Cognitive Psychology Chapter 8

Cabeza et al. (2004)

A brain-scanning study that illustrates a difference between autobiographical memory and laboratory memory. Cabeza measured the brain activation caused by two sets of stimulus photographs—one set that the participant took and another set that was taken by someone else. A few days later they saw the own-photos and the lab-photos they had seen before, along with some new lab-photos they had never seen. As participants indicated whether each stimulus was an own-photo, a lab-photo they had seen before, or a new lab-photo, their brain activity was measured in an fMRI scanner. The brain scans showed that own-photos and lab-photos activated many of the same structures in the brain—mainly ones like the medial temporal lobe (MTL) that are associated with episodic memory, as well as an area in the parietal cortex involved in processing scenes. But in addition, the own-photos caused more activation in the prefrontal cortex, which is associated with processing information about the self, and in the hippocampus, which is involved in recollection. Thus, the pictures of a particular location that people took themselves elicited memories presumably associated with taking the picture and, therefore, activated a more extensive network of brain areas than pictures of the same location that were taken by someone else. This activation reflects the richness of experiencing autobiographical memories.

Real-World Knowledge and Memory: Bartlett's "War of Ghosts" Experiment

A classic study that illustrates the effect of knowledge on memory. Bartlett had his participants read a story from Canadian Indian folklore. After his participants had read this story, Bartlett asked them to recall it as accurately as possible. He then used the technique of repeated reproduction, in which the participants tried to remember the story at longer and longer intervals after they had first read it. At longer times after reading the story, most participants' reproductions of the story were shorter than the original and contained many omissions and inaccuracies. But what was most significant about the remembered stories is that they tended to reflect the participant's own culture. One way to think about what happened in Bartlett's experiment is that his participants created their memories from two sources. One source was the original story, and the other was what they knew about similar stories in their own culture. As time passed, the participants used information from both sources, so their reproductions became more like what would happen in Edwardian England. This idea that memories can be comprised of details from various sources is related to source monitoring.

Misidentification Due to Familiarity: Ross et al. (1994)

A laboratory experiment on familiarity and eyewitness testimony. Participants in the experimental group saw a film of a male teacher reading to students; participants in the control group saw a film of a female teacher reading to students. Participants in both groups then saw a film of the female teacher being robbed and were asked to pick the robber from a photo spread. The photographs did not include the actual robber, but did include the male teacher, who resembled the robber. The results indicate that participants in the experimental group, who had seen the male reading to the students, were three times more likely to pick the male teacher than were participants in the control group. Even when the actual robber's face was included in the photo spread, 18 percent of participants in the experimental group picked the teacher, compared to 10 percent in the control group. This is another example of how familiarity can result in errors of memory.

Schemas and Scripts

A schema is a person's knowledge about some aspect of the environment. We develop schemas through our experiences in different situations. A script is our conception of the sequence of actions that usually occurs during a particular experience.

Are Flashbulb Memories Different from Other Memories?

An experiment in which a group of college students were asked a number of questions on September 12, 2001, the day after the terrorist attacks involving the World Trade Center, the Pentagon, and Flight 93 in Pennsylvania (Talarico & Rubin, 2003). Some of these questions were about the terrorist attacks. Others were similar questions about an everyday event in the person's life that occurred in the days just preceding the attacks. After picking the everyday event, the participant created a two-or three-word description that could serve as a cue for that event in the future. Some participants were retested 1 week later, some 6 weeks later, and some 32 weeks later by asking them the same questions about the attack and the everyday event. One result of this experiment was that the participants remembered fewer details and made more errors at longer intervals after the events, with little difference between the results for the flashbulb and everyday memories. Thus, details fade for flashbulb memories, just as they do for everyday memories.

Brewer and Treyen (1981)

An experiment that studied how memory is influenced by people's schemas. Participants who had come to participate in a psychology experiment were asked to wait in an office while the experimenter checked "to make sure that the previous hour's participant had completed the experiment." After 35 seconds, the participants were called into another room and were told that the purpose of the experiment was to test their memory for the office and that their task was to write down what they had seen while they were sitting in the office. The participants responded by writing down many of the things they remembered seeing, but they also included some things that were not there but that fit into their "office schema." For example, although there were no books in the office, 30 percent of the participants reported having seen books. Thus, the information in schemas can provide a guide for making inferences about what we remember.

Source Monitoring and MPI: Lindsay (1990)

Asked whether participants who are exposed to MPI really believe they saw something that was only suggested to them. Lindsay's participants first saw a sequence of slides showing a maintenance man stealing money and a computer. This slide presentation was narrated by a female speaker, who simply described what was happening as the slides were being shown. The participants were then divided into two groups. Participants in the difficult condition heard a misleading narrative shortly after seeing the slide presentation. This narrative was read by the same female speaker who had described the slide show. Two days later, participants returned to the lab for a memory test on the slide show. Just before the test, they were told that there were errors in the narrative story that they heard right after the slide show and that they should ignore the information in the story when taking the memory test. Participants in the easy condition also heard the misleading story, but it was delayed for 2 days after the slide presentation, being presented right before they took the memory test. In addition, the story was read by a male speaker. As with the difficult group, these participants were also told to ignore the information presented in the misleading narrative.

Flashbulb Memories Are Not Like Photographs

Brown and Kulik's idea that flash-bulb memories are like a photograph was based on their finding that people were able to describe in some detail what they were doing when they heard about highly emotional events like the assassinations of John F. Kennedy and Martin Luther King, Jr. But the procedure Brown and Kulik used was flawed because their participants weren't asked what they remembered until years after the events had occurred. The problem with this procedure is that there was no way to determine whether the reported memories were accurate. The only way to check for accuracy is to compare the person's memory to what actually happened or to memory reports collected immediately after the event.

Jacoby et al. (1989)

Demonstrated a connection between source monitoring errors and familiarity by testing participants' ability to distinguish between famous and non-famous names. In the acquisition part of the experiment, Jacoby had participants read a number of made-up non-famous names. For the immediate test group, participants were tested immediately after seeing the list of non-famous names. They were told to pick out the names of famous people from a list containing (1) the non-famous names they had just seen, (2) new non-famous names that they had never seen before, and (3) famous names. Just before this test, participants were reminded that all of the names they had seen in the first part of the experiment were non-famous. Because the test was given shortly after the participants had seen the first list of non-famous names, they correctly identified most of the old non-famous names as being non-famous. The interesting result occurred for participants in the delayed test group, who were tested 24 hours after first seeing the names and, as for the other group, were told that the names they had seen in the first part of the experiment were non-famous. When tested after this delay, participants were more likely to identify the old non-famous names as being famous. This is a source monitoring problem, because to answer this question you need to determine the source of your familiarity. Are you familiar with the name Sebastian Weissdorf because you saw it 24 hours earlier or because it is the name of a famous person?

Neisser and Harsch (1992)

Did a study in which they asked participants how they had heard about the explosion of the space shuttle Challenger. Participants in Neisser and Harsch's experiment filled out a questionnaire within a day after the explosion, and then filled out the same questionnaire 2 1/2 to 3 years later. Responses in which participants first reported hearing about the explosion in one place, such as a classroom, and then later remembered that they had first heard about it on TV, were common. Right after the explosion, only 21 percent of the participants indicated that they had first heard about it on TV, but 2 1/2 years later, 45 percent of the participants reported that they had first heard about it on TV. Reasons for the increase in TV memories could be that the TV reports become more memorable through repetition and that TV is a major source of news. Thus, memory for hearing about the Challenger explosion had a property that is also a characteristic of memory for less dramatic, everyday events: It was affected by people's experiences following the event and their general knowledge.

Bower et al. (1979)

Did an experiment in which participants were asked to remember short passages about going to a dentist, a doctor, etc. After a delay period, the participants were given the titles of the stories they had read and were told to write down what they remembered about each story as accurately as possible. The participants created stories that included much material that matched the original stories, but they also included material that wasn't presented in the original story but is part of the script for the activity described.

Cultural Life Script Hypothesis

Distinguishes between a person's life story, which is all of the events that have occurred in a person's life, and a cultural life script, which is the culturally expected events that occur at a particular time in the life span. Berntsen and Rubin (2004) asked people to list when import-ant events in a typical person's life usually occur, some of the more common responses were falling in love (16 years), college (22 years), marriage (27 years), and having children (28 years). Interestingly, a large number of the most commonly mentioned events occur during the period associated with the reminiscence bump. This doesn't mean that events in a specific person's life always occur at those times, but according to the cultural life script hypothesis, events in a person's life story become easier to recall when they fit the cultural life script for that person's culture.

Emotion and Memory Consolidation

Emotion has also been linked to improved memory consolidation, the process that strengthens memory for an experience and takes place over minutes or hours after the experience. The link between emotion and consolidation was initially suggested by animal research, mainly in rats, that showed that central nervous system stimulants administered shortly after train-ing on a task can enhance memory for the task. Research then determined that hormones such as the stimulant cortisol are released during and after emotionally arousing stimuli like those used in the testing task. These two findings led to the conclusion that stress hormones released after an emotional experience increase consolidation of memory for that experience.

Why Do People Make Errors in Eyewitness Testimony?

Eyewitness testimony is testimony by someone who has witnessed a crime. The acceptance of eyewitness testimony is based on two assumptions: (1) the eyewitness was able to clearly see what happened; and (2) the eyewitness was able to remember his or her observations and translate them into an accurate description of the perpetrator and what happened. Witness descriptions are often not very accurate, unless carried out under ideal conditions.

False Recall and Recognition

False memories arise from the same constructive process that produces true memories. Thus, construction can cause memory errors, while at the same time providing the creativity that enables us to do things like understand language, solve problems, and make decisions.

Proust Effect

How taste and olfaction can unlock memories we haven't thought of for years. Participants who smelled the odor rated their memories as more emotional than participants who saw the picture. They also had a stronger feeling than the visual group of "being brought back" to the time the memory occurred.

Yay!

I wanted a 50th flashcard because 49 is an unnecessarily ugly number :D

Loftus et al. (1978)

Illustrates a typical MPI procedure. Participants saw a series of slides in which a car stops at a stop sign and then turns the corner and hits a pedestrian. Some of the participants then answered a number of questions, including ones like, "Did another car pass the red Ford while it was stopped at the stop sign?" For another group of participants (the MPI group), the words "yield sign" replaced "stop sign" in the question. Participants were then shown pictures from the slide show plus some pictures they had never seen. Those in the MPI group were more likely to say they had seen the picture of the car stopped at the yield sign (which, in actuality, they had never seen) than were participants who had not been exposed to MPI. This shift in memory caused by MPI demonstrates the misinformation effect.

Flashbulb Memories

In referring to the day of President Kennedy's assassination, Brown and Kulik stated that "for an instant, the entire nation and perhaps much of the world stopped still to have its picture taken." This description, which likened the process of forming a memory to the taking of a photograph, led them to coin the term flashbulb memory to refer to a person's memory for the circumstances surrounding shocking, highly charged events. It is import-ant to emphasize that the term flashbulb memory refers to memory for the circumstances surrounding how a person heard about an event, not memory for the event itself. Therefore, flashbulb memories give importance to events that otherwise would be unexceptional. Brown and Kulik argued that there is something special about the mechanisms responsible for flashbulb memories. Not only do they occur under highly emotional circumstances, but they are remembered for long periods of time and are especially vivid and detailed. Brown and Kulik described the mechanism responsible for these vivid and detailed memories as a "Now Print" mechanism, as if these memories are like a photograph that resists fading.

What Is It Like to Have "Exceptional" Memory?

It is not necessarily an advantage to be able to remember everything; in fact, the mechanisms that result in superior powers of memory may work against the constructive processes that are an important characteristic not only of memory but of our ability to think creatively. Moreover, storing everything that is experienced is an inefficient way for a system to operate because too much storage can overload the system. To avoid this "overload," our memory system is designed to selectively remember things that are particularly important to us or that occur often in our environment. Although the resulting system does not record everything we experience, it has operated well enough to enable humans to survive as a species.

Construction of Memory

Memories are created by a process of construction, in which what actually happened, other things that happened later, and our general knowledge about how things usually happen are combined to create our memory of an event.

Music-Enhanced Autobiographical Memories

Memories elicited by hearing music. These MEAMS are often experienced as being involuntary memories, because they occur as an automatic response to a stimulus. This is in contrast to memories that require a conscious retrieval process. High emotionality and detail have been observed for music-elicited autobiographical memories.

Multidimensional Nature of Autobiographical Memory

Memories extend beyond vision, hearing, touch, taste, and smell. They also have spatial components, because events usually take place in a three-dimensional environment. Memories often involve thoughts and emotions, both positive and negative. All this is a way of saying that memories are multidimensional, with each dimension playing its own, often important, role in the memory. The importance of individual components is illustrated by the finding that patients who have lost their ability to recognize or visualize objects, because of damage to the visual area of their cortex, can experience a loss of autobiographical memory. This may have occurred because visual stimuli were not available to serve as retrieval cues for memories. But even memories not based on visual information are lost in these patients. Apparently, visual experience plays an important role in autobiographical memory.

Making Inferences

Memory reports can be influenced by inferences that people make based on their experiences and knowledge. Brewer (1977) and McDermott and Chan (2006) presented participants with a similar task, involving many more sentences and found that errors occurred for about a third of the sentences.

Misinformation Effect

Misleading information presented after a person witnesses an event can change how the person describes that event later.

Nostalgia

Nostalgia is defined as a memory that involves a sentimental affection for the past.

Pragmatic Inference

Occurs when reading a sentence leads a person to expect something that is not explicitly stated or implied by the sentence. These inferences are based on knowledge gained through experience.

Creating Memories for Events in People's Lives: Creating Childhood Memories

People can be led to believe that they experienced something in their childhood that never actually happened.

Why Do People Think FBM are special?

People's memories for flashbulb events remain more vivid than everyday memories, and people believe that flashbulb memories remain accurate, while everyday memories don't. Thus, we can say that flashbulb memories are both special (vivid; likely to be remembered) and ordinary (may not be accurate) at the same time. Another way of noting the specialness of flashbulb memories is that people do remember them—even if inaccurately—whereas less noteworthy events are less likely to be remembered.

Loftus and Palmer (1974)

Presentation of MPI can alter not only what participants report they saw, but their conclusions about other characteristics of the situation. Showed participants films of a car crash and then asked either (1) "How fast were the cars going when they smashed into each other?" or (2) "How fast were the cars going when they hit each other?" Although both groups saw the same event, the average speed estimate by participants who heard the word "smashed" was 41 miles per hour, whereas the estimates for participants who heard "hit" averaged 34 miles per hour. Even more interesting for the study of memory are the participants' responses to the question "Did you see any broken glass?" which Loftus asked 1 week after they had seen the film. Although there was no broken glass in the film, 32 percent of the participants who heard "smashed" before estimating the speed reported seeing broken glass, whereas only 14 percent of the participants who heard "hit" reported seeing the glass.

Source Monitoring and Source Monitoring Errors

Process of determining the origins of our memories, knowledge, or beliefs is called source monitoring. Misidentifying the source of a memory is called a source monitoring error. Source monitoring errors are also called source misattributions because the memory is attributed to the wrong source. Source monitoring provides an example of the constructive nature of memory because when we remember something, we retrieve the memory and then determine where that memory came from. Source monitoring errors are common, and we are often unaware of them.

Cognitive Hypothesis

Proposes that periods of rapid change that are followed by stability cause stronger encoding of memories. Adolescence and young adulthood fit this description because the rapid changes, such as going away to school, getting married, and starting a career, that occur during these periods are followed by the relative stability of adult life. One way this hypothesis has been tested is by finding people who have experienced rapid changes in their lives that occurred at a time later than adolescence or young adulthood. The cognitive hypothesis would predict that the reminiscence bump should occur later for these people. Reminiscence bump occurs at the normal age for people who emigrated at age 20 to 24 but is shifted to later for those who emigrated at age 34 or 35. Late emigration eliminates the stable period that usually occurs during early adulthood. Because early adulthood isn't followed by a stable period, no reminiscence bump occurs.

What Is Being Done to Improve Eyewitness Testimony?: Lineup Procedures

Recommendation 1: When asking a witness to pick the perpetrator from a lineup, inform the witness that the perpetrator may not be in the particular lineup he or she is viewing. This is important because when a witness assumes that the perpetrator is in the lineup, this increases the chances that an innocent person who looks similar to the perpetrator will be selected. Recommendation 2: When constructing a lineup, use "fillers" who are similar to the suspect. Recommendation 3: Use a "blind" lineup administrator—someone who doesn't know who the suspect is. This reduces the chances that the expectations of the person administer-ing the lineup will bias the outcome. Recommendation 4: Have witnesses rate their confidence immediately—as they are making their identification.

Youth Bias (Koppel and Bernsten, 2014)

Tendency for the most notable public events in a person's life to be perceived to occur when the person is young. They reached this conclusion by asking people to imagine a typical infant of their own culture and gender, and by posing the follow-ing question: ". . . throughout this person's life many important public events will take place, both nationally and internationally, such as wars, the deaths of public figures, and sporting events. How old do you think this person is most likely to be when the event that they consider to be the most important public event of their lifetime takes place?" Most of the responses indicated that the person would perceive most important public events to occur before they were 30. Interestingly, this result occurred when polling both young and older people, and the curves peak in the teens and 20s, just like the reminiscence bump. It is likely that each of the mechanisms we have described makes some contribution to creating the reminiscence bump.

Reminiscence Bump

The enhanced memory for adolescence and young adulthood found in people over 40 is called the reminiscence bump.

Illusory Truth Effect

The enhanced probability of evaluating a statement as being true upon repeated presentation is called the illusory truth effect. Why does repetition increase perceived truthfulness? An answer proposed is that fluency—the ease with which a statement can be remembered—influences people's judgments. Thus, knowledge stored in memory is important (participants are more likely to rate true statements as true), but fluency or familiarity can affect the judgments as well.

Memory and Emotion

The idea that emotions are associated with better memory has some support. In one experiment on the association between emotion and enhanced memory, LaBar and Phelps (1998) tested participants' ability to recall arousing words (for example, profanity and sexually explicit words) and neutral words (such as street and store), and observed better memory for the arousing words. In another study, Dolcos and coworkers (2005) tested participants' ability to recognize emotional and neutral pictures after a 1-year delay and observed better memory for the emotional pictures.

Narrative Rehearsal Hypothesis

The idea that memory can be affected by what happens after an event is the basis of Neisser and coworkers (1996) narrative rehearsal hypothesis, which states that we may remember events like those that happened on 9/11 not because of a special mechanism but because we rehearse these events after they occur. The narrative rehearsal hypothesis makes sense when we consider the events that followed 9/11. Pictures of the planes crashing into the World Trade Center were replayed endlessly on TV, and the event and its aftermath were covered extensively for months afterward in the media. Neisser argues that if rehearsal is the reason for our memories of significant events, then the flashbulb analogy is misleading.

Error Due to Suggestion

The problem with the police officer's question is that it implies that the perpetrator is in the lineup. This suggestion increases the chances that the witness will pick someone. A better way of presenting the task is to let the witness know that the crime suspect may or may not be in the lineup. Increase in confidence due to confirming feedback after making an identification the post-identification feedback effect. This effect creates a serious problem in the criminal justice system, because jurors are strongly influenced by how confident eyewitnesses are about their judgments. Thus, faulty eyewitness judgments can result in picking the wrong person, and the post-identification feedback effect can then increase witnesses' confidence that they made the right judgment. The fact that memories become more susceptible to suggestion during questioning means that every precaution needs to be taken to avoid making suggestions to the witness. This is often not done, but some steps have been taken to help improve the situation.

Results of Lindsay (1990)

The procedure for the difficult condition made it easy to confuse the misleading narrative and the narrated slide show because they occurred one after the other and were both read by the female. The results indicated that 27 percent of the responses of participants in the difficult condition matched the incorrect information that was presented in the misleading narrative. However, in the easy condition, it was easy to separate the misleading narrative from the slide show because they occurred 2 days apart and were read by different speakers. Only 13 percent of the responses for participants in the easy condition matched the misleading narrative. Source monitoring errors (including information from the misleading narrative) were therefore larger in the condition in which it was more difficult to tell the difference between the information presented in the slide show and the misleading narrative.

Self-Image Hypothesis

The self-image hypothesis proposes that memory is enhanced for events that occur as a person's self-image or life identity is being formed. This idea is based on the results of an experiment in which participants with an average age of 54 created "I am" statements, such as "I am a mother" or "I am a psychologist," that they felt defined them as a person. When they then indicated when each statement had become a significant part of their identity, the average age they assigned to the origin of these statements was 25, which is within the span of the remi-niscence bump. When participants also listed events that were connected with each state-ment (such as "I gave birth to my first child" or "I started graduate school in psychology"), most of the events occurred during the time span associated with the reminiscence bump. Development of the self-image therefore brings with it numerous memorable events, most of which happen during adolescence or young adulthood.

Repeated Recall

The technique of comparing later memories to memories collected immediately after the event is called repeated recall. The idea behind repeated recall is to determine whether memory changes over time by testing participants a number of times after an event. The person's memory is first measured immediately after a stimulus is presented or something happens. Even though there is some possibility for errors or omissions immediately after the event, this report is taken as being the most accurate representation of what happened and is used as a baseline. Days, months, or years later, when participants are asked to remember what happened, their reports are compared to this baseline. This use of a baseline provides a way to check the consistency of later reports. Research using the repeated recall task has shown that flashbulb memories are not like photographs. Unlike photographs, which remain the same for many years, people's memories for how they heard about flashbulb events change over time. In fact, one of the main findings of research on flashbulb memories is that although people report that memories surrounding flash-bulb events are especially vivid, they are often inaccurate or lacking in detail.

Misleading Post-Event Information (MPI)

The usual procedure in an experiment in which MPI is presented is to first present the stimulus to be remembered. For example, this stimulus could be a list of words or a film of an event. The MPI is then presented to one group of participants before their memory is tested and is not presented to a control group. MPI is often presented in a way that seems natural, so it does not occur to participants that they are being misled. However, even when participants are told that post-event information may be incorrect, presenting this information can still affect their memory reports. The effect of MPI is determined by comparing the memory reports of participants who received this misleading information to the memory reports of participants who did not receive it.

Cahil et al. (2003)

They showed participants neutral and emotionally arousing pictures; then hey had some participants (the stress group) immerse their arms in ice water, which causes the release of cortisol, and other participants (the no-stress group) immerse their arms in warm water, which is a non-stressful situation that doesn't cause cortisol release. When asked to describe the pictures a week later, participants who had been exposed to stress recalled more of the emotionally arousing pictures than the neutral pictures. There was no significant difference between the neutral and emotionally arousing picture for the no-stress group. What is particularly interesting about these results is that the cortisol enhances memory for the emotional pictures but not for the neutral pictures. Results such as these have led to the conclusion that hormone activation that occurs after arousing emotional experiences enhances memory consolidation in humans.

Errors of Eyewitness Identification

This assumption about the accuracy of testimony is based on the popular conception that memory works like a camera or video recorder, as demonstrated by the results of the nationwide survey described at the beginning of this chapter. Jurors carry these misconceptions about the accuracy of memory into the courtroom, and many judges and law enforcement officials also share these misconceptions about memory. So, the first problem is that jurors don't understand the basic facts about memory. Another problem is that the observations on which witnesses base their testimony are often made under the less than ideal conditions that occur at a crime scene, and then afterward, when they are talking with the police.

Cryptoamnesia

Unconscious plagiarism of the work of others.

What Is Being Done to Improve Eyewitness Testimony?: Interviewing Techniques

We have already seen that making suggestions to the witness ("Good, you identified the suspect") can cause errors. To avoid this problem, cognitive psychologists have developed an interview procedure called the cognitive interview, which involves letting the witness talk with a minimum of interruption and also uses techniques that help witnesses recreate the situation present at the crime scene by having them place themselves back in the scene and recreate things like emotions they were feeling, where they were looking, and how the scene might have appeared when viewed from different perspectives. An important feature of the cognitive interview technique is that it decreases the likelihood of any suggestive input by the person conducting the interview.

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.

Emotions and the Amygdala

When we look at what is happening physiologically, one structure stands out: the amygdala. The importance of the amygdala has been demonstrated in a number of ways. For example, in the experiment by Dolcos and coworkers, brain scans using fMRI as people were remembering revealed that amygdala activity was higher for the emotional words. The link between emotions and the amygdala was also demonstrated by testing a patient, B.P., who had suffered damage to his amygdala. When participants without brain damage viewed a slide show about a boy and his mother in which the boy is injured halfway through the story, these participants had enhanced memory for the emotional part of the story (when the boy is injured). B.P.'s memory was the same as that of the non-brain-dam-aged participants for the first part of the story, but it was not enhanced for the emotional part (Cahill et al., 1995). It appears, therefore, that emotions may trigger mechanisms in the amygdala that help us remember events associated with the emotions.

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. Emotions often run high during commission of a crime, and this can affect what a person pays attention to and what they remember later. In a study of weapons focus, the tendency to focus attention on a weapon that results in a narrowing of attention, Stanny and Johnson (2000) determined how well participants remembered details of a filmed simulated crime. They found that participants were more likely to recall details of the perpetrator, the victim, and the weapon in the "no-shoot" condition (a gun was present but not fired) than in the "shoot" condition (the gun was fired). Apparently, the presence of a weapon that was fired distracted attention from other things that were happening.