neuroscience Flashcards
neuroimaging
pictures of the brain’s anatomy or function, in relation to mental processes.
helps display:
Structure
Brain damages
lesioning
Area of brain is destroyed by heat
Gives people really accurate results in terms of which part of the brain is responsible for what function
clinical observation
Link behaviour back to the damaged areas of the brain
problems with case studies
Not damage to just one particular region
Can’t take one case study and apply those results to a wider range of people with the same brain injury because it could be that it’s not the area that’s damage that is responsible for that particular function
Personality + dominant hand can affect recovery of the brain injury
IQ also affects the results
MRI
Creates a 3D anatomical picture of the brain. ONLY ABOUT STRUCTURE + ANATOMY NOT FUNCTION
pros of MRI
See anatomy
Clots and leaks, which vessels may burst
cons of MRI
Stay completely still in a claustrophobic space + noisy environment
EEG
Detects electrical currents generated by neurons on brain surface by affixing metal electrodes to scalp.
pros of EEG
excellent temporal resolution (picks up fast changes)
Only good at picking up things near the scalp
Very accessible, not wildly expensive to use
Can tell the cognitive state
cons of EEG
poor spatial resolution → can’t look at brain function, spatial resolution = where things are in the brain
Cannot detect anything deeper than the cortex level (far away from the scalp)
fMRI
3D image of brain at work, shows which parts are active. Superimposes activity patterns onto the MRI image.
pros of fMRI
not only gives you the anatomy of the brain, but it also gives you the function of areas of the brain
Detects fast changing aspects of brain physiology (blood flow & oxygen use) without any radioactivity. Blood contains iron, changes in magnetic fields can be detected.
cons of fMRI
Tremendously expensive
High demand → very difficult to get time in the scanners because of their high demand
Have an affinity to metal (metals that are attracted to magnets)
Noisy + claustrophobic
TMS (and pros)
Create temporary brain dysfunction, perform experiments that wouldn’t be possible otherwise.
used for therapeutic purposes
- depression
- uncontrollable ticks
cons of TMS
Only works for areas close to the scalp
Need to have a person with a medical license to use it (need to pay someone to come in to supervise or use it with you)
CNS (central nervous system)
Brain & spinal cord ← makes up the CNS
parts of the Peripheral nervous system
- Somatic nervous system
2. autonomic nervous system
Autonomic nervous system
Regulation of viscera — heart, lungs, blood vessels, digestion, sex organs.
The automatic brain system (looks after automatic responses)
somatic NS
Afferent, efferent & cranial nerves
Afferent nerves
Transmit information FROM sense organs TO brain & spinal cord (CNS).
Efferent nerves
Taking information from your brain to your organs
* What allows you to move your hand away from the hot stove
Cranial Nerves
Control movements of & carry sensations from head & neck.
Vision, hearing, scent
Regulate glandular secretions in head. Mucus, snot Saliva production tears Control visceral functions. Digestion
damage to cranial nerves
- Bells Palsy (droopy face/mouth)
- “suicide disease” controllable facial pain
pons
Arousal (cognitive arousal → awakeness, alertness)
Regulates respiration.
Involved in sleep and dreaming.
Part of your brain that will shut down your voluntary muscles before sleeping
damage to pons
locked-in syndrome
medulla
heavily involved in keeping you alive
Regulation of heart rate, blood pressure, rate of respiration.
Also involved in vomiting, defecations, reflexes and swallowing.
cerebellum
- controls overall bodily balance
- Sequencing & timing of precise skilled movements
- influences thinking (mentally ordering lists)
damage to cerebellum
- Damage (injury, disease or alcohol) results in wide stance & staggering gait.
- tremors during movement & inability to perform rapidly alternating movements.
- impairs performance of tasks requiring exact sequencing
midbrain controls…
Auditory & visual stimuli - eye movement. VERY BASIC
in animals: Control movements used in sexual behaviour & fighting, decrease sensitivity to pain.
cortex
wrinkled part of brain
Humans gain flexibility of behaviour by having a large cortex.
act more as relay stations/ middle managers for information
gyrus
the buldge of the cortex
in charge of psychological functions (allows us to do things)
Precentral gyrus
basic movements
postcentral gyrus
basic skin sensation
sulcus/fissure
No psychological function, just LANDMARKS to divide the lobes up and makes it a lot easier to locate some of our gyri in relation to some of their position to some of the sulci
the lines
grey matter of brain image
the parts of the brain that does most of the functional thinking (thoughts, actions)
white matter of brain image
made up of myelin neurons (part fat, part protein that wraps itself around axons of neurons)
thalamus
- Receiving & relay station for sensory input.
Receives sensory information from the sense organs, performs simple analyses (is it hearing, is it vision?) and passes results on to primary sensory cortex (precentral gryus)
then sends it to other parts of the brain to sense/perceive.
hypothalamus
regulates the body/keeps everything in the body the same (keeps it in check)
fleeing, fighting, feeding, fornication (sexual reproduction)
basal ganglia
Regulation and smoothing of movement - beside thalamus
damage to basal ganglia
- Parkinson’s disease
Movement disorder that progressively gets worse over time
Disintegration of muscle movements - Foreign accent syndrome
Usually caused by a stroke
Wake up speaking in an entire different accent than they did before the accident
3. Huntington’s disease People don’t know they have it until the parents show the signs Uncontrollable movements (writh uncontrollably)
amygdala (limbic system)
Expression of emotion
Affects the processing of NEGATIVE emotions
damage to amygdala
Affects the processing of NEGATIVE emotions
Won’t be able to interpret fear, feel fear, or express fear
Occipital lobe
Back of the brain
Receives input from the eyes (at the front of the head!) via the thalamus
parietal lobe
Important for spatial perception (RIGHT SIDE)
temporal lobe
Receiving area for initial auditory information.
- also deals with smell (olfactory cortex is located here)
^ damage = hallucination of smell
frontal lobe
Responsible for motor output, motor planning.
Primary motor cortex → deals with initial movements
primary motor areas
contralateral control
Right motor cortex controls left side of body
Left motor cortex controls right side of body
LOCATED IN FRONTAL LOBE
damage to primary visual cortex
causes SCOTOMA
hole in visual field
removal of one side of primary visual cortex causes…
hemianopia (complete blindness) on the opposite side.
hemiplegia
Paralysis of one side of the body.
Due to damage to contralateral motor cortex.
Prosopagnosia
damage to temporal/occipital lobes
Difficulty recognizing faces. Some can’t recognize familiar faces, some can’t recognize a face as a face.
Damage to prefrontal cortex
Deficiency in response inhibition.
Inability to plan.
Appear uninvolved, depressed & apathetic.
Some may appear “psychopathic”, acting flagrantly and crudely, being sexually promiscuous and may engage in criminal conduct.
Problems with initiating behaviour/changing strategies
Frontal lobes not fully understood.
apraxia
damage in frontal lobe
Serious disturbances in initiation or organisation of voluntary action.
Unable to perform well known actions.
Motor actions become fragmented & disorganised.
neglect syndrome
People with right-sided parietal damage tend to neglect the left side of space (seldom vice versa)
right side of brain is dominant for…
Spatial attention – neglect.
Melody (tone of voice) – amusia. Facial recognition – prosopagnosia. Recognition of natural objects – agnosia.
Left side dominant for:
Language – aphasia.
Recognition of manufactured objects – agnosia. Voluntary action – apraxia. Also for handedness.
why do some people go through split brain surgery?
relieves intractible epilepsy
splits corpus callosum –> prevents/lessens the severity of seizures
Left hemisphere function in the split brain
Can’t name objects or words presented in LEFT visual field.
Can’t name objects held in LEFT hand.
BUT can understand words in the left visual field (demonstrated by pointing)
Suggests that the right brain can understand, but cannot speak.
Callosal agenesis
people who are naturally “split-brained”
dendrites
Receive nerve impulses (messages) from other neurons.
Axons:
send action potential
soma
metabolism/maintenance of the cell (keeps it in check) → the powerhouse
axon terminals
Secrete neurotransmitters in synapse.
Motorneurons (efferent neurons):
Begin in CNS, exit through spinal cord, end on muscle fibre.
Sensory neurons (afferent neurons):
Begin at sense organ (retina, skin, tongue) convey information to brain, via spinal cord.
Interneurons:
Interposed between other neurons, do much of the computation in the brain.
glial cells
Act as guidewires for growing neurons.
action potential
Abrupt, short-lived reversal in the electrical charge of an axon
Antagonists
Drugs that block or inhibit postsynaptic effects.
Agonists
Drugs that facilitate postsynaptic effects.
venom of black spider
- releases ACH
stimulates neurotransmitter release
nicotine
stimulates postsynaptic receptor molecules
small doses = pleasurable
curare
blocks postsynaptic receptor molecules (inhibits synaptic transmission)
cocaine + prozac
Some drugs inhibit the process of reuptake so that molecules of the neurotransmitter continue to stimulate the postsynaptic receptors for a long time.
