Chapter 6: Long-Term Memory: Structure
Korsakoff’s syndrome: a condition caused by a prolonged deficiency of vitamin B1 (usually as a result of
chronic alcoholism) that leads to the destruction of areas in the frontal and temporal lobes, which cause
severe and permanent impairments in memory
Anterograde amnesia: the loss of the ability to assimilate or retain new knowledge
Retrograde amnesia: the loss of memory for events that have happened in the past
Distinguishing Between Long-Term Memory and Short-Term Memory
Long-term memory (LTM): the system that is responsible for storing information for long periods of
time; “archive of information about past events in our lives and knowledge we have learned
Long-term and Short-term Processes
Long-term memory covers a span that stretches from about 30 seconds ago to your earliest memories.
Although all of these memories are contained in LTM, recent memories tend to be more detailed, and
much of this detail and often the specific memories themselves fade with the passage of time and as other
Although retaining information about the past is an important characteristic of LTM, we also need to
understand how this information is used. We can do this by focusing on the dynamic aspects of how LTM
operates, including how it interacts with working memory to create our ongoing experience.
LTM provides both an archive that we can refer to when we want to remember events from the past, and a
wealth of background information that we are constantly consulting as we use working memory to make
contact with what is happening at a particular moment.
Serial Position Curve
Memory is better for words at the beginning of the list and at the end of the list than for words in the
Primacy effect: superior memory for stimuli presented at the beginning of a sequence (possible
explanation: participants had time to rehearse these words and transfer them to LTM)
Recency effect: superior memory for stimuli presented at the end of a sequence (possible explanation:
most recently presented words are still in STM – no delay; delay caused by counting for 30 sec eliminated
the recency effect)
Coding in Long-term Memory
STM – auditory and visual coding most prominent
LTM – can use auditory and visual coding too, but semantic is the predominant type of coding
Recognition memory: the identification of a stimulus that was encountered earlier Locating Short-and Long-term Memory in the Brain
o Double dissociation: poor STM, functioning LTM/ functioning STM, poor LTM; STM and LTM
operate independently and are served by different mechanisms
o The removal of H.M.’s hippocampus helped eliminate his seizures, but they also eliminated his
ability to form new LTMs.
o Some brain imaging experiments have demonstrated activation of different areas of the brain for
STM and LTM.
o Probe words that were from the beginning of the list (now long-term memory) activated areas of
the brain associated with both long-term memory and short-term memory.
It would be expected that both areas would be activated because words at the beginning
of the list would be in LTM (primacy effect) and would then be transferred into STM when
they were being recalled.
o Probe words from the end of the list only activated areas of the brain associated with short-term
It would be expected that only short-term areas would be activated because the recently
presented words would be recalled directly from short-term memory.
Some other experiments have shown that tasks that involve either STM or LTM can activate the same
areas of the brain.
This could be because…
1)…there is constant interplay that occurs between STM and LTM.
2)…STM and LTM may share some of the same mechanisms.
Types of Long-term Memory
EXPLICIT (conscious) IMPLICIT (unconscious)
Episodic Semantic Priming Procedural memory Conditioning
(personal events) (facts, knowledge)
Explicit memory (conscious, declarative) consists of episodic memory (memory for personal experiences)
and semantic memory (stored knowledge, memory for facts).
Implicit memory (unconscious, non-declarative) consists of priming (a change in response to a stimulus
caused by previous presentation of the same or a similar stimulus), procedural memory (skill memory; memory for doing things), and classical conditioning (occurs when pairing an initially neutral stimulus
with another stimulus