❃ Cognitive Psych Exam 4 ❃
Summary: A Quote from the Loftus Talk
" Just because somebody tells you something and they say it with confidence, just because they say it with lots of detail, just because they express emotion when they say it...it doesn't mean that it really happened. We can't reliably distinguish true memories from false memories, and we really need *independent* *corroboration*."
Wason Selection Task
(1) A minimum of how many cards do you need to flip to verify the validity of the following rule?: "If a card has a vowel on one side, =P, then it has an even number on the other side" = Q ◦ To apply modus ponens (P --> Q) ◦ To apply modus tollens (~Q --> ~P) (2) Which cards would you actually flip to check the rule? --> E card (P) & 7 card(~Q) ❃ Typical Patterns: ◦ many people pick the E card (modus ponens applied) and the 4 card (affirming the consequent applied) --> people often make invalid inferences ◦ People find it difficult to apply modus tollens
Silveira found that subjects in (a)________ performed BEST in solving the Cheap Necklace problem, thus (b)________ the so-called incubation effect in her study.
(a) Group 3 (A 4-hr interruption in the middle); (b) successfully demonstrating
Which of the following statements about experts' and novices' knowledge and problem solving behaviors is TRUE?
(a) Physics experts classify problems according to guiding principles, whereas novices do so on the basis of surface-level features; (b) Chess experts can remember chess board configurations better than novices, but only when they are asked to remember the configurations from actual chess games
A dog says, "All cats have four legs. I have four legs. Therefore I am a cat." This is an example of (a) ________ reasoning. Obviously, the dog's reasoning is (b) ________.
(a) deductive; (b) invalid
According to formal logic, which forms of reasoning are considered to be INVALID (or reasoning fallacies)?
(a) denial of the antecedent (b) affirmation of the consequent
The results of the ZAPS False Memory experiment discussed during the 03/19 (T) lecture were generally consistent with what was expected on the basis of previous research (e.g., Roediger & McDermott's original false memory study). However, the "false alarm" rate (i.e., the rate of incorrectly saying "yes") for the target "lure" word (e.g, "SLEEP") was much (a)________ than expected, perhaps because, knowing that this is an experiment on false memory, participants (= you) likely used a rather (b)________ response criterion in saying "yes" to various candidate words presented on each trial.
(a) lower; (b) conservative
You are being tested on Wason's 2-4-6 task. Suppose that your current hypothesis about the underlying rule is that all three digits must be even and that the sequence takes the form of "x, x+2, x+4." If you want to avoid demonstrating a confirmation bias in this situation, which of the following digit sequences should you NOT produce?
(b) 3-5-7 (c) 100-102-104
Source 2: Influences from Schemas (Schemata) and Scripts leading to false memory
* Both are types of semantic memory (general knowledge) • *Schema* = general knowledge about what is typical in a *situation/object* • *Script*= general knowledge about what is typical in an *event/episode* --> Examples of schema: Your knowledge of objects that are typically present in a professor's office or in a kitchen --> Example of scripts: Your knowledge of the sequence of events that usually take place in a restaurant or at the airport
What are the basic rules featured in a technique known as cognitive interview for eliciting information from eyewitnesses?
* Encouraging the reporting of every detail, regardless of how trivial it might seem * Describing the incident in several different orders * Mental (or even physical) reinstatement of the crime scene/experience before recall
Which of the following statements applies to the results of research on differences between how experts and novices solve problems?
* Experts possess more knowledge about their fields than novices. * Experts often group problems differently than novices, based on principles. * Experts often get off to a slower start than novices because they do not necessarily jump in to start solving the problem right away.
Which of the following phenomena CAN easily be interpreted as an illustration of the idea that human memory is reconstructive?
* In a video segment shown in class, after seeing a series of photographs depicting different objects, the host, Alan Alda, incorrectly remembered that a bottle of water was in the picnic scene he witnessed earlier, even though it was only in the photographs he saw * In an in-class demo involving verbatim recall of short sentences, many people accidentally used semantically related words (e.g., "castle" instead of "palace") in their recall, which were presented as part of an additional list of words to remember
Which of the following statements are TRUE?
* Memory connections can both help and hurt memory accuracy. * When events are misremembered, they tend to be remembered as more normal, or more consistent with expectations, than they actually were. * The greater the density of connections that are associated with a particular episode, the more likely it is that intrusion errors will occur.
Which of the following is TRUE about autobiographical memories?
* Recollection is better for memories that seem more directly relevant to the self. * When an event is forgotten, reconstruction tends to favor seeing the self in a positive light. *Reconstruction of past events will often be consistent with current views of the self.
Which of the following statements is true regarding SCRIPTS?
* Scripts are a type of semantic memory * Scripts can be a source of memory distortions * Because of scripts, we do not have to mention all the relevant steps involved in a particular event (e.g., going to a restaurant) in everyday conversations
Based on current knowledge, which of the following are the most well-established reasons for a traumatic childhood memory to come to light after many years?
* There was retrieval failure, but a cue finally appeared that triggered the memory. * The memory was consciously remembered all along, but it was not talked about before. * The memory is false and was created, probably with the help of suggestion from an outside party.
Which of the following is true of the "narrowing" of focus that is often found in memories of emotional events?
* the narrowing is a product of attention; when you focus your attention, your memory ends up similarly focused. * Emotion can actually have a negative effect on your memory for the non-central aspects of an event. * Different emotions may be associated with different behavioral goals, and this may affect your attention.
Which of the following would be due to schemata?
*INFO* *FROM* *SCHEMA* *CHANGES* *DETAILS* * Participants remember seeing books on the shelves in an academic office even when there were none. * When people give accounts of past events, they are easily able to fill in the holes in their memory by making inferences, which are usually correct. * During recall of a story taken from the folklore of Native Americans, British participants systematically change the facts to be more in line with their worldview.
What is the best problem solving approach for getting an A in a course?
*Ill-defined* problem solving
What statements pertaining to the overall state of memory is TRUE?
*Some forgetting is beneficial because it allows us to generalize. * Schemata allow us to direct our attention more efficiently so that we can encode more useful memories. *There are principles that apply to all of memory, as well as principles that apply only to specific sorts of memory.
Source 1: Automatically activation of related concepts leading to false memory
*Word recall task (ZAPS False Memory) • "Lure" words (e.g., "sleep") were strongly activated *Sentence recall task • Semantically similar concepts can also intrude into your memory (e.g., "palace" à "castle")
Sources of Failures in Problem Solving: B) Inappropriate Mental Set and Functional Fixedness
1) *Mental-Set*: a preconceived notion about how to approach a problem based on a person's experience or what has worked in the past (more general*) ◦ The tendency to keep using a non-optimal strategy based on previous successful experiences (ex: #'s ordered in alphabetical order- 8,5,4,9,1,7,6,3,2,0) ◦ Famous EX: Luchin's *water-jar* problem (relates to gestalt psychology) 2) *Functional-Fixedness*: an effect that occurs when the ideas a person has about an objects function inhibits the person's ability to use the object for a different function (about a *specific* object's function) ◦ Difficulty in seeing alternative uses for common objects ◦ EX: using a shoehorn as a spoon to eat soup ◦ Famous EX: the "two strings" problem *BOTH* *are* *about* *MENTAL* *RIGIDITY*
Sources of Failures in Problem Solving: A) Failure to select/use appropriate heuristics
1) Generate & Test: is highly complex and/or has many possible options (ex; figuring out a 4 digit passcode) 2) Hill climbing: requires you to temporarily move *away* from the goal state (ex; tower of hanoi puzzle) 3) Means-ends Analysis: requires you to create and keep track of many subgoals (or use pen/paper to overcome working memory limitations) making it more demanding/ difficult to keep track of many different goals (ex; missionaries & cannibals puzzle) 4) Working Backwards: (a) has many paths leading to the goal state and (b) there are many intervening steps between the initial and goal states (ex: water lily puzzle)
Two Important Distinctions in Problem Solving
1) The nature of the problem space ◦ Well-defined vs. ill-defined problems 2) The nature of the problem solving process ◦ Algorithm vs. heuristics
Which of the following are characteristics distinguishing experts in a particular domain from novices?
1. Experts have more automatized routines to deal with different types of problems. 2. Experts have more knowledge than novices in their domain of expertise. 3. Experts organize their knowledge more effectively.
Seven Sins of Memory (according to Schacter, 2002)
1. Transience 2. Absentmindedness 3. Blocking 4. Source misattribution 5. Suggestibility 6. Bias 7. Persistence
Different Sources of False Memories
A. *Semantic memory* ◦ Automatically activation of related concepts ◦ Schemas & scripts B. *Episodic* *memory* ◦ Errors due to inaccurate/insufficient initial encoding ◦ Errors due to familiarity ◦ Errors due to suggestion --> *highly* *relevant* to *eyewitness* *testimony*
Why do people make errors in eyewitness testimony?
A. Errors associated with perception and attention ◦ inaccurate/insufficient encoding (eyewitness ID demo) ◦ The *weapon* *focus* effect; the tendency to focus on a weapon can result in a narrowing of attention -- often due to strong emotional reactions -- the presence of a weapon decreases the recall of all aspects of the crime scene
Summary: Why do people make errors in eyewitness testimony?
A. Errors associated with perception and attention ◦ Inaccurate or insufficient encoding ◦ The weapon focus effect B. Misidentifications due to familiarity ◦ Familiarity --> source confusion C. Errors due to suggestion ◦ The misinformation effect ◦ Development of fully fleshed out false memories
What are the main sources of failures or difficulties in problem solving?
A. Failure to select/use appropriate heuristics B. Inappropriate mental set and functional fixedness C. Incorrect or incomplete representations of the problem D. Lack of relevant domain-specific knowledge
Which of the following "false memory" results discussed during the 03/19 (T) lecture can be considered memory errors that primarily reflect the contributions of SEMANTIC memory processes?
A. Falsely recalling the word "sleep" after hearing/seeing a list of words all related to the concept of "sleep" (e.g., "awake," "snooze") B. Falsely using the word "castle" (instead of "palace") in the verbatim recall of a short sentence ("The knight rode around the palace searching for a place to enter")
Why do people make errors in eyewitness testimony?
B. Misidentification due to familiarity ◦ A vague sense of familiarity w/o conscious recollection can lead to misidentification (--> *source* *confusion*) -- Steve Titus's case -- Ross et al. 1994 study
Why do people make errors in eyewitness testimony?
C. Erros due to suggestion ◦ *Suggestion* can lead to elaborate false memories ◦ The *misinformation* effect -- subsequent events can contaminate memory -- related tot the picnic scene false memory demo
Which of the following statements is true about creativity?
Creativity may result from the correct combination of ordinary processes and personal characteristics. * FEEDBACK: Creativity can involve a combination of ordinary processes that are brought together in a novel manner, by a person with a set of helpful characteristics.
__________ intelligence, or acquired knowledge, increases with age, while __________ intelligence, which is flexibility of thought, peaks in early adulthood and then declines.
Crystallized; fluid
Which of the following statements about the "reconstructive" nature of human memory is TRUE?
Each time we recall an event from LTM, we assemble relevant bits and pieces of information stored in different parts of the brain and reconstruct that episode
Overview of Thinking/Problem solving: A Running Theme
Human thinking often operates on the basis of *rules* *of* *thumb* and frequently deviates from ideal or *fail-safe* procedures
Is this an example of Valid or Invalid inference? What type of reasoning is this called? If i start exercising today, I will be able to lose 10 pounds in 2 months. I did not start exercising today, therefore, I will not be able to lose 10 pounds in 2 months.
Invalid inference; Denial of the antecedent (b/c you are denying the initial portion)
Which of the following statements about memory over the lifespan is most accurate?
Most adults have particularly clear and detailed memories of their late teens and 20s
"If a person is drinking a beer, then the person must be over 21 years old." Subjects are asked to test this rule using information on four cards; each card has a person's beverage on one side and the person's age on the other. The four cards are now presented as follows: "beer," "coke," "19 years old," and "22 years old." Which of the following describes the behavior of most college students who complete this variation of the four-card task?
Most people correctly turn over the "beer" and "19 years old" cards
Which of these features reliably distinguishes false memories from true memories?
Nothing that we know of reliably distinguishes true from false memories --> Results from studies show that true and false memories do not differ in the amount of detail, speed of recall, or level of emotionality. Thus, there is no single characteristic that reliably distinguishes them.
Which of the following observations MOST CLEARLY suggest that participants may be using the "hill climbing" heuristic?
Problem solving often gets stalled if a problem requires participants to move briefly away from the goal state to ultimately to reach the goal
ZAPS False Memory: What might be some of the reasons why the false recognition of the "lure" words was so low in the class data? *KNOW* *FOR* *EXAM*
Relatively conservative response criterion used =general tendency to avoid saying yes b/c you know the procedure is about *false* *memory* so you were more cautious/hesitant in general --> low "false alarms" also low "hits" (therefore results suffered overall accuracy)
What is the main source of false memories for word and sentence recall tasks?
Semantic memory --> due to knowledge of different words &/or synonyms
Which of the following is a good example of a well-defined problem?
Solving the Tower of Hanoi puzzle
*Multiple* heuristics can be applied to the *same* problem even though some heuristics might be more helpful than others for that problem: TRUE or FALSE?
TRUE
According to Loftus, false memories can sometimes have good influences on our behaviors, such as promoting healthy eating.
TRUE
Studies of eyewitness testimony show that witnesses' memories are *very* *sensitive* to minor changes in the wording used during questioning such as the use of " vs. "the".
TRUE
Which of the following statements about creative thought is most likely to be true?
The "aha" experience implies only that we've discovered a new approach to a problem, not that we've discovered the right solution. * FEEDBACK: Studies have revealed that people have "aha" moments even when they answer the question wrong.
In light of the memory sins and the prevelance of false memories, According to Schacter, is human memory is a poorly designed system that comes with serious flaws?
The fact that memory is reconstructive is a good thing. Those sins may simply be some necessary negative side effects that come with the efficiency and malleability of human memory.
A problem-solving set is...
The starting assumptions that a person uses when trying to solve a new problem. These assumptions are often helpful, because they guide the person away from pointless strategies. But these assumptions can sometimes steer the person away from worthwhile strategies, so they can be an obstacle to problem solving. * can make it hard to "think outside the box."
Which of the following statements is the MOST accurate?
There is little or no relation between memory confidence and memory accuracy. --> People can be very confident of memories that are not accurate. The fact that a memory is correct can increase confidence, but this does not affect the accuracy because it comes after the fact.
What is a benefit of problem-solving sets?
They allow you to focus your search. * FEEDBACK: Problem-solving sets narrow the range of options that you consider.
What is the most likely reason why people would have a hard time solving the problem of how to support a candle on a wall?
They had trouble seeing past the most salient functions of the available tools. * FEEDBACK: This is called functional fixedness, which is a state in which people are unable to find new functions for common objects.
Although human memory is malleable, implanting false memories is very difficult *even* when subjects are given advanced warning about it or when they are instructed to memorize info as is (verbatim).
True
Which of the following statements is TRUE regarding eyewitness memory?
When a lineup is used, it is better to present the individuals in the lineup sequentially to the witness (i.e., one by one) than simultaneously (i.e., all at once)
When faced with an ill-defined problem, which of the following is the best first step?
add structure to better define the problem
Consider the following reasoning: "If P, then Q; Q is true; Therefore, P is also true." This reasoning represents an instance of:
affirmation of the consequent
The misinformation effect occurs when a person's memory for an event is modified by misleading information presented ________.
after the event
A food recipe specifies what ingredients are to be added together, in what amounts, in what order, and under what conditions. From the perspective of problem solving, such a recipe would be:
an algorithm
The most likely source of memory errors illustrated by the DRM procedure (ZAPS false memory) is:
automatic activation of related concepts
Loftus's "lost in the mall study" showed that:
bout a quarter (25%) of college students developed detailed false memories of an event that never took place in their childhood
Suppose that you have an assignment to write a review of the literature on a topic in cognitive psychology. If you used means-ends analysis, you would:
break the problem into parts (e.g., select a topic, locate resources, etc.) and then solve each part
According to Silveira's research discussed during the 04/04 (TH) lecture, the incubation effect:
can be best explained by the forgetting of inappropriate mental set or problem-solving approaches
Of the following real-world phenomena, the confirmation bias BEST explains the observation that people
can cite several reasons for their position on a controversial issue but none for the opposing side.
The process through which memories are biologically "cemented in place" is called...
consolidation --> memories acquire some degree of permanence through the creation of new (or altered) neural connections.
Which hypothesis about forgetting points to the fact that over time, relevant brain cells die off and connections between memories gradually weaken?
decay hypothesis --> Decay involves the loss of information over time and hence leads to forgetting.
Consider the following (obviously nonsense) reasoning statement: "If a person has five letters in his or her name, then he or she is a Glirple." Angie reasons that, because he has a four-letter name, Fred cannot possibly be a Glirple. According to formal logic, Angie's reasoning represents a case of ________.
denying the antecedent
Regarding the use of analogies in problem solving....
explicitly using analogies in teaching leads to better use of those analogies by students. * FEEDBACK: Analogies help in problem solving, but students do not tend to use them on their own
Problem-solving heuristics do NOT...
guarantee a feasible solution. * FEEDBACK: Heuristics are fast and efficient but not always accurate. *BUT* they *do*.... ◦ Increase the efficiency of problem-solving strategies. ◦ Strategically decrease the size of the problem space. ◦ Involve a trade-off between accuracy and efficiency.
Suppose you live in WESTERN Massachusetts and need to get to San Francisco to close a business deal by the following night. Because the only available flights are in Boston, you drive EAST to Boston to catch the first flight to San Francisco that morning. This solution, which involves going to EAST first (even though your ultimate goal is to fly WEST), would NOT have been possible if you had exclusively employed a...
hill climbing strategy * FEEDBACK: Hill climbing requires you to go toward your goal at all times. Driving east to go west is moving backward to go forward.
The weapon focus effect illustrates how_____ can lead to memory distortions.
inaccurate/insufficient initial encoding
Many people had difficulty coming up with correct/acceptable solutions for both versions (the 4-straight-lines version and 1-straight-line version) of the Nine-Dot problem. This difficulty MOST LIKELY stems from which of the following stumbling blocks to problem solving?
inappropriate mental set
Some less-than-optimal solutions people generate when working on Luchin's famous "water jar" problem provide a nice illustration of which of the following stumbling blocks to problem solving?
inappropriate mental set
Making probable (but not necessarily certain) conclusions based on evidence involves _______
inductive reasoning
A study found that rugby players' recall of the names of opposing teams suffered based on the number of intervening games, and not based on the mere passage of time. This study demonstrates that...
interference is a major contributor to forgetting --> because it does not matter how much time has passed. All that matters is how many games have already occurred.
Results of the Deese-Roediger-McDermott (DRM) procedure demonstrate that...
intrusion errors based on semantic knowledge --> People are likely to infer that a word was on the list when in fact it was not
Which of the following is likely to INCREASE the intrusion of schematic knowledge in later recall?
making an effort to fill in the gaps in one's memories --> this is likely to increase the use of schemata in order to guess what might have happened.
The strategy whereby one compares the current state to the goal state, often using this information to break a large problem into smaller subproblems, is called
means-end analysis. * FEEDBACK: Means-end analysis involves always assessing how close you are to the goal state.
Earning a degree in psychology can be described as an exercise in problem solving. To finish your degree, you need to complete a number of upper-level courses. To enroll in those courses, you must have successfully completed a course in statistics. But before you can take statistics, you need to have passed an introductory psychology course. This sort of thinking behind achieving your goal illustrates the idea behind the problem solving heuristic known as:
means-ends analysis
Intelligence as measured by IQ is most similar in...
monozygotic (identical) twins.
An ill-defined problem can be defined as a problem for which:
one cannot clearly specify the initial state, the goal state, and/or the available operators
Actions that take the problem from one state to another are known as ________.
operators
What were the performance patterns seen for the vowel/number version and the age/beverage version of Wason Selection Task?
people failed to correctly apply modus tollens for the vowel/even-odd version but did fine with the age/beverage version.
Wallas argued that creative thought proceeds through four stages in which order?
preparation --> incubation --> illumination --> verification
Memories that are not lost within a few years of their acquisition have..
probably achieved a state of relatively permanent storage --> Permanent storage relates to memories that are not likely to be lost.
In the Gick and Holyoak paradigm (1980), participants were required to solve the tumor problem. Those who demonstrated the fastest solution times were the participants who...
read the "general and fortress" solution and were told to apply it to the tumor problem. * FEEDBACK: Analogies work best when the parallels are pointed out.
In the Deese-Roediger-McDermott (DRM) procedure, participants are asked to remember a list of words like "bed, snooze, awake, tired, dream, rest," which are all words concerning the topic of sleep, although the word "sleep" is not on the list. After this procedure, participants...
recall the word "sleep" being on the list even if they were explicitly warned to be careful --> This is a task that is designed to induce false memories by priming a concept that is not explicitly presented.
An intelligence test is __________ if it gives consistent answers on different occasions. It is __________ if it actually measures intelligence.
reliable; valid * FEEDBACK: Measurement reliability involves consistency; measurement validity involves measuring what it claims to measure.
In a basic recall task, participants read a story about a character named Nancy and her behavior at a party. During recall, participants...
remembered more details and made more inferences about the story if they received a prologue giving additional context --> The prologue creates a context, which is then used to generate details, even ones that were not explicitly mentioned in the paragraph.
From our experience, we have extracted information about what is typical or frequent about a particular SITUATION or OBJECT (e.g., what can usually be found in a kitchen). This type of knowledge is often called:
schemas (schemata)
A person's ability on a specific verbal task is likely to be __________ correlated with their ability on a different verbal task, but __________ correlated with their ability on a numerical task.
strongly; less strongly * FEEDBACK: Because of general intelligence (g), most intellectual abilities are positively correlated with each other. However, abilities in the same class of abilities (e.g., linguistic, numerical) are even more highly correlated.
It was starting to rain, and Kevin didn't have an umbrella or a hat. After a few moments of thought, he held his psychology textbook over his head to keep himself dry. Kevin was able to _________.
successfully overcome functional fixedness
The misinformation effect illustrates how ______ can lead to memory distortions.
suggestibility
Studies of eyewitness memory:
support the view that memory is reconstructive in nature
While under hypnosis, people
tend to talk more about the event they are being questioned about.
When presented with a list of words along with a theme (e.g., bed, rest, slumber, dream, tired), participants often (mis)recall the theme word as part of the list (e.g., sleep). This procedure is commonly referred to as __________.
the DRM procedure
Which of the following problems provides an example of how functional fixedness can hinder solution of a problem?
the Two-String problem
According to the video segment shown during the 03/19 (T) lecture, which of the following brain structures serves as a sort of "index" for our memories, helping you keep track of where different bits and pieces of your memories from a particular episode are stored?
the hippocampus
Which of the lab experiments show that *suggestion* plays an important role in false memories?
the misinformation effect and the "lost in the mall" study
Research on eyewitness testimony has shown that the more confident the person giving the testimony is of their memories, ________
the more convincing the testimony is to a jury
What is "The "reminiscence bump" ?
the name for the pattern of particularly good memory for late adolescence and early adulthood.
Amber lives in a housing development between two parallel streets that both connect to a freeway. She usually takes the street to the south when heading southbound on the freeway to work, but that street is closed for repairs for three months. Amber takes the street to the north during that time. After the street to the south is re-opened, she continues to take the street to the north, even though it is a longer route. Continuing to take the street to the north represents:
the operation of a mental set
Inappropriate mental set EX: The nine dot problem
the preconceived notion that the four straight lines must stay inside the box & can't be manipulated (= *rigid* *mental* *set*) makes it difficult to find a solution for this problem -- you literally have to go *outside* the box
The "weapon focus" effect refers to the finding that:
the presence of a weapon hinders memory for other parts of the event
The "buying/selling horses" problem (covered during the 04/04 lecture) provide a nice illustration of the idea that:
the way in which the problem is represented can greatly affect problem difficulty
In the original false-memory study conducted by Roediger and McDermott, participants heard a list of 15 words (bed, rest, awake, dream, etc.), all united by a common theme (i.e., sleep). The list, however, did not include that theme word itself (i.e., sleep). Participants later judged whether or not a particular word was presented in the list. In this original study (after which the ZAPS False Memory experiment was modeled), the researchers found that:
they judged (incorrectly) that "sleep" was in the list almost as often as they judged (correctly) that "dream" was in the list
Chess experts are better at remembering chess positions than novices because they...
treat groups of pieces as subgoals.
In one study, participants saw a video of a car wreck and were then asked questions about what they had seen. Participants who heard the question "How fast were the cars going when they hit each other?"
were less likely than those individuals who had heard "smashed into each other" to recall that they had seen broken glass --> The words "smashed into each other" led people to remember the cars as traveling faster and hence was likely to elicit the memory of broken glass.
The "Water Lily" problem discussed during the 04/02 (T) class illustrates the effectiveness of which of the following problem solving heuristics?
working backwards
From the perspective of a "problem space," using a heuristic means that...?
you only search a portion of the problem space
Example of Inductive Reasoning
• Premise: None of my female friends shows much interest in horror movies, but my brothers love them • Conclusion: There are more male horror movie fans than female fans --> This is probable but not guaranteed! Conclusions from inductive reasoning can be viewed as "hypotheses"
Lab Simulation of "Recovered" Memories: The "Lost in the Mall" Study (Loftus)
◦ About 25% of college students "recall" details of the event that never took place ❃ Illustrates the powerful impact of suggestion on memory --> implanting false memories
Lab Simulation of "Recovered" Memories: Imagination Inflation Paradigm (Loftus)
◦ Imagining a low-likelihood childhood event (ex= spilling punch everywhere at a wedding reception) ◦ Subjects rated their confidence levels of those events before and after --> Their confidence levels of an event actually happening increased after visually imagining those events happening
Inappropriate mental set EX: Luchin's (1942) Water Jug Problem
◦ Obtain an exact amount of water/ the desire amount using three different size jars labeled A,B, & C ◦ People fail to see the solution A+C due to the tendency to keep repeating solutions that worked in past experiences.
Examples of "Ideal" or "Fail-safe" Procedures
◦ Problem solving: Algorithms (fail-safe) ◦ Reasoning: Formal logic (ideal) ◦ Decision making: Normative models (ideal)
Ross et al. 1994 study
❃ 2 groups; ◦ Experimental group = view film of male teacher reading to students ◦ Control group = view film of female teacher reading to students --> THEN both groups view film of the female teacher getting robbed ❃ The test= pick robber from photo-spread ❃*RESULTS*= experimental group did much better at identifying the robber in the photo spread than the control group --> *familiarity* *creates* *source* *confusion*
General Problem Solving Heuristics
❃ 4 Commonly used problem solving heuristics: A. Generate and test B. Hill climbing C. Means-ends analysis D. Working backwards ** Different heuristics can be applied to the same problem (ex: TOH and M&C puzzles) ** The ease and effectiveness of applying a particular heuristic depends on the nature of the problem --> Selecting an *appropriate* heuristic is crucial for *effective* problem solving
"Recovered" Memories
❃ A highly controversial issue ◦ Some people suddenly remember traumatic events that happened to them a *long* time ago ❃ Some cases are *falsely* *implanted* memories (ex= being abducted by a UFO) ❃ Loftus's research shows that it is *possible* to implant false *recovered* memories in experimental settings
Valid vs. Invalid Inferences for Conditional Reasoning
❃ According to formal logic: Logically *valid* inferences: ◦ Modus ponens ◦ Modus tollens Logically *invalid* inferences ◦ Denial of the antecedent ◦ Affirmation of the consequent
2) The Nature of the Problem Solving Process; Algorithm vs Heuristics
❃ Algorithm: a *procedure*, if followed correctly, *guarantees* that one reaches the *goal* state ◦ May not be the most efficient approach -- Trying to identify the PIN number you can't remember (e.g., 0000, 0001, 0002, etc.) -- too time consuming ◦ Ex= following a well-specified cooking recipe ❃ Heuristic: a *rule* *of* *thumb* approach for problem solving ◦ *Fast* & *easy* to use, and often *effective* ◦ *No* *guarantee* that the correct solution will be reached ◦ Early problem solving research focused on identifying commonly used heuristics b/c it is clear that most ppl prefer using heuristics over algorithms for problem solving
Heuristic: D) Working Backwards
❃ Analyzing the goal state to determine the last step needed to achieve it, then the next-to-last step, etc. ◦ Ex: solving a geometric proof problem by starting with the last step ◦ PRO: Highly effective for some problems (ex: water lily puzzle/task) ◦ CON: It is *not* effective for solving... (a) Problems with many paths that can lead to the goal state (it is difficult to work backwards) (b) Problems with many intervening steps (ex: TOH puzzle with *many* disks, and the missionaries & cannibals puzzle)
Human Performance on Conditional Reasoning
❃ Applying formal logic rules ensures valid conclusions (= "ideal" procedure) ❃ But humans do not always follow formal logic: ◦ People find it difficult to apply modus tollens ◦ People often make invalid inferences (such as denial of the consequent and affirmation of the antecedent) ◦ Example: Wason's card selection task (Wason Selection)
Heuristic: C) Means-Ends Analysis
❃ Comparing the goal state to the current state and choosing a step that maximally reduces the difference ◦ Ex: Newell & Simon's quote -- "I want to take my son to nursery school. What's the difference between what I have and what I want? = Distance. What changes distance? = My automobile. My automobile doesn't work. What is needed to make it work? = A new battery. What has new batteries? = My auto repair shop. I want the repair shop to put in a new battery; but the shop doesn't know I need one..." ❃ PRO: It often involves *breaking-up* a problem into *smaller* problems and creating subgoals ◦ Ex: solving the TOH puzzle by creating multiple subgoals (first clear the left peg) until you reach the goal state (getting all the disks to the right peg) ❃ CON: *Demanding* and often *difficult* to apply: ◦ Keeping track of subgoals heavily taxes working memory
Different Metaphors of Memory
❃ Computer: a dominant/popular analogy in cognitive psych ❃ Camcorder ❃ Filing cabinet ❃ Kaleidoscope; reassembling bits and pieces --> These are not good metaphors representing human memory b/c memories are *NOT* *accurate* *reflections* of the *actual events* we experience --> We *reconstruct* a memory by *combining* *elements* from the *original* *event* available in *LTM*
What Is Problem Solving?
❃ Defined as: the process of coming up with a series of actions that enables the person to achieve their goal ❃ Newell and Simon's (1972) characterization of a problem: -- "A person is confronted with a problem when he wants something and does not know immediately what series of actions he can perform to get it" ❃ Metaphor: *search* through space
Two Forms of *Invalid* Logical Inference
❃ Denial of the Antecedent: ◦ If Tom is late, then his boss will get mad; Tom was not late; Therefore, his boss did not get mad. ❃ Affirmation of the Consequent: ◦ If Tom is late, then his boss will get mad; His boss got mad; Therefore, Tom was late
Hypothesis Testing
❃ Different approaches to hypothesis testing: • Confirmation: Seeking evidence that is consistent with your belief • Disconfirmation: Seeking evidence that might be inconsistent with one's belief to test the hypothesis (this is most Effective and scientifically important) ❃ Example: A rooster crowing in the morning causes the sun to rise • Confirmation: See what happens after a rooster crows • Disconfirmation: See what happens if he doesn't crow
Deductive Reasoning
❃ Drawing a *logically* *certain* and *specific* conclusion from a set of general premises ◦ From general to specific ◦ EX: Syllogistic Reasoning: -- All dancers drink water (All X are Y). Some actors are dancers (Some A are X). Therefore some actors dink water (Some A are Y) * Valid reasoning= if the premises are true, the conclusion must be true
Cognitive Interview Method
❃ Effective in eliciting info from eyewitnesses ❃ Four general retrieval rules: 1. Mental (or physical) context reinstatement of the crime environment during the crime= *encoding* *specificity* 2. Encouraging the reporting of every detail (even trivial detail) 3. Describing the incident in several different orders 4. Reporting the incident from different viewpoints (e.g., another witness) - put yourself in another witnesses' perspective
Flashbulb Memories
❃ Even Highly Vivid Memories Are Likely Contaminated ◦ Usually involve highly emotional events and are recalled vividly and confidently ◦ Why are flashbulb memories memorable? • The contribution of emotion • The frequent retelling (and repeated hearing) of stories
Novices vs. Experts in Problem Solving
❃ Experts have a *larger* *knowledge-base*: ◦ Chess experts have stored a large number of basic chess patterns (or "chunks") ◦ Being able to recognize game patterns quickly helps experts grasp the essence of the current game situation and find the most promising continuation • Evidence: Chess experts' memory of chess board configurations after very brief (5 sec) exposure ❃ Experts' knowledge is more *systematic* and better *organized* ◦ EX: Which one of the physics problems below is the "odd man out"? -- Physics novices classify problems according to surface-level features -- Physics experts classify problems according to guiding principles (ex; the law of physics) ❃ Experts and novices differ in the way they initially *approach* the problem ◦ Identifying exactly what problem/issue you're dealing with is critical for effective problem solving • Experts first try to define the problem more precisely (i.e., constrain the problem space first) • Novices tend to jump right in and start working on the problem
Sources of Failures in Problem Solving: D) Lack of Domain-Specific Knowledge
❃ General heuristics often need to be enhanced by domain-specific knowledge for effective problem solving ◦ Ex; playing chess (need to know game rules, effective game strategies, etc.) ◦ Solving physics problems (need to know laws of physics, relevant formulas, etc) ❃ Not having such knowledge (or failing to access it when needed) leads to problem solving failures
Experts and novices differ in the way they initially approach the problem
❃ Identifying exactly what problem/issue you're dealing with is critical for effective problem solving • Experts try to define the problem more precisely (i.e., constrain the problem space first) • Novices tend to jump right in and start working on the problem
Guidelines for preserving eyewitness memory
❃ Let witnesses' recall things from their own memory- ask open ended questions ❃ Caution the witness against guessing what happened ❃ When using lineups: 1. Select the lineup fillers that fit the witness's description of the perpetrator (short vs tall) 2. Instruct the witness that the perpetrator may or may not be in the lineup --> don't guess 3. Show one person at a time - use sequential rather than simultaneous lineups 4. Avoid giving any feedback to the witness after the lineup
Problem solving as search through space
❃ Metaphor: Search through a *space* toward a *goal* ❃ Key elements in a *problem* *space*: ◦ Initial/current state ◦ Goal state ◦ Operators (tools or *actions* that lead you from one state to another) ◦ Optional: Constraints (certain states or operators/actions are not allowed) -- ex: the missionary and cannibal puzzle
The Misinformation Effect
❃ Misleading *post-event* information (MPI) can affect later recall ❃ Wording of a sentence ("a" vs "the") can change the way people remember things ◦ "Did another car pass the red Honda while it was stopped at the yield sign?" ◦ "Did you see a/the tree?" ◦ "How fast were the cars going when they ___ each other?" --- using the words "smashed" would help people remember that the cars were going really fast
Valid Inferences: 2 rules of formal logic
❃ Modus Ponens: ◦ If Tom is late, then his boss will get mad. Tom was late; Therefore, his boss got mad. ❃ Modus Tollens: ◦ If Tom is late, then his boss will get mad; His boss did not get mad; Therefore, Tom was not late
Mental Set & the Incubation Effect: Silveira's (1971) Cheap Neckalce Problem
❃ Objective: ◦ 4 chains with 3 links each ◦ Need to make one complete chain ◦ Costs 2 cents to open link ◦ Costs 3 cents to close link ◦ You only have 15 cents to spend ❃ This problem is difficult for many people b/c they tend to adopt an inappropriate mental set to approach this problem ❃ The study: ◦ 30 mins to solve the problem -- group 1: continuously worked on it for 30 mins -- group 2: a 20-30 min interruption in the middle -- group 3: A 4-hr interruption in the middle ◦ Subjects "talked aloud" during problem solving (= constant verbal reporting of strategies) ❃ Findings: ◦ Main difficulty = Strong tendency to keep going back to failed approaches ◦ This tendency was reduced after a long break ◦ Silveira said the incubation effect= *forgetting* or *dissipation* of inappropriate mental set or approaches
Eyewitness Testimony
❃ One situation in which accurate memories are *crucial* ◦ the witness' confidence level strongly influences the jury's verdict ◦ BUT high confidence doesn't necessarily mean accurate memories ❃ Accurately remembering what happened at the crime scene is extremely difficult ◦ Not an ideal situation to encode episodic info--> inaccurate/insufficient initial encoding
Wason Selection Task: Interesting Context Effect
❃ People do much better if a concrete context is provided -- "If a person is under 21, then the person must be drinking a nonalcoholic beverage" -- Cards include: "18 years of age," "25 years of age," "drinking tea," & "drinking beer." ❃ When detecting whether a social contract has been violated, subjects often make logically correct choices: ◦ This effect may reflect evolutionary significance of detecting cheaters.
Hypothesis Testing and Confirmation Bias
❃ People show a strong confirmation bias, despite the importance of disconfirmation in hypothesis testing ◦ Famous evidence: Wason's 2-4-6 task • Task requirement: Generate a probable hypothesis/sequence of numbers, other than 2-4- 6, (via inductive reasoning) and test it -- Figuring out the rule underlying the digit triplets (2-4-6 is "yes") by producing other triplets
Sources of Failures in Problem Solving: C) Incorrect or Incomplete Representations of the Problem
❃ Problem representations also affect problem difficulty ◦ Example: The "buying/selling horses" problem -- A man bought a horse for $600 and sold it for $700. Then he bought it back for $800 and again sold it for $900. How much profit did he make? ❃ How you mentally represent the problem is often crucial for success ◦ Example: The "book worm" problem ❃ Representational difficulties sometimes stem from working memory limitations -- It is difficult to accurately represent all relevant pieces of info in working memory (sometimes better to use pen & paper) ◦ Example 1: "Matrix reasoning" problem (difficult b/c you have to juggle many different rules and apply them correctly) ◦ Example 2: "Brothers & Sisters" Riddle (difficult when you start from the beginning, easier if you start from the end) (ANSWER= *my* *son*) -- Mentally keeping track of different elements of the riddle places a heavy demand on limited working memory
Inductive Reasoning
❃ Reaching a *probable* & *general* conclusion, based on a set of specific facts ◦ From specific to general ◦ EX=A quote from Sherlock Holmes; "the murderer was a man. He was more than six feet high, was in the prime of life [...]. In all probability the murderer had a florid face, and the fingernails of his right hand were remarkably long." -- These specific conclusions may not be true
What Is Reasoning?
❃ Reasoning is all about making inferences that allow you to go beyond what you already know in order to draw new conclusions ❃ An important distinction: ◦ Deductive reasoning vs. Inductive reasoning
Main Research Focus in Deductive Reasoning
❃ Researchers have tried to examine people's reasoning by: ◦ Comparing it to the principles of "formal logic" and noting the differences ❃ Examples from conditional reasoning: ◦ Drawing a conclusion based on an "if-then" proposition ◦ If the Broncos win the next game, they'll make it to the playoffs
Roles of Schemas and Scripts
❃ Schemas and scripts are often useful because they serve as *default* *options* and help us fill in *gaps* ◦ No need to mention all the relevant things/steps for familiar concepts or events ❃ But they can also cause problems: ◦ Stereotyping ◦ Memory of things that do not fit your schemas or scripts may be distorted ◦ Memory of concepts/events that do not fit your schemas or scripts may be distorted
False Memories: Evidence for the Reconstructive Nature of Human Memory
❃ The *reconstructive* *nature* of human memory is evident in the *errors* people often make: * False memories * Errors in the eyewitness testimony in court * The reconstructive process is *constantly* *operating* so it's easy to *implant* *false* *memories* --> Ex= Word & sentence recall using DRM procedure (ZAPS false memory task) --> Ex= Recall of visual scenes (video shown in 3/19 class)
Mental Set & the Incubation Effect
❃ The benefit of setting a problem aside for a while ◦ "Sleep on it" ◦ This effect is not always present ❃ How can this effect be explained? ◦ Myth: our unconscious mind is continuously working on the problem ◦ Counter-evidence: Silveira's study involving the "cheap necklace" problem
Wason's 2-4-6 Task
❃ The main finding: Confirmation bias ◦ Subjects fail to generate disconfirming guesses; • They keep generating confirming guesses • Even when disconfirming evidence is explicitly provided, subjects often do not use it! (= belief perseverance) ❃ Conclusion: People do not use optimal ways to generate and test hypotheses • Confirmation bias is strong even among scientists
Experts and novices differ in their use of heuristics
❃ Their repertoires of heuristics are similar • BUT experts tend to work forward whereas novices "work backward" (working backwards heuristic) in math and physics problem solving -- Experts' ability to recognize the problem type quick enables them to "work forward" effectively
Heuristic: A) Generate and Test
❃ Trial and Error approach; Trying a variety of solutions one at a time and eliminating those that do not work ◦ Example: You forgot the password for an account you haven't used for a while, so you try your current passwords one by one ◦ Can be applied to the TOH and M&C puzzles ❃ It's effectiveness depends on the range of possible solutions --> it's effective only when the number of possible solutions is small ◦ May not be effective for highly complex problems (ex: 5-disk TOH puzzle; M&C puzzle)
Heuristic: B) Hill Climbing
❃ Trying to always move closer to the goal state ◦ Includes multiple operators = choose the action that moves you in the direction of the goal state ◦ Ex: solving the TOH puzzle by always trying to move disks from left to right ❃ Useful and *non-demanding* ◦ People often spontaneously use this strategy to solve problems, but there are certain *costs* ** It may not work for problems that require *temporarily* moving away from the goal state (ex: trying to solve Rubik's cube one face/color at a time, or moving a disk in a backward direction (TOH & missionaries and cannibals puzzles)) --> the crucial step of moving the smallest disk from the goal peg back to the initial peg (right to left) would be extremely difficult if you always move it from left to right
1) The Nature of the Problem Space
❃ Well-defined problems: ◦ Solving the Tower of Hanoi puzzle (starting configuration --> goal configuration) ◦ Constructing a proof in algebra ❃ Ill-defined problems: ◦ Writing a paper on democracy ◦ Figuring out how to throw a surprise birthday party for your friend ❃ What *differentiates* well-defined from ill- defined problems? ◦ Whether or not *all* *3* *key* *elements* of a problem space (= initial state, goal state, & operators) can be specified
Main Points in the Video: "Recall of visual scenes" (Evidence for the Reconstructive Nature of Human Memory)
❃ What is the primary source of false memory in the "picnic-scene" task? --> *episodic* *memory* b/c subsequent exposure to the pictures of things that *didn't* happen contaminated his memory of the original picnic scene ❃ How is our memory represented in the brain? --> it is very malleable/changeable --> memory consists of all the bits and pieces of an event & the hippocampus reassembles all those pieces --> Emotions can make some events more memorable ❃ According to the neuroimaging study shown, what differentiated true and false memories? --> the true memory lit up the auditory cortex for the words that were *actually* heard, whereas the false memory didn't light up the auditory cortex
Memory Metaphor according to Loftus
❃ Wikipedia page
Main Points of the Loftus TED Talk
❃Memory is malleable and reconstructive • The prevalence of false memories • The ease of "implanting" false memories ❃It is *impossible* to encode, store, and retrieve information as is ❃Steve Titus's wrongful conviction --> Unreliability of eyewitness memory ❃ *Repressed* memories: ◦ Suddenly remembering "long forgotten" horrific events as a result of certain types of psychotherapy
