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
