Unit 3 Multiple Choice and Short Answer Flashcards
general consequences of lack of sleep
- Lower motivation
- Impaired judgement
- Slower cognitive processing
- More errors/accidents, even risk of death
- Weight gain (cravings)
What is the longest a human has gone without sleep?
11 days (264 hours)
lack of sleep as a fatality
- Rats kept awake for 2 weeks died
- Fatal Familial Insomnia (FFI) - insomnia that worsens until death; fatal after 6-30 months without sleep
EEG waves of different sleep states
- Relaxed wakefulness - Alpha waves
- Stage 1 - Theta waves
- Stage 2 - Sleep spindles, K-complex
- Stages 3/4 - Delta waves
- REM sleep - fast, random, sawtooth waves; similar to relaxed wakefulness!
How long are sleep cycles?
~90 min
place cells in sleep and memory replay (Diekelmann & Born, 2010)
Place cells in the hippocampus respond when an animal is in a specific location. In this study, recordings from 5 different place cells in the hippocampus were taken while rat runs in a triangle maze.
We see the same pattern of place cell firing when mouse runs a maze and when the mouse sleeps, as if they are replaying the experience while sleeping.
place cells
cells in the hippocampus that respond when an animal is in a specific location; in this manner, the hippocampus maps our spatial environment
Study shows that place cells have same pattern of firing when rat runs a maze and sleeps, indicating memory replay while sleeping.
effect of sleep on implicit skill learning task (Stickgold et al., 2001)
Individuals were presented with either a letter T or L in the periphery, and were asked to identify the letter. This study revealed that overnight interval between training and testing (i.e., one night’s sleep) led to significant improvement on the implicit skill learning task, and this skill improvement remained for many days.
Also revealed that lots of slow wave sleep (SWS) at the beginning of the night = more learning, and lots of REM sleep at the end of the night = more learning. I.e., SWS at beginning of night and REM at end is most impactful for learning.
How does type of sleep and when it occurs affect learning?
Stickgold et al., 2001, study of sleep and implicit skill learning task found that learning is maximized when:
1. Lots of slow wave sleep (SWS) at beginning of night
2. Lots of REM at end of night
No learning improvements when the opposite was seen.
memory engram model of how memory is encoded during sleep (systems consolidation of memory)
During slow wave sleep (SWS), the hippocampus recruits areas of the cortex to help replay recently encoded memories for consolidation purposes. In this situation, there is a recently encoded hippocampal part of a representation AND a recently encoded neocortical part of a representation. Think of this as “training” the cortex to encode memory on its own. This is known as “systems consolidation.”
During REM sleep, however, after memories are fully consolidated, the hippocampus is no longer involved, and memories are just encoded by the cortex. There are new synaptic connections between nodes in the cortex, and connections within nodes are strengthened. Think of this as the cortex (now independent from hippocampus) driving other areas of the cortex to permanentize the memory engram.
How do sleep spindles correlate with learning in infants?(Klinzing, Niethard & Born, 2019)
Babies were trained on a language learning task in which they were shown objects, and a certain word or name was played to help the baby learn the name of the object.
Infants who took a nap before testing showed an N400 EEG component in response to words that were incorrectly paired with objects, while infants who did not take a nap did not exhibit this effect, showing that only infants who took a nap developed object category representation (i.e., learned).
The reliability of the N400 peak was correlated with the power of sleep spindles during the nap. I.e., learning correlates to sleep spindles during nap.
How do sleep needs change with age?
- Newborns - 12-18hr sleep needs
- Infants - 14-15hr sleep needs
- Toddlers - 12-14hr sleep needs
- Preschoolers - 11-13hr sleep needs
- School-age children - 10-11hr sleep needs
- Teens - 8.5-9.25hr sleep needs
- Adults - 7-9hr sleep needs
Distribution of this sleep changes over development as well (e.g., napping)
sleep phase delay
12-21 year olds (adolescents) have a sleep phase delay, meaning they go to bed and wake up later (1-3h delay) than any other age group; this is a natural, biological phenomenon that is also visible in other mammalian species and is observed around the time of puberty
suprachiasmatic nucleus (SCN)
the SCN contains the “circadian pacemaker,” regulating the timing and consolidation of the sleep-wake cycle; the SCN is largely dictated by signaling from both light-entrainable oscillators in the retina, which provide light information, and food-entrainable oscillators in the gastrointestinal system, which provide information for when you should eat/sleep based on when you sleep/eat
light-entrainable oscillators
circadian clocks located in the retina that provide light information to the suprachiasmatic nucleus (SCN), helping to regulate the sleep-wake cycle
food-entrainable oscillators
circadian clocks located in the gastrointestinal system that indirectly provide information about food consumption to the suprachiasmatic nucleus (SCN), helping to regulate when you should eat/sleep based on when you sleep/eat
How does when we go to sleep change with age?
We go to sleep earlier when we are young, but ALL teenagers (whether night owls or not) exhibit sleep phase delay and go to bed later than the rest of the population. This sleep phase delay fades as we continue to age into the mid-late 20s and normalizes.
Also note that males tend to go to bed later than females.
How does when we go to sleep differ between males and females?
Males tend to go to sleep later than females from ages 10-40, but sleep times equalize from 40 onward
What is the effect of later school start times (i.e., more sleep) on academic achievement, daytime tiredness, behavioral persistence, and attitude? (Perkinson-Gloor et al., 2013)
A study in Switzerland found that school that started later (meaning 1+ extra hour of sleep) showed improved academic metrics in Math and German as well as improvements to daytime tiredness, behavioral persistence, and positive attitudes toward life.
In this manner, total sleep duration is a predictor of daytime tiredness (negative correlation), and daytime tiredness shows negative correlation with behavioral persistence, which has positive correlation to academic achievement and positive outlook on life.
How does lack of sleep affect driving?
Lack of sleep is heavily correlated with impaired driving skills and fatigue-related crashes…
1. Teen drivers who sleep less than 8 hours are 1/3 more likely to crash than those who sleep 8 or more hours
2. Lack of sleep reduces ability to process info, sustain attention, have accurate motor control, and react normally, all of which are crucial driving skills
3. Being awake for 18 hours is similar to BAC of 0.08, which is legally drunk
Who causes the majority of fatigue-related crashes?
Majority of fatigue-related crashes are caused by drivers under 25; this may be an indictment of school start times + sleep phase delay in adolescents
What is the prevalance of drowsy driving?
- At least 5% of adults admit to falling asleep at the wheel
- In 2017, 91,000 police-reported crashes involved drosy drivers
- In 2019, an estimated 697 fatal crashes involved drowsy driving
What is the impact of later school start times on car accidents? (Vorona et al., 2011)
Study comparing two high schools found that the school with the later start time resulted in fewer crashes among teen drivers both before school and after school compared to the school with the earlier start time. I.e., more sleep = less teen accidents
How prevalent are recommendations for later school start times?
As supported by a plethora of research…
1. Many prominent organizations such as The American Academy of Pediatrics and the CDC recommend that start times for middle and high school should be moved back
2. School districts worldwide are moving start times back to 8:30 or later
How does later school start time affect student sleep and student grades? (Dunster et al., 2018)
Study between two Seattle schools found that students who start school later got more sleep and performed better in first period classes
Socioeconomic status (SES) is a complex mixture of ____.
Complex mixture of:
1. Income level
2. Education level
3. Job prestige
4. Marital status
socioeconomic status (SES) as a predictor of future outcomes
SES is a strong predictor of life/educational outcomes such as vocab ability, school entry skills, graduation rates, and lifetime earnings
How have the black-white and rich-poor reading gaps changed over time? (Reardon, 2011)
Before segregation, there was a major gap in reading test scores between black and white children, but this gap has largely been closed.
However, as this gap closed, the reading gap between rich and poor children has been expanding steadily over time.
How has financial inequality changed over time? (Reardon, 2011)
The financial inequality gap has been increasing over time; there is a large gap between 50th percentile and 10th percentile income families, and an even larger gap between 90th percentile and 10th percentile.
How does SES correlate to school achievement? (Heckman, 2006)
kids enter school at age 6 with lower school abilities (worse grades) in the lower income quartiles than in higher income quartiles, and this trend continues throughout education, with low-income children continuously performing worse than high-income children
Is SES correlation to academic achievement a matter of “better schools?”
No! Middle-class students eligible for free lunch still scored better on math tests than low-income students in every school, even in the same classroom.
How does gray matter development differ across SES levels? (Hanson et al., 2013)
high SES children have greater development in total gray matter, frontal gray matter, and parietal gray matter than both mid SES and low SES children
How does parental education affect brain surface area? (Noble et al., 2015)
increased parental education is correlated with increased brain surface area, largely in temporal lobe and PFC; there is a linear increase in surface area for every 3 years of parental education
How does family income affect brain surface area? (Noble et al, 2015)
as family income increases, brain surface area increases, until about $50,000, then surface area minimally increases/plateaus as income further increases; specifically, there is a non-linear increase in brain surface area from $0-$50,000 family income
What brain regions exhibit functional differences on the basis of SES?
- Left perisylvian - language
- Anterior cingulate - cognitive control
- Medial temporal - declarative memory
- Lateral prefrontal - working memory
- Parietal - spatial cognition
- Occipito-temporal - visual cognition
Behavioral battery confirms this
What tests were conducted to analyze the left perisylvian/language system component of the SES behavioral battery? (Noble, McCandliss, and Farah, 2007)
- PPVT - experimenter says a word, child points to corresponding picture
- CTOPP - Blending words subtest (e.g., what word do the following sounds make?)
These collectively test high (semantic) and low (phenomic) aspects of language.
A correlation was found between this left perisylvian/language system and SES, and it was revealed that language skills mediate SES effects on cognitive conflict (ACC/cognitive control).
What tests were conducted to analyze the parietal/spatial cognition system component of the SES behavioral battery? (Noble, McCandliss, and Farah, 2007)
- NEPSY Arrows - 8 arrows point toward center, 2 of 8 point directly at the center dot, goal is to say which point at center dot and which don’t
- Mental Rotation - hands (L or R) presented at various orientations, goal is to say whether hands can be superimposed by rotating
A correlation was found between this parietal/spatial cognition system and SES.
What tests were conducted to analyze the medial temporal/declarative memory system component of the SES behavioral battery? (Noble, McCandliss, and Farah, 2007)
- NEPSY delayed memory for faces - children asked to say if image showed a boy or a girl, goal is to identify old faces after 20 min delay
- Incidental picture pair learning task - pairs of “Snodgrass” pictures shown, then 10 min delay, goal is to identify shown pair (out of 3)
A correlation was found between this medial temporal/declarative memory system and SES.
What tests were conducted to analyze the lateral prefrontal/working memory system component of the SES behavioral battery? (Noble, McCandliss, and Farah, 2007)
- Spatial working memory task
- Delayed non-match to sample - hold simple, nonverbalizable figural shape in memory; 4 sec study, 1 sec delay, ask if it matches
A correlation was found between this lateral prefrontal/working memory system and SES.
What tests were conducted to analyze the anterior cingulate/cognitive control system component of the SES behavioral battery? (Noble, McCandliss, and Farah, 2007)
- Go/no-go task - press button for all animals except the cat; 50 go, 10 no-go, measure failures to inhibit responses
- NEPSY auditory attention and response set - recorded words played at 1/sec, put red square in box when red is heard; phase 2 involves putting yellow for red, red for yellow, and blue for blue
A correlation was found between this anterior cingulate/cognitive control system and SES. It was also found that these SES effects on cognitive conflict are mediated by language skills.
What tests were conducted to analyze the orbitofrontal/reward processing system component of the SES behavioral battery? (Noble, McCandliss, and Farah, 2007)
- Reversal learning task - 2 decks of cards, 1 good, 1 bad, after successful learning the good and bad decks are switched; successful reversals are counted and measured
- Delay of gratification - noisy present wrapping with child’s back turned, measure time child avoids turning around
This orbitofrontal/reward processing system is the only cognitive domain of the behavioral battery in which NO correlation with SES was found.
How does SES affect different brain systems and their corresponding behaviors (SES behavioral battery)? (Noble, McCandliss, and Farah, 2007)
The SES behavioral battery was a study of 150 1st-grade children across SES levels that involved the conduction of multiple tests to analyze the effect of SES across six broad anatomical/cognitive domains:
1. Left perisylvian/language system
2. Parietal/spatial cognition system
3. Medial temporal/declarative memory system
4. Lateral prefrontal/working memory system
5. Anterior cingulate/cognitive control system
6. Orbitofrontal/reward processing system
This study ultimately found a correlation between SES and each of the cognitive domains except for orbitofrontal/reward processing, and also showed that SES effects on cognitive conflict were mediated by language skills, and that home and school environment modulated SES effects.
How do home and school environments modulate effects of SES on cognitive behavior (SES behavioral battery)? (Noble, McCandliss, and Farah, 2007)
- High performing supportive school offsets low parental education level
- Supportive, stable home environment offsets low family income
What is the hypothesized relationship as to how SES drives cognitive processes?
What are the effects of SES on early linguistic abilities? (Fernald et al., 2012)
Follow-up of 1995 study of “30 million word gap” found:
1. # of words spoken in home increases with SES
2. Accuracy of word knowledge increases with SES
3. Improved language processing speed correlated with SES
4. Grammatical complexity of speech increases with SES
5. Affirmations increase with SES
What is the “30 million word gap?”
derived from 1995 study, suggests that children up to age 4 from a lower socioeconomic status heard 30 million fewer words than children from a higher socioeconomic status
How are dendrites different in isolated vs. “enriched” environments?
isolated rats have decreased dendrite # and decreased dendrite complexity relative to rats in an “enriched” environment; the truth is that it’s not really the “enrichment” causing these effects, but rather the absence of an impoverished environment
What are the effects of chronic stress on the brain?
Heightened HPA axis activation that causes a sustained fight-or-flight response via the prolonged release of glucocorticoids (dangerous), leading to:
1. PFC atrophy
2. Hippocampus atrophy
3. Amygdala hypertrophy, and later atrophy
How do the neuronal effects of stress on dendrites change with age? (McEwen & Morrison, 2013)
Exposure to chronic stress causes dendritic shrinkage, and young animals are able to fully recover from this shrinkage, while recovery is blunted partially or completely in middle aged/aged animals. Dendrite count naturally decreases with age, however, so middle/old aged animals actually lose less dendrites than young (but still can’t recover).
How does SES impact emotion regulation and its neural substrates? (Kim et al., 2013)
Poverty was measured in 49 children at age 9, then at age 24, fMRI studies were conducted during an emotion regulation task.
It was revealed that low SES at age 9 correlates to low lateral PFC (amygdala) activity during emotion regulation at age 24 UNLESS took into account chronic stress.
What is significant about chronic stress with regard to SES?
chronic stress largely modulates effects of SES on the brain; e.g., in study of SES and emotion regulation, it was revealed that low SES at age 9 correlates to low lateral PFC (amygdala) activity during emotion regulation at age 24 UNLESS took into account chronic stress
How might environmental factors contribute to SES-related brain differences (environmental inequality)?
In certain situations, large amounts of neurotoxins may cause detriments to brain function. High-SES areas are able to fight pollution/prevent introduction of neurotoxins better than low-SES areas, which may help explain SES-related brain differences. This is known as environmental inequality, and environmental inequality correlates with SES on a state-by-state basis.
How does SES correlate with attention as shown by EEG? (Hackman & Farah, 2008)
Two unique stories were played in each ear, with visual cues indicating which story should be attended to.
In those with high maternal education (high SES), ERP shows smaller amplitude activity on the ignored side than the attended side. In those with low maternal education (low SES), however, there is less of a difference between attended and non-attended stimuli, suggesting that low SES correlates with reduced attention abilities.
What are the effects of family-based preschool programs on emotion and cognition? (Neville et al., 2013)
Study of three preschool interventions found that the PCMC-A family-based intervention had significant effects on parent emotion, child emotion, and child cognition (not as large an impact here) relative to child-based interventions, showing that supporting families and not just children is most effective.
What are the effects of family-based preschool programs on attention? (Neville et al., 2013)
Study of three preschool interventions found that a significant difference in ERP amplitude representing the attended side and nonattended side was present ONLY after PCMC-A family-based intervention (there was no difference in peaks prior to intervention), not in child-based interventions.
Given previous study showing worse attention in low-SES individuals, this may be applicable to low-SES children to improve attention. Also shows that supporting families and not just children is most effective.
How does preschool affect low-SES children? (Reynolds et al., 2011)
Review of 1970s Chicago study showed that preschool had strongest effect in those with lowest level of maternal education; i.e., preschool has greatest impact on low-SES children.
There was also a bigger impact in males than females.
Why do SES studies largely implicate maternal education?
mother’s education is the best predictor of educational ability
rate-of-return of preschool programs and invested capital discrepancy
preschool programs have the greatest rates of return to human capital investment, yet not a lot of money is invested into preschool programs; benefits-to-cost ratio of $8.74, meaning $1 investment returns $8.74
What is the effect of direct cash transfer (i.e., increasing SES) on baby brain development? (Troller-Renfree et al., 2022)
A study gave families monthly cash gifts in order to measure SES on baby brain development. This is a direct test of causality (randomized controlled trial) of SES on brain development and function, which is extremely challenging.
High-cash group showed greater EEG beta and gamma activity, which is correlated with future success.
eye tracking as a predictor of Autism Spectrum Disorder (ASD)
Eye tracking at 2-6 months acts as a predictor of ASD: children with ASD show high eye fixation that decreases with age, while neurotypical children have lower eye fixation that ramps up then flatlines with age.
High risk siblings (having sibling w/ autism) w/o symptoms show similar trend to neurotypical children, while high risk siblings w/ symptoms but no diagnosis show slightly similar trend to ASD but not as extreme.
