Retaining Information in the Brain






Explicit memories are language-based facts and experiences
that can be brought to conscious awareness.
The network: left and right frontal lobes <--> hippocampus.
Fig. 24.1 With left-hippocampus damage, people have trouble
remembering verbal information, but they have no trouble
recalling visual designs and locations. With right-hippocampus
damage, the reverse is true. (Schacter, 1996).
Memories are not permanently stored in the hippocampus. If a
rat's hippocampus is removed 3 hours after it learns the location
of food, long-term storage is disrupted; 48 hours later does not
.(Tse et al. 2007).
During deep sleep, the hippocampus processes memories for
later retrieval. Frontal cortex and hippocampus appear to be
having a dialogue during sleep. (Euston et. al. 2007).
Cortex areas surrounding the hippocampus support the
processing and storing of explicit memories.
Retaining Information in the Brain






Fig. 24.2 Implicit memories, created by classical conditioning,
are laid down in the cerebellum. The movie 'Memento' borrows
the LeDoux (1996) experiment.
With a damaged cerebellum, the conditioned reflexes of
classical conditioning cannot occur. (Daum & Schugens, 1996).
The basal ganglia are deep brain structures involved in motor
movement, facilitating formation of procedural memories for
skills.
The basal ganglia receive input from the cortex but do not
return signals for conscious awareness of procedural learning.
We all experience infantile amnesia primarily because the
hippocampus is one of the last brain structures to mature. This
leads evolutionary psychologists to theorize that explicit
(language-based) memories are relatively new. (Bauer et. al.
2007).
Retaining Information in the Brain






Fig. 24.3: Memorize for the next exam.
Stress hormones provoke the amygdala (two limbic system,
emotion-processing clusters) to intitiate a memory trace in the
frontal lobes and basal ganglia and to boost activity in the brain's
memory-forming areas. (Buchanan, 2007).
Emotional arousal can sear certain events into the brain, while
disruptuing memory for neutral events around the same time.
(Birnbaum et al. 2004).
Emotions can persist without our conscious memory of what
caused them. (Feinstein et al., 2010).
Memory serves to predict the future and to alert us to potential
dangers. Weaker emotions mean weaker memories. (Cahill, 1994).
Flashbulb memories are noteworthy for their vividness and the
confidence with which we can recall them. They are, however,
susceptible to the misinformation effect.
Retaining Information in the Brain






Fig. 24.4 Long Term Potentiation is the Holy Grail of
Neuroscience.
It is an increased efficiency of potential neural firing.
Drugs that block LTP interfere with learning. (Lynch & Staubli,
1991)
Mutant mice engineered to lack an enzyme needed for LTP can
learn a maze. (Silva et al., 1992)
Rats given a drug that enhances LTP with learn a maze in half the
time. (Service, 1994).
Injecting rats with a chemical the blocks the preservation of LTP
erases recent learning. (Pastalkova et al., 2006).

LTP can be disrupted by electroconvulsive therapy.

LTP can be disrupted by head trauma. (Yarnell & Lynch, 1970).

LTP can be enhanced by glutamate, or CREB. (Fields, 2005)
Retaining Information in the Brain






Boosting CREB production might trigger increased production
of other proteins that help reshape synapses and transfer shortterm memories into long-term memories.
Sea slugs (Aplysia), mice and fruit flies with enhanced CREB
production have displayed enhanced learning.
Blocking CREB-producing amygdala neurons can permanently
erase an intrusive auditory fear memory. (Han et al., 2009).
Propranolol can remove the traumatic memories that lead to a
stress disorder. (Pitman et al., 2005).
You will be using this section of the Myers text for your long
essay work on the movie 'Memento'.
Memorize Fig. 24.5 for the next exam.