attention chapter 4 Lori

Attention:

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

Selective Attention

attending to one thing while ignoring others

Divided Attention:

paying attention to more than one thing at a time

Studying Selective Attention
Research Method: Dichotic Listening

• One message is presented to the left ear and
another to the right ear
• Participant “shadows” (i.e., repeats aloud) one
message to ensure he is attending to that
message

Results of Dichotic Listening Study

• 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 (picking out some salient bits
of information)
– Change in gender is noticed
– Change to a tone is noticed

Early selection model—

Broadbent’s Filter Model

Intermediate selection model—

Tresiman’s Attenuation Theory

Late selection model—

McKay (1973)

Broadbent’s Filter Model

Message (stimuli) is filtered before incoming
information is analyzed for meaning

Broadbent’s Filter Model (steps)
(1) Sensory memory

-Fraction of a second
-Transfers all information to next stage

Broadbent’s Filter Model (steps) (2) Filter

-Identifies attended message based on physical
characteristics
-Only attended message is passed on to the next
stage

Broadbent’s Filter Model (steps) (3) Detector

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

Broadbent’s Filter Model (steps) (4) Short-term memory

-Receives output of detector
-Holds information for 10-15 seconds and may transfer
it to long-term memory

Cocktail Party Phenomenon:

When we are able to discern our own name being said while in a noisy
setting, such as a cocktail party

Treisman’s Attenuation Theory
(1) Attenuator

-Analyzes incoming information based on:
physical characteristics
language
meaning
-Attended to message is let through the attenuator at
full strength
-Unattended message is let through at a much
weaker strength

Treisman’s Attenuation Theory- (2) Dictionary units

contain words, each of which
have thresholds for being activated
Words that are common or important have low thresholds;
they are activate readily
Example: your name, common words such as book, pencil, car
Uncommon words have high thresholds; they are activated less
readily
Example: words like brusque, parsimony

Late Selection Models

These models propose that the selection of stimuli for final
processing does not occur until after information has been
analyzed for meaning

Late Selection Models-Study by McKay (1973)

In attending ear, participants heard ambiguous sentences
(Example: They were throwing stones at the bank.)
In unattended ear, participants heard a biasing word—either
river —or— money
*Participants were unaware of the presentation of the biasing words

Load Theory of Attention

predicated on two concepts:
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

Stroop effect

Task which tests processing capacity and load
Name of the word interferes with the ability to name the
ink color
Cannot avoid paying attention to the meanings of the
words

Overt Attention

Eye movements can give us some indication of a
person’s attention and perception
Types of eye movements studied include:
-Saccades: rapid movements of the eyes from one
place to another
-Fixations: short pauses on points of interest

Bottom-up determinants of eye movements
include Stimulus Salience:

=Areas of a stimulus that stand out and capture
attention
Depends on characteristics of the stimulus
Color and motion are highly salient

Top-down determinants of eye movements include
Scene Schema:

=knowledge about what is contained in typical scenes;
schema help guide fixations from one area of a
scene to another
Task:
Eyes movements tend
to precede motor actions
by a fraction of a second

Precueing:

directing attention without moving the eyes. Participants respond
faster to a light at an expected location than at an unexpected location.

Divided Attention

Practice enables people to simultaneously do two things
simultaneously that were initially difficult to do together.

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

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 – 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 study (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

Inattentional Blindness:

A stimulus that is not attended is not perceived,
even though a person might be looking directly at
it.

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

Binding:

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

Feature Integration Theory (FIT)
(1) Preattentive stage

– Automatic
– No effort or attention
– Unaware of process
– Object analyzed into features

Treisman and Schmidt (1982)

Participants report combination of features from
different stimuli
Illusory conjunctions occur because features are “free
floating

Feature Integration Theory (FIT)
(2) Focused attention stage

– Attention plays key role
– Features are combined