Cognitive Psych Exam #2

Attention

The ability to focus on specific stimuli or locations in our environment

Types of Attention – Selective

Attending to one thing while ignoring others

Types of Attention – Divided

Paying attention to more than one thing at a time

Dichotic listening (Who and how the research happened)

– Colin Cherry (1953)

– One message is presented to the left ear and another to the right ear.

– Participant “shadows” one message to ensure he is attending to that message.

– Can we completely filter out the message to the unattended ear and attend only to the shadowed message?

Dichotic listening (What does the research suggest about what we are able to notice?)

Participants could not report the content of the message in unattended ear:

– Knew that there was a message

– Knew the gender of the speaker

Dichotic listening (What does the research suggest about what we are able to notice?)

However, unattended ear is being processed at some level:

– Cocktail party effect

– Change in gender is noticed

– Change to a tone is noticed

Everything with models of selective attention – Early

Where does the attention filter occur?

– Early in processing

– Later in processing

Everything with models of selective attention – Early

Early Selection Model Basics

– Broadbent’s filter model

– Filters message before incoming information is analyzed for meaning

Everything with models of selective attention – Early

Sensory memory

– Holds all incoming information for a fraction of a second

– Transfers all information to next stage

Everything with models of selective attention – Early

Filter

– Identifies attended message based on physical characteristics

– Only attended message is passed on to the next stage

Everything with models of selective attention – Early

Detector

Processes all information to determine higher-level characteristics of the message

Everything with models of selective attention – Early

Short-term memory

– Receives output of detector

– Holds information for 10–15 seconds and may transfer it to long-term memory

Everything with models of selective attention – Early

Broadbent’s Model Could Not Explain

– Why participant’s name gets through

– Why participants can shadow meaningful messages that switch from one ear to another

– Dear Aunt Jane (Gray & Wedderburn, 1960)

– Participants would hear “Dear 7 Jane” in the attended ear and “9 Aunt 6” in the unattended ear

Everything with models of selective attention – Intermediate

Intermediate selection model

– Treisman’s attenuation model

– Attended message can be separated from unattended message early in the information-processing system.

– Selection can also occur later.

– Treisman’s model has been called a “leaky filter” model.

Everything with models of selective attention – Intermediate

Attenuator

– It analyzes incoming message in terms of physical characteristics, language, and meaning.

– Attended message is let through the attenuator at full strength.

– Unattended message is let through at much weaker strength.

Everything with models of selective attention – Intermediate

Dictionary unit

– Contains words, each of which has a threshold for being activated

– Words that are common or important have low thresholds

– For example, your name has a low threshold

– Uncommon words have high thresholds

Everything with models of selective attention – Late

Late selection model

– MacKay (1973)

– Selection of stimuli for final processing does not occur until after information has been analyzed for meaning.

Everything with models of selective attention – Late

MacKay Experiment Basics

– In attended ear, participants heard ambiguous sentences.

– “They were throwing stones at the bank.”

– In unattended ear, participants heard either “river” or “money.”

Everything with models of selective attention – Late

MacKay Experiment Results

– Participants chose which was closest to the meaning of attended message:

– “They threw stones toward the side of the river yesterday.”

– “They threw stones at the savings and loan association yesterday.”

– Meaning of the biasing word affected participants’ choice.

– Participants were unaware of the presentation of the biasing words.

– MacKay and other theorists proposed that most of the incoming information is processed to the level of meaning before the message to be further processed is selected.

Load theory of attention

Processing capacity

– How much information a person can handle at any given moment

Perceptual load

– The difficulty of a given task

Load theory of attention

Perceptual Load Types

High-load (Difficult)

– Tasks use higher amounts of processing capacity

Low-load (Easy)

– Tasks use lower amounts of processing capacity

Stimulus salience

– Areas that stand out and capture attention

– Bottom-up process (Bottom-up Determinants of Eye Movement)

– Depends on characteristics of the stimulus

– Color and motion are highly salient

Scene Schema

– Knowledge about what is contained in typical scenes

– Help guide fixations from one area of a scene to another

Feature Integration Theory

Preattentive Stage

– First Stage

– Automatic

– No effort or attention

– Unaware of process

– Object analyzed into features

Feature Integration Theory

Focused Attention Stage

– Attention plays key role

– Features are combined

Feature Integration Theory

Researchers

– Treisman and Schmidt (1982)

– Participants report combination of features from different stimuli.

– Illusory conjunctions occur because features are “free floating.”

– Illusory conjunctions: Combining features from different stimuli

Feature Integration Theory

How It Works

– Mostly bottom-up processing

– Top-down processing influences processing when participants are told

what they would see

– Top-down processing combines with feature analysis to help one perceive things accurately

Memory

– Processes involved in retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present

– Active any time some past experience has an impact on how you think or behave now or in the future

Modal Model of Memory (Atkinson and Shiffrin (1968))

Memory Types

Sensory memory

– initial stage that holds all incoming information for seconds or fractions of a second

Short-term memory

– Holds five to seven items for about 15 to 20 seconds.

Long-term memory

– Can hold a large amount of information for years or even decades

Modal Model of Memory (Atkinson and Shiffrin (1968))

Control processes

– Active processes that can be controlled by the person; strategies associated with the different types of memory

– Rehearsal

– Strategies used to make a stimulus more memorable

– Strategies of attention that help you focus on information that is particularly important or interesting

Sensory memory

What are some examples?

– Initial stage that holds all incoming information for seconds or fractions of a second

– Transfers all information to next stage

– Retention, for very brief periods of time, of the effects of sensory stimulation.

– Information decays very quickly

Persistence of vision

– Retention of the perception of light

– Trail of light from a moving sparkler

Iconic Memory

– Brief sensory memory of the things that we see

– Responsible for persistence of vision

Echoic Memory

– Brief sensory memory of the things that we hear

– Responsible for persistence of sound

– Example: saying “What?” to a friend, then knowing exactly what they said before they can respond

Short-term memory (STM)

How long does it store information?

– Holds five to seven items for about 15 to 20 seconds

– Includes both new information received from the sensory stores and information recalled from long-term memory

Short-term memory (STM)

Measuring duration of short-term memory (Peterson & Peterson, 1959)

– Read three letters (e.g., FZL), then a three-digit number (e.g., 403)

– Begin counting backwards by threes from that number

– After a set time, recall three letters

– After 3 seconds of counting, participants performed at 80%

– After 18 seconds of counting, participants performed at 10%

– Reduction in performance explained by decay, the vanishing of a memory trace due to the passage of time and exposure to competing stimuli

Short-term memory (STM)

Capacity of short-term memory

– Digit span: how many digits a person can remember

– Typical result: five to eight items

Chunking

– Small units can be combined into larger meaningful units

– Chunk is a collection of elements strongly associated with one another but weakly associated with elements in other chunks

Short-term memory (STM)

Ericsson and coworkers (1980)

– Trained a college student, S.F., with average memory ability to use chunking

– Student had initial digit span of 7

– After 230 one-hour training sessions, S.F. could remember up to 79 digits

– Chunking them into meaningful units

Short-term memory (STM)

Alvarez and Cavanagh (2004)

– Used colored squares as well as complex objects

– Used the change detection procedure

Working memory (WM)

vs

Short-term memory (STM)

Same

– Working memory is a similar concept to short-term memory

Different

– STM holds information for a brief period of time

– WM is concerned with the storage, processing and manipulation of information, and is active during complex cognition

Working memory (WM)

(Baddeley and Hitch (1974))

– Limited-capacity system for temporary storage and manipulation of information for complex tasks such as comprehension, learning, and reasoning

– Working memory is set up to process different types of information simultaneously

– Has trouble when similar types of information are presented at the same time

Long-term memory

– Can hold a large amount of information for years or even decades

– “Archive” of information about past events and knowledge learned

– Works closely with working memory

– Storage stretches from a few moments ago to as far back as one can remember

– More recent memories are more detailed

Baddeley’s working memory models

(old and revised)

Phonological loop

Three phenomena that support the idea of a phonological loop

– Phonological similarity effect

– Word length effect

– Articulatory suppression

Phonological loop

Phonological similarity effect

– Letters or words that sound (not look) similar are confused

– For example, F may be confused for S or X, rather than for E, when recalling a list of letters seen on a screen

Phonological loop

Word length effect

– Memory for lists of words is better for short words than for long words

– Takes longer to pronounce and rehearse longer words and to produce them during recall

Phonological loop

Articulatory Suppression

– Speaking prevents one from rehearsing items to be remembered

– Reduces memory span

– Eliminates word length effect

Visuospatial sketch pad

– Creation of visual images in the mind in the absence of a physical visual stimulus

– Shepard and Metzler (1971)

– Mental rotation task

– Tasks that called for greater rotations took longer

Central executive

Acts as the attention controller

– Focus, divide, switch attention

– Controls suppression of irrelevant information

– Perseveration: repeatedly performing the same action or thought even if it is not achieving the desired goal

– A common behavior of patients with frontal lobe damage

Examples of situations where

working memory will have trouble

– Working memory is set up to process different types of information simultaneously

– Has trouble when similar types of information are presented at the same time

Phonological similarity effect

– Letters or words that sound (not look) similar are confused

– For example, F may be confused for S or X, rather than for E, when recalling a list of letters seen on a screen

Word length effect

–Memory for lists of words is better for short words than for long words

–Takes longer to pronounce and rehearse longer words and to produce them during recall

Articulatory suppression

– Speaking prevents one from rehearsing items to be remembered

– Reduces memory span

– Eliminates word length effect

Frontal and prefrontal cortex

(association with memory)

Perseveration: repeatedly performing the same action or thought even if it is not achieving the desired goal

– A common behavior of patients with frontal lobe damage

Prefrontal cortex responsible for processing incoming visual and auditory information

– Monkeys without a prefrontal cortex have difficulty holding information in working memory

The prefrontal cortex is important for holding information for brief periods of time

The frontal and prefrontal cortex do not become adequately developed until about 8 months of age

– May explain why infants do not understand object permanence

Primacy effect vs Recency effect

– Primacy effect gave more time to rehearse information, more likely to enter long-term memory (LTM)

– Recency effect: Stimuli still in STM

– Notice that memory is better for words presented at the beginning of the list (primacy effect) and at the end (recency effect).

Different types of coding (visual,

auditory, and semantic)

Code	Short-Term Memory	Long-Term Memory
Visual	Holding an image in the mind to reproduce a visual pattern that was just seen (Della Sala et al., 1999.)	Visualizing what the Lincoln Memorial in Washington, D.C., looked like when you saw it last summer
Auditory	Representing the sounds of letters in the mind just after hearing them (Conrad,  1964)	Repeating a song you have heard many times before, over and over in your mind
Semantic	Placing words in an STM task into categories based on their meaning (Wickens et al., 1976)	Recalling the general plot of a novel you read last week (Sachs)

Comparing coding in STM and LTM

Auditory coding is the predominant type of coding in STM.

– Coding based on the sound – like repeating a telephone number.

Semantic coding is the most likely form of coding for LTM.

– Coding based on the meaning – like remembering the plot of a story.

Parts of the brain primarily

responsible for STM and LTM

HM

– Surgery removed hippocampus

– Retained short-term memory (STM) but unable to transfer info to long-term memory (LTM)

– Unable to form new LTMs

KF

– Accident damaged parietal lobe

– Impaired STM (reduced digit span) but functional LTM

– Able to form and hold new memories

Double dissociation

– STM and LTM seem to be caused by different mechanisms, which can act independently.

Episodic memory

– Memory for experiences

– Involves mental time travel

– Tied to personal experience; remembering is reliving

– “Self-knowing”

Semantic memory

– Memory for facts

– Does not involve mental time travel

– General knowledge, facts

– “Knowing”

How time affects memories

Forgetting is not an “all-or-nothing” process

– Familiarity: semantic memory

– Recollection: episodic memory

How time affects memories

Remember/Know procedure

– Semanticization of remote memories

– Loss of episodic details for memories of long-ago events

How time affects memories

Forgetting ? with longer intervals after encoding

increases

Constructive episodic simulation

hypothesis

– Episodic memories are extracted and recombined to create simulations of future events

– Helps us to anticipate future needs and guide future behaviors

– Adaptive function similar to mind wandering

– Some researchers have suggested that one of the reasons that the mind wanders is to help people plan for the future by helping create simulations of the future from our episodic memories

Implicit memory

– Occurs when learning from experience is not accompanied by conscious remembering

Three of the main types of implicit memory:

1.Procedural memories

2.Priming

3.Conditioning

Procedural memories

– Skill memory: memory for actions

– May have no memory of where or when learned

– Perform procedures without being consciously aware of how to do them

– People who cannot form new LTMs can still learn new skills (e.g., HM)

Priming

– Presentation of priming stimulus changes person’s response to a test stimulus

Repetition priming

– Test stimulus the same or similar to priming stimulus

– Called implicit memory; person may or may not remember original presentation of priming stimuli

Propaganda effect

– More likely to rate statements read or heard before as being true

– Involves implicit memory because it can occur when people are not aware of previously seeing or hearing statement

– Implications for advertisements

Open-ended Questions (1-2 sentence answers)

List four words that would have a

low threshold for being activated for

the typical MC student, according to the dictionary unit in Treisman’s

Attenuation Model.

Ritalin

Contusion

Epidermis

Hestia

Open-ended Questions (1-2 sentence

answers)

Who was Phineas Gage and what did

his case study teach us about the

brain? Include how his behavior

changed.

Accident caused damage to Gage’s frontal lobe.

Accident changed Gage’s personality from an upstanding citizen to a person with low impulse control, poor ability to plan, and poor social skills.

Open-ended Questions (1-2 sentence

answers)

Describe one of the following case

studies, including the specific part of the brain that was affected and the resulting changes in behavior: HM, KF, KC, or LP.

KF

– Accident damaged parietal lobe

– Impaired STM (reduced digit span) but functional LTM

– Able to form and hold new memories