Final Flashcards
- What are endogenous rhythms? Describe circadian and circannual rhythms and why they are important for certain species. What external stimulus helps reset rhythms?
When animals generate rhythms that prepare it for seasonal changes.
Circadian – humans generate a 24-hr wake-sleep rhythm.
Circannual – about a year. Birds have this.
Sunlight is important for resetting rhythms.
- What is the suprachiasmatic nucleus (SCN), where is it located and what is its role?
It’s the main driver of sleep and body temp rhythms. It’s located in the hypothalamus.
a. Describe the retinothalamic path and what type of information it delivers to the SCN.
It’s a small branch of the optic nerve. Delivers info from the retina (vidual) to SCN.
b. How could looking at a phone or tablet late at night affect sleep through the retinothalamic pathway?
Input from the retina comes from special ganglion cells who responds mostly yo short wavelength (blue) light. Phones etc. emit short-wavelength light and exposure late in the day can phase-delay the circadian rhythm.
- What is the pineal gland and how does it affect sleep?
The pineal gland produces melatonin and modulates sleep patterns in both circadian and seasonal cycles.
a. What hormone does the pineal gland secrete and how does it affect sleep cycles?
It releases melatonin which influences both circadian and circannual rhythms.
- What is sleep?
A state that the brain actively produces. An alternation in consciousness with decreased response to stimuli.
- What is a coma?
Extended period of unconsciousness. Low level of brain activity. Little to no respons to stmuli.
a. What does it mean to be in a minimally conscious state?
Some deliberate movements (eye tracking), some attempt to communicate.
b. What does it mean to be in a persistent vegetative state?
Coma lasting more than a month. Less likely to recover consciousness the longer this lasts.
- What is EEG and what does it do?
4 types of brainwaves associated with sleep. Records electrical potentials of neurons.
- What is a polysomnograph?
Combination of EEG and recording of eye movements.
- Describe the EEG wave pattern and any behavioral characteristics (e.g., muscle inhibition, eye movement, etc.) associated with the following stages of sleep:
a. Relaxed wakefulness:
steady series of alpha waves.
- Describe the EEG wave pattern and any behavioral characteristics (e.g., muscle inhibition, eye movement, etc.) associated with the following stages of sleep:
b. Stage 1
theta waves. People at this stage can be awakened easily, but may deny that they were sleeping. May experience a vivid visual image, or psychological experiences such as feeling like you’re falling.
- Describe the EEG wave pattern and any behavioral characteristics (e.g., muscle inhibition, eye movement, etc.) associated with the following stages of sleep:
c. Stage 2:
Theta waves continue but sleep spindles (rapid, short burst of electrical activity) and K-complexes (large fluctuation in voltage) start to occur.
- Describe the EEG wave pattern and any behavioral characteristics (e.g., muscle inhibition, eye movement, etc.) associated with the following stages of sleep:
d. Stage 3 & 4:
Delta waves. Sensory input to cortex is reduced, and neurons synchronize their activity. Can still process some info, but irrelevant stimuli is filtered out but parents can still hear their babies cry. Hard to wake up, disoriented when awakened.
- Describe the EEG wave pattern and any behavioral characteristics (e.g., muscle inhibition, eye movement, etc.) associated with the following stages of sleep:
REM:
Show flurry of beta wave activity. Brain activity is high, but body is mostly paralyzed. Eyes dart back and forth rapidly beneath eyelids. Associated with dreaming.
- What are PGO waves and with what stage of sleep are they associated?
High-amplitude electrical potentials. Associated with REM sleep.
- Briefly describe how humans cycle through stages of sleep during the course of a night.
You start in stage 1 and slowly progress through states 2,3, and 4. First hours you don’t spend time in REM sleep but as time goes on you spend more time in REM sleep..
- What neurotransmitter increases in activity during sleep?
Neurons that release GABA because it weakens communication between neurons.
- What happens in the thalamus during sleep?
Neurons in the thalamus become hyperpolarized.
- What are orexins?
Neuropeptide that regulates wakefulness and transitions among sleep stages.
- What is insomnia?
Inability to sleep.
- What is obstructive sleep apnea and how is it treated?
Breathing during sleep is disrupted or even stopped for short periods. Treated with continuous positive airway pressure (CPAP) device.
- What is narcolepsy? What is believed to be the underlying cause and how is it treated?
A rare, chronic brain disorder involving poor control of sleep/wake cycles. Lacks the hypothalamic cells that produce and release orexin. Can also be an autoimmune reaction where the immune system attacks part of the body.
Treatment – stimulant drugs such as Ritalin.
- What is REM Behavior Disorder? (study tip: how does it differ from sleepwalking or night terrors?)
Normal paralysis that accompanies REM sleep is disabled. Often unpleasant dreams with vocal sounds and sudden, often violent arm and leg movements.
- What is Somnambulism (sleepwalking)?
Behavior during slow-wave, non-REM sleep, typically within 1-2 hours after falling asleep. May appear awake, but disconnected from others. Usually not accompanied by dreaming.
- What are night terrors?
Intense anxiety, more severe than nightmares. Usually awakens screaming. Occur in non-REM sleep. Dream content (if any) is simple – like single image.
- List and describe two important functions of sleep (why we need it.)
Restoration – allows the body and brain to rest and repair itself. After physical activity, such as marathon, people sleep longer than usual.
Facilitation of learning – neural connections made during awake learning are strengthened during sleep.
- What changes in sleep after learning? Are there certain brain regions that are more active and is there a sleep stage we get more of versus other stages?
During times of increased learning, more REM occurs. Hippocampal activity in sleep correlates with degree of learning/memory.
- Why may dreaming be important for learning and memory? We discussed some evidence for this in class.
People who dream about a task while sleeping may be especially likely to perform better. It’s good for problem solving.
- What are some effects of sleep deprivation discussed in class? (Study tip: note what happens after a few hours, a few days, and what tends to occur with REM sleep).
Light effects; 3-4 hours – more sleepy. Bad mood. Decreased vigilance.
Larger effects; complex cognitive functions (prefrontal cortex). Preform worse on tasks involving assimilating information, planning strategies, innovative, insightful thinking, and working memory.
After 2-3 days: microsleeps – 2-3 second periods that subject may be sitting or standing, but eyelids droop and they are unresponsive to external stimuli.
Proceed more rapidly into REM as REM deprivation increases. REM rebound – more time spent in REM when deprivation is over.
- Why do we dream, according to the Activation Synthesis Theory?
Dreams are byproduct of mental processes produced by random brain activation/neural firing during REM sleep. Brain areas that normally interpret sensory input tries to make sense of the random activity by synthesizing it with stored memories. Sensory stimuli, such as sounds in the room, occasionally get incorporated into the dream.
PGO waves are internally generated info and originate from the brainstem. The brain processes these signals and interprets them in terms of information stored in memory. These activations can expand to activate higher-level neurons as well, evoking visual images, sounds, etc. creating dreams.
- Why do we dream, according to the Clinico-Anatomical Theory and how does it differ from the activation synthesis theory?
Like AS theory, sees dreaming as a result of stimuli generated within the brain, but less emphasis on pons, PGO waves or REM sleep. Stimuli generated within the brain are combined with recent memories. Dreams are a form of thinking that takes place under unusual circumstances.
- Can you tell whether a fetus in the first 6 weeks of development is male or female? Why or why not?
No because there are both Mullerian ducts (precursors to female internal structures) and Wolffian ducts (precursor to male internal structures).
- Briefly describe what happens if the fetus as a Y chromosome present (male) and or absent in terms of sex differentiation in fetal development.
If Y present, then SRY gene on this chromosome causes undifferentiated gonads to develop into testes.
Because females don’t have the SRY gene, undifferentiated gonads turn into ovaries.
a. What develops from the Woffian ducts?
Male internal structures – seminal vesicles and vas deferens.
b. What develops from the Mullarian ducts?
Female internal structures – oviducts, uterus.
- What is androgen insensitivity syndrome (AIS) and what happens during does it occur fetal sex differentiation?
Someone have XY chromosomes and produces normal amounts of androgens (including testosterone). Lack receptors that allow cells to responds to androgens – develops external female anatomy. Usually doesn’t know until puberty. Breast develop. Hibs broaden, but no mens (never developed ovaries. Physically, she develops as a female.
- What does it mean to be intersex, and how can this occur in males? How can this occur in females? How can it affect behavior in childhood?
True hermaphrodite (rare) has some testicular and ovarian tissue. May be fertile as either male or female, not both.
More common type: intermediate appearance of anatomy due to atypical hormone pattern during development.
Genetic male with low levels of testosterone may lead to more female appearance.
Genetic female exposed to more testosterone may be partly musicalized.
- What is congenital adrenal hyperplasia (CAH) and how does it affect development and subsequent behavioral interests in childhood and adulthood?
CAH is overdevelopment of adrenal gland from birth – affects girls.
In genetic male, extra testosterone causes no problem.
In a genetic female, various degrees of masculinization of external genitals. Ovaries and other internal organs are less affected.
Brains during prenatal development exposed to more testosterone compared to other girls, so behavior is somewhat masculinized. Tendency to play more with boys’ toys vs other girls, but less than boys.
Adolescence and beyond: interest of more rough sports, fewer style magazines, more likely to enter male-dominated occupations.
- What are steroid hormones?
Sex hormones. Estrogens and androgens.
- Briefly describe the roles of these three sex hormones: androgens (including testosterone) estrogens and progesterone.
Androgens: more in males.
Estrogen: more in females.
Progesterone: another predominantly female hormone. Prepare uterus for implantation.
- What is the difference between organizing effects and activating effects of hormones? Give 1-2 examples of each type of effect.
Organizing – produce long-lasting structural effects. Determines whether the body develops male or female genitalia. Breast development (girls), changes in voice and facial hair (boys).
Activating – more temporary. Influences sex drive. Pregnancy; emotional arousal, aggressive behavior, learning/cognition.
Organizing effects set stage for activating effects.
- What are the effects of exposure to high levels of testosterone for females in utero in terms of genital development and behavioral interests later in childhood?
Elevated preference for boys’ toys at age 3.5. Tens to spend more time than average playing with toy trains.
- What is the medial preoptic area, and how does it affect male sexual behavior (Hint: a certain neurotransmitter is involved).
Located in hypothalamus. Crucial site in the control of sexual behavior in males. Dopamine.
- How may testosterone affect single vs. multiple mate preference?
Men and women with higher testosterone levels are more likely than average to seek additional sex partners, even after they marry or establish a long-term relationship.
- What are some behavioral changes (including mate preferences) in females that are a result of hormone fluctuations during the menstrual cycle?
Women tend to be more drawn to masculine features during time of ovulation. Women shown videos or photos of men and asked to choose preference for short term relationship – more likely to choose man perceived as more athletic, competitive and assertive.
Hormones associated with fertility move women’s mate preferences toward men who look and act more masculine.
