Chapter 6: Long Term Memory - Structure

Evidence that episodic and semantic memory involve different mechanisms

(1)double dissociation of episodic and semantic memory in patients with brain damage (2)brain imaging, which indicates that overlapping but different areas are activated by episodic and semantic memories.

Describe the alumni LTM study

1. Alumni asked to come back and recall the street names and landmarks of their college town 2. Remembered 40% of the information (similar 6 vs 46 years post grad). 3. Suggests information is retained for a long time.

Two types of declarative memories?

1. Episodic; memories associated with a particular time and place (experience) 2. Semantic; memories for general knowledge (i.e. toothbrush in a bathroom)

Distinguish between explicit memory and implicit memory.

1. Explicit (declarative) memories, such as episodic and semantic memories, are memories we are aware of. 2. Implicit memory (non-declarative; procedural, priming, classical conditioning) occurs when learning from experience is not accompanied by conscious remembering - unaware.

What conclusions about the separation of STM and LTM followed from neuropsychology studies involving HM and KF?

1. HM; removal of hippocampus to eliminate seizures. Couldn't form new long-term memories (anterograde amnesia). Showed LTM is associated with the hippocampus. 2. KF; Damage to PL led to poor STM. 3. Together, this demonstrates double dissociation and that STM and LTM are served by separate brain regions.

Describe the following evidence that indicates overlap between episodic memory for the past and the ability to imagine future events: (1) memory of people who have lost their episodic memory; (2) brain imaging evidence.

1. KC lost EM and was unable to use his imagination to describe personal events that might happen in the future. DB was the same too, but could imagine events not personally relevant. 2. fMRI; brain regions active in thinking about the past were active in thinking about the future - similar neural mechanisms involved.

Describe neuropsychological evidence for a double dissociation between episodic and semantic memory.

1. KC; damage to HC. Lost episodic memory but not semantic. 2. LP; Lost semantic but not episodic memories. 3. Together, demonstrate double dissociation between both memories.

implicit (non declarative) memory

1. LTM performance affected by prior experience with no necessary awareness of the influence 2. Measured with indirect memory tests

What can we conclude about similarities and differences in STM and LTM based on the way coding occurs in both?

1. Type of coding depends on the task. 2. STM - most likely auditory coding 3. LTM - most likely semantic (meaning) coding

tests for priming

1. Word completion (prime word followed by a word with blank letter that you fill in) 2. Lexical decision task 3. Stereotyping; i.e. reading certain words influences subsequent behaviour

Describe an adaptive function of episodic memory

A function of episodic memory is to help anticipate future needs and guide future behavior, both of which can be important for survival.

Lexical decision task

A procedure in which a person is asked to decide as quickly as possible whether a particular stimulus is a word or a nonword. Result: Faster RT to make lexical decision after a related prime.

How have episodic and semantic memory been distinguished from one another? Consider both the definitions and Tulving's idea of mental time travel.

According to Tulving, episodic memory involves mental time travel (self-knowing or remembering). The experience of semantic memory (knowing) does not.

What is procedural memory? Why is procedural memory considered a form of implicit memory?

Also called skill/motor memory. It demonstrates automaticity because it is memory for doing things that usually involve learned skills.

What is expert-induced amnesia, and how does it relate to an important property of procedural memory?

Amnesia that occurs because well-learned procedural memories do not require attention. This demonstrates automaticity because people don't seem to remember the process of the procedure(s).

Why is classical conditioning a form of implicit memory?

An example of classical conditioning causing implicit memory is provided by a situation we described earlier, in which you meet someone who seems familiar but you can't remember how you know him or her.

How did Baddeley support that LTM is based on meaning?

Baddeley found that words with similar meanings are harder to remember compared to words that sound similar

HM had ___memories but not ____ memories

Implicit (i.e. procedural; mirror-drawing task); explicit

Does listening to music improve/interfere with memory?

It depends: 1. People with musical experience with neutral music did better 2. People with no musical training with positive music did better 3. There is a link between enjoying music and dopaminergic reward system 4. People without musical training were able to benefit from the emotional boost of the music, but were not distracted by the music.

How does the remember/know procedure distinguish between episodic and semantic memories?

It's based on the idea that recollection (remember) is associated with episodic memory, and familiarity (know) is associated with semantic memory.

long term memory capacity

Large, no one knows, but perhaps 10^13 pieces of information (Landauer).

LTMs relationships with WM

Makes contact with working memory to create our ongoing experience.

duration of long term memory

Memory beyond 30 seconds/not current.

long term memory versus short term memory (coding)

Memory for words stored in LTM relies on meaning. Memory for words stored in STM relies on sound

Describe the effects of music on Alzheimer's and dementia

Music had a positive effect - their behaviour positively changed as if they were "returned back to normal". Consider this effect on Clive Wearing.

What is the remember/know procedure? How has it been used to measure how memory changes over time?

Participants are presented with a stimulus they have encountered before and are asked to respond with (1)remember if the stimulus is familiar and they also remember the circumstances under which they originally encountered it; (2)know if the stimulus seems familiar but they don't remember experiencing it earlier; or (3)don't know if they don't remember the stimulus at all.

Describe how personal significance can make semantic memories easier to remember. What happens to the "personal significance effect" in people who have lost their episodic memories due to brain damage?

Personal semantic memories can make semantic memories more accessible, except not in people who have lost their episodic memories due to brain damage.

Describe how differences between STM and LTM have been determined by measuring serial position curves.

The primacy and recency effects that occur in the serial position curve have been linked to long-term memory and short-term memory, respectively.

Relationship between semantic and episodic memories

They are not completely independent. Both involved in constructing memories 1. Semantic memory built from episodes 2. We interpret episodes from semantic memory

graded amnesia

When amnesia is most severe for events that occurred just prior to an injury and becomes less severe for earlier, more remote events.

serial position curve

a plot of the percentage of participants remembering each word against the position of that word in the list.

How has the remember/know procedure been used to measure how memory changes over time?

discovered semanticization of remote memories

What is the constructive episodic simulation hypothesis?

episodic memories are extracted and recombined to construct simulations of future events.

semanticization of remote memories

loss of episodic nature/details of memories.

What is autobiographical memory? How does the definition of autobiographical memory incorporate both episodic and semantic memory?

memory for specific experiences from our life, which can include both episodic and semantic components (personal semantic memories).

priming

occurs when the presentation of one stimulus (the priming stimulus) changes the way a person responds to another stimulus (the test stimulus).

repetition priming

occurs when the test stimulus is the same as or resembles the priming stimulus. It is a type of implicit memory because the priming effect can occur even though participants may not remember the original presentation of the priming stimuli.

What is the propaganda effect, and why could it be considered a form of priming?

participants are more likely to rate statements they have read or heard before as being true, simply because they have been exposed to them before. It involves implicit memory because it can operate even when people are not aware that they have heard or seen a statement before, and may even have thought it was false when they first heard it.

representation of episodic memory

sensory experience

representation of semantic memories

store conceptual/general information

primacy effect

tendency to remember words at the beginning of a list well. Due to longer rehearsal time available for words at the beginning of the list.

recency effect

tendency to remember words at the end of a list especially well, due to to storage in STM.

coding

the form in which stimuli are represented (i.e. pattern of firing by neurons)