Midterm 2 Flashcards
Research methods for studying the brain
- ppl curious about brain functions were limited to studying either people who had suffered brain damage or the bodies of people who had died using tools such as scalpels and magnifying glasses.
- EEG machines, PET scanners, fMRI magnets
- new technology measures the anatomy and it’s biochemistry
Neurons
- nerve cells have projections (dendrites) that receive stimulation from (axons)
- afferent nerves: long, extend from CNS to rest of body ; messages travel up dendrites to brain to report what body is feeling and doing
- efferent nerves: extra long axons, send impulses and instructions from CNS back to muscles, glands , and other organs.
thalamus
- in mid brain
- regulates arousal and serves other functions
hypothalamus
- lies underneath the thalamus
- it’s nerves extend throughout the brained secretes several hormones
amygdala
- important role in emotion
- behind hypothalamus
- link perceptions and thoughts about the world with emotional meaning
- when amygdala removed, less aggressive and less fearful, eat non edible things, increased and unusual sexual behavior
- people with anxiety disorders have large activity in amygdala all the time
- POSITIVE EMOTION: social attraction and sexual responsiveness
- reward or threat
- brain assess stimulus–> amygdala respond by increasing heart beat, raise blood pressure, release hormones(cortisol and epinephrine)
hippocampus
-tube shaped structure near amygdala , important in processing memories
cortex
- 6 layers
- outermost layer=neocortex; more complex and more wrinkled than other animals
-frontal cortex= cognition ability to plan ahead and anticipate consequences and fro aspects of emotional experience such as empathy and moral reasoning
brain damage
- parts of brain are lesioned by being cut off from other brain structures or removed completely
- should not assume animals and humans in all respects, knowledge about animal brains is surely relevant to understanding human brains
- small amount of research addresses effects of surgery on human brains
EEG(electroencephalography)
view directly what the brain is doing
-electrodes are placed on the scalp to pick up electrical signals generated by brain activity
MEG(magnetoencephalograpy)
uses delicate sensors to detect magnetic indications of brain activity
-determine WHEN the brain is active but not specific to WHERE
DISADVANTAGE
-so sensitive they can be easily disrupted
CT scan
- xrays
- PET scan (creates a map of brain activity by following the location
- -follows location of a harmless radioactive tracer injected into the bloodstream
fMRI
monitors magnetic pulses generated by oxygen in the blood to map where the brain is most active at a given moment.
DISADVANTAGE
-blood oxygen level that are measured are not absolute number it is a calculated difference
- participant lie in small cylinder with loud buzzing noises ( dangerous)
- expensive
- difficult to use
ADVANTAGE
- becoming more reliable
- correlation between Brin activation and emotional traits
neural context
disadvantage of functional measurements
- most studies look at small areas of the brain at a time
- don’t know if activity is caused by nearby area also being active at the same time
anterior cingulate
- located within midbrain
- chronic anxiety, fearfulness, sociability, and sexuality
- related to whether people are attractive or threatening
- contribute to motivation and emotions
- ESPECIALLY IMPORTANT FOR NORMAL EMOTIONS BC IT PROJECTS INHIBITORY CIRCUITS INTO AMYGDALA
- emotional responses and impulsive behavior
- NOT DIRECTLY RESPONSIBLE FOR NEGATIVE EMOTIONS BUT FOR COMPUTING MISMATCHES BETWEEN EXPECTED AND ACTUAL STATES OF THE WORLD
- MISMATCHES TRIGGER NEGATIVE EMOTIONS (when received unpleasant surprise)
- when chronically overactive , 1 result= neuroticism
frontal cortex
left side associated with pleasance , right side associated with wanting to withdraw from something unpleasant or frightening
-left side inhibits responses to unpleasant stimuli so left side can can promote good feelings and dampen and ones
- active left brain=emotional stability
- active right frontal cortex= high level of neuroticism
lessons of psychosurgery
- patients with pathological levels of agitation and emotional arousal had overactive frontal lobes
- same area as GAGE
- make them less emotional , more rational and calmer
- people with severe emotional problems may have done some of them good
- -damage to emotional lives/decision making capabilities have been outweighed by their relief from miserable and uncontrollable degree of emotional overexcitement
brain systems
-systems or circuits within brain more important than discrete areas
- fMRI study examined persistence
- –trait associated with high levels of brain activity
-results of psychosurgery so erratic and disappointing
- neural connect effect
- brain parts work together and constantly interact with the rest of the body and outside world
neurotransmitters
- critical for communication between neurons
- neurotransmitter travel across the synapse to the next neuron in line
-if excitatory effect ,neuron fires and releases neurotransmitters
hormones
- biological substances that affect the body in locations different from where they were produced
- released from adrenal glands or hypothalamus spread through bloodstream
epinephrine
(adrenaline) functions within the brain as neurotransmitter but released from adrenal glands as hormone in response to stress
- also works as neurotransmitter and hormone with different associated behavior
- work in PNS
- think of adrenaline rush and it’s effect, fight or flight response
oxytocin
(love hormone) -functions in both CNS and PNS
- hormone that responds to stress
- in females promotes nurturant and sociable behavior along with relaxation and reduction of fear - exact opposite of fight or flight
- decrease anxiety and increase attachment behavior between mothers and children
- when families are present this causes women to bond better with children
testosterone
- causes aggressive behavior
- more use of hardcore drugs, numerous sex partners, weed
- higher traits of avoidance, dominance and loneliness
- fatherhood lowers testosterone levels temporarily
- high testosterone men better as EMS and firefighters if extraverted
The Big Five and the Brain
-stability traits= emotional stability(inverse of neuroticism), agreeableness , and conscientiousness
ASSOCIATED WITH SEROTONIN
-plasticity traits= extraversion and openness
ASSOCIATED WITH DOPAMINE
Biology: cause and effect
- bio processes are the effect of behaviors or experiences as often as they are the causes
ex: stressful environment= raise cortisol levels, as will feeling depressed and anxious and result (not cause ) may be a smaller brain
