Study Questions: Learning and Memory
1. What is an engram, and what were Lashley’s critical mistakes in looking for the
An engram is a physical representation of memory. Lashley trained rats then cut
or leaisoned certain areas of the cortex, where the tissue was removed had no
effect on performance, but the amount of tissue removed did. Lashley’s false
assumptions were that memory is in discreet regions of the cortex and that all
memories are physiologically the same.
There are different types of memories and different brain areas important for
2. What are implicit memory and explicit memory? What brain regions are
important for each?
Implicit Memory: A type of memory in which previous experiences aid in the
performance of a task without conscious awareness of these previous experiences.
You don’t necessarily realize you’re using memory. Skills and habits, emotional
assosiations and conditioned reflexes. The striatum, motor areas of cortex,
cerebellum and amygdala are important.
Explicit Memory: Deliberate recall of information that one remembers as a
memory. Remembering events (episodic memory), and knowing facts (semantic
memory). The hippocampus is important as well as nearby cortical areas and the
3. What are some differences b/t shortterm memory (working memory) and long
term memory? What brain region is important for working memory?
Short Term Memory: Small capacity, fades quickly unless rehearsed, once
forgotten it is gone, working memory is an alternate way of thinking of STM.
Lasts hours to days without rehearsal, where car is parked, when/where lunch date
is. The time needed for consolidation verie, especially depending on familiarity of
topic and emotional content. The prefrontal cortex is important for working
Long Term Memory: Infinite capacity, lasts indefinitely. Could be forgotten then
later remembered with appropriate cues. Phone numbers, name of grade school
teachers. Condolidated memories can be reconsolidated.
Hebb made the disdinction: No one mechanism could account for all types of
learning, we form memories almost instantaneously (too fast for any chemical
process, especially if it was then stable enough to retain that memory forver) and
some last a lifetime.
4. What were some of HM’s impairments; what could he still do?
They removed much of the temporal lobe including the hippocampus which led to
Anterograde amnesia. He lost declarative (explicit) memory and spatial memory.
His procedural memory (type of implicit) and working memory were intact.
5. With regard to memory, what are some functions of the hippocampus?
In adolescents, a smaller size is correlated with better memory performance, in
older people more memory impairment in those whose hippo shrank faster. A
smaller volume is seen in epilepsy and other psychological disorders. The
hippocampus is active during formation of memories and during recall, also with
consolidation of declarative/explicit memory. There is increased activity in the hippocampus while doing a special task, damage leads to impairment of spatial
tasks. In London taxi drivers there is a larger posterior hippo and positive
correlation to time being a taxi driver.
6. What other brain regions are important in learning and memory, and what type of
learning do they subserve?
Cerebellum: Important for learning a conditioned response and aslo for motor
learning (skills) and cognitive stuff
Parietal Lobe: If this is damaged, don’t spontaneously elaborate on memories
Temporal Lobe: Damage causes semantic dementia. SD: loss of factual
knowledge. This is most likely because it is a hub for retrieving knowledge not
the location of storage.
Prefrontal Cortex: Learning reward and punishment. Also working memory.
7. What is a Hebbian synapse?
This is a synapse that increases effectiveness because of a simultaneous activity in
pre and postsynaptic and postsynaptic neurons. “Cells that fire