Chapter 4: Attention
Attention: the ability to focus on specific stimuli or locations
Selective attention: the focusing of attention on one specific location, object, or message
In the case of visual attention, the process of shifting attention from one place to another by moving the
eyes if called overt attention because the movements of the eyes provide observable signals of how
attention is changing over time.
There are other types of attention as well – covert attention, which occurs when attention is shifted
without moving the eyes, commonly referred to as seeing something “out of the corner of the eye”.
Divided attention: attending to two or more things at once; can be overt, covert, or a combination of the
According to William James, we focus on some things to the exclusion of others. Selective attention also
keeps us from perceiving whatever isn‟t being attended. This idea is generally correct, but it needed to be
revised to account for the fact that some unattended info is sometimes perceived.
Selective Attention as Filtering
Many of the early experiments involved the idea of a “filter” that acted on incoming info, keeping some
info out and some info in for further processing (used mainly auditory stimuli).
Dichotic listening procedure:
Different messages are presented to the two ears.
Ptcs are instructed to pay attention to the message presented to one ear (the attended message),
repeating it out loud, and to ignore the message presented to the other ear (unattended message).
Showing: the procedure of repeating a message out loud
o Used to ensure that ptcs are focusing their attention on the attended message
When asked what they had heard in the unattended ear, ptcs could only say that they could tell there was a
message and could identify it as a male or female voice.
Early selection model – Broadbent‟s filer model of attention: proposed that information passes through
the following stages…
Messages Sensory Memory Filter – (attended message) Detector To memory
Sensory memory: holds all of the incoming info for a fraction of a second and then transfers it to the next
Filter: identifies the attended message based on its physical characteristics – tons of voice, pitch, speed,
accent Detector: processes info to determine higher-level characteristics of the message, such as its meaning
Short-term memory: receives the output of the detector; holds info for 10-15 s and also transfers info into
long-term memory, which can hold info indefinitely
This model was also called a bottleneck model because the filter restricts info flow.
Broadbent‟s model had some predictions that turned out not to be correct – he thoughts that info in the
unattended info should not be accessible to consciousness.
This was disproved by an experiment demonstrating…
The cocktail party effect: a person is selectively listening to one message amount many yet hears his/her
own name or some other distinctive message such as “Fire!” that is not being attended
Some experimenters showed that info presented to the unattended ear is processed enough to provide the
listener with some awareness of its meaning.
Ptcs presented with “Dear 7 Jane” (attended) and “9 Aunt 6” (unattended) – they heard “Dear Aunt Jane”
Anne Treisman‟s modification of Broadbent‟s theory – Attenuation theory of attention (“leaky filter
Messages Attenuator Attended message Dictionary unit To memory
--> Unattended message -->
Attenuator: analyzes the incoming message in terms of 1) its physical characteristics, 2) its language –
how it‟s grouped into syllables of words, and 3) meaning – how sequences of words create meaningful
Treisman proposed that the analysis of the message proceeds only as far as is necessary to identify the
Ex: if there are two messages, one in a male voice and one in a female voice, then analysis at the physical
level is adequate to separate the low-pitched male voice from the higher-pitched female voice. If,
however, the voices are similar, then it might be necessary to use meaning to separate the two messages.
Dictionary unit: contains stored words, each of which has a threshold (the smallest signal strength that can
barely be detected) for being activated
According to Treisman, words that are common or especially important, such as the listener‟s name, have
low thresholds, so even a weak signal in the unattended channel can activate that word, and we hear our
name from across the room.
Late selection models of attention: proposed that most of the incoming info is processed to the level of
meaning because the message to be processed is selected
Cognitive Resources, Cognitive Load, and Task-Irrelevant Stimuli Cognitive resources: refers to the idea that a person has a certain cognitive capacity, which can be used
for carrying out various tasks
Cognitive load: the amount of a person‟s cognitive resources needed to carry out a particular cognitive
Low-load tasks: easy, well-practiced; use up only a small amount of the person‟s cognitive resources
High-load tasks: difficult, maybe not as well-practiced; use more of a person‟s cognitive resources
Nilli Lavie has proposed that the amount of cognitive resources that remain as a person is carrying out a
primary task determines how well the person can avoid attending to task-irrelevant stimuli.
Flanker compatibility task: task in which ptcs are told to carry out a task that requires them to focus their
attention on specific stimuli and to ignore other stimuli
Compatible flankers: associated with the same response as the target; fastest response
Incompatible: associated with a different response than that target; slowest response
Neutral: no association; intermediate response
Because pushing a key in response to an easily visible target is easy, this task wouldn‟t use all of a
person‟s cognitive resources, so some of them would remain available. If this is so, we would expect that
the flankers stimuli will be processed even if the ptc doesn‟t intend to processes them.
When you are involved in a low-load task, you are able to process additional information because
cognitive resources are available. In contrast, if you are involved in a high-load task, potentially
distracting stimuli are more easily ignored due to the unavailability of cognitive resources.
Stroop effect: it takes longer to name the colors of words than the colors of shapes; names of the words
cause a competing response and therefore slow responding to the target – the color of the ink; the task-
irrelevant stimuli are extremely powerful, because reading words is highly practiced and has become so
automatic that it is difficult not to read them
The ability to divide attention – focus on two or more tasks – depends on a number of factors, including
practice and the difficulty of the task.
Divided Attention Can Be Achieved With Practice: Automatic Processing
Automatic processing: a type of processing that occurs 1) without intention and 2) at a cost of only some
of a person‟s cognitive resources
Practice makes divided attention possible as it eventually results in automatic processing.
Divided attention is possible and can become automatic if tasks are easy or well-practiced.
Divided Attention When Tasks Are Harder: Controlled Processing Controlled processing: paying attention to specific stimuli in a much more focused and controlled way for
a harder task than for a well-practiced, easy task
Divided attention becomes difficult and can require controlled processing when the task is made too hard.
Distractions While Driving
There is a connection between cell phone use and traffic accidents. A survey of accidents and cell phone
use in Toronto showed that the risk of a collision was four times higher when using a cell phone than
when a cell phone was not being used.
The problem isn‟t driving with one hand. It is driving with fewer cognitive resources available to focus
attention on driving.
People identify talking on cell phones while driving as risky, but they think others are dangerous, not
Attention and Visual Perception
Attention is so important that, without it, we may fail to perceive things that are clearly visible in our field
Inattentional blindness: being “blind” to a stimulus presented simultaneously with an attended target
Change detection task:
1. Ptcs presented with