Course: PSYC*1000 (DE)
Professor: Harvey Marmurek
Schedule: Summer, 2012
Textbook: Psychology – Tenth Edition in Modules authored by David G. Myers
Textbook ISBN: 9781464102615
Module 24: Storage: Retaining Information in the Brain
What is the capacity and location of our long-term memories?
Arthur Conan Doyle’s A Study in Scarlet, Sherlock Holmes offers a popular theory of memory capacity – a
little empty attic. Contrary to this model, our capacity for storing long-term memories is essentially limitless.
Retaining Information in the Brain
Karl Lashley trained rats to find their way out of a maze, surgically removed pieces of their brain’s cortex and
retested their memory.
Despite the brain’s vast storage capacity, we do not store information as libraries stores their books, in discrete,
precise locations. Instead, many parts of the brain interact as we encode, store, and retrieve the information that
forms our memories.
Explicit-Memory System: The Frontal Lobes and Hippocampus
What is the role of the frontal lobes and hippocampus in memory storage?
The network that processes and stores your explicit memories includes your frontal lobes and
hippocampus. When you summon up a mental encore of a past experience, many brain regions send input to your
frontal lobes for working memory processing. The left and right frontal lobes process different types of memories.
Recalling a password and holding it in working memory, for example, would activate the left frontal lobe. Calling up
a visual party scene would more likely activate the right frontal lobe.
Cognitive neuroscientists have found that the hippocampus, a temporal-lobe neural centre located in the
limbic system, is the brain’s equivalent of a “save” button for explicit memories. Brain scans revealed that new
explicit memories of names, images, and events are laid down via the hippocampus.
Damage to this structure therefore disrupts recall of explicit memories. 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 problem is reversed.
Sub regions of the hippocampus also serve different functions. One part is active as people learn to
associate names with faces. Another part is active as memory champions engage in spatial mnemonics. The rear
area, which processes spatial memory, grows bigger the longer a London cabbie has navigated the maze of streets.
Memories aren’t permanently stored in the hippocampus. Instead it is a loading dock where brain registers
and temporarily holds the elements off remembered episode – smell, feel, sound, and location. Then, like older files
shifted to a basement storeroom, memories migrate for storage elsewhere. Removing a rat’s hippocampus 3 hours
after it learns the location of some tasty new food disrupts this process and prevents long-term memory formation;
removal 48 hours later does not.
Sleep supports memory consolidation – deep sleep – the hippocampus processes memories for later
Implicit-Memory System: The Cerebellum and Basal Ganglia
What role do the cerebellum and basal ganglia play in our memory processing?
Your hippocampus and frontal lobes are processing sites for your explicit memories. But you could lose
those areas and still, thanks to automatic processing, lay down implicit memories for skills and conditioned
associations. Joseph LeDoux – amnesia patient couldn’t remember physician, but could remember the pain of the
tack pricking her hand. Having been classically conditioned.
The cerebellum plays key role in forming and storing the implicit memories created by classical conditioning.
With a damaged cerebellum, people cannot develop certain conditioned reflexes, such as associating a tone with an
impending puff of air.
Basal ganglia, deep brain structures involved in motor movement, facilitate function of our procedural
memories for skills. The basal ganglia receive input from the cortex but do not return the favour of sending
information back to the cortex for conscious awareness of procedural learning.
Our implicit memory system, enabled by the cerebellum and basal ganglia, helps explain why the reactions
and skills we learned during infancy reach far into the future. Yet as adults, our conscious memory of our first three
years is blank, an experience called infantile amnesia. Which parts of the brain are elemental for implicit memory processing, and which parts play a key role in explicit
Our explicit memories differ from our implicit memories of skills and procedures. Our implicit memories are
processed by more ancient brain areas, which apparently escaped damage during the accident.
Your friend has experienced brain damage in an accident. He can remember how to tie his shoes but has a hard
time remembering anything told him during a conversation.