Description
1. You are required to have 3 posts in each discussion and these three posts must be made on three separate days. The first post is the initial response to the question that appropriately and completely addresses the topic. This must be completed by 11:59 p.m.(EST) Thursday night. It is best to post it at the beginning of the week. The remaining two posts are responses to two different classmates. The first response to a classmate is due Saturday at 11:59 p.m.(EST) and the second response to a classmate is due on Sunday at 11:59 p.m.(EST). Responses to me do not count as a response to another student; however, I will interact with each of you throughout the course. I encourage you to respond back. If you do not post on three separate days you will lose points (possible 15 point deduction).
*There will be a deduction of 5 points per day that the initial post is late. Posts are not accepted after the week closes on Sunday night.
2. Your initial post (your response to the topic) must contain a citation. It is your ideas supported by research. Please refer to the APA Power Point in the Start Here section of the classroom for information on proper formatting. There will be a deduction of 20 points for failure to cite a source within your initial post and to provide a reference at the end of your initial post.
3. Your initial post must be a minimum of 300 words and each response must be a minimum of 200 words. Please double-check your word count. Only posts that meet the word count requirements receive credit.
4. Post your word count at the end of each post. There will be a 5 point deduction for each failure to provide a word count.
5. Please address fellow students and professor by name. There will be a 5 point deduction for each failure to address by name.
6. Please use spell-check and proper grammar. Points will be deducted for each spelling and grammatical error up to 10 points for each post.
Psych Discussion Post
Due By
Cited Source – In Text and Reference
Word Count
Point Value
Post 1 – Initial Response is well organized, includes a citation, addresses topic, and demonstrates critical thinking
Thursday
Yes – mandatory
300
50 points
Post 2 – Response to 1st student is well organized, includes classmate’s name, addresses topic, and demonstrates critical thinking
Saturday
Not required, but must cite any work used
200
25 points
Post 3 – Response to 2nd student is well organized, includes classmate’s name, addresses topic, and demonstrates critical thinking
Sunday
Not required, but must cite any work used
200
25 points
PSYCHOLOGY DISCUSSION RUBRIC
Criteria
Exemplary (100%)
50/50
Above Average (89%)
45/ 50
Satisfactory (79%)
40/ 50
Approaches Standard (69%)
35/ 50
Needs Improvement (59%)
30/ 50
Unsatisfactory (0)
0/ 50
Initial Post (50)
Reveals mastery of the material, critical assessment, and thorough exploration of the subject matter. Demonstrates mastery of grammar, punctuation, spelling, mechanics, and usage and with no errors.
Reveals some mastery of the material although further exploration would have increased the value of the post; some critical assessment although portions of the material may be vague. Demonstrates proficiency of grammar, punctuation, spelling, mechanics, and usage with fewer than three errors
Reveals knowledge of the subject matter although more exploration is needed; some critical assessment was noted although more in-depth perspective would have enhanced the work. Understanding of grammar, punctuation, spelling, mechanics, and usage with fewer than five errors
May highlight what the reading material offers but does not apply further exploration of the subject matter; critical assessment is lacking. Improvement in some areas of grammar, punctuation, spelling, mechanics, and usage; fewer than ten errors but retains clarity throughout most of post.
Uses personal opinion only without any exploration of additional possibilities; no critical assessment is noted. Needs improvement in grammar, punctuation, spelling, mechanics, and usage; more than fifteen errors; errors affect clarity of post.
Unable to score because there was no engagement in the discussion.
Criteria
25/25 per post
22/ 25 per post
20/ 25 per post
17/ 25 per post
15/ 25 per post
0/ 25 per post
Peer Responses (25 per post)
Promotes further discussion on the subject matter through thought-provoking peer responses; demonstrates depth of analysis of topic and peer’s post;Makes use of source support, as needed, and in proper APA format, grammar, punctuation, spelling, mechanics and usage with no errors
Promotes further discussion on the subject matter through meaningful comments that demonstrate understanding of topic and peer’s post. Makes use of source support, as needed, but may not fully use proper APA format, grammar, punctuation, spelling, mechanics and usage with fewer than three errors
Engages peers but does not promote further consideration of the material so that additional learning takes place. Uses some source support, though it may not be scholarly or in the appropriate APA format, grammar, punctuation, spelling, mechanics and usage with fewer than five errors.
Peer engagement does not encourage depth of academic thought or is based on personal opinion only.Uses some source support, though it may not be scholarly or in the appropriate APA format, with fewer than ten errors in grammar, spelling, mechanics and usage
Peer responses do not add substance or promote engagement in the discussion in a meaningful way; comments are superficial or off topic.Extremely limited or no source support noted; improper or missing APA format, and grammar, spelling, mechanics affect clarity
Unable to score because there was no engagement in the discussion.
Please use the following guidelines in our discussion forum and in all communication at Keiser University:
I will “listen” to others respectfully.
I recognize that online learning is devoid of physical cues that often support communication and will strive to use language that clearly expresses my views.
I will strive to utilize language that is thoughtful, respectful, and collegial when communicating with my fellow students.
When I disagree with someone, I will critique his/her ideas in a respectful and constructive manner.
I will try to understand other people’s behaviors and perspectives rather than simply criticize them.
I will avoid stereotypes and humor that is disparaging of others.
I will avoid texting language, slang, or other non-professional communication.
Week 2 Topic:
“Addiction” (Garrett & Hough, 2022, p. 129).
The neurological basis for addiction is detailed in your textbook. Addiction, or “Use Disorders” as they are referred to in the Diagnostic Statistical Manual (DSM 5), have destroyed lives, families, and communities. The American Medical Association has defined addiction as a chronic, relapsing, brain disease.
Explain why addiction is considered a “brain disease”.
Addiction literally changes the brain. Dopamine, is the primary neurotransmitter involved in addictions. What is the role of dopamine in rewards? What happens to the dopamine levels of an individual who is diagnosed with an addiction and is now attempting to get sober? How does this affect their hopes for sobriety?
Now, based on your research and reading of addiction and the brain, do you think it is a good idea to treat addictions with medication? Why? Why not? (Support your answers with evidence) (Garrett & Hough, 2022, p. 151).
To post to the discussion, click on the “Week 2 Discussion” title above, then Create Thread.
Unformatted Attachment Preview
Chapter 5: Drugs, Addiction, and
Reward
Introduction
• Drugs can be addictive regardless of their
legality.
• Caffeine.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
2
Psychoactive Drugs (1 of 7)
• Drug: medicine or other substance that
changes the body’s functioning.
• Agonists.
• Antagonists.
• Psychoactive drugs: drugs with
psychological effects such as anxiety relief
or hallucinations.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
3
Psychoactive Drugs (2 of 7)
• Addiction: preoccupation with obtaining a drug,
compulsive use, and a tendency to relapse after
quitting.
• Withdrawal: negative reaction when drug use is
stopped.
• Dependence: need to keep taking a drug to avoid
withdrawal.
• Physical dependence.
• Psychological dependence.
• Tolerance: more of the drug required to produce
same effects.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
4
Psychoactive Drugs (3 of 7)
Opiates and Opioids (1 of 2)
• Opiates: derived from opium poppy.
• Analgesic.
• Hypnotic.
• Euphoric.
• Opioids: not derived directly from opium, but
may affect same endogenous receptors.
• Heroin.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
5
Psychoactive Drugs (4 of 7)
Opiates and Opioids (2 of 2)
• Heroin: most notoriously abused opiate;
synthesized from morphine.
• Endogenous endorphins: body’s own
neurotransmitters for receptors opioid
drugs act on.
• Endogenous: generated within the body.
• Endorphins: endogenous opioids.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
6
Psychoactive Drugs (4 of 7)
Depressants (1 of 3)
• Drugs that reduce CNS activity.
• Sedative.
• Anxiolytic.
• Hypnotic.
• Alcohol, barbiturates, and
benzodiazepines are all types of
depressants.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
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Psychoactive Drugs (4 of 7)
Depressants (2 of 3)
• Delirium tremens: severe reaction to
alcohol withdrawal resulting in
hallucinations, delusions, confusion, and in
extreme cases seizures and possible
death.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
8
Psychoactive Drugs (4 of 7)
Depressants (3 of 3)
• Barbiturates: drugs that in small amounts act
selectively on higher cortical centers,
especially those involved in inhibiting
behavior.
• Benzodiazepines: drugs that act at
benzodiazepine receptor on the GABAA
complex to produce anxiety reduction,
sedation, and muscle relaxation.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
9
Psychoactive Drugs (5 of 7)
Stimulants (1 of 3)
• Drugs that activate CNS to produce
arousal, increased alertness, and elevated
mood.
• Cocaine.
• Amphetamines.
• Nicotine.
• Caffeine.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
10
Psychoactive Drugs (5 of 7)
Stimulants (2 of 3)
• Cocaine: drug extracted from South American
coca plant—produces euphoria, decreases
appetite, increases alertness, and relieves fatigue.
• Amphetamines: group of synthetic drugs that
produce euphoria and increase confidence and
concentration.
• Bath salts: variety of synthetic drugs related to cathinone, a
stimulant found in the khat (Catha edulis) plant.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
11
Psychoactive Drugs (5 of 7)
Stimulants (3 of 3)
• Nicotine: primary psychoactive and
addictive agent in tobacco.
• Caffeine: active ingredient in coffee and
tea, which produces arousal, increased
alertness, and decreased sleepiness.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
12
Psychoactive Drugs (6 of 7)
Psychedelic Drugs
• Compounds that cause perceptual
distortions in the user.
• Serotonergic.
• Catecholaminergic.
• NMDA receptor agonists.
• Designer drugs.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
13
Psychoactive Drugs (7 of 7)
Marijuana
• Dried and crushed leaves and flowers of
the plant Cannabis sativa.
• Cannabinoid: group of compounds
including anandamide and 2-arachidonyl
glycerol (2-AG).
• Illegality of marijuana has led to creation of
synthetic marijuana, which may be lethal.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
14
Addiction (1 of 6)
• Neither pleasurable effects from a drug
nor withdrawal fully account for drug use
motivation.
• Reward: positive effect an object or
condition has on the user.
• Mesolimbic pathway: reward circuit.
• Ventral tegmental area.
• Nucleus accumbens.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
15
Addiction (2 of 6)
Synaptic Plasticity and Addiction (1 of 2)
• Addiction creates functional and structural
changes in the brain that persist long after
drug usage stops.
• Mesocorticolimbic dopamine system: system
consisting of ventral tegmental area and the
brain regions receiving its dopaminergic
projections, including nucleus accumbens,
prefrontal cortex, amygdala, and
hippocampus.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
16
Addiction (3 of 6)
Synaptic Plasticity and Addiction (2 of 2)
• Hypofrontality: reduced activity in frontal
regions that control working memory,
behavioral inhibition, and response to
environment.
• Cravings persist after years of drug
abstinence.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
17
Addiction (4 of 6)
Treating Drug Addiction (1 of 3)
• Treatment strategies:
• Agonist treatments.
• Methadone.
• Antagonist treatments.
• Aversive treatments.
• Antidrug vaccines.
• Comorbidity: addiction often appears in
combination with mental or emotional personality
disorders which can complicate rehabilitation.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
18
Addiction (5 of 6)
Treating Drug Addiction (2 of 3)
• Agonist treatments: replace addicting drug with
another drug with similar effect.
• Methadone: synthetic opioid used to treat opioid
addiction.
• Antagonist treatments: involve drugs that block
effects of the addicting drug.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
19
Addiction (6 of 6)
Treating Drug Addiction (3 of 3)
• Aversive treatments: cause a negative reaction
when person takes the drug.
• Antidrug vaccines: molecules that attach to the
drug and stimulate immune system to make
antibodies that will degrade the drug.
• Comorbidity: addiction often appears in
combination with mental or emotional personality
disorders which can complicate rehabilitation.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
20
The Role of Genes in Addiction
(1 of 2)
• Heritability of addiction first established
with alcoholism.
• Type 1 alcoholic.
• Type 2 alcoholic.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
21
The Role of Genes in Addiction
(2 of 2)
• Genetic influences affect how drugs are
metabolized, neurotransmitter/receptor
levels, and other addiction risk factors.
• Drugs also impact genetic function.
• Methylation: attachment of a methyl group to DNA,
which suppresses a gene’s activity.
• Addiction research sheds light on complex
mechanisms of addiction.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
22
In Perspective
• Immense costs of drug abuse:
• Human suffering.
• Loss of health, productivity, and life.
• Billions spent on treatment and incarceration.
• Studying drug abuse gives insight into the
brain and biological forces that mold
human behavior.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
23
Chapter 6: Motivation and the
Regulation of Internal States
Introduction
• Prader-Willi syndrome: short stature,
learning difficulties, and reduced impulse
control.
• Includes excess of a hormone that increases
appetite and a deficit in neurons that inhibit eating.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
2
Motivation and Homeostasis (1 of 9)
• Motivation: set of factors that initiate,
sustain, and direct behaviors.
• Behavior unable to be explained solely in terms of
outside stimuli.
• Instinct: complex behavior that is
automatic, unlearned, and unmodifiable,
occurring in all members of a species.
• Migration and parental behavior in animals.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
3
Motivation and Homeostasis (2 of 9)
• Drive theory: body maintains a condition of
homeostasis.
• Homeostasis: the state in which any particular system
is in balance or equilibrium.
• Drive: an aroused condition.
• Incentive theory: people motivated by
external stimuli, not just internal needs.
• Arousal theory: people behave in ways that
keep them at preferred level of stimulation.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
4
Motivation and Homeostasis (3 of 9)
• Set point: point of homeostasis (or
equilibrium) to which the system returns.
• Temperature regulation:
• Ectothermic animals (snakes and lizards).
• Endothermic animals (birds and mammals).
• Preoptic area: brain area in hypothalamus
that contains separate warmth-sensitive
and cold-sensitive cells.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
5
Motivation and Homeostasis (4 of 9)
• Thirst: dry mouth and throat influence
when to drink, not how much to drink.
• Hypovolemic thirst: condition of thirst
occurring when blood volume drops due to
loss of extracellular water.
• Osmotic thirst: condition of thirst occurring
when fluid content decreases inside
body’s cells.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
6
Motivation and Homeostasis (5 of 9)
• Subfornical organ (SFO): brain structure
adjacent to third ventricle that senses and
regulates internal water balance with
OVLT.
• Organum vasculosum lamina terminalis
(OVLT): brain structure adjacent to third
ventricle that senses and regulates
internal water balance with SFO.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
7
Motivation and Homeostasis (6 of 9)
• Both SFO and OVLT are circumventricular
organs.
• Circumventricular: outside blood-brain barrier with
direct access to blood circulation.
• Some SFO and OVLT neurons are
osmoreceptors.
• Osmoreceptor: fires more as volume decreases
due to fluid loss.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
8
Motivation and Homeostasis (7 of 9)
• Median preoptic nucleus (MnPO): brain
structure adjacent to third ventricle that
integrates information from SFO and
OVLT.
• Hypovolemic thirst often signaled by
baroreceptors in arteries of heart.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
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Motivation and Homeostasis (8 of 9)
• Angiotensin II: hormone that informs brain
of drop in blood volume, stimulating
receptors in SFO and OVLT.
• Takes 10–20 minutes for body to realize
deficit has been eliminated and stop
sending stimulatory signals.
• Satiety: the satisfaction of appetite.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
10
Motivation and Homeostasis (9 of 9)
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
11
Hunger: A Complex Drive (1 of 15)
• Hunger in many ways is more complicated
than thirst.
• Food selection varies widely in animal
kingdom:
• Herbivores: plant-eating animals.
• Carnivores: meat-eating animals.
• Omnivores: animals that eat both meat and plants.
• Taste primaries: sour, sweet, bitter, salty, and
umami.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
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Hunger: A Complex Drive (2 of 15)
• Sensory-specific satiety: behavioral pattern
that means the more an individual eats a
particular food item, the less appealing the
food becomes.
• Learned taste aversion: avoidance of foods
associated with illness or poor nutrition.
• Learned taste preference: preference not for
a nutrient itself but for the flavor of food
containing the nutrient.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
13
Hunger: A Complex Drive (3 of 15)
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
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Hunger: A Complex Drive (4 of 15)
• Ability of humans to fast and take food in
intermittently requires complex and wellmonitored storage system for nutrients.
• Area postrema: region in brain outside
blood-brain barrier that induces vomiting if
activated by toxins.
• Duodenum: initial 25 cm of the small
intestine where most digestion occurs.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
15
Hunger: A Complex Drive (5 of 15)
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
16
Hunger: A Complex Drive (6 of 15)
• Glucose: a simple sugar which is a common
metabolic product of carbohydrate digestion.
• Amino acids: an end product of protein
digestion.
• Fatty acids: an end product of fat digested in
the intestine.
• Glycerol: an end product of fat digested in the
liver.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
17
Hunger: A Complex Drive (7 of 15)
• Absorption phase: the few hours after a meal
when the body lives off the nutrients arriving
from the digestive system.
• Insulin: hormone that enables body cells to
take up glucose for energy and certain cells
to store excess nutrients.
• Diabetes: condition that results when
pancreas is unable to produce enough insulin
(Type 1) or the body’s tissues are relatively
unresponsive to insulin (Type 2).
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
18
Hunger: A Complex Drive (8 of 15)
• Glycogen: converted form of glucose stored
in short-term reservoirs around body.
• Fasting phase: period in which blood glucose
drops and the body falls back on its energy
stores.
• Glucagon: hormone that causes liver and
skeletal muscles to transform stored
glycogen back into glucose.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
19
Hunger: A Complex Drive (9 of 15)
• Arcuate nucleus (ARC): master hypothalamic
center for food intake control.
• NPY/AgRP neurons.
• POMC neurons.
• Lateral hypothalamus: brain region that
initiates eating and controls aspects of
feeding behavior and metabolic responses.
• Orexin: neuropeptide that increases eating
and increases wakefulness in response to
food deprivation.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
20
Hunger: A Complex Drive (10 of 15)
• Paraventricular nucleus (PVN): brain region
that regulates eating and metabolic
processes.
• Ventromedial hypothalamus (VMH): brain
region that produces satiety and increases
metabolism.
• Ghrelin: orexigenic peptide hormone
synthesized in the stomach and released into
bloodstream during fasting.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
21
Hunger: A Complex Drive (11 of 15)
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
22
Hunger: A Complex Drive (12 of 15)
• Optimal satiation requires interaction of
mouth, stomach, and intestinal factors.
• Cholecystokinin (CCK): peptide hormone
that is best known satiety signal, released
by stomach and small intestine as food
passes into duodenum.
• Limits meal size and aids digestion.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
23
Hunger: A Complex Drive (13 of 15)
• Peptide YY3-36 (PYY): peptide hormone
released in intestines in response to food,
suppressing appetite over longer period of
time.
• Leptin: peptide hormone secreted by fat
cells that inhibits eating.
• Reduces meal size and total daily intake.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
24
Hunger: A Complex Drive (14 of 15)
TABLE 6.1 Summary of Feeding Signals.
STIMULUS
PATHWAY AND ACTION
Initiate eating
1. Glucose and
fatty acids
(nutrients)
Low levels in the circulatory system are detected by receptors in the arcuate nucleus (ARC),
lateral hypothalamus (LH), and ventromedial hypothalamus (VMH) to increase eating. High
levels reduce eating.
2. Glucose and
fatty acids
(nutrients)
Receptors are located on the vagus nerve; low levels cause the ARC, LH, and VMH to increase
eating. High levels reduce eating.
3. Ghrelin
(peptide hormone)
Ghrelin is released by the stomach during fasting; it circulates in the bloodstream to the ARC,
where it activatesAgRP neurons to release neuropeptide Y (NPY).
Terminate eating
4. Stomach
volume
(mechanical)
Stretch receptors send a signal about stomach volume via the vagus nerve to the nucleus of
the solitary tract.
5.C holecystokinin
(CCK; peptide
hormone)
CCK is released by the stomach and small intestine; it is detected by the vagus nerve, which
activates inhibitory neurons in the PVN.
continued
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
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Hunger: A Complex Drive (15 of 15)(cont.)
continued
Long-term control
6. Peptide YY3-36
(PYY)
PYY is released by the intestines and carried in the bloodstream to the ARC, where it
inhibits NPY release.
7. Leptin
Leptin is released by fat cells and carried in the bloodstream to the ARC; it inhibits NPY
release and activates POMC neurons.
8. Insulin
Insulin is released by the pancreas and travels in the bloodstream to the ARC; it inhibits
NPY release and activates POMC neurons.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
26
Obesity (1 of 4)
• Body mass index (BMI): quantifier of
leanness or obesity calculated by dividing
person’s weight in kilograms by squared
height in meters.
• Increased health risks.
• Cannot be characterized by lack of
impulse control, inability to delay
gratification, or maladaptive eating style.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
27
Obesity (2 of 4)
• Diet and activity level influence obesity, but sleep
deprivation can as well.
• Obesity gene: gene on chromosome 6 linked to
obesity in mice, signified as ob.
• Diabetes gene: gene on chromosome 4 linked to
obesity in mice, signified as db.
• Epigenetic: modifications to DNA that turn genes
“on” or “off” without changing gene’s DNA
sequence
• Methylation.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
28
Obesity (3 of 4)
• Basal metabolism: energy required to fuel
brain and other organs and to maintain body
temperature.
• Metabolism will increase or decrease in order
to defend a set point weight.
• Goal of 10% weight reduction can be more
practical than return to normal weight.
• 10% reduction also associated with reduced risk for
chronic disease.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
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Obesity (4 of 4)
• Some weight loss interventions are
drastic, but standard treatment remains
dietary restriction.
• Serotonin could play a role in weight
control.
• Psychological therapeutic approaches
treat out-of-control eating as an addictive
behavior.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
30
Anorexia, Bulimia, and Binge
Eating Disorder (1 of 3)
• Often as puzzling as obesity, but much
deadlier.
• Anorexia nervosa: eating disorder known as
“starving disease” wherein the individual
restricts food intake to maintain weight at a
level so low it threatens health.
• Bulimia nervosa: eating disorder that also
involves weight control, but the behavior is
linked to bingeing and purging.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
31
Anorexia, Bulimia, and Binge
Eating Disorder (2 of 3)
• Binge-eating disorder: eating disorder
where individuals frequently eat large
amounts of food during a short period of
time, wherein they feel they cannot control
what or how much they eat.
• Other disorders: night eating disorder,
pica, rumination, and avoidant/restrictive
food intake disorder.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
32
Anorexia, Bulimia, and Binge
Eating Disorder (3 of 3)
• Anorexia and bulimia may have social
environmental causes, but there seem to
be genetic links as well.
• Eating disorders typically comorbid with
other psychological disorders.
• Serotonin may also play a role in
understanding eating disorders as well.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
33
Chapter 7: The Biology of Sex and
Gender
Introduction
• Gender dysphoria: distress people feel
when their gender identity does not match
their sex at birth.
• Humans are attached to dichotomies,
especially that of male and female.
• Typing people as male or female may not
be as simple or appropriate as we think.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
2
Sex as a Form of Motivation (1 of 7)
• Sex is a motivated behavior like hunger.
• Arousal and satiation:
• Excitement phase.
• Plateau phase.
• Orgasm.
• Resolution.
• Coolidge effect: quicker return to sexual
arousal when a new partner is introduced.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
3
Sex as a Form of Motivation (2 of 7)
Hormonal Control of Sexual Behavior (1 of 2)
• Androgens: class of hormones responsible
for male characteristics and functions.
• Testosterone.
• Estrogens: class of hormones responsible for
female characteristics and functions.
• Progesterone: hormone produced in males to
create testosterone and females to control
sexual reproduction.
Garrett, Brain and Behavior, 6th Edition. © SAGE Publications, 2021.
4
Sex as a Form of Motivation (3 of 7)
Hormonal Control of Sexual Behavior (2 of 2)
• Oxytocin: hormone and neuropeptide that
promotes sexual arousal and social bonding.
• Castration (orchidectomy): removal of the
gonads (testes or ovaries).
• Hypogonadism: disorder in which little or no
hormones are produced by ovaries or testes.
• Estrus: ovulation period.
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Sex as a Form of Motivation (4 of 7)
• Medial preoptic area (MPOA): one of the
more significant brain structures involved
in male and female sexual behavior.
• Medial amygdala: brain structure that
contributes to sexual behavior in animals
of both sexes
• Amygdala.
• Sexually dimorphic nucleus (SDN).
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Sex as a Form of Motivation (5 of 7)
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Sex as a Form of Motivation (6 of 7)
Odors, Pheromones, and Sexual Attraction
• Pheromones: airborne chemicals released
by an animal that have physiological or
behavioral effects on another animal of the
same species.
• Vomeronasal organ (VNO): a cluster of
receptors also located in the nasal cavity.
• Main point from section (brief)
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Sex as a Form of Motivation (7 of 7)
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The Biological Determination of
Sex (1 of 5)
• Sex: biological characteristics that divide
human beings into categories of male and
female.
• Gender: behavioral characteristics
associated with being male or female.
• Gender role: behaviors considered appropriate for
either sex.
• Gender identity: person’s subjective feeling of
being male, female, a combination, or genderless.
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The Biological Determination of
Sex (2 of 5)
• Gonads: testes and ovaries, the primary
reproductive organs.
• Ovaries: organ where ova (eggs) eventually
develop.
• Müllerian ducts.
• Testes: organs that will produce sperm.
• Müllerian-inhibiting hormone.
• Wolffian ducts.
• Dihydrotestosterone.
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The Biological Determination of
Sex (3 of 5)
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The Biological Determination of
Sex (4 of 5)
• Organizing effects: hormonal effects that
mostly occur prenatally and shortly after birth
and affect structure, are lifelong in nature,
and do not disappear when hormone is
removed.
• Activating effects: hormonal effects that can
occur in any time in life and cause reversible
changes.
• Childhood dimorphism: non-genital
differences minimal in childhood.
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The Biological Determination of
Sex (5 of 5)
Prenatal Hormone Influences on Brain and
Behavior
• Hormonal influences responsible for
maturation affect behavior as well.
• Aromatization: testosterone in a neuron
converted to estradiol.
• Behavioral differences affect not only sexual
behavior, but also spatial activity and learning
performance.
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Gender-Related Behavioral and
Cognitive Differences (1 of 2)
• Differences between men and women difficult
to make sense of.
• Unclear if differences are influenced by
biology or are product of rearing and
experience.
• Cognitive performance differences:
• Girls have greater verbal ability.
• Boys excel in visuospatial ability.
• Boys excel in mathematical ability.
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Gender-Related Behavioral and
Cognitive Differences (2 of 2)
Origins of Male-Female Differences
• Best evidence that these differences are partially
result of experience is that they have decreased
over years as gender roles and expectations have
changed.
• Increasing gender equality reducing differentiation in
academic achievements.
• Biological differences in brain exist between men
and women:
• Differences in more grey versus white matter.
• Structural connectivity differences within and between brain
hemispheres.
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Biological Origins of Gender
Identity (1 of 5)
• Some believe gender identity formed in first
few years of life by combination of rearing
and genital appearance, while others believe
chromosomal and hormonal makeup are
more involved.
• Transgender individuals feel disjunction
between assigned sex at birth and gender
identity.
• May transition socially and/or medically to bridge gap
between assigned sex and gender identity.
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Biological Origins of Gender
Identity (2 of 5)
• Several studies suggest unique
developmental path in brains of transgender
individuals, with various brain structures more
closely resembling those of the identified sex
than their birth sex.
• Third interstitial nucleus of the anterior
hypothalamus (INAH3): structure that is
larger in men than in women; thought to be
the human counterpart of the sexually
dimorphic nucleus.
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Biological Origins of Gender
Identity (3 of 5)
• Bed nucleus of the stria terminalis (BNST):
brain structure also larger in males than
females; closely connected to amygdala,
hippocampus, and prefrontal cortex.
• Both INAH3 and BNST have been
reported to be cis female-sized in MtF
transgender individuals and closer to cis
male-sized in FtM transgender individuals.
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Biological Origins of Gender
Identity (4 of 5)
• 46,XY intersex: genetic condition in which
individual has an X and a Y chromosome in each
cell but, due to incomplete masculinization, has an
ambiguous or female external genitalia.
• Androgen insensitivity syndrome: form of 46,XY
intersex caused by genetic absence of androgen
receptors, resulting in insensitivity to androgen.
• 46,XX intersex: partially masculinized by excess
androgens or hormone treatment, resulting in
more or less musicalized external genitalia.
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Biological Origins of Gender
Identity (5 of 5)
• Congenital adrenal hyperplasia (CAH):
condition resulting from genetic defect in
enzymes that cause individual’s adrenal
glands to produce large amounts of
androgens during and after fetal
development.
• Slight cognitive shifts with verbal/spatial
ability appear in 46,XY and 46,XX individuals.
• “Neutral-at-birth” versus “sexuality-at-birth.”
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Sexual Orientation (1 of 3)
• Estimates of homosexuality vary, as do
definitions, sampling methods, and
individuals’ willingness to admit to
homosexual behavior.
• Average estimate of 3.5% in the United States.
• Canada, Australia, United Kingdom, and Norway
estimates range between 1.2% and 2.1%.
• Americans think on average 23% of U.S.
population is gay or lesbian.
• Social influence hypothesis.
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Sexual Orientation (2 of 3)
• Genetics believed to play a role in sexual
orientation, as well as prenatal influences.
• Long-term homosexual mating patterns have
been observed in other animals.
• Medicalization of homosexuality presents
concerns:
• May present homosexuality as a defect or curable.
• Potential for medically correcting a “gay gene” in the
womb or parents aborting a fetus carrying such gene.
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Sexual Orientation (3 of 3)
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Chapter 8: Emotion and Health
Introduction
• Traumatic injuries may have unexpected
effects on the brain.
• Prefrontal cortex is necessary for making
judgments about behavior and
consequences.
• Emotion enriches our lives and motivates
our behavior.
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Emotion and the Nervous System
(1 of 5)
• Emotion: an increase or decrease in
physiological activity accompanied by
feelings that are characteristic of the emotion.
• Often accompanied by characteristic behavior or facial
expression.
• James Lange theory: emotional experience
results from physiological arousal that
precedes it.
• Different emotions are result of different patterns of
arousal.
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Emotion and the Nervous System
(2 of 5)
• Cognitive theory: belief that identity of an
emotion is based on cognitive assessment of a
situation.
• Physiological arousal contributes only to emotion’s
intensity.
• Mirror neurons: fire both when we engage in a
specific act and while observing that act in
others.
• Limbic system: network of structures arranged
around upper brain stem.
• Central to emotion, motivation, learning, and memory.
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Emotion and the Nervous System
(3 of 5)
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Emotion and the Nervous System
(4 of 5)
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Emotion and the Nervous System
(5 of 5)
• Amygdala: small limbic system structure near lateral
ventricle of temporal lobes involved in variety of
emotions.
• Anxiety and fear research.
• Skin conductance response (SCR): measure of
sympathetic nervous system activity obtained by
recording changes in skin’s electrical conductance
during sweat gland activation.
• Anterior cingulate cortex (ACC): brain structure best
known for roles in attention, decision-making, and
impulse control.
• Also plays major role in emotion.
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Stress, Immunity, and Health (1 of 4)
• Stress: condition in environment that makes
unusual demands on an organism.
• Threat, failure, or bereavement.
• Stress is also an internal condition.
• Hypothalamus-pituitary-adrenal axis: brain
region consisting of hypothalamus, pituitary
and adrenal glands.
• Cortisol: glucocorticoid that produces
additional physiological stress responses.
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Stress, Immunity, and Health (2 of 4)
• Prolonged stress has negative side effects:
• Memory interference.
• Appetite changes.
• Diminished sexual desire and performance.
• Depleted energy.
• Disrupted mood.
• Compromised immune system.
• Worsened concentration.
• Sudden cardiac death: excessive sympathetic
activity with stress sends heart into fibrillation,
contracting so rapidly that it pumps little or no
blood.
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Stress, Immunity, and Health (3 of 4)
• Associations have been found between
personality traits and vulnerability for or
protection against disease.
• Type D “distressed” personality linked to increased
risk of cardiovascular disease.
• Personality characteristics such as
introversion are moderately heritable, as is
vulnerability to stress.
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Stress, Immunity, and Health (4 of 4)
Pain as an Adaptive Emotion
• Congenital insensitivity to pain: rare
genetic disorder of PNS in which people
are unable to sense pain.
• Pain is a sense uniquely intermingled with
emotion.
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