13.4 Flashcards
What does sleep accomplish?
What are some lines of evidence for sleep being a biological adaptation?
Energy-conserving for when food is scarce; prey sleep less than predators; when food is high in nutrients, animals can spend more time sleeping; switching off the brain during sleep conserves energy
What is the basic rest-activity cycle (BRAC)?
Recurring cycle of temporal packets (about 90-minute periods in humans), during which an animal’s level of arousal waxes and wanes
What is evidence for 90-minute BRACs in humans?
Infants feeding/sleep periods; classes, work periods, exercise sessions, mealtimes, etc. tend to be divided into 90 minute sessions; REM occurs at intervals of about 90 minutes
What are some psychological effects of reoccurring sleep deprivation?
Poorer cognitive performance on attention tasks; deficits in maintaining sustained attention
What are microsleeps?
Brief periods of sleep lasting a second of so
What are some studied effects of R-sleep deprivation?
Increased tendency to enter R-sleep in subsequent sleep sessions; more than usual amount of R-sleep during the first sleep after deprivation
What is episodic memory?
Conscious information such as autobiographical memories and knowledge of facts
What is implicit memory?
Unconscious processes such as motor skills.
What are the three proposed phases of memory?
Labile phase, storage phase, and recall phase
What is the labile phase of memory?
Memory is encoded, is fragile, and must compete with existing memories and the addition of new memories; risk of memory being abolished; associated with waking state
What is the storage phase of memory?
A relatively permanent representation of the memory is formed; depends of biochemical and genetic activities that underlie structural changes in the nervous system - which are better formed during sleep
What is the recall phase of memory?
Puts memory to work at some future time and integrates it into existing memory stores; can be accomplished in replay during sleep as well.
What does the multiple processes theory propose?
Different kinds of memory are stored during different sleep states: explicit memory during NREM and implicit memory during REM
What kind of memory is stored during NREM sleep according to the multiple processes theory?
Explicit memory
What kind of memory is stored during REM sleep according to the multiple processes theory?
Implicit memory
What do sequential process theories propose?
Different features of memory are improved in different ways during different sleep states: first refined in NREM and stored in REM
What do storage process theories propose?
Brain regions that handle different kinds of memory during waking continue to do so during sleep
What is the synaptic homeostasis memory theory of sleep? (3 points)
Sleep allows synapses that have been active during waking to return to a relatively quiet state during sleep. Synapses return to a more plastic state so they are able to be engaged during the next waking period. Synapses that have been involved in a recent learning experience take longer to return to rest state and are in an optimal condition in NREM sleep to undergo structural changes.
What are place cells?
Hippocampal neurons maximally responsive to specific locations in the world
How is sleep related to place cells?
During sleep, correlations between activity and place cells strengthen (example: rat and food search)
In what stage of sleep do place cells’ learning take place?
NREM
Three contemporary explanations for sleep propose that it is a(n) ______ adaptation, a(n) ________ process, or an aid in storing _______
biological; restorative; memories
_________ memory is associated with N-sleep, and ______ memory is associated with R-sleep
Explicit; implicit
In rats performing a spatial task, correlations develop between ________ firing in the hippocampus that is then replayed in _________ sleep
Place cells; NREM
