilated pupils Inhibits digestion Inhibits saliva production Contracts rectum
Outline James Lange theory
Event →arousal→interpretation→emotion
Hypothalamus detects threat/stressor activates ANS sympathetic Division releases adrenaline causes physiological changes as parts of fight or flight eg increased breathing rate.only then does brain interpret the emotion based on changes. If no physiological changes no emotion eg stand in front of class and heart rate doesn’t increase you are not scared as no physiological changesm
Evaluate James Lange theory
+ real life examples
Fear of public situation (phobia) can develop as result anxiety created from public embarrassment (falling)
Shows emotion and avoidance are result of physiological reaction as predicted
- challenged by cannon-bard theory
Some emotions eg embaressment at same time as psychological changes blushing
Additionally not all physiological changes don’t lead to emotion eg sports
This explains some emotional situation that that Lange’s theory can not.
-may be too simplistic
Challenged by 2 factor theory, need arousal plus social cues to correctly label emotion.
Therefore Lange’s theory does not explain how a person decides the emotion they are experiencing.
sensory neuron
from PNS to CNS
- long dendrite
- short axon
relay neuron
connect sensory to motor
- short dendrite
- short axon
motor neuron
- from CNS to muscles/glands
- short dendrite
- long axon
cell body
nucleus containing DNA
dendrites
carry electrical signals from neighboring neurons to cell
axon
carries signals away from the cell body and down the length of the neuron,
terminal button
- end of axon
- communicate with the neuron
synapse
area at the end of 2 neurons that allows a signal to pass from one neuron to the next
what is an electric transmission?
- when a neuron is in a resting state the inside of the cell is negatively charged compared to the outside
- when firing, the charge inside the cell changes which creates an action potential
- this creates the electrical signal (impulse) that travels down the axon to the end of the neuron
neurotransmitter
chemical released from synaptic vesicles
synaptic transmission
process by which neighboring neurons communicate with each other
presynaptic neuron
neuron that transmits the message
postsynaptic neuron
neuron that is receiving the message
release of neurotransmitters
electrical signal causes vesicles (in presynaptic terminal button) to release
reuptake of neurotransmitters
- neurotransmitter in synaptic cleft attaches to postsynaptic receptor sites
- chemical message turns into electrical impulse
- remaining neurotransmitters reabsorbed
excitatory neurotransmitters
some neurotransmitters (adrenaline) generally increase the positive charge of the next neuron-makes it more likely to fire
inhibitory neurotransmitters
some neurotransmitters (serotonin) generally increase the negative charge of the next neuron- makes it less likely to fire
what causes electrical impulses?
when there are more excitatory signals than inhibitory signals the neuron fires
what is the structure of the brain?
frontal lobe location
- front of brain
- controls thinking and planning
- motor area controls movement
parietal lobe location
- behind frontal lobe
- somatosensory area is where sensations are processed
occipital lobe location
- back of brain
- controls vision
occipital lobe location
- back of brain
- controls vision
cerebellum location
- receives information from spinal cord and the brain
- coordinates movement, balance, attention and language
- “little brain”
localisation
motor areas
damage to the left hemisphere affects the right side
somatosensory area
-damage means less ability to feel pain
visual area
-damage to left hemisphere affects right visual field
auditory area
-may cause potential or total hearing loss
Language area
- usually only in the left hemisphere
- Broca’s area (controls speech): leads to difficulty remembering and forming words
- Wernicke’s area (left temporal lobe): leads to difficulty understanding and producing meaningful speech
Language area
- usually only in the left hemisphere
- Broca’s area (controls speech): leads to difficulty remembering and forming words
- Wernicke’s area (left temporal lobe): leads to difficulty understanding and producing meaningful speec
outline Penfield’s study of the interpretive cortex (9s)
A: to investigate the function of the temporal lobe using the Montreal procedure
M: operated on patients with severe epilepsy, he could stimulate areas of the brain in a conscious patient who reported their experiences
R:-when stimulation was applied to the different areas the patients reported different things:
-visual cortex=colors, shadows and crude outlines of objects
-somatosensory cortex=tingling sensation or a false sense of movement
-temporal lobe (in either hemisphere)=experiences and feelings (hallucinations) associated with those experiences, including deja vu
C: area stimulated in the temporal lobe has a role in storing memories of previous events
stored in 2 different ways:
facts of the experience and facts for the individual
the interpretive cortex stores info on feelings
evaluate Penfield’s study (9s)
+*precise method
P- used a precise method of studying the brain
E- could stimulate the exact same part of the brain and have verbal reports from awake patients
L- useful in enabling a “map of our brain functions” and would benefit neuroscience immensely
-unusual sample
P- unusual sample
E- all participants had severe epilepsy
L- may not reflect people that have “normal” brains
what is a CT scan?
- large doughnut shaped scanner that rotates
- take lots of pictures which are combined to give a detailed picture
what is a PET scan?
- measures metabolic activity
- patient is injected with radioactive substance (radiotracer)
- when the substance is taken up by the brain the most active areas will absorb more of it
- brain activity is show on computer screen in different colors (red and yellow=more active than blue)
what is an fMRI scan?
- measures blood oxygen levels in the brain
- active brain area=more oxygen so more blood is directed to it
- picked up through radio signals and produce 3D images on a computer screen
evaluate the use of fMRI scans
strengths:
- shows important info about which areas are being used at what time
- safe (no radiation used)
- superior (extremely clear images)
weaknesses:
- very expensive
- must stay very still
- time lag causes problems when interpreting info
evaluate the use of PET scans
strengths:
- shows brain in action
- shows localisation of function
weaknesses:
- extremely expensive
- sometimes difficult to interpret
- unethical (radioactive injection)
evaluate the use of CT scans
strengths:
- useful for revealing abnormal structures (tumors+structural damage)
- quality is higher than x-rays
weaknesses:
- high levels of radiation (cant be used often)
- only produce still images (structural info) theres no info on activity of the “live brain”
