Biology and Behavior ch 4-8 Review

What is the stereotaxic instrument used for?

used mostly with animals

• stereotaxic instrument - places an electrode or other device at a precise location in the brain

  • electrode - wire to transmit electricity

  • cannula - tube to transmit fluid

• stereotaxic atlas - shows the location of key structure on images of a series of brain sections

which microscope shows images in 3D?

scanning electron microscopes

• beams of electrons

what are the consequences of scientific fabrication?

introduces erroneous (wrong) information into the body of scientific knowledge

• results in the pursuit of false leads by others consumes scarce resources and sidetracks researchers from more fruitful lines of research

• fabrication in clinical research can slow therapeutic progress and harm lives

what are the drawbacks of correlational research?

correlation = causation

what are the variables in experimental studies?

independent variable

• manipulated

dependent variable

• measured

extraneous variable

• noise

what are the benefits of using animals in research?

advancements in science

mice genetic lines specified to study diseases

• mouse genome known better than other animals

what are the types of brain imaging techniques?

EEG - sums the electrical activity of neurons between two electrodes; detects fast-changing brain activity but is poor at localizing it

CT - forms 3-D image of brain by combining X-Rays of cross sections of brain; image structure and damage

MRI - measures variations in hydrogen concetrations in brain tissue; image structure and damage

PET - image produced by the emissions from injected substances that have been made radioactive; tracks changing activity, detects receptiors, etc.

fMRI - detects increase in oxygen levels during neural activity; tracks changing activity

how does the cannula stimulate the brain?

chemicals inserted in through the cannula directly into the brain

how do electrodes stimulate the brain?

electrical impulse sent into specific areas in the brain

• can be used as treatment for disorders wirh impaired signaling such as Parkinson’s

how does the Position Emission Tomography (PET) scan work?

injecting or ingesting radioactive substance into the bloodstream to be absorbed by tissue

• advantages

  • provides great detail about path of blood and oxygen in body

  • indicates body’s processign of glucose

• disadvatages

  • radioactive chemicals in body

  • diabetic patients blood glucose must be tested beforehand

    • glucose combined with radioactive tracer before injection

what is the difference between agonists and antagonists

agonists - increases activity in the body or its functioning

antagonists - decrease activity in the body or its functioning

what effects can psychoactive drugs have on the body?

analgesic

• relieve pain

hypnotic

• sleep inducing / perception altering

euphoria

• feel good

anxiolytic

• reduce anxiety

sedation

• induce deep sleep

which classes of psychoactice drugs reduce brain activity and inhibit behavior?

alcohol, barbiturates, and benzodiazepines

• sedation

  • calming, reduces agitation and irritability

• anxiolytic

  • reduces anxiety

• hypnotic

  • induces sleep

what are benzodiazepines?

safer drugs for treating anxiety

• reduces anxiety, creates sedation and relaxes muscles

  • valium, xanax,

  • rohypnol - reputation as the date rape drug

what characterizes an addiction?

preoccupation with obtaining a drug, compulsive use of the drug, and relapse

• withdrawl

  • negative reaction that occurs when drug use is stopped

• tolerance

  • less responsive to the drug

  • requiring increasing amounts

how does alcohol affect the body?

alcohol (ethanol)

• most used and abused depressant

• inhibits glutamate (excitatory transmitter)

effects on behavior

• can be a stimulant

• at higher doses = calming and sleep

• decreases prefrontal cortex activity and lower inhibition

• increase aggression

effects on health

• chronic liver and brain damage

what is conditioned tolerance and how is it related to overdoes?

learned tolerance is a problem. a learned association between tolerance and environment.

• when a drug is taken in a different setting - overdose

• occurs often with highly addictive drugs (cocaine, heroin, meth)

how does cocaine affect the body?

stimulants activate the CNS

• produces arousal

• increased alertness

• relieves fatigue

• decreases appetite

• elevated mood

neurotransmitters

• blocks dopamine and serotonin

• blocks norepinephrine reuptake

what contributes to relapse?

sensitization to drug from repeated use

• causes change in the brain and reduction of prefrontal cortex

• onset of withdraw

withdrawal can involve

• anxiety

• decreased motivation

• decreased pleasure

long-term impairment from drug use include

• poor impulse control

• poor decision making

• poor emotional understanding

which neurotransmitters are affected by which psychoactive drugs?

acetylcholine

• transmitter at muscles; in brain, involved in learning, etc

Monoamines

serotonin

• involved in mood, sleep and arousal, aggression, depression, obsessive-compulsive disorder, and alcoholism

dopamine

• contributes to movement control and promotes reinforcing effects of food, sex, and abused drugs; involved in schizophrenia and parkinson’s disease

norepinephrine

• hormone released during stress. functions as a neurotransmitter in the brain to increase arousal and attentiveness to events in the environment; involved in depression

epinephrine

• a stress hormone related to norepinephrine; plays a minor role as a neurotransmitter in the brain

Amino Acids

glutamate

• the principal excitatory neurotransmitter in the brain and spinal cord. vitally involved in learning and implicated in schizophrenia

gaba

• predominant inhibitory neurotransmitter. its receptors respond to alcohol and the class of tranquilizers called benzodiazepines

glycine

• inhibitory transmitter in the spinal cord and lower brain. the poison strychnine causes convulsions and death by affecting glycine activity

what are mirror neurons?

neurons that fire when we either perform an action or observe someone else performing an action

• useful for imitation learning and modeling behavior

which part of the nervous system is triggered during fight or flight response?

sympathetic nervous system (SNS)

what research did Eckman contribute to the theories of emotion?

first to demonstrate manipulating facial muscles corresponds to emotions

studied tribes in isolated areas to discover universal emotional responses

what are the 3 theories of emotion?

James- Lange

• emotions result from thr experience of physiological reactions in the body

Cannon-Bard

• emotions and bodily responses both occur at the same time due to ways that parts of the brain process info

Schachter-Singer Cognitive

• influenced by the cognitive label we apply to explain the physiological changes we have experienced

how does botox effect emotion?

reported less negative mood

try to imitate being angry

• but less activity in the amygdala

can delay emotional responses

what neurotransmitters/hormones are secreted by the adrenal gland in response to stress?

short-term stress

• norepinephrine

• epinephrine

long-term stress

• cortisol

what happens when the hypothalamus is stimulated?

produes a variety of emotions

• warmth, pleasure, fear, rage, fatigue

stress

• hormones controlled by hypothalamus

what effect does stress have on the body?

short-term

• can be beneficial

• increase immune response

long-term stress

• cause damage to the brain over time

  • hippocampus damage affects memory. can increase amygdala size while decreasing frontal cortex

• decreases appetite, sexual desire, energy, and mood

• cardiovascular system particularly vulnerable to prolonged stress

  • heart attack and failure rate increases due to even minor stressors

how does the amygdala process fear?

processes the emotional significance of stimuli

• fear and anxiety

generates immediate emotional and behavioral reactions

2 pathways

• “quick and dirty” - processes sensory info in an instant

• somewhat slower but leads to more deliberate and thorough evaluations

involved in the perception of social stimuli

• we ‘read’ someone’s facial expression

• amygdala helps interpret them

how is emotion connected to the prefrontal cortex?

the left and right prefrontal lobes are affected by different emotions

• right frontal - negative emotions; left frontal - positive emotions

• injury to the prefontal lobes can impair emotional experiences

  • causes people to have impaired judgement and make poor decisions