Long-term memory and Encoding
Long-Term Memory (LTM) and Encoding
Encoding: Acquiring information and transferring it to LTM.
Encoding involves processes to get information into LTM. Examples include:
Repeating information.
Rhyming words.
Using words in a sentence.
Some encoding methods are more effective than others.
Term "coding" refers to the form in which the information is represented (visual, sound, meaning)
Retrieval
Retrieval: Transferring information from LTM to working memory for conscious awareness.
Success in exams depends on effective retrieval.
Retrieval success depends on how information was encoded during learning.
Memory Storage
What types of events are people most likely to remember?
Is memory for extraordinary events (e.g., 9/11) special?
Why is eyewitness testimony unreliable, and can this be improved?
What memory system properties cause both functionality and errors?
Memory as a Process
Memory involves retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present.
Memory is complex and not simply writing something, storing it, and retrieving it later.
Memory involves different types of memory, encoding techniques, and retrieval strategies.
Information can be lost during storage.
Retrieval may not always be successful.
Analogy: Memory is like writing on a file card with disappearing ink; some information may be lost or changed during retrieval.
Memory Accuracy
Many people believe memory works like a video camera, but this is erroneous.
Everything is not necessarily recorded accurately, and recorded information is subject to change.
Memories are constructed based on actual events, combined with other experiences and general knowledge.
Autobiographical Memory (AM)
Memory for specific experiences from our life, including episodic and semantic components.
Episodic memory: Reliving an event through mental time travel.
Semantic memory: Knowledge about the event.
Characteristics of Autobiographical Memory
Multidimensional: Consisting of spatial, emotional, and sensory components.
Selective: Remembering some events better than others.
Multidimensional Nature of AM
Autobiographical memories are complex, detailed, and vivid.
They consist of spatial, emotional, and sensory components.
They often involve self-reflection and visual imagery.
Patients with visual memory loss also experience impaired AM, even for non-visual memories, suggesting the crucial role of visual experience.
Brain Activation and AM
Own-photos (photos taken by participants) and lab-photos (photos taken by someone else) activate similar brain structures (medial temporal lobe, parietal cortex).
Own-photos cause more activation in the prefrontal cortex (processing information about the self) and hippocampus (recollection/mental time travel).
Autobiographical memories activate a richer network of brain areas, reflecting complex constructive processes (searching, monitoring, self-referential processing).
Autobiographical memories often elicit intense emotions, activating the amygdala (associated with emotion).
Memory Over the Lifespan
Personal milestones and highly emotional events are memorable.
Events significant to a person's future life are remembered well.
Transition points in people's lives are particularly memorable.
Reminiscence Bump
For people over 40, memory is enhanced for adolescence and young adulthood (ages 12-28).
Childhood Amnesia
Few memories from the first 4-5 years of life due to an immature, developing memory system.
Hypotheses Explaining the Reminiscence Bump
Self-Image Hypothesis: Memory is enhanced for events that occur when a person's self-image or life identity is being formed.
People create "I am" statements that define them, and events connected to those statements are memorable when they happen during adolescence/young adulthood.
Cognitive Hypothesis: Periods of rapid change followed by stability cause stronger consolidation of memories.
Adolescence and young adulthood involve rapid changes (leaving home, making new friends, starting a career) followed by the relative stability of adult life.
People who experience rapid changes later in life (e.g., emigration) show a later reminiscence bump.
Cultural Life Script Hypothesis: Culturally expected events that occur at a particular time in the life span.
Events in a person's life story are easier to recall when they fit the cultural life script for that person's culture.
The Reminiscence Bump
The reminiscence bump appears to be present particularly for positive experiences.
Each of these mechanisms makes some contribution to creating the reminiscence bump.
Memory for "Exceptional" Events
Memorable events are significant, important to the person, and often associated with emotions.
Memory and Emotion
Emotions are associated with "special" events.
Emotion and Enhanced Memory
Arousing words and emotional pictures are better remembered.
Amygdala activation is higher for successfully retrieved emotional pictures.
Emotion enhances recollection-related activity in the hippocampus.
Damage to the amygdala impairs memory for emotional parts of stories.
Emotion and Memory Consolidation
Emotion has been linked to improved memory consolidation, which strengthens memory for an experience over time.
Stress hormones released after an emotional experience increase consolidation of memory for that experience.
Cortisol enhances memory for emotional pictures but not neutral pictures.
Hormone activation subsequent to arousing emotional experiences enhances memory consolidation in humans.
Emotions Can Impair Memory
Emotions can cause focusing/narrowing of attention, decreasing memory for other objects.
Weapon focus: Focusing attention on a weapon during a crime.
The presence of a gun decreases memory for other details of the crime scene, including the perpetrator's face.
Flashbulb Memories
Memories for circumstances surrounding how a person learned about a public, highly charged event (e.g., 9/11).
Flashbulb memories are not like photographs; they change over time like other memories.
People's belief that their flashbulb memories are accurate remains high, but accuracy is often similar to everyday memories.
Emotions and Flashbulb Memories
The special nature of flashbulb memories can be traced to the emotional nature of flashbulb events.
Strong emotions may enhance the subjective sense of remembering (vividness, confidence) but decrease memory for details.
Emotion's effect on memory. Participants viewed 60 pictures: 30 neutral, such as a landscape, and 30 negative, such as a picture of a car crash. These pictures were framed in one of them four different colored boarders (Figure 8.6a). One hour later, participants saw the original 60 pictures plus 60 new pictures. For each picture, they (1) made a confidence rating between 1 and 6, where 1 indicated they were sure they had not seen the picture, and 6 indicated they were sure they had seen the picture before; (2) made a "remember/know/new" judgment in which “remember” meant they remembered seeing the picture when it was originally presented, “know” meant that the picture is familiar but they don't remember experiencing it earlier, and “new” meant they had never seen the picture. (3) for the pictures they rated as “remember,” they had to indicate the color of the frame that had surrounded the picture. The results in Figure 8.6b, indicate that participants were more likely to say they remembered emotional (negative) pictures than neural pictures (left pair of bars). Another result, not shown on the graph, was that 67% of the emotional pictures received a confident rating of 6 (“I’m sure I saw the picture before”), but only 51% of the neutral pictures received a 6.
Rehearsal, Media Coverage, and Flashbulb Memories
We remember events like 9/11 not because of a special mechanism but because we rehearse these events after they occur (narrative rehearsal hypothesis).
Extensive media coverage can cause people to "remember" things that didn't actually occur.
What people believe they remember accurately may not be accurate at all.
The constructiveness of memories is based on what actually happened plus additional influences.
Constructive Nature of Memory
What people report as memories are constructed based on what actually happened plus additional factors, such as the person's knowledge, experiences, and expectations.
The mind constructs memories based on a number of sources of information.
Bartlett's "War of the Ghosts" Experiment
Participants read a story from Canadian indigenous folklore and were asked to recall it as accurately as possible.
At longer times after reading the story, most participants' reproductions of the story were shorter than the original and contained many omissions and inaccuracies.
Their reproductions tended to reflect the participant's own culture.
Participants created their memories from the original story and what they knew about similar stories in their own culture.
Source Monitoring and Source Monitoring Errors
Source monitoring: Determining the origins of our memories, knowledge, or beliefs.
Source monitoring error: Misattributing the source of a memory.
Source monitoring provides an example of the constructive nature of memory.
Cryptoamnesia
Unconscious plagiarism of the work of others.
People believe that they have produced a new idea when in fact they have simply unwittingly retrieved an old, previously encountered idea from memory.
Johnson (2006) describes memory as a process that makes use of a number of types of information.
The "Becoming Famous Overnight" Experiment: Source Monitoring and Familiarity
Participants read a list of non-famous names and were then tested on their ability to distinguish between famous and non-famous names.
After a delay, participants were more likely to identify the old non-famous names as being famous.
Sebastian Weissdorf become famous (or Valerie Marsh, or any of the other people from the first list) overnight?
How Real-World Knowledge Affects Memory
Inferences and Prior Knowledge Can Influence Memory
Influence of Person’s Schemas for that Environment has on that Person’s Memory
False Recall and Recognition
The fact that knowledge in the real world can cause errors
Pragmatic Inference
When reading a sentence leads a person to expect something that is not explicitly stated or necessarily implied by the sentence.
Schemas and Scripts
Schema: A person's knowledge about some aspect of the environment.
Script: Our conception of the sequence of actions that usually occurs during a particular experience.
Schemas/scripts can influence our memory by setting up expectations about what usually happens in a particular situation.
False Recall and Recognition
Illustrates false recall of items that were not actually presented.
False memory: Remembering sleep when it isn't on the list.
Memory Can Be Modified or Created by Suggestion
Information presented by others can influence a person's memory for past events.
The Misinformation Effect
Misleading information presented after a person witnesses an event that can change how the person describes that event later.
This misleading information is referred to as misleading post-event information, or MPI.
Misleading Post-Event Information (MPI)
MPI can alter not only what participants report they saw, but their conclusions about other characteristics of the situation as well.
MPI as Causing Interference
The original information is forgotten because of retroactive interference, which occurs when more recent learning (the misinformation in this example) interferes with memory for something that happened in the past (the actual event).
MPI as Causing Source Monitoring Errors
The source monitoring perspective involves a person incorrectly concludes that the source of their memory for the incorrect event (the give way sign) was the slide show, even though the actual source was the experimenter's statement after the slide show.
Creating False Memories for Early Events in People's Lives
This is when researchers Hyman, Husband and Billings (1995) managed to create false memories in students for long ago events using the procedure, originally developed by Loftus and colleagues.
People make errors in eyewitness testimony.
Errors of Eyewitness Identifications
There are many instances in which errors of eyewitness testimony have resulted in the conviction of innocent people.
Errors Associated with Perception and Attention
Witness reports will, of course, be inaccurate if the witness doesn't perceive what happened in the first place.
Number of experiments have presented participants with films of actual crimes or staged crimes and then asked them to pick the perpetrator from a photo spread (photographs of a number of faces, one of which could be the perpetrator).
The Weapon Focus Effect
Observation that the presence of a weapon impairs eyewitness recall for the details of the crime scene, including those associated with the perpetrator's face.
The weapon can be a very "informative
