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Chapter 4

Attention

Some Questions to Consider

Is it possible to focus attention on just one thing, even when lots of other things are going on at the same time?
Under what conditions can we pay attention to more than one thing at a time?
What does attention research tell us about the effect of talking on cell phones while driving a car?
Is it true that we are not paying attention to a large fraction of the things happening in our environment?

Attention

The ability to focus on specific stimuli or locations in our environment
Selective: attending to one thing while ignoring others
Divided: paying attention to more than one thing at a time
http:// study.com/academy/lesson/attention-as-part-of-cognitive-development-definition-process.html

Selective Attention

Ability to focus on one message and ignore all others
We do not attend to a large fraction of the information in the environment
We filter out some information and promote other information for further processing
Try this famous test of selective attention:
https://www.youtube.com/watch?v=vJG698U2Mvo

Research Method: Dichotic Listening

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?

Research Method: Dichotic Listening

Results of Dichotic Listening

Participants could not report the content of the message in unattended ear
Knew that there was a message
Knew the gender of the speaker
However unattended ear is being processed at some level
Cocktail party effect
https://www.youtube.com/watch?v=9yRm7iWwFws
http://www.wwltv.com/videos/news/local/eyewitness/2014/08/29/14397630/

Models of Selective Attention

Where does the attention filter occur?
Early in processing
Later in processing
Early selection model
Broadbent’s filter model
Intermediate selection model
Tresiman’s attenuation theory
Late selection model
e.g. McKay (1973)

Broadbent’s Filter Model

Early-selection model
Message is filtered before incoming information is analyzed for meaning

Broadbent’s Filter Model

Sensory memory
Holds all incoming information for a fraction of a second
Transfers all information to next stage
Filter
Identifies attended message based on physical characteristics
Only attended message is passed on to the next stage, allowing us to ignore unimportant and unnecessary white noise around us.

Broadbent’s Filter Model

Detector
Processes all information to determine higher-level characteristics of the message
Short-term memory
Receives output of detector
Holds information for 10-15 seconds and may transfer it to long-term memory

Broadbent’s Model Could Not Explain

In the dichotic listening task, if a person is asked to listen to only what comes in the right ear, they have no trouble ignoring the message coming into the left ear, unless it’s their name.
If they hear their name they attend to it even if they didn’t want to.
Cocktail party phenomenon
Participants can shadow meaningful messages that switch from one ear to another
Dear Aunt Jane (Gray & Wedderburn, 1960)

Treisman’s Attenuation Theory

Intermediate-selection model
Attended message can be separated from unattended message early in the information-processing system
Selection can also occur later

Treisman’s Attenuation Theory

Attenuator
Analyzes incoming message in terms of physical characteristics, language, and meaning
Attended to message is let through the attenuator at full strength
Unattended message is let through at a much weaker strength
But it is still let through.

Treisman’s Attenuation Theory

Dictionary unit
Contains words, each of which have thresholds for being activated
Words that are common or important have low thresholds; even a weak signal can activate that word
Uncommon words have high thresholds; signal must be higher (person must be paying more attention) for those words to be heard and remembered.

Treisman’s Attenuation Theory

Late Selection Models

Selection of stimuli for final processing does not occur until after information has been analyzed for meaning
McKay (1973)
In attending ear, participants heard ambiguous sentences
“They were throwing stones at the bank.”
In unattended ear, participants heard either
“river”
“money”

Late Selection Models

McKay (1973)
In test, participants had to choose which was closest to the meaning of attended to message:
They threw stones toward the side of the river yesterday
They threw stones at the savings and loan association yesterday
The meaning of the biasing word affected participants’ choice
Participants were unaware of the presentation of the biasing words
Here is a good video that explains all three types of theories of selective attention:
https://www.youtube.com/watch?v=QM3FZOR2XdA

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
High-load (difficult) tasks use higher amounts of processing capacity
Low-load easy) tasks use lower amounts of processing capacity

The Stroop Test

Stroop effect
Name of the word interferes with the ability to name the ink color
Cannot avoid paying attention to the meanings of the words

The Stroop Test

Overt Attention

Eye movements, attention, and perception
Overt attention involves actively moving our eyes to scan a scene or situation.
To do this we make saccadic eye movements
Saccades: rapid movements of the eyes from one place to another
Periodically we stop on things to see if they are what we are looking for
Fixations: short pauses on points of interest
Studied by using an eye tracker

Bottom-up Determinants of Eye Movement

Stimulus salience: areas that stand out and capture attention
Color, contrast between objects, and movement are all salient and capture our attention
The red apple is salient
Bottom-up process
Depends on characteristics of the stimulus
Color and motion are highly salient

Top-Down Determinants of Eye Movements

Scene schema: knowledge about what is contained in typical scenes
Help guide fixations from one area of a scene to another
People look longer (their attention is captured and they become fixated) when something appears in a scene that is unexpected.
A computer printer in a kitchen.
Eyes movements are determined by task
Eyes movements preceded motor actions by a fraction of a second

My kids like these scenes from Highlights magazine. Our attention is captured more quickly by the things that obviously don’t belong.

Top-Down Determinants of Eye Movements

Covert Attention:
Attention without Eye Movements

Covert attention occurs when we are paying attention to something but not looking at it.
A soccer player shooting a penalty kick will look one way but kick the other to trick the goalie to jump the wrong way for a save.
Precueing: directing attention without moving the eyes
Participants respond faster to a light at an expected location than at an unexpected location
Even when eyes kept fixed

Covert Attention:
Attention without Eye Movements

Divided Attention

Practice enables people to simultaneously do two things that were difficult at first
Schneider and Shiffrin (1977)
Divide attention between remembering target and monitoring rapidly presented stimuli
Memory set: 1-4 target characters
Test frames: could contain random dot patterns, a target, distractors

Divided Attention

Automatic processing occurs without intention and only uses some of a person’s cognitive resources

Divided Attention – Distractions
While Driving

100-car naturalistic driving study
Video recorders placed in cars
Risk of accident is four times higher when using a cell phone
Strayer and Johnston (2001)
Simulated driving task
Participants on cell phone missed twice as many red lights and took longer to apply the brakes
Same result using “hands-free” cell phone

https:// www.youtube.com/watch?v=AVql9kZbsd4

Attention and Visual Perception

Inattentional blindness: a stimulus that is not attended is not perceived, even though a person might be looking directly at it

Attention and Visual Perception

Object-Based Visual Attention

Location-based: moving attention from one place to another
Object-based: attention being directed to one place on an object

Object-Based Visual Attention

Egly et al. (1994)
Participants saw two side-by-side rectangles, followed by a target cue
Reaction time fastest when target appeared where indicated
Reaction time was faster when the target appeared in the same rectangle

Object-Based Visual Attention

The enhancing effect of attention spreads throughout the object
Attention can be based on the
Environment
static scenes or scenes with few objects
Specific object
dynamic events

Change Detection

Change blindness: if shown two versions of a picture, differences between them are not immediately apparent
Task to identify differences requires concentrated attention and search

Change Detection

Attention and Experiencing a Coherent World

Binding
The process by which features such as color, form, motion, and location are combined to create our perception of a coherent object