The Memory Function of Sleep
Group 1
Amanda Ayoub
Hannah Stolarczyk
Stephanie Regan
Alicia Iafonaro
1. What is memory consolidation?
•
•
Process that encodes new
memories so they can be
retrieved later in time
Two specific processes for
memory consolidation
–
–
Synaptic consolidation: occurs the
first few hours after learning
System consolidation: memories
that are dependent on
hippocampus become
independent over period of weeks
or years
1. What kinds of memory are
consolidated in sleep?
•
•
•
Declarative (explicit) and
Procedural (implicit)
memories, as well as
emotional information,
consolidated during sleep
Retention of declarative
information
Improvement in performance
of procedural tasks
2. What are examples of implicit and explicit learning, and
how are they connected with consolidation during sleep? What
else is known about what sort of memory is best consolidated?
•
•
Encoding of declarative memories
(facts) is typically explicit, whereas
procedural memory (how do to
something) encoding can involve both
implicit and explicit processes.
Sleep benefits are greater for memories
formed from explicitly encoded
information that was more difficult to
encode or previously weakly encoded.
It also has a higher benefit for
memories relevant to behavior.
2. Cont.
•
•
Sleep enhances the
consolidation of memories for
intended future actions and
plans.
Several studies indicate that
sleep helps consolidation in all
major memory systems, but it
generally favors memories
explicitly encoded and
relevant to behavior
3. Describe what happens to memory representations
during sleep. Discuss related findings from studies in
some detail. What conclusions can be drawn?
•
Sleep reorganizes newly
encoded representations.
This enables the
development of new
associations and extracts
invariant features from
complex stimuli.
•
Also allows memory
representations to convert
from implicit to explicit
3. Cont.
•
•
Contrasting, it’s thought that
memory systems compete and
reciprocally interfere during
waking, and disengage during
sleep allowing for consolidation to
take place in the different systems.
There may be a sequential
contribution of interaction and
disengagement during
consolidation during the different
stages of sleep
What is meant by different memory
“systems,” and what is going on with
them in the context of this article?
•
•
Memory systems – different types of memory
–
Declarative (Explicit)
–
Non-declarative (Implicit)
Different memory systems are thought to be
mediated by distinct neural systems

5. Discuss, with some completeness, what the article has to
say about sleep stages and consolidation. Include findings for
animals and humans. In this, the importance of REM, SWS,
REMD should be discussed.
In humans, SWS and REM sleep
The sleep stages are:
dominate the early and late

REM (rapid eye movement)
part of nocturnal sleep


REMD (REM sleep deprivation)
SWS-rich, early sleep
SWS (slow-wave sleep) or deep consistently benefits the
sleep
consolidation of declarative
memories
REM-rich sleep benefits nondeclarative types of memory
(procedural and emotional
aspects of memory)
5 Continued...

These results are consistent with the ‘dual-process hypothesis’



SWS supports declarative, hippocampus-dependent memory
REM sleep supports non-declarative, hippocampus-independent
memory.
Happens when SWS and REM take place in succession.
5 Continued...



In rats, showed that REMD is only
effective during specific periods
after learning the “REM sleep
windows”
During post learning sleep, the
amount and intensity of REM sleep
increases even several hours or
even days after learning,
depending on the kind of task and 
amount of initial training
Memory is particularly impaired if
REMD coincides with these
periods.
Evidence shows that REM
sleep favors the
consolidation of emotional
aspects of a memory (could
account for the strong REMD
effect observed)