Lecture 7Memory & Thinking

Visiting Assistant PROFESSOR YEE-SAN

TEOHDepartment of Psychology

National Taiwan University

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Unless noted, the course materials are licensed under Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Taiwan (CC BY-NC-SA 3.0)

GENERAL PSYCHOLOGY

Memory

How do we remember things?

3 Aspects of the Memory Process

AcquisitionGaining new knowledge -

establishing new memories in long-

term storage

Not just copying information - requires some intellectual engagement with the material.

What we think about it is what is actually stored in memory….which has implications for:

a.What you will remember.

b.Under what circumstances you will remember.

c.How accurate your memory will be.

Intentional Learning

Deliberate memorization.

Placing of new info in memory when person anticipates that his/her memory will be tested later.

E.g. Revising for General Psychology exam.

Incidental Learning

Learning that takes place without any intention to memorize.

Often occurs without the awareness that learning is actually occurring.

E.g. Remembering what you ate for dinner last night without trying to memorize that fact.

Stage Theory of Memory

Sensory Memory

“Raw” sensory information.

Information enters the senses, triggering neural messages that are sent to the brain.

i. Iconic memory: Visual sensory information.

ii. Echoic memory: Auditory sensory information.

Short-Term/Working Memory (STM/WM)

Place where you hold a small amount of information while you’re ‘working’ on it.

Can hold for very short periods of time.

Long-Term Memory (LTM)

Can hold vast amounts of information for extended periods of time.

More permanent storage place.

Primacy & Recency Effects

Free Recall: A test of memory that asks for as many items in a list as the subject can recall regardless of order.

i.Primacy Effect = Tendency to recall the first items on a list more readily than those in the middle.

ii.Recency Effect = Tendency to recall items at the end of the list more readily than those in the middle.

Why?

There’s a limit on how many things someone can think about at once.

Limit to how many items can be maintained in working memory.

Recency Effect

New words entering working memory will bump out the words that were there a moment ago.

Last few words don’t get bumped out because no new information was presented to bump them out, so those items are still in working memory.

Primacy Effect

Primacy effect must involve long-term memory.

The first few words presented get more attention and rehearsal than the later ones, which enables them to be more likely to be established in long-term memory.

The capacity of working memory

Working memory capacity is 7 items, plus or minus 2

Chunking: Reorganizing materials in memory so that more can be remembered.

FYIUSATHXBRB

(12 items)

Chunk into 4 units?

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(4 items).

Establishing long-term memories

Importance of Active Engagement

LTM is not automatic.

Requires mental engagement.

Not all information we are exposed to gets established in LTM.

The more we make sense or process the material, the more likely that memory will be retained.

LTM & Understanding

Greater levels of activity in the brain (especially in the hippocampus &

prefrontal cortex) during initial memory acquisition

Greater probabilities of retention later on.

Best study techniques?

Techniques that emphasize efforts toward understanding the material are likely to pay off with good memory later on.

Mechanical strategies (repetition) may produce no benefit at all.

Memory Connections

Mnemonics: Deliberate techniques that people use to help them memorize new information.

Memory storage

Memory Trace

Record in the nervous system that actually preserves a memory of a past experience.

Memory Consolidation

Biological process taking place for a period of time (several hrs) after an event is experienced.

Transforms memories from transient & fragile status to more permanent & robust state.

Time period allows creation of new pattern of communication among neurons to represent the newly acquired memory.

Significance of Memory Consolidation

Memory retrieval

Retrieval Processes

What can help memory retrieval?

Retrieval Cues

Stimulus that helps one to recall a memory.

Cue needs to recreate the context in which the original learning occurred.

E.g. Childhood memories might return to those who return to their hometown and see the city buildings and their old home.

Context Reinstatement

When we put ourselves back into the same mental or physical state that we were in during the initial learning.

We can improve our ability to remember the information.

E.g. Memory for lists of words learned on land vs. underwater.

Encoding Specificity

Retrieval is most likely if the context at the time of recall is similar to the original encoding context.

Memory trace is specific – represents copy of original material + your thoughts & understanding.

Specificity has powerful effects on retrieval because the retrieval cues must reflect the content or context of the original stimulus.

Example:

“Something heavy” will be a good cue for the word “piano” if you were shown the word in the context of:

“The man lifted the [piano]”

But not in the context of:

“The man tuned the [piano]”

Why Do We Forget?

Why Do We Recall the Wrong Info?

Forgetting

Ebbinghaus (1964/1885)- Memory declines with the passage of time, but the decline is uneven, being sharpest soon after learning, and then becoming more gradual.

Exceptions for new learning

Dissimilar InformationNo interference found when the new learning consists of dissimilar material.E.g. Learning how to skate will not interfere with your memory of Intro to Psyc material.

Consistent InformationNo interference found when the new learning is consistent with older learned information.E.g. Taking college psyc course will help you remember the information learnt in high school psyc course.

Intrusion Errors

Memory mistakes in which someone remembers elements that did not actually occur as part of an earlier event, so that these other elements are mixed into the memory.

Intrusions are often small…

E.g. Thinking you called your mum last night when it was

really 3 nights ago.

But can be large errors…

E.g. Recalling an event that never happened.

The Misinformation Effect

When people are presented with incorrect information (misinformation) about an event they witnessed, this incorrect information is often incorporated into their original memory of an event.

How can misinformation be introduced?

Leading questions or through other people’s reports.

Intrusions from Schematic Knowledge

Intrusions from Semantic Associations

Deese-Roediger-McDermott (DRM) Paradigm

Tendency to falsely recall a target word from a set list of words centered around that target word.

Example: List of words all related to ‘sleep’, but ‘sleep’ is not on list – incorrectly remember ‘sleep’ as being on the list.

Varieties of Memory

Explicit MemoryImplicit Memory

Types of explicit memory

Semantic Memory

Type of explicit memory that includes knowledge of words and concepts.

Knowledge is not tied to any time or place.

Also called generic memory.

E.g. “What is the capital of Taiwan?”

Episodic Memory

Type of explicit memory which includes memory for specific events (episodes).

E.g. 16th Birthday, or what you had for breakfast this morning.

A Few Types of Episodic Memory- Autobiographical Memory- Flashbulb Memories- Memory for Traumatic Events

Memory for Traumatic Events

Sometimes traumatic events are not recalled until much later – this can be explained by:

(a)Physical duress – e.g. sleep deprivation, head injuries, alcohol abuse, which can disrupt memory process.

(b)Extreme stress assoc with the event may disrupt the biological processes needed for establishing memory in the first place.

(c)Repressed – pushed out of consciousness by defense mechanisms designed to shield a person from psychological harm.

Flashbulb Memories

Vivid, detailed memories said to be produced by unexpected, highly distinctive, and emotionally important events.

Most examples involve negative events that trigger fear, horror, or grief.

E.g. when the Twin Towers were hit on Sept 11.

While flashbulb memories are associated with strong confidence in their accuracy, they are not often associated with actual accuracy (e.g. Neisser & Harsch, 1992).

Of course, flashbulb memories involve stress at the time of encoding, which may enhance people’s memories – at least for certain aspects of the event (e.g. Buchanan & Lovallo, 2001).

Implicit memory

Procedural Memory

Example of Implicit-Explicit Memory Distinction

H.M – Patient with epilepsy treated surgically; most of hippocampus, amygdala removed.

Resulted in anterograde amnesia – couldn’t form new explicit memories.Could acquire implicit memories from specialized testing.Could be taught how to work his way through a maze.But no recollection of ever having seen the maze or learning how to work the maze.

Thinking

Mental Representations

• Content of thought – how our thoughts are represented in the mind.

• Contents stand for some object or event, allowing us to think about those things even in their absence.

Mental representations can also stand for things that exist only in our minds.

Internal symbols, actions, images, or words.

Types of Mental Representation

Analogical

Shares some of the physical characteristics of an object.

Usually takes form of mental images.

E.g. When trying to remember whether a person had short or long hair, one will usually call to mind a mental image of the person’s head to mentally “see” the hairstyle.

Types of Mental Representation

Symbolic

Does not correspond to the physical characteristics of that which it represents.

E.g. The word ‘mouse’ does not resemble the small rodent it represents. (as opposed to the picture of a mouse)

Mental Images

• Our mental images are like pictures.

• Neuroimaging studies show that many of the same brain structures are active during both visual perception & visual imagery.

• Primarily in the occipital lobe.

Classic Study of Mental Imagery

Participants are asked to memorize the map of a fictitious island and form a mental image of it.

Then asked to imagine a black speck traveling from one location to another.

Time needed for speck to “travel” across the mental image was directly proportional to the distance between the 2 points on the original map.

Duck-Rabbit Study

• Picture of duck/rabbit is easily reinterpreted.• But the corresponding mental image (duck,

rabbit) is already organized and interpreted to some extent.

• Mental images can’t be easily reinterpreted .

4 Types of Directed Thinking

JudgmentReasoning

Decision MakingProblem Solving

Judgment

Judgment

Drawing conclusions from experience.

Various steps are used to reach beyond the evidence encountered so far.

Involves some extrapolation and some element of risk that the extrapolation will be mistaken.

Judgment

Example

We conclude that we like all movies with the actor Tom Cruise, because we have liked all the movies that we have seen him in it.

But this judgment may be a mistake because we might come across a movie with him in it that we may not like.

Using Heuristics to Make a Judgment

Rule of thumb that can describe how humans solve particular problems.

Strategies that help us make judgments more quickly but at the cost of occasional mistakes.

The Availability Heuristic

Rule of thumb often used to assess how often one has encountered a particular event or object.

When examples of events come easily to mind – we conclude that circumstance is a common one.

Errors – very vivid events will be easily remembered but may also be rare.

The Representativeness Heuristic

Rule of thumb by which we estimate the probability that an object/event belongs to a certain category based on how prototypical it is of that category.

Strategy assumes that each member of the category is “representative” of that category – so we know what to expect the next time.

Errors – generalizing the results of a single case to other cases or situations.

Reasoning

Reasoning

Drawing implications from our beliefs.

“If I believe in X, what other claims follow from this?”

Deduction = Derive new assertions from premises (assertions already in place).

If Premise A (Engineers are good at math); Premise B (Tao is a an engineer);

then C (Tao is good at math).

Why is Reasoning Important?

Allows us to use our knowledge in new ways.

E.g. We know that if it’s raining, today’s BBQ will be canceled; we see that it is raining, so we can reason that the BBQ will be canceled.

Provides means of testing our beliefs.

E.g. You reason that if someone likes you, s/he will say “yes” with enthusiasm if you ask him/her out; you can test that theory and find out if the person likes you.

Confirmation Bias

Tendency to seek or endorse evidence to support one’s beliefs, and ignore or dismiss evidence that will challenge our beliefs.

E.g. Compulsive gambling – remember wins vividly which reinforces belief that I can win again, remember losses as near wins , bad luck.

Decision Making

Utility Theory

One should always consider the possible outcomes of a decision and choose the most desirable one.

Attractiveness of the outcome: Choose the option with the greatest benefit & the least cost.

Likelihood of achieving that outcome: Choose the option that gives the greatest likelihood of achieving the things you value.

Framing

Our decisions can be influenced by how a question is phrased or how our options are described.

Affects the subjective desirability of an event by changing the standard of reference for judging that desirability.

E.g. Comparing all outcomes to the worse possible result (50% failure rate); vs, comparing them to the best possible result (50% success rate).

Problem Solving

Problem Solving

The thinking we do when we know what our goal is, but need to find a sequence of steps that will move us towards that goal.

Means-end Analysis: Strategy in which one continually evaluates one’s current position & resources with respect to one’s goal.

What is the difference between my current state and goal?

What means do I have available for reducing this difference?

Example of M-E Analysis

“I want to get to class”

What is the difference between my current state & my goal? [Distance]

What means do I have available for reducing this difference? [My bike]

Means-End Analysis

Replaces initial problem with a series of subproblems.

Initial goal gets broken down into a series of subgoals, and the subgoals can be broken down into smaller subproblems.

Automaticity

Ability to do a task without paying attention to it.

Automaticity in reading in adults

Stroop Task

Participant must name the color a word is printed in.

As fast as possible.

The Stroop Effect

Significant decrease in the speed of naming colors.

Reading becomes automatic so participants can’t help but read the word “red”.

Competing responses – responses become slower than when reading non-color related words or nonsense words.

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