R.J. Erwin/ Photo Researchers
The Clark’s nutcracker can locate 6,000 caches of
buried pine seeds during winter and spring.
Storing Memories in the Brain
Long-term potentiation (LTP)
An increase in a synapse’s firing potential after brief,
rapid stimulation. Believed to be a neural basis for
learning and memory.
Memories seems to leave permanent neural traces or
paths. Experience modifies the brain’s neural networks.
Increased activity in a particular pathway, neural
interconnections form or strengthen.
(LTP)and increased receptor
Both Photos: From N. Toni et al., Nature, 402, Nov. 25 1999. Courtesy of Dominique Muller
As learning takes place, a
doubling of the receptor sites
means that the receiving
neuron has increased
sensitivity for detecting the
presence of the
that may be released by the
sending neuron. (from Toni
& others, 1999.)
Scott Barbour/ Getty Images
LO 6.5 Different types of long-term memory
Retrieval refers to getting information
out of the memory store.
Spanky’s Yearbook Archive
Spanky’s Yearbook Archive
In recall the person must retrieve
information learned earlier, using
effort, e.g., a fill-in-the blank test requires
1. The capital of France is ______.
In recognition the person has to
identify an item previously learned
amongst others, e.g., a multiple-choice
test requires recognition.
1. Name the capital of France
The process of retrieving a memory follows a
similar principle like a spider’s web; each piece of
info is interconnected with others.
A stimulus for remember
Memory by association
Memories are held in storage by a web of
associations. These associations are like
anchors that help retrieve memory.
Scuba divers recalled more words
underwater if they learnt the list
underwater, and recalled more words on
land if they learned the list on land
(Godden & Baddeley, 1975).
Fred McConnaughey/ Photo Researchers
Courtesy of Carolyn Rovee-Collier,
Jorgen Schytte/ Still Pictures
Inability to retrieve information, due to
1. Encoding Failure
We cannot remember what we did not
Which penny is real?
2. Storage Failure
Poor durability of stored
memories leads to their decay.
Ebbinghaus showed this with his
Andrew Holbrooke/ Corbis
Tip-of-the-tongue (TOT) is a retrieval failure
phenomenon. Given a cue (What makes the blood
cells red?) the subject says the word begins with an H
Sleep avoids retroactive interference thus
leading to better recall.
How reliable are memories?
Misinformation Effect: Incorporating
misleading information into one's
memory of an event.
Eyewitnesses reconstruct memories when
questioned about the event.
Depiction of the actual accident.
A week later they were asked; Was there
any broken glass? Group B (smashed into)
reported more broken glass than Group A
Broken Glass? (%)
Group A (hit) Group B (Smashed into)
Repressed or Constructed?
False Memory Syndrome :
Are memories of abuse repressed or
Leading psychological associations of the
world agree on the following about
childhood sexual abuse.
In relearning the individual shows
how much time (or effort) is saved
when learning material a second time.
Tree Tree 50%
1 day later
Kite Kite increase!
It took 10 trials It took 5 trials
to learn this list to learn the list