444 MIDTERM 1 READINGS

The degree of_____activity measured during initial encoding of items cued for remembering and forgetting accurately predicts the subsequent magnitude of differential offline sleep dependent consolidation --> so what signal may reflect the tagging of items for sibqequent consolidation by sleep? do the same tags determine the form that memory processing takes during sleep? is tagging absolutely required for sleep dependent consolidation to occur?

The degree of hippocampal activity measured during initial encoding of items cued for remembering and forgetting accurately predicts the subsequent magnitude of differential offline sleep dependent consolidation This hippocampal signal while awake may reflect the tagging of items for subsequent consolidation by sleep It is unknown whether the same tags determine the form that memory processing takes during sleep or whether the form of processes is determined by events during sleep Also, unclear if tagging is absolutely required for sleep dependent consolidation to occur

The distribution of REM towards the latter portion of the night is linked to a _____ which can be gauged by the ____ The distribution of SWS towards the earlier part of the night is mediated by the _______ highest at ____

The distribution of REM towards the latter portion of the night is linked to a circadian oscillator which can be gauged by the oscillation of body temperature The distribution of SWS towards the earlier part of the night is mediated by the prior period of wakefulness- the homeostatic sleep system, highest at sleep onset and diminishing across the night as sleep pressure wanes or recovery takes place

Conclusions: Do all animals sleep? It might well be more accurate to view sleep as ... so is sleep a universal state with the same underlying functions in all species?

The evidence that all animals have a state that meets the accepted definitions of sleep is quite poor --> Many marine mammals, terrestrial animals and birds that migrate for long dis- tances and large herbivores and animals with exposed sleeping sites might not show the periods of greatly reduced awareness, or the rebound after deprivation that defines sleep, during certain periods of their lives It might well be more accurate to view sleep as a behavior whose presence, quality, intensity and functions vary between species and across the lifespan. sleep is not a universal state with the same underlying vital function in all species - Different animals have used sleep to maximize energy savings by reducing body and brain energy consumption, increasing survival by seeking out a safe sleeping site, releasing hormones and conducting a variety of recuperative pro- cesses → Some species appear to be able to accomplish these processes during the waking state.

Direct retinal input travels thru the _____- a monosynaptic pathway by which information about the environmental light dark cycle reaches the SCN The 3 cone system and rods- the visual photoreceptors are not required for transmitting light signals to the circadian system- a distinct set of ____ in the inner retinal layer that project to the SCN are intrinsically photosensitive- ______is the active photopigment Daytime and nighttime retinal exposure to _____ (460nm) light improves reaction time, reduces attentional failures and improves EEG correlates of alertness

Direct retinal input travels thru the retinohypothalamic tract- a monosynaptic pathway by which information about the environmental light dark cycle reaches the SCN The 3 cone system and rods- the visual photoreceptors are not required for transmitting light signals to the circadian system- a distinct set of ganglion cells in the inner retinal layer that project to the SCN are intrinsically photosensitive- melanopsin is the active photopigment Daytime and nighttime retinal exposure to monochromatic blue (460nm) light improves reaction time, reduces attentional failures and improves EEG correlates of alertness

Sleep in reptiles - why id there a discrepancy in studies? turtles?

Discrepancies in studies → theres a difficulty of equating observable physiological changes in reptiles with those in mammals, so that in some cases it has been concluded that REM sleep exists in the absence of eye movement or muscle tone suppression unclear whether episodes labeled REM sleep were adequately distinguished from waking. turtles: - the EEG correlates of quiescent behavior increased after disruption of quiescent states - There was no periodic activation of brainstem neuronal activity during quiescence resembling that seen in REM sleep ---> general and marked reduction in neuronal activity immediately upon cessation of waking activity, with little further reduction during extended periods of inactivity - no forebrain slow waves were reported in any of these studies

does constant routine procotol allow for the complete unconfounded separation of circadian and homeostatic influences on neurobehavioural and physiologic variables? in the Kleitman forced desynchrony protocol, sleep and wake are distributed more evenly in the entire circadian cycle- therefore possible to....

no However, in the Kleitman forced desynchrony protocol, sleep and wake are distributed more evenly in the entire circadian cycle- therefore possible to average data over the successive circadian cycles or successive sleep wake episodes to separate these components

is the effectiveness of explicit waking instructional cues on consolidation is time sensitive? what study showed this? do we know the precise neural mechanism that create waking instructional tags and mechanisms controlling selective consolidation during sleep?

*The effectiveness of explicit waking instructional cues on consolidation is time sensitive- requiring sleep within 24 h of encoding --> Participants not allowed to sleep the night after item learning and then tested after two subsequent nights of recovery sleep showed nonspecific memory retention, with reduced recall differences between to-be-remembered and to-be-forgotten items. These findings establish not only that explicit waking tags used for sleep- dependent processing degrade over 24 h, but that they do so faster than the item memories themselves, suggesting that tags may be distinct from their associated memories. We don't know the precise neural mechanism that create waking instructional tags and mechanisms controlling selective consolidation during sleep --> Neural mechanisms of tagging that support conversion of early phase LTP into late phase LTP have been identified but we don't know if its related to sleep related tagging

Does sleep facilitate 2 complementary objects for declarative memory? (what does sleep do short term to our memories, longterm? consequence?)

- First, initial process of consolidating individual item (episodic) memories that are novel- short term - Over a longer term, sleep may begin the process of extraction (of meaning) and abstraction (building associational links with existing information) thereby creating more adaptive semantic networks. Ultimately, only the conceptual meaning of such experiences would remain Forgetting individual items is the price we pay for remembering general rules

Eg 2. Transitive inference: reflects the building of inferential relationships based on individual item premises- like if A>B and B>C, we infer that A>C - explain results? therefore sleep facilitates....? specifically those of greater...

- Subjects were taught 5 premise pairs which embedded a hierarchy - When tested 20h after training, subjects showed no evidence of having extracted any inferences - After 12h awake during daytime- moderate knowledge of first and second order inferences - After 12h or 24h including a night of sleep- markedly superior second order inference ability ****Therefore, sleep facilitated inferring of transitivity rules, specifically those of greatest associative distance and enhanced subsequent decision making

When evaluating sleep in animals we must consider: 3 things

- The elevation of sensory thresholds that we use to define our sleep is not absolute - Vigorous exercise will tend to produce a 'rebound' of inactivity without being perceived by the subject or observers as sleep. - individuals can close their eyes for long periods of time with completely unimpaired consciousness.

Therefore, with total sleep loss, ____tends to be preferred over___ do both states show evidence of homeostatic regulation? when will recovery prefer rem over SWS? Chronic restriction of nocturnal sleep, an irregular sleep schedule, or frequent disturbance of nocturnal sleep can result in a ______, characterized by premature ____sleep, that is _____ Such episodes can be associated with ______, _____, or an increased incidence of ____

--> Therefore, with total sleep loss, SWS tends to be preferred over REM, which only recovers after recuperation of SWS- therefore both states show evidence of homeostatic regulation Chronic restriction of nocturnal sleep, an irregular sleep schedule, or frequent disturbance of nocturnal sleep can result in a peculiar distribution of sleep states, characterized by premature REM sleep, that is, Sleep Onset REM Periods. Such episodes can be associated with hypnagogic hallucinations (vivid, dream-like sensation that an individual hears, sees, feels, or even smells and that occurs near the onset of sleep), sleep paralysis, or an increased incidence of hypnic myoclonia.

Two predictions about the impact of sleep on declarative memory?

1. Declarative memories from the day prior should be more resistant to interference the next day, due to the increased cortico-cortical connections formed during over- night consolidation 2. If the strengthening of cortico-cortical connections takes place during sleep, then blocking sleep after hippocampal learning should negate this offline transfer, preventing the development of independence from the hippocampus, and decrease the capacity for new hippocampal learning the next day- this may explain why the hippocampus is less activated when learning the next day after sleep deprivation- related to decreased ability to form episodic memories

REM sleep provides an optimal biological state for achieving such affective 'therapy' for 3 reasons: 1. Increased activity within ____and____ structures during___ may first offer the ability for .... 2. Second, the neurophysiological signature of REM involving dominant_____within subcortical as well as cortical nodes may offer large-scale ...... at night, allowing the ....... in the context of pre-existing neocortically stored semantic memory 3. These interactions during REM take place within a brain that is devoid of_______, the influence of which has been linked to states of high stress and anxiety disorders

1. Increased activity within limbic and paralimbic structures (including the hippocampus and amygdala) during REM may first offer the ability for reactivation of previously acquired affective experiences 2. Second, the neurophysiological signature of REM involving dominant theta oscillations within subcortical as well as cortical nodes may offer large-scale network cooperation at night, allowing the integration and greater understanding of recently experienced emotional events in the context of pre-existing neocortically stored semantic memory 3. These interactions during REM take place within a brain that is devoid of aminergic (serotonin, dopamine and norepinephrine - keeps PGO wave amplitudes low) neurochemical concentration, the influence of which has been linked to states of high stress and anxiety disorders

Core body temp records from participant in Mammoth Cave, Kentucky who underwent a 28 hour imposed sleep wake schedule were compared to lab data collected from the same participant living on a 24 hour routine - what is a 24 hr schedule/ - what is a 28 hour schedule? Separated the influence of _____ from that of the circadian pacemaker This is called _____protocol

24 hr schedule- 7 cycles of body temp rhythm over 1 week 28 hour schedule- 7 cycles of body temp but only 6 sleep wake cycles Separated the influence of timing of the sleep wake schedule from that of the circadian pacemaker This is called forced desynchrony protocol

A pathological increase in REM (as commonly occurs in depression) may disproportionately _______ so much that it would create an autobiographical history dominated by ____ how do antidepressants help this situation?

A pathological increase in REM (as commonly occurs in depression) may disproportionately amplify the strength of negative memories so much that it would create an autobiographical history dominated by negative memory excess The selective decrease of REM, as occurs with many anti-depressants, would predict a reduction of such negative memory consolidation and bias, although it may curtail the degree of affect decoupling that can take place

A person who is sleep deprived shows a sleep pattern that favours ___during recovery- recovery sleep is also ____and ____ when does REM sleep show a rebound after sleep loss?

A person who is sleep deprived shows a sleep pattern that favours SWS during recovery- recovery sleep is also prolonged and deeper A person who is sleep deprived shows a sleep pattern that favours SWS during recovery- recovery sleep is also prolonged and deeper REM sleep shows a rebound on the subsequent recovery nights after an episode of sleep loss

how does this study describe sleep dependent memory triage? Shifts the description away from a.... towards a .... Describes a further stage that ..... It favors a view of consolidation not as....but as a.....

A process of sleep dependent memory triage that first identifies which memories go thru sleep dependent memory processing and then determines the form that this processing should take -->Shifts the description away from a uniform memory consolidation towards a complex offline process that is v selective in terms of which memories are consolidated by sleep --> Describes a further stage that directs a given memory into one of several possible pathways of memory evolution Such evolution leads to multiple forms of integrated knowledge, potentially governed by a range of neural systems and facilitated by varied stages of sleep - It favors a view of consolidation not as an end goal but as a stepping stone along a path that leads to the building and updating of generalized knowledge and beliefs about the world in which we live

what signal ascent back to lighter NREM stages after first cycle through n3? pattern we see after first N3?

A series of body movements signal ascent back to lighter NREM stages a brief episode of stage 3 sleep, followed by 5-10 mins of N2 interrupted by body movements preceding the initial REM episode

Nap paradigm for testing REM's importance in consolidation A significant and selective _____ was observed in the nap group, was correlated with the amount of ____ and the ____ why is REM an important stage? Neurophysiologically, _____oscillations have been proposed as a carrier frequency allowing disparate brain regions that initially encode information to selectively interact offline, in a coupled relationship. By doing so, REM ____may afford the ability to promote the strengthening of specific memory representations across distributed networks

A significant and selective offline enhancement of emotional memory was observed in the nap group, was correlated with the amount of REM sleep and the speed of entry into REM (latency) REM is an important stage as neurochemically levels of limbic and forebrain acetylcholine are markedly elevated- Known importance of Ach in long term consolidation of emotional learning, this REM state may result in a selective facilitation of affective memories Neurophysiologically, theta oscillations have been proposed as a carrier frequency allowing disparate brain regions that initially encode information to selectively interact offline, in a coupled relationship. By doing so, REM theta may afford the ability to promote the strengthening of specific memory representations across distributed networks

Across the night- Stage 1 accounts for ____% Stage 2 accounts for ____% SWS accounts for ___% REM sleep ___%

Across the night- Stage 1 accounts for 2-5% Stage 2 accounts for 45-55% SWS accounts for 10-20% REM sleep 20-25%

Advanced age is characterized by what that plays an important role in homeostatic? Aging is assotiated with malfunction or decrease in sensitivity of what? may explain why older people are less tolerant of ...?

Advanced age is characterized by a deterioration of the circadian variation of many physiological processes that play an important role in homeostatis Aging is assotiated with malfunction or decrease in sensitivity of the SCN to environmental cues to adjust circadian rhythm to a natural 24 hour cycle- may explain why older people are less tolerant of shift work and jet lag

sleep microarchitecture changes with aging? have been interpreted to reflect...

Age related decrease in number and amplitude of spontaneous and evoked k complexes and sleep spindle densities Have been interpreted to reflect an age related alteration of thalamocortical regulatory mechanisms which could be used to identify the changes in neurobiology of the brain with advancing age

Aging effects on sleep important to consider for _____ as major ____ become more prevalent with age Aging usually associated with decreases in the amount of ____and increases in _____ --> Attributed to an increased number of ....that occur in the elderly

Aging effects on sleep important to consider for pulmonologists as major respiratory disorders become more prevalent with age Aging usually associated with decreases in the amount of slow wave sleep and increases in stage 1 and 2 non-rapid eye movement sleep --> Attributed to an increased number of spontaneous arousals that occur in the elderly

All circadian systems exhibit a characteristic photic PRC, in which the largest light-induced phase shifts are generated in the____ Phase delays are generated in response to ......, and phase advances are generated from .... ______ can shift the phase of the human pacemaker in morning and late afternoon or evening as well as at night. This has important clinical implications, such as use of...

All circadian systems exhibit a characteristic photic PRC, in which the largest light-induced phase shifts are generated in the biologic night. Phase delays are generated in response to light stimuli late in the biologic day and early in the biologic night, and phase advances are generated from stimuli in the late biologic night and early biologic day Appropriate light intensities can shift the phase of the human pacemaker in morning and late afternoon or evening as well as at night. This has important clinical implications, such as use of phototherapy to reset circadian phase in delayed or advanced sleep phase disorder

newborn dolphins, killer whales and their mothers. - what is different about these species near birth? - are there USW what do The cetacean mothers do during the postpartum period? rebound? how could one describe this pattern?

All land mammals show maximal sleep and maximal immobility at birth → but newborn killer whales and dol- phins are continuously active, in the manner seen in adults of small dolphin species, for 4-6 weeks after birth. some USW might be present at these times, the eyes are open bilaterally when they surface at average intervals of less than 1 min, indicating that any slow wave pattern could not last longer than this period The cetacean mothers also cease eye closure and floating behavior during the postpartum period. the neonate and mother gradually return to the adult pattern over a 1-2 month period → no rebound One could describe the maternal and neonatal pattern as sleep with well- coordinated motor activity, accurate sensory processing, alert observation of and response to threats in the environ- ment and without the likelihood of any EEG slow waves or eye closure lasting more than 60 s (doesnt conform to the behavioural definition of sleep)

what is the influence of social and work related factors on circadian rhythms? what is rotating shift work?how does it effect sleep? Sleep inertia-decrements in neurobehavioural performance and alertness that immediately follow the sleep to wake transition- has been shown to persist for 2 hours after a long sleep episode and is most profound within the first few minutes after awakening what is sleep inertia? how long does It persist after a long sleep episode?

Although circadian and homeostatic drives for sleep influence the choice of sleep and wake times through a feedback pathway, social factors (e.g., child care, school and work responsibilities, entertainment, social interaction) and environmental factors (e.g., noise, artificial light, alarm clocks) often override those biologic determinants Rotating shift work- when people choose to work in direct opposition to the modulation of circadian and homeostatic regulatory systems, resulting in internal temporal dissociation, fragmented sleep, and impaired wake. Sleep inertia - decrements in neurobehavioural performance and alertness that immediately follow the sleep to wake transition (grogginess)- has been shown to persist for 2 hours after a long sleep episode and is most profound within the first few minutes after awakening

why is sleep important before learning Morris et al study indicated that_____memory was significantly disrupted by a night of pretraining sleep loss Harrison and Horne- significant impairments in retention in subjects deprived of sleep for 36h; also had worse......., resulting in lower predictive ability of performance Drummond et al- sleep deprived people had less active ______during learning,_____had higher activity, and ____were active in the sleep deprived group but not in the controls Therefore, sleep deprivation prior to learning leads to inability of _____ to engage normally in learning, combined with potential compensation attempts by ______ which may in turn facilitate recruitment of _____

An important need for sleep before learning- prepare specific brain networks for initial encoding of information Morris et al study indicated that temporal memory was significantly disrupted by a night of pretraining sleep loss Harrison and Horne- significant impairments in retention in subjects deprived of sleep for 36h; also had worse insight into their memory encoding performance, resulting in lower predictive ability of performance Drummond et al- sleep deprived people had less active medial temporal lobe during learning, prefrontal cortex had higher activity, and parietal lobes were active in the sleep deprived group but not in the controls -->Therefore, sleep deprivation prior to learning leads to inability of medial temporal lobe to engage normally in learning, combined with potential compensation attempts by prefrontal regions which may in turn facilitate recruitment of parietal lobe function

Another factor that may determine integrative process selection is the extent and nature of simultaneous memory reactivation during sleep - occurs in what stage? When reactivation of a recently formed memory is accompanied by .....multi-item integration may occur When a new single-item memory is reactivated in conjunction with ...., item integration may occur And if neither occurs, then sleep-dependent processing may be limited to...

Another factor that may determine integrative process selection is the extent and nature of simultaneous memory reactivation during sleep, which has been shown to occur not only in NREM sleep but also in REM sleep When reactivation of a recently formed memory is accompanied by the parallel activation of a larger set of recently formed memories, multi-item integration may occur And if neither occurs, then sleep-dependent processing may be limited to the comparatively straightforward consolidation and enhancement of the recently encoded item-memory itself

Auditory response- series of tones played over earphones and subject is asked to respond each time a tone is heard Reaction times become longer closer to ______ and responses absent with EEG change to _____

Auditory response- series of tones played over earphones and subject is asked to respond each time a tone is heard Reaction times become longer closer to stage 1 sleep and responses absent with EEG change to unequivocal sleep

Basically, what does sleep onset do to memory? Another interpretation is that.... One may infer that if sleep persists for about 10 minutes, memory is.... However, new studies have shown that sleep has an important role in?

Basically, sleep inactivates the transfer of storage from short- to long-term memory. Another interpretation is that encoding of the material before sleep onset is of insufficient strength to allow recall. One may infer that if sleep persists for about 10 minutes, memory is lost for the few minutes before sleep. However, new studies have shown that sleep has an important role in learning and memory- consolidation of perceptual and motor learning esp.

First sleep cycle: Begins with stage 1 sleep, which persists only for____mins at the onset - what is sleep like at this stage? A common sign of severely disrupted sleep is an increase in occurrences and percentage of ...

Begins with stage 1 sleep, which persists only for 1-7 mins at the onset. Sleep is easily discontinued, low arousal threshold and it occurs as a transitional stage throughout the night A common sign of severely disrupted sleep is an increase in occurrences and percentage of stage 1 sleep

Behavioural definition of sleep?

Behavioural definition: sleep is a reversible behavioural state of perceptual disengagement from and unresponsiveness to the environment Typically, but not always accompanies by postural recumbence, behavioural quiescence, closed eyes and other indicators commonly associated with sleep

DRUGS what are the effects of Benzos on sleep? Tricyclic antidepressants, monoamine oxidase inhibitors, and certain selective serotonin reuptake inhibitors tend to suppress _____ Fluoxetine is also associated with ____across all sleep stages Withdrawal from drugs that suppress a stage tends to be associated with ....? Eg. Acute withdrawal from a benzo is likely to produce increased ____, from a tricyclic antidepressant will increase ____- this can result in abnormal SOREMPs (can lead to incorrect diagnosis of narcolepsy)

Benzodiazepines- suppress SWS, no consistent effect on REM sleep. Tricyclic antidepressants, monoamine oxidase inhibitors, and certain selective serotonin reuptake inhibitors tend to suppress REM sleep. Fluoxetine is also associated with rapid eye movements across all sleep stages ("Prozac eyes"). Withdrawal from drugs that suppress a stage tends to be associated with a rebound of that stage. Eg. Acute withdrawal from a benzo is likely to produce increased SWS, from a tricyclic antidepressant will increase REM- this can result in abnormal SOREMPs (can lead to incorrect diagnosis of narcolepsy)

Sleep in birds - do birds have REM? NREM? migration?

Birds have been reported to have both REM and non-REM sleep as defined by electrographic criteria, although REM sleep periods tend to be shorter than those in most mam- mals even when confined to cages, EEG and behaviorally defined sleep were reduced by two-thirds during the seasons when they would have migrated in the wild --> This was not accom- panied by any reduction in accuracy or performance on a repeated acquisition task. --> There were no signs of the pathologies seen in sleep-deprived rats and no sleep rebound at the end of the period

Born et al.- offline improvement on a word pair associates task following sleep, attributed to___ sleep, rich in ____ Memories tested after a night of sleep were significantly more resistant to____

Born et al.- offline improvement on a word pair associates task following sleep, attributed to early night sleep, rich in SWS- in addition to classically defined slow delta waves, the very slow cortical oscillation appears to be important for consolidation of declarative memories Memories tested after a night of sleep were significantly more resistant to interference

How to integrate two models of neural reactivation and neural homeostasis? Can be argued that both reflect either an _____or an _____associated with ____and ____ Both could offer complementary benefits at the network level and may account for overnight memory improvements The homeostasis model would also predict that sleep deprivation, specifically the prevention of ____, would also negate effective new learning the next day, due to ______ Thus, any region that exhibits ____, and is involved in representing memory (e.g. _____, would display a corresponding inability to ....

Can be argued that both reflect either an increased neural reactivation or an increase in slow wave activity associated with homeostasis and synaptic downscaling Both could offer complementary benefits at the network level and may account for overnight memory improvements The homeostasis model would also predict that sleep deprivation, specifically the prevention of SWS, would also negate effective new learning the next day, due to over-potentiation of synaptic connections. Thus, any region that exhibits SWA, and is involved in representing memory (e.g. hippocampus), would display a corresponding inability to code further information beyond a normal waking duration

are Circadian oscillations/ biological clocks found in all species ? what are the defining characteristics of circadian oscillations?

Circadian oscillations/ biological clocks are found in all species from prokaryotes to humans Defining characteristics- endogenous rhythmicity that persists independent of periodic changes in the external environment, a near-24-hour period and the capacity for environmental input to modify or reset the timing or phase.

Consolidation is super important, but ____ and ___are more important --> These two processes form the basis of ____ and ____

Consolidation is super important, but association and integration are more important lol These two processes form the basis of generalized knowledge and creativity

Treatment of SDB _______- for OSA patients but is not always well tolerated, esp in the elderly Conservative management of OSA thru...? Certain _____ may worsen apnea and should be avoided Other treatments include...

Continuous positive airway pressure (CPAP)- for OSA patients but is not always well tolerated, esp in the elderly CPAP doesn't reduce CSA-CSR for a large number of patients with CHF -CPAP doesn't reduce CSA-CSR for a large number of patients with CHF Conservative management of OSA thru weight loss, limiting alcohol consumption and avoidance of supine position during sleep Certain myorelaxant hypnotics (benzos) may worsen apnea and should be avoided Other treatments include- noninvasive ventilation, oxygen therapy and drugs like theophylline, beta blockers, acetazolamide

REM - characterized by? In cats, REM sleep phasic activity is epitomized by bursts of______ waves which are accompanied by ______ and what other events that correspond to phasic event markers in humans? Mental activity in REM is associated with ____

EEG activation, muscle atonia and episodic bursts of rapid eye movements In cats, REM sleep phasic activity is epitomized by bursts of ponto-geniculo-occipital waves which are accompanied by rapid eye movements, twitching of distal muscles, middle ear muscle activity and other events that correspond to phasic event markers in humans Mental activity in REM is associated with dreaming Activated brain in a paralyzed body

sleep onset can EMG's pinpoint sleep onset? how can an EOG detect sleep onset? what do we notice on EEG's during the onset of sleep? Occurs after the start of ____ do these changes occur with perceived sleep onset?

ELECTROMYOGRAM- may show a gradual diminution of muscle tonus as sleep approaches, but rarely does a distinct EMG change pinpoint sleep onset, also EMG of a relaxed person is not differentiated from that of sleep ELECTROOCULOGRAM- as sleep approaches, shows slow, possibly asynchronous eye movements that usually disappear within several minutes of the EEG changes - Occasionally this coincides with a person's perceived sleep onset but subjects report they are still awake ELECTOENCEPHALOGRAM- changes from clear rhythmic alpha activity to relatively low voltage mixed frequency pattern - Occurs after the start of slow eye movements - The onset of stage 1 EEG patterns, may or may not coincide with perceived sleep onset, that's why some researchers require the presence of specific patterns like K complex or sleep spindle to acknowledge sleep onset

Eg 1. Artificial grammars: the ability of sleep to support rule extraction can be seen in children as early as _____ - explain

Eg 1. Artificial grammars: the ability of sleep to support rule extraction can be seen in children as early as 15 months - 15 month old infants were exposed to an artificial grammar - When tested 4 h later, infants who had napped showed knowledge of this grammar whereas those who hadn't napped didn't Early life rule learning can be sleep dependent- can account for high demand for sleep during developmental years

Item integration in sleep Eg. Incorporation of novel words into one's mental lexicon - after sleep vs morning? what predicted the degree of lexical integration? Participants who had more____sleep showed more benefit Sleep thus facilitates ....

Eg. Incorporation of novel words into one's mental lexicon- integration was observed only after a night of sleep and not after an equivalent period of wakefulness and the number of sleep spindles during the post training night predicted the degree of lexical integration the next morning Participants who had more REM sleep showed more benefit Sleep thus facilitates integration of new memories into existing networks, producing new associations and relationships, reflected in superior task performance

Elderly tend to go to bed earlier and wake up earlier compared to younger people Originally attributed to a ___ May result from an inability to ....particular circadian phases or be attributed to presence of...and ...

Elderly tend to go to bed earlier and wake up earlier compared to younger people Originally attributed to a phase advance of the circadian oscillator May result from an inability to sustain sleep at particular circadian phases or be attributed to presence of evening napping and advanced illumination

Sleep in fish - what is the methodogolgical issue here? zebrafish? - rest deprivation? - anatomy of wake control systems?

Fewer than 10 fish species have been examined for rest or sleep behavior in laboratory studies. Zebrafish → circadian variations in responsiveness and activity and decreased response to stimuli were seen after rest deprivation --> could be completely blocked for long periods by light, with no evidence of subsequent rebound --> The anatomy of systems known to have a major role in sleep-waking control in mammals is radically different in zebrafish

None of these models need necessarily be wrong- aspects of each may be important From a reactivation perspective, the predominance of _____would take place in the _____ phase of the night, leaving cortico-cortical connections for later processing during ____and ____ At the same time, SWS may...... leaving only those representations which are strongest - including those strengthened by______ interplay - for processing during these latter periods of sleep, dominated by ______- which help with LTP.

From a reactivation perspective, the predominance of hippocampal-neocortical interaction would take place in the early SWS-rich phase of the night, leaving cortico-cortical connections for later processing during stage-2 NREM and REM. At the same time, SWS may downscale cortical plasticity, leaving only those representations which are strongest - including those strengthened by hippocampal-neocortical interplay - for processing during these latter periods of sleep, dominated by faster frequency oscillations- which help with LTP.

2 Models of sleep dependent memory processing ?

HIPPOCAMPAL NEOCORTICAL DIALOGUE SYNAPTIC HOMEOSTASIS HYPOTHESIS

Human relational memory- ability to..? Learnt 5 premise pairs that had an embedded hierarchy that was not made explicit to the subjects Subjects tested after 20 min showed...? The 12 h waking interval group displayed ... BUT if the 12 h period contained a night of sleep...? These findings demonstrate that human memory integration ......requiring _____ pro- cesses. Furthermore, sleep appears to preferentially facilitate this integration by ....? Supplementary benefit may be _____ as when it is formed into a hierarchy, it is less info to remember

Human relational memory- ability to generalize previously acquired associations to novel situations - Subjects tested after 20 min showed no evidence of inferential ability - The 12 h group displayed highly significant relational memory, - BUT if the 12 h period contained a night of sleep they had a 25% higher advantage in relational memory These findings demonstrate that human memory integration takes time to develop, requiring slow, offline associative pro- cesses. Furthermore, sleep appears to preferentially facilitate this integration by enhancing hierarchical memory binding Supplementary benefit may be improved efficiency of memory storage as when it is formed into a hierarchy, it is less info to remember

does human sleep deprivation for 11 days produce the earliest signs of autonomic changes in rats? what happens in human sleep deprivation? ______= a rare genetic condition reported in humans, is not analogous to the disk-over-water method of sleep deprivation (study above) because it is characterized by massive brain degeneration and autonomic dysregulation

Human sleep deprivation for as long as 11 days and chronic sleep restriction does not produce even the earliest signs of the autonomic changes seen in rats - Body tempera- ture tends to fall in sleepy humans (instead of rising in rats) - Humans gain rather than lose weight Fatal familial insomnia, a rare genetic condition reported in humans, is not analogous to the disk-over-water method of sleep deprivation (study above) because it is characterized by massive brain degeneration and autonomic dysregulation

how long is the INTRINSIC PERIOD OF THE HUMAN CIRCADIAN PACEMAKER? gender differences?

INTRINSIC PERIOD OF THE HUMAN CIRCADIAN PACEMAKER: 24.15 HOURS Significantly shorter in women than men

Two overarching categories encompass most of the memory evolution process? which can lead to false memory are these categories unique to sleep?

ITEM INTEGRATION: assimilates newly learned memory representations into preexisting schemas- expanding the schema MULTI ITEM GENERALIZATION: combines new item memories, creating an entirely new schema -->Can lead to false memory --> Can promote identification of a rule or set of rule governing the information set and can allow extrapolation to never before seen items- patterns/categories etc These categories are not unique to sleep, but below is evidence that sleep contributes to each of these forms of memory evolution in a manner superior to that in waking

what happens if this sleep to forget, sleep to remember process doesnt work? what may explain why this happens in ptsd? 2 things

If this process is not achieved, the magnitude of visceral autonomic 'charge' remaining within autobiographical memory networks will persist, resulting in the potential condition of chronic anxiety If this process of divorcing emotion from memory is not achieved, it will increase the amount of REM as the strength of the emotional tag associated with the memory will remain high- it is such a cycle of REM sleep dreaming (nightmares) that is associated with PTSD --> The exceptional magnitude of trauma-induced emotion at the time of learning may be so great that the system is incapable of initiating/completing one or both these processes, leaving some patients unable to depotentiate, integrate and hence 'overcome' the experience Alternatively, it may be the hyperarousal status of the brain during REM sleep in these patients potentially lacking sufficient aminergic demodulation

what is Hypnic Myoclonia? what is one hypothesis for why these occur? increased frequency of these events in..?

If you awaken someone shortly after stage 1, the person reports the mental experience of losing a direct train of thought and of experiencing vague and fragmentary imagery Hypnic myoclonia- a general or localized muscle contraction very often associated with rather vivid visual imagery. One hypothesis- the onset of sleep in these instances is marked by a dissociation of REM sleep components, wherein a breakthrough of the imagery component of REM sleep (hypnagogic hallucination) occurs in the absence of the REM motor inhibitory component. A response by the individual to the image, therefore, results in a movement or jerk Increased freq of such events in those with irregular sleep schedules- so increased probability of REM sleep occurring at wake to sleep transition (also happens more in infancy and in certain sleep disorders)

Human Dose- Response Curve to Circadian Phase-Resetting Effects of Light In addition to wavelength and circadian phase, the degree of light induced phase shift also depends on ____and _____ how?

In addition to wavelength and circadian phase, the degree of light induced phase shift also depends on light stimulus intensity and consecutive days of exposure More light intensity and more exposure= more shift

Multi item generalization in sleep what two types of generalizations does sleep facilitate? ___ is extracted from sets, ___ are extracted from relations

In gist extraction, sleep can combine info from a collection of new items to identify commonalities even when individual item memories are forgotten This works for recall, not recognition- sleep dependent benefit for recollection, not familiarity In rule extrapolation, several reports have demonstrated that sleep can promote the extraction of overarching rules that govern recently studied sets of information. In each case, implicit knowledge of pat- terns and rules was gained during sleep and led to improved performance upon awakening, often without explicit awareness Gist is extracted from sets, rules are extracted from relations

Circadian rhythms are expressed in many physiologic and neurobehavioural variables, so the phase of the pacemaker can be estimated by using any of these variables as a marker --> what are the different physiological markers? In humans, ______is the preferred marker as it can... _____ can be even more precise, as it is less influenced by sleep and posture --> The endogenous circadian ____ rhythm can be reset to any desired phase within___to___ days by light exposure --> what is something that affects the endogenous temp cycle that also affects this rythym amplitude? - what are the practical advantages to using this as a marker?

In humans, body temp rhythm is the preferred marker as it can accurately represent the underlying pacemakers characteristics under certain conditions Melatonin can be even more precise, as it is less influenced by sleep and posture --> The endogenous circadian melatonin rhythm can be reset to any desired phase within 2 to 3 days by light exposure --> Photic stimuli designed to suppress the amplitude of the endogenous circadian temp cycle also suppress the melatonin rhythm amplitude Practical advantages to using melatonin as circadian marker- melatonin in human saliva correlates well with that in plasma and it allows the evaluation of circadian phase non-invasively

In natural-light-only conditions, the internal circadian clock is synchronized to.... at a significantly _____ circadian phase how does reading from an electric tablet effect circadian melatonin phase? So, nocturnal artificial light can... bc it affects ____

In natural-light-only conditions, the internal circadian clock is synchronized to solar time with melatonin onset near sunset and melatonin offset before wake time and after sunrise, at a significantly earlier circadian phase Evening reading from an electronic tablet that emits short-wavelength- enriched visible light delays endogenous circadian melatonin phase and the timing of REM sleep and increases evening alertness, sleep latency, and morning sleepiness compared with reading a printed book So, nocturnal artificial light can interfere with sleep and lead to chronic sleep deficiency- bc it affects melatonin levels

Neurobehavioural Functions: interaction of sleep homeostat and circadian rhythm to keep up neurobehavioural functions: In the first half of the day following wake time, there is ....because ....so both ___ and ___ are high In the latter half of the waking episode, when ____ would otherwise cause alertness and cognitive performance to decline, the ___rises and opposes that decline, thereby sustaining a ....

In the first half of the day following wake time, there is little homeostatic sleep drive because it was discharged by the prior sleep episode, so both alertness and cognitive performance are high In the latter half of the waking episode, when homeostatic sleep drive would otherwise cause alertness and cognitive performance to decline, the circadian drive rises and opposes that decline, thereby sustaining a high, stable level of alertness throughout the normal waking day.

In young adults, ____ dominates the NREM portion of the sleep cycle at the beginning and then___ episodes are longer in the later part of the night when do brief periods of wakefulness tend to occur?

In young adults, SWS dominates the NREM portion of the sleep cycle at the beginning and then REM episodes are longer in the later part of the night Brief periods of wakefulness tend to intrude later in the night, near REM transitions and don't last long enough to be remembered in the morning

changes in sleep pattern with age - Infancy- max ___ hours - how does sleep need change with age? - ___hours in adulthood --> what is one opinion on if the amount of sleep changes from adulthood to elderly?

Infancy sleep duration is at a lifetime maximum- max 16 hours Sleep need decreases with age, 7-8 hours in adulthood there is evidence that sleep duration further decreases from young adulthood into our older year --> However, some people say its just that sleep in the elderly becomes fragmented and is consolidated thru daytime naps- amount of sleep doesn't change

One potential advantage of testing associative connections and building cross linked systems of knowledge is creativity what is creativitY? Performance on tests of cognitive flexibility using anagram word puzzles is more than ____% better following awakenings from____sleep compared with____ awakenings --> show greater ____effect Study of dreams from REM indicates that there isn't a .....but a more ____process of semantic integration during sleep

It is the ability to take existing pieces of information together and combine them in novel ways that lead to greater understanding and offer new advantageous behavioural repertoires Performance on tests of cognitive flexibility using anagram word puzzles is more than 30% better following awakenings from REM sleep compared with NREM awakenings --> Show greater priming effect with weakly related words after REM and strong priming exceeds weak priming in NREM Study of dreams from REM indicates that there isn't a concrete replay of daytime experiences but a more associative process of semantic integration during sleep

what is the Mechanism that underlies these effects on hippocampal dependent learning tasks ? what did they find in animals after performance on special taks and novel experiences? Homologous evidence found in humans using a virtual maze task and PET- the amount of _____reactivation was proportional to the amount of next day task improvement, suggesting that reactivation is associated with _____memory improvement

Mechanism that underlies these effects on hippocampal dependent learning tasks is the reactivation of memory representations at night In animals- firing patterns of hippocampal and cortical networks, expressed during waking performance of spatial tasks and novel experiences, appear to be 'replayed' during subsequent SWS Homologous evidence found in humans using a virtual maze task and PET- the amount of SWS reactivation was proportional to the amount of next day task improvement, suggesting that reactivation is associated with offline memory improvement

how does melatonin concentrations change with age?

Melatonin concentrations decrease from puberty, eventually reaching levels similar to daytime concentrations in old age- may contribute to increased frequency of sleep related disorders with aging

Meta-analysis shows total sleep ___ with age, __mins per decade - which stages decrease? - rem? plateau at __ gender diffs? Health related quality of life reduced when sleep less than__hours

Meta-analysis shows total sleep decreases with age, 10 mins per decade N3 decreases REM decreases, plateau at 60 - Men have greater decreased in total slept me, decreased percentage of n3 and rem sleep and increased n2 and wake time after sleep onset - Women increased sleep latencies Health related quality of life reduced when sleep less than 7 hours

Sleep in land mammals - most studies done on.... - do these animals meet criteria fro sleep? large herbivores?

Most systematic studies of mammalian sleep have been con- ducted in only a few domesticated species [48] including rats, mice, cats, dogs and monkeys. --> these species meet, and indeed created, the conventional defi- nition of sleep. large herbi- vores such as the giraffe and elephant that dont sleep much → These species have been observed to migrate for large distances over periods of weeks --> studies on these animals have generally been done in zoos where food is in constant supply, predator threats are nonexistent and migrations are impossible --> sensory response threshold measurement, sleep deprivation and rebound tests and the recording of physiological variables are not generally possible in zoos, making it difficult to distinguish quiet waking states from true sleep **The vulnerability of the large herbivores in the wild suggests that it would be highly maladaptive for them to have the greatly reduced sensory responsiveness that defines sleep.

Sleep dependent consolidation: discriminatory selection: Muller and Pilzecker first proposed that item memories were not encoded in a permanent form but required ... Jenkins and Dallenbach discovered the superior preservation of item memories across... This led to models of ________during sleep

Muller and Pilzecker first proposed that item memories were not encoded in a permanent form but required a process of consolidation over time Jenkins and Dallenbach discovered the superior preservation of item memories across a night of sleep relative to time awake This led to models of active memory processing during sleep

NARCOLEPSY- Abnormally short delay to ___, marked by ___ Results in..? 3 things

NARCOLEPSY- Abnormally short delay to REM, marked by SOREMPs (sleep onset rem period) Results in hypnagogic hallucinations, sleep paralysis and cataplexy

NREM is divided into ____ stages defined by_____ and arousal threshold is lowest in __ and highest in ___ what does the EEG look like in NREM? what are the characteristics of nREM

NREM is divided into 4 stages defined by EEG patterns and arousal threshold is lowest in 1 and highest in 4 Synchronous EEG sleep spindles, K complexes and high voltage slow waves Usually minimal or fragmentary mental activity- relatively inactive yet actively regulating brain in a movable bod

Takashima et al- examined the effect of daytime naps on episodic declarative memory consolidation Napping between training and testing The duration of ____ correlated positively with later recognition memory performance, yet negatively with _____ in the __

Napping between training and testing The duration of NREM SWS correlated positively with later recognition memory performance, yet negatively with retrieval related activity in the hippocampus

Photic suppression of melatonin secretion ---> explain how this works how did they discover this system?

Neural pathway from SCN to the pineal gland allows for regulation of the pineal output of melatonin by the SCN including inhibition of melatonin release by retinal light exposure through a retinohypothalamic pathway Preservation of this process in otherwise totally blind people suffering from damage to the outer retina lead to the discovery of the distinct visual system that mediates photic entrainment --> the loss of conscious light perception does not necessarily indicate the loss of photic input to the circadian timing system, although that is the case in most blind individuals without light perception.

Consequences of OSA: 4

Neurocognitive dysfunction such as excessive daytime sleepiness and decreased quality of life resulting from sleep fragmentation Metabolic dysfunction and cardiovascular disease- likely result of the intermittent hypoxia and sympathetic stimulation during OSA Obesity- linked to prevalence of OSA, aging may increase risk for OSA bc prevalence of obesity increases in elderly Congestive Heart Failure- OSA may worsen left ventricular function and contribute to development of CHF

New concept of selectivity- what does this mean? allows organism too..? example of this?

New concept of selectivity- memory consolidation during sleep doesn't lead to uniform preservation of all recently encoded memories- more evidence for a sleep dependent memory process that determines what info is retained as well as the form in which it is retained --> This selectivity allows the organism to adapt to env change rapidly and effectively, guided by the most relevant info from its autobiographical history, optimally integrated into memory networks --> Eg. Emotional memories can undergo preferential preservation during sleep, esp during REM. Sleep can separate affectively relevant from irrelevant components of a single episodic memory for selective consolidation

Newborns transition from wake to sleep is through ____sleep the cyclic alteration of NREM-REM has a period of____mins compared with ___in the adults Infants only gradually acquire a consolidated nocturnal sleep cycle and fully developed EEG patterns of the NREM sleep stages emerge over the first___- __months of life

Newborns- transition from wake to sleep is through REM sleep; the cyclic alteration of NREM-REM has a period of 50-60 mins compared with 90 mins in the adults Infants only gradually acquire a consolidated nocturnal sleep cycle and fully developed EEG patterns of the NREM sleep stages emerge over the first 2-6 months of life

Sleep spindles? Nishida and Walker- sleep spindle activity has a strong predictive relationship with amount of ____ The mechanistic benefit of sleep spindles may be related to their ______; a range suggested to facilitate _____ Increase of spindle activity may represent a local, endogenous trigger of ________- corresponding topographically to the underlying memory representation does this apply to procedural memory? episodic learning?

Nishida and Walker- sleep spindle activity has a strong predictive relationship with amount of memory improvement The mechanistic benefit of sleep spindles may be related to their faster stimulating frequency; a range suggested to facilitate long-term potentiation Increase of spindle activity may represent a local, endogenous trigger of intrinsic synaptic plasticity- corresponding topographically to the underlying memory representation Applies to procedural memory and episodic learning as well

what 2 disorders are quite common in CHF (congestive heart failure) patients? CSA manifests as a type of periodic breathing called ______- cycle of ...

OSA and CSA are quite common in CHF patients CSA manifests as a type of periodic breathing called Cheyne-Stokes respiration- cycle of waxing and waning breaths with periods of apnea Aging is a major factor affecting the risk of CSA CSR associated with CHF

Olfactory response- depends on sleep state and odorant but respond in stage _____ only - why is the olfactory system not a good sentinel system during sleep?

Olfactory response- depends on sleep state and odorant but respond in stage 1, not later stages- a tone will arouse people in every stage but a smell will not- olfactory system is not a good sentinel system during sleep

with age On average, the circadian clock is set ..... -> what accounts for this? how does the amplitude of some endogenous circadian rhythms change? does the intrinsic circadian period shorten with age? Older participants are much less vulnerable to ....and..

On average, the circadian clock is set to an earlier hour, and the amplitude of some endogenous circadian rhythms is lower in older people than it is in young adults (endogenous = built in- but effected by zeitgeibers) Older people usually awaken at an earlier circadian phase, they are typically exposed to light earlier, this earlier light exposure, which will reset the circadian pacemaker to an earlier hour, likely accounts for the earlier average entrained circadian phase observed in older people However, intrinsic circadian period does not shorten with age in healthy humans - This is the duration of the endogenous, free-running circadian "day" of a person who is blind to light, which has been measured at 24.70 hours. Older participants are much less vulnerable to the adverse effect of sleep loss and misalignment of circadian phase on neurobehavioural performance

One study on sleep deprivation in rats (not eliminated but reduced by 70-90%) found? what did deprivation do? is this found in other mammals or other sleep deprived rats? sleep deprivation in pigeons?

One study showed that sleep deprivation in rats (not eliminated but reduced by 70-90%) produces a consistent behavioral and physiological syndrome leading to death within 2-3 week - Deprivation greatly increased body temperature and food intake, but weight fell rapidly. A stereotyped pattern of fur discolor- ation and skin lesions occurred. Then body temperature fell and death followed. No similar syndrome has been described in mice or other mammals commonly observed in laboratories, or in rats' sleep deprived by other means Sleep deprivation in pigeons by the same technique used in rats is not lethal and produces none of the metabolic and thermoregulatory changes observed in rats

Whether sleep need changes with aging is a complex question- contradictory findings --> One view is that...? effect of napping on elderly? Excessive ____ is common in the elderly and may be indicative of cognitive impairment thus, when sleep need is assessed by total sleep time and daytime functioning - are healthy elderly ppl more sleepy than their counterparts?

One view is that total sleep time may not decline with age but the way in which sleep is consolidated becomes altered- eg napping Elderly are usually sleepier during the day On one hand there is evidence that napping in healthy individuals improves daytime functioning; the other hand, there is evidence that napping is associated with a higher risk of all cause mortality in some studies Excessive daytime somnolence is common in the elderly and may be indicative of cognitive impairment Thus, when sleep need is assessed by total sleep time and daytime functioning, healthy elderly people are no sleepier than their younger counterparts

Other conditions in which short REM sleep latency can occur include...? High prevalence of REM sleep onsets in young adults and adolescents with ___

Other conditions in which short REM sleep latency can occur include infancy, in which sleep onset REM is normal; sleep reversal or jet lag; acute withdrawal from REM suppressant compounds; chronic restriction or disruption of sleep; and endogenous depression High prevalence of REM sleep onsets in young adults and adolescents with early rise times

predictions as to the fate of memory and the emotion Over time, the ______would improve, and the extent to which these [negative] emotional experiences are strengthened would be proportional to the amount of _____, as well as how _____ do These same predictions hold in the inverse direction for the magnitude of emotional reactivity induced at the time of recall? - Subjects who were deprived of sleep the first night after learning arousing emotion picture slides showed not only _____but also a lack of ____ when re-exposed to these same emotional picture slide at recognition testing

Over time, the veracity of the memory itself would improve, and the extent to which these [negative] emotional experiences are strengthened would be proportional to the amount of post-experience REM sleep obtained, as well as how quickly it is achieved (REM latency) These same predictions would hold in the inverse direction for the magnitude of emotional reactivity induced at the time of recall - Subjects who were deprived of sleep the first night after learning arousing emotion picture slides showed not only reduced recall of the information (the sleep to remember component of the hypothesis) but also a lack of reduction in amygdala reactivity when re-exposed to these same emotional picture slide at recognition testing

PATTERN OF SLEEP IN A HEALTHY YOUNG ADULT- the normal human adult enters sleep through _____sleep, REM sleep does not occur until _____minutes or longer thereafter, and NREM sleep and REM sleep alternate through the night, with about a ___ cycle

PATTERN OF SLEEP IN A HEALTHY YOUNG ADULT- the normal human adult enters sleep through NREM sleep, REM sleep does not occur until 80 minutes or longer thereafter, and NREM sleep and REM sleep alternate through the night, with about a 90-minute cycle

are PGO waves detectable in humans?

PGO waves are not usually detectable in humans, thus rapid eye movements are the commonly used marker of REM phasic activity

Performance in the 3 hours before the onset of _____(i.e., the wake maintenance zone) is significantly improved compared with performance during...... This effect is greater after ...? when ____ is high can Neurobehavioral performance be preserved during this circadian wake maintenance zone even under conditions of chronic sleep restriction?

Performance in the 3 hours before the onset of melatonin secretion (i.e., the wake maintenance zone) is significantly improved compared with performance during a 3-hour block earlier in the biologic day, despite a longer time awake. This effect is greater after extended wakefulness (i.e., on day 2 of a circadian rhythm), when homeostatic sleep pressure is high Neurobehavioral performance, as measured by reaction time, can be preserved during this circadian wake maintenance zone even under conditions of chronic sleep restriction

OTHER FACTORS INFLUENCING SLEEP PROBALEMS IN THE ELDERLY what factors may be detrimental to nocturnal sleep? ____ also affect sleep quality, esp bc elderly have more n1 and n2 sleep which can increase arousal and disruption

Poor sleep hygiene, dietary habits, excessive daytime napping, and increased nocturia may be detrimental to nocturnal sleep. Environmental factors like noise also affect sleep quality, esp bc elderly have more n1 and n2 sleep which can increase arousal and disruption Also have other medical conditions that make sleep consolidation difficult, medications can also promote insomnia

why is it challenging to study sleep in elderly? 3 reasons

Presence of comorbidities high in elderly - Exclude, or are these exclusions of "super healthy" not representative? Debate about healthy aging Cant apply some sleep research protocols to vulnerable populations so makes it harder to study sleep in the elderly Clinical samples reflect referral biases that are complicated in the field of sleep and aging -- Elderly may be less prone to sleepiness from sleep deprivation or sleep apnea -- Less likely to be referred with a clinical complaint -- More isolated from younger cohort - fewer people to recognize potential abnormality in sleep

What sleep disorders increase with aging? what is SDB?

Prevalence of sleep disorders increases with aging- restless sleep syndrome, REM behavior disorder, sleep disordered breathing SLEEP DISORDERED BREATHING- SDB is a broad term that encompasses a range of breathing disorders- snoring, upper airways resistance syndrome, obstructive sleep apnea, central sleep apnea

Experiences that evocate emotions not only encode more strongly but appear to persist and improve over time --> which sleep stage is involved in affective human memory consolidation? Compared consolidation of emotionally arousing and non-arousing picture stimuli following a 12 h period across a day or a night of sleep A specific emotional memory benefit was observed only following_____ sleep

REM dependent hypothesis of affective human memory consolidation A specific emotional memory benefit was observed only following late night sleep- a period rich in NREM 2 and REM

how long is REM episode in first cycle? arousal threshold? what are the theories for this? what is diff for the arousal threshold in rem for cats?

REM episode in first cycle is short lived (<10 mins) arousal threshold is variable Theories for this variable REM threshold- at times, the person's selective attention to internal stimuli precludes a response or that the arousal stimulus is incorporated into the ongoing dream story REM Sleep in cats has the highest threshold and for them is called deep sleep- not in humans!

___ is more sensitive to temperature related disruption- thermoregulating ability is minimal

REM is more sensitive to temperature related disruption- thermoregulating ability is minimal Extremes of temp in sleeping environment tend to disrupt sleep

the cycle between NREM and REM throughout the night - which gets longer across the night? - what occupies less time across the night? The average length of the first NREM REM cycle is about ____ minutes, the second and later cycles are around ___ mins

REM sleep episodes usually become longer across the night 3 and 4 sleep occupy less time in the second cycle and may disappear from later cycle as stage 2 expands to occupy the NREM part The average length of the first NREM REM cycle is about 70-100 minutes, the second and later cycles are around 90-120 mins

REM sleep is character- ized by a pattern of discharge that closely resembles that of ____in most brain regions. are brainstem neurons active? cortical neurons? awareness levels?

REM sleep is character- ized by a pattern of discharge that closely resembles that of waking in most brain regions. Brainstem neurons are highly active at rates often equal to or exceeding rates in active waking Cortical neurons also show a waking pattern of activity, with the EEG in many species being indistinguishable from that of wak- ing loss of environmental awareness

REM sleep occurs with a circadian distribution that peaks in the_____ coincident with the trough of core ____ - when would rem occur at the onset of sleep? Sleep onset is likeliest to occur on the ____ of the _____ cycle. A secondary peak of sleep onset also occurs- around ____and offset of sleep occurs on the ____of the___curve

REM sleep occurs with a circadian distribution that peaks in the morning hours coincident with the trough of core body temp rhythm If sleep onset is delayed until early morning, REM tends to predominate and can even occur at onset of sleep Sleep onset is likeliest to occur on the falling limb of the temperature cycle. A secondary peak of sleep onset also occurs- around afternoon napping and offset of sleep occurs on the rising limb of the body temp curve

what is THE KLEITMAN PROTOCOL?

THE KLEITMAN PROTOCOL- Separation from 24-hour environmental and behavioural cues Nathaniel Kleitman- first investigator to study human circadian rhythms in absence of periodic 24 hour cues in the external environment

Memory is strongly modulated by smell- following learning of a spatial memory task that was paired with the smell of rose, the odour was not re-presented again at retrieval but during ____that night- a time where we assume consolidation occurs Relative to control, re-perfusion of the rose scent at night resulted in significantly ____ the next day The re-presentation of the odour resulted in greater reactivation of the _____during____ Supports the role of____in consolidation of individual declarative memories and may indicate an active reprocessing of ______during ____

Relative to control, re-perfusion of the rose scent at night resulted in significantly improved recall the next day The re-presentation of the odour resulted in greater reactivation of the hippocampus during SWS Supports the role of SWS in consolidation of individual declarative memories and may indicate an active reprocessing of hippocampal bound info during SWS Relative to control, re-perfusion of the rose scent at night resulted in significantly improved recall the next day The re-presentation of the odour resulted in greater reactivation of the hippocampus during SWS Supports the role of SWS in consolidation of individual declarative memories and may indicate an active reprocessing of hippocampal bound info during SWS

what is OBSTRUCTIVE SLEEP APNEA- OSA? Expose sufferer to ...?

Repetitive collapse (apnea) or partial collapse (hypoapnea) of the pharyngeal airway during sleep- these airway obstructions lead to increasingly powerful respiratory efforts until the airway reopens and breathing is restored, often in association with an arousal from sleep Expose sufferer to intermittent hypoxia and hypercapnia, large swings in intrathoracic pressure as well as surges in sympathetic activation- all of which have deleterious consequences

SYNAPTIC HOMEOSTASIS HYPOTHESIS: Role for sleep in regulating the ____ of the brain- principally the ___ Model by who? what is the brain state involved here? what is the role of ^ under this hypothsesis?

Role for sleep in regulating the synaptic connectivity of the brain- principally the neocortex Model by Tomoni and Cirelli NREM SWS- a brain state that promotes the decrease of synaptic connections Plastic processes such as learning and memory occurring during wake result in a net increase in synaptic strength in diffuse brain circuits The role of SWS is to selectively downscale or depotentiate synaptic strength back to baseline levels, preventing synaptic overpotentiation This would leave more efficient and refined memory representations the next day, affording improved recall

SLEEP APNEA SYNDROMES- may be associated with suppression of ___or ___sleep secondary to sleep related breathing problem. what do successful treatments do?

SLEEP APNEA SYNDROMES- may be associated with suppression of SWS or REM sleep secondary to sleep related breathing problem. Successful treatment can product large rebounds of SWS or REM sleep when first implemented

SLEEP FRAGMENTATION - occurs in association with ..? In upper airway resistance syndrome, what are important markers? why? Often associated with an increase in sleep stage ___

SLEEP FRAGMENTATION- occurs in association with a number of sleep disorders as well as medical disorders involving physical pain or discomfort PLMS, sleep apnea, chronic fibrositis, Parkinsons, allergic rhinitis, juvenile rheumatoid arthritis In upper airway resistance syndrome, EEG arousals are important markers because the respiratory signs of this syndrome are less obvious than in frank obstructive sleep apnea syndrome, and only subtle indicators may be available. Often associated with an increase in sleep stage 1

SWS decreases by ____ during later adolescence, even when.. --> this may be due to? By age ___ SWS is diminished - gender diffs? changes in rem sleep into old age? ______increase with age, often associated with occult sleep disturbances like periodic limb movements and respiratory irregularities In elderly people there is a profound increase in ____

SWS decreases by 40% during later adolescence, even when the length of nocturnal sleep remains constant - The age-related decline in nocturnal SWS, which parallels loss of cortical synaptic density, may be causally related to this cortical resculpting. By age 60, SWS is diminished, particularly in men, women maintain it for longer REM sleep percentage is maintained well into healthy old age (lecture says it decreases) Arousals during sleep increase with age, often associated with occult sleep disturbances like periodic limb movements and respiratory irregularities In elderly people there is a profound increase in interindividual variability

when is SWS maximal? Kids up to mid adolescence also skip their first _____ perhaps because of...

SWS is maximal in young kids and decreases over age, it is also qualitatively different Kids up to mid adolescence also skip their first REM episode, perhaps because of the quantity and intensity of slow wave activity early in the night

Selective memory evolution: are these paths of integration applied universally and uniformly?

Selective memory evolution: these paths of integration are applied neither universally nor uniformly - there is a discriminatory selection of integration processes --> In circumstances where no one form of integrative processing is clearly preferable, a selection from several possibilities appears to be made during sleep

Behavioural Concomitants of Sleep Onset Simple behavioural task- sleepy volunteers were asked to tap 2 switches alternately, this behaviour continues after the onset of ______ and may persist for several seconds after the EEG changes to _____behaviour then ceases and recurs only after EEG reverts to ____

Simple behavioural task- sleepy volunteers were asked to tap 2 switches alternately, this behaviour continues after the onset of slow eye movements and may persist for several seconds after the EEG changes to stage 1 sleep pattern, behaviour then ceases and recurs only after EEG reverts to wake

Sleep and changes in posture, light intensity, and activity level generate a drop in _____ relative to wake- this sleep induced ____combines with the ____driven decline in___ during biological night is urine volume influenced by sleep?

Sleep and changes in posture, light intensity, and activity level generate a drop in body temperature relative to wake- this sleep induced drop in temperature combines with the circadian driven decline in body temp during biological night Urine volume exhibits a robust oscillation under constant routine conditions that is also influenced by sleep wake state

Sleep can also selectively retain memories on the basis of _____ even when such knowledge is provided after learning

Sleep can also selectively retain memories on the basis of waking knowledge of potential monetary reward, even when such knowledge is provided after learning --> Being told of a future test after encoding new info enhances sleep dependent consolidation of that memory- episodic item/spatial/ procedural memory --> Explicit instructions to either remember or forget individual items immediately after their encoding can significantly modulate the course of their consolidation during sleep. Such studies further suggest that sleep can specifically, and perhaps actively, control forgetting as well as remembering

how can sleep deprivation effect affective reactivity? sleep loss effect on positive and negative daytime experiences?

Sleep deprivation is commonly associated with reports of irritability and affective volatility Progressive increase in emotional disturbance as you restrict sleep, subjective descriptions also indicated increasing complaints of emotional difficulties Sleep loss has been shown to amplify negative emotional consequences of daytime events while blunting the positive benefit associated with rewarding or goal- enhancing activities

sleep is defined as ...? - what is a further criterion of sleep? - how does this tell us there is some vital function of sleep

Sleep is defined as: rapidly reversible state of immobility and greatly reduced sensory responsiveness. further criterion is that sleep is homeosta- tically regulated, namely that lost sleep is made up with an increased drive for sleep and a consequent 'sleep rebound.' maladaptive for animals to be driven to make up for lost sleep at a time of danger and stress unless some vital function was being subserved. → evolution might well have produced species that have states that can be better described as quiet waking than as sleep.

Sleep must be distinguished from... why? Sleep must be distinguished from _____and____ states that have distinct physiological correlates Sleep must also be distinguished from just ____ so sleep =

Sleep must be distinguished from circadian changes in alertness controlled by the supra- chiasmatic nucleus and other body clocks --> Most animals need to adjust their activity to optimal conditions of prey availability, predator threat, sexual opportunities, temperature and other variables affecting survival that vary with time of day. --> Hence, even when completely sleep deprived, most animals exhibit a marked circadian rhythm of alertness and activity, and reduced responsiveness and inactivity. → these periods cant be assumed to be sleep Sleep must be distinguished from hiber- nation and torpor, states that have distinct physiological correlates Sleep must also be distinguished from just rest Sleep = the summation of the circadian and home- ostatically regulated sleep processes that determines our alertness --> Sleep persists in animals in which circadian rhythms have been elimi- nated

Do all animals sleep? what is the assumptions amount neuroscientists?

Some animals never exhibit a state that meets the behavioral definition of sleep. Others suspend or greatly reduce 'sleep' behavior for many weeks during the post- partum period or during seasonal migrations without any consequent 'sleep debt. Theres an assumption among neuroscientists that all animals sleep and that sleep deprivation is lethal → suggest that a universal, vital function is accomplished in sleep

do marine mammals show REM? reptiles fish and insects?

Some marine mammal species do not show evidence for REM sleep, and convincing evi- dence for this state in reptiles, fish and insects is lacking.

Stage 2 NREM sleep- signaled by ____ and _____; ___mins in the first sleep cycle what is the arousla threshold in n2? As stage 2 progresses,______ activity begins to appear in EEG - transitions to stage 3 (criteria- high voltage slow wave activity for more than ____ but less than____ of the EEG) - how long does stage 3 last in first sleep cycle? when do we know its stage 4?

Stage 2 NREM sleep- signaled by sleep spindles and k complexes; 10-25 mins in the first sleep cycle -- high arousal threshold As stage 2 progresses, high voltage slow wave activity begins to appear in EEG transitions to stage 3 (criteria- high voltage slow wave activity for more than 20% but less than 50% of the EEG) stage 3 lasts for only a few minutes in first sleep cycle and is transitional to stage 4 Stage 4 NREM- when high voltage slow wave sleep is more than 50% of EEG activity; 20-40 minutes; highest threshold for waking

HIPPOCAMPAL NEOCORTICAL DIALOGUE Structures within the ______ lobe- esp ______- crucial for formation and retrieval of new declarative memories --> Reinstatement of recently formed memories by .... The info initially requires ____binding, but over time, by way of _____ processes, is eventually integrated into _____ _____ structures- storage site for consolidated episodic memories and as a consequence, ___is not needed for retrieval how does Hippocampus activity during sleep allow the info to be activated in the cortex, independent of the hippocampus

Structures within the medial temporal lobe- esp hippocampal complex- crucial for formation and retrieval of new declarative memories --> Reinstatement of recently formed memories by binding together patterns of cortical activation that were present at the time of initial learning The info initially requires MTL binding, but over time, by way of slow offline processes, is eventually integrated into neocortical circuits --> Neocortical structures- storage site for consolidated episodic memories and as a consequence, MTL is not needed for retrieval Hippocampus also plays an important role in reactivating these networks during sleep- this reactivation, over many sleep cycles, strengthens the initially weak connections between neocortical sites, this strengthening allows the info to be activated in the cortex, independent of the hippocampus

Subjects with more _____recall more items cued for remembering but also recall fewer items cued for forgetting- so it suggests that sleep dependent mechanisms not....but... what is the Loop of recurring activity during these _____ in a network of brain regions implicated in differential remembering and forgetting:

Subjects with more spindles recall more items cued for remembering but also recall fewer items cued for forgetting- so it suggests that sleep dependent mechanisms not only actively promote remembering but also actively support forgetting Loop of recurring activity during these sleep spindles in a network of brain regions implicated in differential remembering and forgetting: medial temporal cortex, prefrontal cortex and posterior parietal cortex

NONPHOTIC CIRCADIAN PHASE RESETTING AND REENTRAINMENT- what are these? Appropriately timed exposure to exercise results in _____

Such as social cues, exercise, food, environmental cues other than light Appropriately timed exposure to exercise results in phase advances

pattern of change in when elderly gp to sleep? this results in..

Tend to go to sleep earlier in the evening sue to phase advance in normal circadian cycle Development of sleep related respiratory disorders occur more Obstructive Sleep Apnea (OSA) and Central Sleep Apnea or Cheyne's-Stoke respiration (CSA-CSR) associated with congestive heart failure (CHF) occur more Associated with systemic hypertension, cardiovascular disease, metabolic disorders like diabetes impaired neurocognition

The ____ curve is used to characterize the synchronizing effects of light on a circadian pacemaker In humans, measurement of the phase of endogenous circadian rhythms on a constant routine has been used to estimate both the initial circadian phase of the pacemaker before a stimulus and the final circadian phase after a stimulus, with the difference representing the _______

The phase-response curve is used to characterize the synchronizing effects of light on a circadian pacemaker In humans, measurement of the phase of endogenous circadian rhythms on a constant routine has been used to estimate both the initial circadian phase of the pacemaker before a stimulus and the final circadian phase after a stimulus, with the difference representing the phase shift

The ____ is the primary environmental signal that synchronizes circadian systems in a wide array of species, including humans

The light dark cycle is the primary environmental signal that synchronizes circadian systems in a wide array of species, including humans

The magnitude of the circadian rhythms of sleepiness and performance increases with increasing _____ Thus, what happens when an increasing homeostatic sleep pressure combines with an adverse circadian phase?

The magnitude of the circadian rhythms of sleepiness and performance increases with increasing homeostatic sleep drive. Thus, when increasing homeostatic sleep pressure combines with an adverse circadian phase, the drive for sleep is so great that slow eye movements and lapses of attention often intrude involuntarily during wake

Sleep in marine mammals - what is diff about sleep in marine mammals? sleep in ____ such as the fur seal and sea lion - on land? in water?

The standard criteria defining sleep have often been modified for descriptions of sleep in marine mammals marine mammals can sleep with one- half of the brain at a time and that they can swim while sleeping. sleep in otariids, such as the fur seal and sea lion: - On land: sleep in the fur seal generally resembles that in most terrestrial mammals. The EEG is bilaterally syn- chronized and the animal closes both eyes, appears unre- sponsive and cycles between REM and non-REM sleep - in the water: it usually shows an asymmetrical pattern of behavior, with one of the flippers being active in maintaining body position while the other flipper is inactive --> can have slow waves in one hemisphere with the contralateral eye being closed. The other eye is generally open or partially open. --> REM sleep time is greatly reduced in the water and little or no rebound of lost REM sleep is seen when the fur seal returns to land, even after several weeks in the water

The _____ in the ______ is the central neural pacemaker of the circadian timing system what drive daily rhythms in peripheral systems?

The suprachiasmatic nucleus (SCN) in the anterior hypothalamus is the central neural pacemaker of the circadian timing system -- Mammalian Circadian Pacemake Multiple distributed circadian oscillators drive daily rhythms in peripheral systems and pacemakers like the SCN convey internal synchrony to these distributed oscillators

Rhythmicity in some variables is independent of sleep wake state- which variables are independent of sleep-wake state ? 2

The temporal pattern of melatonin is relatively unchanged whether a participant is asleep or awake all night but does show age dependent and sleep deprivation related amplitude changes, posture also influences melatonin concentrations somewhat Overall profile of cortisol is relatively unchanged if you stay awake one night but will elevate if you stay awake the following afternoon and evening

A hypothesis of emotional memory: sleep to forget and sleep to remember, respectively --> what is the idea here? Neuroimaging studies have shown that initial exposure and learning of emotional stimuli is associated with greater______, relative to neutral stimuli However, when participants were reexposed to these same stimuli many months later, a change in the......occured ____decreased So _____remains the same but_____ decreases

There is a reduction in the affective tone associated with the recall of emotional experiences- there's not the same magnitude of autonomic reactivation as that at the time of learning/experience- suggesting that over time, the affective blanket over the memory has been removed while the info within the experience remains **The hypothesis predicts that this decoupling preferentially takes place overnight, such that we sleep to forget the emotional tone, yet sleep to remember the tagged memory of that episode Neuroimaging studies have shown that initial exposure and learning of emotional stimuli is associated with greater activation in the amygdala and hippocampus, relative to neutral stimuli However, when participants were reexposed to these same stimuli many months later, a change in the profile of activation occurred- the amygdala activity decreased So strength of the memory (hippocampal activity) remains the same but emotional reactivity (amygdala activity) decreases

what hormones are sensitive to sleep wake state? ... sleep inhibits_____release during peak of the endogenous circadian ____rhythm, which would otherwise occur in the middle of the night - this suppression is associated with_______and relative ___ power in the EEG ____, ____, and____ levels show increase during sleep -->____ levels blunted by sleep deprivation are increased during wakefulness the following day so that average 24 hour levels are similar Even in the absence of sleep,____and ____ also have an endogenous circadian component that is lowest a few hours after habitual wake-up time, and ___ responses to exogenous growth hormone-releasing hormone exhibit a circadian rhythm ____ levels exhibit circadian rhythmicity in interaction with energy intake and expenditure and sleep duration ____ levels exhibit a day night variation related to energy intake related to the presence of sleep and to sleep duration Ultradian variations in ____ (^ bp)release from the kidney are closely linked to timing of the REM-NREM cycle: increased delta power in EEG is associated with increased levels of ____ and decreased SWS is associated with a decrease

Thyroid stimulating hormone- sleep inhibits TSH release during peak of the endogenous circadian TSH rhythm, which would otherwise occur in the middle of the night- this suppression is associated with slow wave sleep and relative delta power in the EEG Growth hormone, prolactin, and para thyroid hormone levels show increase during sleep Growth hormone levels blunted by sleep deprivation are increased during wakefulness the following day so that average 24 hour levels are similar Even in the absence of sleep, prolactin and parathyroid hormone also have an endogenous circadian component that is lowest a few hours after habitual wake-up time, and Growth hormone responses to exogenous growth hormone-releasing hormone exhibit a circadian rhythm Leptin levels exhibit circadian rhythmicity in interaction with energy intake and expenditure and sleep duration Ghrelin levels exhibit a day night variation related to energy intake related to the presence of sleep and to sleep duration Ultradian variations in renin release from the kidney are closely linked to timing of the REM-NREM cycle: increased delta power in EEG is associated with increased levels of renin and decreased SWS is associated with a decrease

memory near sleep onset ? During a presleep testing session, word pairs were presented to volunteers over a loudspeaker at 1-minute intervals. The subjects were then awakened either 30 seconds or 10 minutes after the onset of sleep (defined as EEG stage 1) and asked to recall the words. - what did they find? - so In the 30-second condition - what memory stores were accessible? - In the 10-minute condition?

Transition from wake to sleep tends to produce a memory impairment It is as if sleep closes the gate between short and long term memory stores --> the 30-second condition was associated with a consistent level of recall from the entire 10 minutes before sleep onset. --> In the 10-minute condition, however, recall paralleled that in the 30-second group for only the 10 to 4 minutes before sleep onset and then fell abruptly from that point until sleep onset. In the 30-second condition, therefore, both long-term (4 to 10 minutes) and short-term (0 to 3 minutes) memory stores remained accessible. In the 10-minute condition, by contrast, words that were in long-term stores (4 to 10 minutes) before sleep onset were accessible, whereas words that were still in short-term stores (0 to 3 minutes) at sleep onset were no longer accessible; that is, they had not been consolidated into long-term memory stores.

changes In sleep Quality and Circadian Rhythms? But are these a part of aging or secondary to other comorbitidies that arise with age? Age related increase in insomnia is abolished when .... are considered

Trouble initiating sleep, disrupted sleep, early morning awakening, nonrestorative sleep But are these a part of aging or secondary to other comorbitidies that arise with age- much evidence points to the latter- after controlling for comorbidities, the high rates of insomnia reported in the elderly became lower Age related increase in insomnia is abolished when social satisfaction and activity status are considered --> Age related sleep problems are probably just secondary to medical illnesses rather than aging per se

Under entrained conditions, a consolidated bout of sleep is maintained with minimal wake during the scheduled sleep episode by initiating the sleep episode WHEN? during entrained conditions, homeostatic drive for sleep is greatest after .....and facilitates.... in the latter half of the sleep episode, as homeostatic drive declines what maintains elevated sleep drive thru the end of the sleep episode?

Under entrained conditions, a consolidated bout of sleep is maintained with minimal wake during the scheduled sleep episode by initiating the sleep episode at the end of the wake maintenance zone (3 hours before onset of melatonin secretion) during entrained conditions, homeostatic drive for sleep is greatest after an extended bout of wake at sleep onset and facilitates sleep in the first half of the night; in the latter half of the sleep episode, as homeostatic drive declines, the circadian drive for sleep becomes greater, thus maintaining elevated sleep drive thru the end of the sleep episode- the 2 drives interact to maintain sleep throughout the night

is it easy to distinguish the relative contributions of the sleep homeostat and that of the circadian pacemaker to a given recurrent daily characteristic, symptom, or disorder of sleep or wakefulness? how do we dissociate these factors in the lab? Clinically feasible techniques, such as measurement of ______ can provide useful information about circadian phase

Under ordinary circumstances, when people sleep at night in darkness and are awake in daylight, it is difficult to distinguish the relative contributions of the sleep homeostat and that of the circadian pacemaker to a given recurrent daily characteristic, symptom, or disorder of sleep or wakefulness It is currently possible, although difficult, to experimentally dissociate these factors for research purposes (e.g., using the forced-desynchrony protocol in humans or suprachiasmatic lesions in animals). Clinically feasible techniques, such as measurement of dim-light salivary melatonin onset, can provide useful information about circadian phase

Until ___years the percentage of__sleep decreases linearly at __5 per decade Percentage of ___ sleep also diminishes, although more subtly Net result of an increase in____ ____continues to decline due to increased sleep latency, arousals from sleep and time awake after sleep onset Probably bc of age related... and... who are more effected by aging ? (men or women)

Until 60 years the percentage of n3 sleep decreases linearly at 2% per decade Percentage of REM sleep also diminishes, although more subtly Net result of an increase in n1 and n2 Sleep efficiency continues to decline due to increased sleep latency, arousals from sleep and time awake after sleep onset Probably bc of age related neural degeneration and changes in hormonal systems Men are more affected by aging than women- interesting bc women usually self report shorter and poorer sleep

Visual response- bright light placed infront of subject's eyes and asked to respond when a light flash is seen EEG 1 and 2 - how often is response absent? example of what?

Visual response- bright light placed infront of subject's eyes and asked to respond when a light flash is seen EEG 1 and 2, response is absent more than 85% of the time Respond they didn't see the flash- example of perceptual disengagement from the environment

Wagner et al- demonstrated sleep dependent creative insight Subjects analyzed and worked thru a series of 8 digit string problems - what did they find When retested after a night of sleep? - Those who didn't sleep prior to retesting? Therefore, sleep serves a _____ role in memory processing beyond consolidation and aims to .....

When retested after a night of sleep, subjects solved it 16.5% faster Those who didn't sleep prior to retesting has less than 6% improvement 60% of subjects who slept discovered a shortcut to solving it, only 25% of those who didn't sleep had this insight Therefore, sleep serves a meta level role in memory processing beyond consolidation and aims to intelligently assimilate and generalize these details offline

Fenn et al demonstrated how sleep is involved in memory generalization- subjects were trained and tested on a grammar task which required forming new mappings from complex acoustical sounds to preexisting linguistic categories, which then generalized to new stimuli- involved both declarative and procedural memory When tested after a 12h waking interval? If retested after a night of sleep,?

When tested after a 12h waking interval, performance had declined If retested after a night of sleep, their ability for memory generalization was restored

this paper analyzes what 2 disorders?

Will analyze Obstructive Sleep Apnea (OSA), central sleep apnea or Cheyne's-Stokes respiration (CSA-CSR) including its association with congestive heart failure

does NREM sleep vary from the forced desynchrony protocol? slow wave? EEG- low freq sleep spindle activity in NREM sleep parallels the endogenous circadian ____rhythm Timing and internal structure of sleep are profoundly dependent on an interaction between robust circadian and homeostatic regulatory factors, with ______predominant in the regulation of REM sleep and with _____ factors predominant in the regulation of slow wave sleep

With the forced-desynchrony protocol, significant and substantial circadian and sleep-dependent variations in NREM sleep propensity were also observed, whereas the robust sleep-dependent decline in slow wave activity was associated with only a small but statistically significant variation of slow wave activity as a function of circadian phase (so slow wave sleep doesnt rlly get affected as much by the circadian phase being messed up) EEG-low freq sleep spindle activity in NREM sleep parallels the endogenous circadian melatonin rhythm Timing and internal structure of sleep are profoundly dependent on an interaction between robust circadian and homeostatic regulatory factors, with circadian factors predominant in the regulation of REM sleep and with sleep dependent factors predominant in the regulation of slow wave sleep

does REM sleep propensity vary with circadian phase? Spontaneous desynchrony, free-running participants who chose to go to bed near the peak of the REM sleep propensity rhythm usually exhibited _____episodes

YES REM sleep propensity varies with circadian phase Spontaneous desynchrony, free-running participants who chose to go to bed near the peak of the REM sleep propensity rhythm usually exhibited sleep-onset REM sleep episodes

Acute presleep alcohol intake can produce increase in____and suppression of ____ early in the night, which can be followed by _____ in the later portion of the night as the alcohol is metabolized Acute effects of marijuana include ____, slight reduction of____ chronic ingestion of THC produces..?

acute presleep alcohol intake can produce increase in SWS and suppression of REM early in the night, which can be followed by REM rebound in the later portion of the night as the alcohol is metabolized Acute effects of marijuana include minimal sleep disruption, slight reduction of REM chronic ingestion of THC produces long term suppression of SWS

what are the 4 examples to show multi item generalization in sleep?

artificial grammar in 15 month old transitive inference probabilistic learning insight

Healthy young participants were allowed to sleep normally or sleep deprived prior to a fMRI, and during scanning they performed an affective stimulus viewing task involving the presentation of picture slides ranging in a gradient from emotionally neutral to negative both groups expressed significant______activation in response to increasingly negative stimuli, but those in the sleep deprived condition exhibited ...... --> There was also a ______ in the extent of ____volume recruited in response to the aversive stimuli in the sleep deprived group ---> There was a loss of_____ in between the ____ and the _____in the sleep deprived group - a region known to have strong inhibitory projections and hence modulatory impact on the ____- failure of _____ by the prefrontal lobe A night of sleep maintains the functional integrity of the ____ circuit and thus governs appropriate emotional behavior A similar emotional dysfunction is found in many ___disorders which express co-occurring sleep abnormalities

both groups expressed significant amygdala activation in response to increasingly negative stimuli, but those in the sleep deprived condition exhibited a remarkable +60% greater magnitude of amygdala reactivity -->There was also a threefold increase in the extent of amygdala volume recruited in response to the aversive stimuli in the sleep deprived group ---> There was a loss of functional connectivity in between the amygdala and the mPFC in the sleep deprived group- a region known to have strong inhibitory projections and hence modulatory impact on the amygdala- failure of top down inhibition by the prefrontal lobe A night of sleep maintains the functional integrity of the mPFC- amygdala circuit and thus governs appropriate emotional behavior A similar emotional dysfunction is found in many mood disorders which express co-occurring sleep abnormalities

Sleep in amphibians

bullfrog Rana catesbeiana ( a diurnally active species) concluded that although levels of activity varied in a circadian pattern, the animals were more responsive during periods of inactivity than when they were active. --> Very vulnerable to rpedation - --> 'have survived only because they rest without loss of vigilance' Concluded that they do not sleep tree frog Hyla septentrionalis → concluded that this species slept No evidence of REM sleep was seen in either species. In both species of frogs, forebrain EEG is at maximum voltage during alert active states and at minimum voltage during rest states → rest and sleep states are not universally associated with high-voltage cortical activity and must ultimately be defined behaviorally

The circadian pacemaker interacts with sleep-wake regulatory processes to influence many physiologic variables: what are these? 4 what can influence elements of this system?

hormone levels, autonomic nervous system activity, neurobehavioral performance, and the propensity for and timing and internal structure of sleep. Environmental, social, behavioral, and genetic factors, pharmacologic agents, and age influence most elements of this system

what is "sleep rebound"? this 'rebound' sleep is disproportionately made up by increased amounts of_____ during sleep in rats and pigeons, the effects of long-term sleep deprivation can be completely reversed by a rebound made up almost entirely of ____sleep

if we reduce our sleep for 1 or 2 h, we will be sleepy the next day and when allowed to sleep will repay this 'sleep debt' by significantly increasing sleep time. this 'rebound' sleep is disproportionately made up by increased amounts of slow waves during sleep in rats and pigeons, the effects of long-term sleep deprivation can be completely reversed by a rebound made up almost entirely of REM sleep Common function served by these two diff patterns of brain activity

impact of sleep deprivation may be worse for ______ material- Severe disruption of encoding and retention for ___and ____ memory, relative resistance of _____memory what is the structure critical for new episodic info?

impact of sleep deprivation may be worse for emotional material- Severe disruption of encoding and retention for neutral and positive emotional memory, relative resistance of negative emotional memory Significant and selective deficit in bilateral regions of the hippocampus- structure critical for new episodic info

effects of aging on the pathophysiology of OSA: increases in age are associated with____ Most obvious factor predisposing to OSA? _____ changes with age may also affect susceptibility Arousal threshold? what is stable in elderly ? so it must be attributed to changes in...

increases in age are associated with apnea prevalence Most obvious factor predisposing to OSA- size or caliber of the airway- large airway less prone to collapse lung volume changes with age may also affect susceptibility Arousal threshold- debated whether theres an aging effect Ventilatory control is stable in the elderly so OSA in elderly is primarily attributed to changes in anatomy and physiology of the Upper Airway

Mechanisms of memory evolution: are the physiological sleep mechanisms regulating associative memory evolution clear? For item integration- ____sleep has been implicated in promoting the discovery of associative solutions on the remote associates task, also for solving anagrams, identifying weak semantic priming- therefore ____ has been identified as a state favorable for associative learning Integration of novel words into an existing mental lexicon is correlated with _____ Examples of multi item integration have also demonstrated relationships with ___, whereas other examples have associations w __

no - unclear --> Different sleep stages clearly have different functions in these varied memory evolution processes but we don't have enough studies to predict sleep stage dependencies For item integration- REM sleep has been implicated in promoting the discovery of associative solutions on the remote associates task, also for solving anagrams, identifying weak semantic priming- therefore REM has been identified as a state favorable for associative learning Integration of novel words into an existing mental lexicon is correlated with sleep spindles- a NREM sleep oscillation Examples of multi item integration have also demonstrated relationships with REM, whereas other examples have associations w NREM

is there sleep in unicellular organisms? sleep in insects? what did rest deprivation do? bees? _____ appear to show a behavioral state which satisfies all the behavioral criteria of sleep → unclear if its homologous or analogous to the sleep in humans

no claim of sleep occur- rence in unicellular organisms. But ample evidence that some cyanobacteria, protists, euglenozoa and dinoflagellates show circadian rhythms of activity cockroaches, bees and scorpions have quiescent behaviors with elevated arousal thresholds --> Rest deprivation, studied in cockroaches, did not produce a significant or consistent increase in rest time during the recovery period but did produce increases in metabolic rate Circadian changes in sensory response thresholds have been documented in bees No increase in rest duration after deprivation but there were changes in movement parameters Drosophila appear to show a behavioral state which satisfies all the behavioral criteria of sleep → unclear if its homologous or analogous to the sleep in humans

non-REM sleep is characterized by greatly reduced activity in ______ the predominant change on the EEG is from ..... to..... high-voltage slow waves and spindles are present in the____ acetylcholine release? what ia reduced far below the level in quiet waking that lowers overall energy consumption?

non-REM sleep is characterized by greatly reduced activity in brainstem systems - Forebrain neuronal activity rates are reduced below those of quiet waking - the predominant change is from irregu- lar discharge patterns to a rhythmic pattern of discharge. Cortical release of acetyl- choline is minimal during non-REM sleep During non-REM sleep, forebrain meta- bolic activity is reduced far below the level in quiet waking → loweds bodys overall energy consumption

_____, ______ and______ neurons, which are tonically active throughout waking states, are silent in REM sleep --> The reduction in activity of the ______ neurons has been linked to the reduction in muscle tone that occurs in REM sleep --> the reduction in activity of the______neurons has been related to the loss of consciousness occurring in sleep

noradrenergic, serotonergic and histaminergic neurons, which are tonically active throughout waking states, are silent in REM sleep --> The reduction in activity of the noradrenergic neurons has been linked to the reduction in muscle tone that occurs in REM sleep

Maquet et al- what did one night of post-training sleep deprivation do to hippocampal activity? First-night sleep deprivation also prevented an increase in_____with the _____

one night of post-training sleep deprivation, even following recovery sleep, significantly impairs the normal modulation of hippocampal activity associated with episodic memory recollection First-night sleep deprivation also prevented an increase in hippocampal connectivity with the medial prefrontal cortex (mPFC)

Eg 3. Probabilistic learning? Eg 4. Insight?

probabilistic learning: sleep enhances this form of multi item generalization - greater improvement in sleep group was accompanied by more accurate knowledge insight: sleep dependent processing can also lead to explicit declarative awareness of rules and associations --> Sleep has been shown to prime the brain for explicit discovery after awakening for both a shortcut for a math task and remote association task linking word triplets

Sleep in dolphin and other cetaceans? show only.... is there asymmetry in their motor activity? are there different response thresholds between the hemisphere tht has slow waves and the one that doesnt? Brian motor systems? how long can they maintain vigilance without sleep? is there rebound?

show only unihemi- spheric slow waves (USW). They never show high-voltage waves bilaterally When they swim while having USW, there is no asymmetry in their motor activity -- Regardless of which hemi- sphere is showing slow wave activity, they tend to circle in a counterclockwise direction the sleep behavior of these animals is indistinguishable from that of quiet waking No evidence has been presented for elevated sensory response thresholds contralateral to the hemisphere that has slow waves brain motor systems must be bilaterally active to maintain the bilaterally coordinated movement → Therefore, forebrain and brainstem activity must differ radically from that seen in terrestrial mam- mals during sleep dolphins are able to maintain continuous vigilance for 5 days with no decline in accuracy At the end of this period there was no detectable decrease of activity or evidence of inattention or sleep rebound such as would be expected of a sleep-deprived animal - Some cetaceans are always active - never float at top or sink to bottom

does sensory processing continue at some level after the onset of sleep? for what info?

yES Sleeping humans are able to maintain sensory sensitivity- one study showed that sleeping humans were differentially responsive to auditory stimuli --> Low arousal threshold for your own name vs someone else's- in light sleep, softly calling your name will arouse you, other similarly applied nonmeaningful stimuli will not -->Likelihood of an appropriate response during sleep was improved when an otherwise nonmeaningful stimulus was made meaningful by linking the absence of response to punishment

When endogenous circadian rhythms are entrained or synchronized to the 24 hour day, the temporal profile of each of these parameters is affected by a combo of factors- what are these? To take apart and see the effects of the circadian system, the constant routine protocol has been used- what is this?

timing of sleep wake state, the circadian pacemaker, posture, mood, exercise and environmental lighting To take apart and see the effects of the circadian system, the constant routine protocol has been used- participants undergo continued enforced wakefulness during the day and night in a constant posture at a constant level of minimal physical activity and in constant, relatively dim, ambient illumination --> The temporal profile of many physiologic variables are altered and the components of these rhythms that are driven by endogenous circadian pacemaker can be separated from those that reflect changes in the sleep-wake state, posture, or periodic external environment

can we say with confidence that all herbivores meet the standard criteria for sleep throughout their lifespan? what is something that animals experience in the wild that would likely influcence sleep/wake? Is REM present in all terrestrial animals?

we cannot say with confidence that all herbivores meet the standard criteria for sleep throughout their lifespan Hun- ger, a normal condition in the wild, has been found to greatly reduce sleep in the rat, and it might be expected to do so in other species under conditions where waking would increase the probability of feeding when no food is likely to be found, increased sleep is the best survival strategy REM sleep is present in all terrestrial mammals so far examined, occupying the great- est amount of the 24 h cycle in the egg-laying mammal platypus

can the The neurobehavioral variables influenced by the circadian pacemaker and the sleep homeostat influence the sleep-wake state? what did they find that draws attention to a potential feedback pathway from the pineal gland to the SCN through circulating melatonin what effect does exogenous melatonin have on the human circadian pacemaker? Examination of the temporal profile of endogenous melatonin secretion during the forced-desynchrony protocol shows a daily circadian increase in melatonin levels coincident with _______ This melatonin rise might....

yes - The neurobehavioral variables influenced by the circadian pacemaker and the sleep homeostat can influence the sleep-wake state Studies demonstrating that melatonin receptors can be found on cells within the human SCN draw attention to a potential feedback pathway from the pineal gland to the SCN through circulating melatonin. Several physiologic studies suggest that exogenous melatonin has a phase-resetting effect on the human circadian pacemaker Examination of the temporal profile of endogenous melatonin secretion during the forced-desynchrony protocol shows a daily circadian increase in melatonin levels coincident with a decrease in wake. This melatonin rise might open a gate that allows sleep to occur.