Pranking Memory. How is information stored in LTM? Information is stored based on meaning. Information to be remembered collects together because it is.

Pranking Memory

How is information stored in LTM?

• Information is stored based on meaning.

• Information to be remembered collects together because it is related, so meaning of one concept is derived from its relationship to other concepts

Example Semantic Network

Schema Theory

• Schemas provide a skeleton structure, which is filled in with details from an experience

• Schema knowledge also organized around scripts– Knowledge about what occurs during routine

activities

Reconstructive Memory

• Memories are reconstructed, and as such, subject to the influence of expectations– Sir Frederic Bartlett (1932)– “The War of the Ghosts”

Schemas and Memory Errors

• Schematic processing is among the most pervasive sources of predictable errors in memory.

• Why?

• The graduate student office study

Grad Student Office

• Most everyone recalled that the office had a chair, desk and walls.

• Some participants recalled schema consistent items, like books that were not present.

What is false memory?

• False memory refers to the circumstances in which we are possessed of positive, definitive memories of events – although the definitiveness may vary – that did not actually happen to us.

Some Factors Reducing the Accuracy of Eyewitness Memory

Wait…why eyewitnesses?• Eyewitnesses generally

are taken off guard by the crime– They are often preoccupied

with their own thoughts and plans

• The criminal’s actions are often brief and swift

• Criminals take steps to avoid recognition– e.g., they wear disguises

• Eyewitnesses are subject to:– Inattentional blindness– Change blindness– Prior expectations– Post-event information– Weapon focus

Inattentional Blindness

• A failure to see fully visible objects or events because attention is focused elsewhere.

Change Blindness• The phenomenon in which some prominent feature of the visual

environment is dramatically changed without the perceiver apparently noticing

• It seems our LTM for complex scenes is much less detailed than we often believe

Prior Expectations

• Hastorf and Cantril (1954)– Design:

• Dartmouth and Princeton students watched an American football game between the two schools

• They were asked to detect violations of rules

– Results:• Princeton students detected twice as many

violations by Dartmouth than did Dartmouth students

• Remember Schemas?

Post-event Factors

• Information provided after an event, both visual or verbal, can dramatically affect eyewitness memory.

Post-event Factors: The Misinformation Paradigm

• The contents of our memories are subject to interference from any number of sources.– Based on the underlying idea that memory is

reconstructive

Post-event Factors: Leading Question Effect

• Loftus and Palmer (1974)• Can cause witnesses to remember episodes

differently– estimate the speeds of the cars when they

• smashed• bumped• collided• hit• contacted

Implanting False Memories

• As previously discussed, memory for events can be altered to include false information.– E.g., Misinformation

• Can an entirely false memory be implanted?

The “Lost-in-the-Mall” Paradigm

• Participants are presented with scenarios of past events.

• Some of the events are true (corroborated by relatives and friend)

• One or more of the events is false.• Memory for all events is tested at multiple

time points.

The “Lost-in-the-Mall” Paradigm

• Interesting findings.– 25% of participants falsely recalled being lost in a

shopping mall. (Loftus & Pickrell, 1995)– 37% of participants recalled false events such as

being rescued by a lifeguard (Heaps & Nash, 2001) – 25.5% recalled spilling a bowl of punch on the

parents of the bride at a wedding. (Hyman, Husband, & Billings, 1995)

Sample Interview from (Hyman, Husband, & Billings, 1995)

I: Next one looks like an eventful wedding reception. Lookslike you were 5 years old. You’re at a wedding of a familyfriend, playing with some other kids, while you’re runningaround uh you bump into a table and spill punch on the parentsof the bride.S: [laughs] I don’t remember that either. That’s pretty funnythough [laughs]I: [laughs] Yeah, that seems like it would be kind of eventful.S: Yeah, God, maybe my mom never talks about these. Shenever talked about, she’s never told me about that, jeez, that’sfunny. A wedding. I wonder whose wedding it could be…man, I want to talk to her and find out where she’s getting these,cause…a wedding reception. I can totally see myself like running around and bumping into the table. I would do that.

Final Interview

I: The next one I have is an eventful wedding at age 5.S: Yeah I thought about this one too. I definitely think it’s afriend of my mothers for some reason and the people I spillpunch on, I picture them to be a heavy set man, not fat butlike tall and big, and I picture him having a dark suit on, likegreyish dark hair and balding on top, and uh I picture him witha square face and I picture him being kind of irritated or mad,then the woman, I see her in a light coloured dress that has likeflowers on it, I think I see flowers on it and stuff, and I see like a big red punch thing down the front of them, can see that. Her hair hadn’t turned grey yet, it was still dark, it was brown.

Implanting False Memories

• What about implausible or impossible events?– Participants who viewed an advertisement for Disney

World that included an image of Bug Bunny were significantly more likely to recall meeting Bugs during a trip to the theme park (Braun, Ellis, & Loftus, 2002).

• Many of the participants who falsely remembered the event recalled specific details including shaking hands or hugging Bugs.

– Participants presented with articles and testimony about demonic possession where more confident that they had witnessed such an event as a child (Mazzoni, Loftus, & Kirch, 2001).

Implanting False Memories

• Frenda, Knowles, Saletan, and Loftus (2012)– What did they do?

– What did they find?