• Refers to selecting
certain stimuli from
among many and
resources on those
• The selection of some
for further processing in
• Allows us to focus on
what is important at
the moment and to
ignore the rest.
William James (1890)
• Described attention as, “the taking possession by the
mind, in clear and vivid form, of one out of what seem
several simultaneously possible trains of
thought….Focalization (and) concentration of
consciousness are of its essence” (pp.403-404)
• When attention fails, we are left scatterbrained and
unable to function.
Cognitive research on cell
phones as a distraction should
inform our public policy debates
about whether they should be
prohibited while driving in much
the same way that alcohol use is
• Is a commonly diagnosed
psychiatric disorder that occurs most
often in children younger than
seven. They are easily distracted and
excessively restless and impulsive.
• ADHD is diagnosed when
inattention, hyperactivity, and
impulsivity are frequent and severe,
beyond the range of normal
behavior in young children.
Address the selective nature
Postulate a bottleneck in the
flow of information from
initial sensory processing to
registration in conscious
• Refers to the ability to perceive a particular stimulus of
interest while ignoring numerous other stimuli.
• Two or more stimuli share cognitive resources.
LISTENING – both
ears receive stimuli in
participants are asked
to attend to only one
ear or channel.
• SHADOWING – the
participant repeats aloud
the stimuli presented to the
attended channel and
ignores the stimuli
presented in the unattended
• Refers to an attentional filter that operates after sensory
processing but prior to meaningful semantic processing.
• The model also included a store of conditional
probabilities about past events, what today is called long-
• Proposed a model to account
for the findings with the
• Refers to an attentional filter that lowers the strength of the
sensory signal on the unattended channel.
• The degree of perceptual analysis received by an item depends
only in part on its signal intensity.
• Refers to an attentional filter
that operates after meaningful
semantic processing but prior
to response preparation.
• All stimuli are recognized but
are narrowed to the most
pertinent ones during response
• The words are fully perceived,
but then the perceiver responds
only to the most pertinent item.
• Selective attention may result from filtering of the
unattended channel. The filter could occur at an early
stage, just after sensory processing, or at a late stage, after
semantic processing. A third possibility is that the
unattended channel is attenuated rather than filtered
• Address the allocation of resources to specific
• Recognize that one or more bottlenecks exist
but add the assumption that mental processes
compete for limited resources as well.
• Capacity theory
assumes that attention
is limited in overall
capacity and that our
ability to carry out
depends, in part, on
how much capacity the
most of the capacity,
leaving little, if any,
for the unattended
• The capacity approach conceives of attention as mental
effort. The more a task requires of a limited pool of
available capacity, the more mental effort the person
• Example: try to solve these two arithmetic problems in
your head: a. 6 x 6 = ?
b. 32 x 12 = ?
• Mental effort increases as the proportion of available
attentional capacity increases. One way to measure
mental effort is through increases in reaction time to a
secondary task that competes for limited attentional
capacity with a primary task.
• Multiple resource theories elaborate Kahneman’s
approach. The ability to perform two tasks concurrently
depends not just on their respective demands on capacity
but also on the specific resources required (e.g.,
perceptual vs. cognitive).
C.D. WICKENS (1980)
• Three dimensions of resources:
• Auditory vs. Visual perceptual modalities
• Perceptual-Cognitive resources vs. Response resources
• Verbal vs. Spatial Processing Codes
• Stroop (1935) devised an ingenious and somewhat
diabolical test to study automatic reading. The color terms
occur automatically and effortlessly. The color terms are
printed in an incompatible color of ink. The task is to say
aloud the color of the ink while ignoring the meaning of
the word itself.
• Errors and delays in responding are the usual result.
• Require little, if any, mental effort. Moreover, they occur
without intentional control; even when an individual
attempts to stop an automatic process from operation, it
unfolds anyway, as demonstrated by the Stroop effect.
• Operate outside the scope of conscious awareness.
• Processes develop automatically either through genetic
programming or as the result of extensive practice.
• Posner and Snyder categorized a process as automatic if it
met three criteria:
• Occurs unintentionally
• Occurs unconciously
• Operates without depleting attentional resources
• Intentional, conscious, and demanding of attention
• They demand extensive mental effort, they require
intentional control to operate, and they enter conscious
NEURAL BASIS OF SELECTION
• Neurons in the occipital
cortex act as feature
detectors tuned to respond
maximally to highly specific
visual features, such as a line
at a particular orientation.
• The line must stimulate a specific area in the retina of the eye,
which defines the receptive field for the neuron in question.
• A group of cells in the retina—the receptive field—all map onto a
specific neuron in the cortex that is “looking for” the feature to
which it is tuned.
• The control of these
changes in receptive
fields lies in the
thalamus, a structure
deep in the midbrain that
serves as a crossroad for
an extremely large
number of sensory
• Positron emission
scans with humans
increased blood flow—
neural activity—in a
portion of the thalamus
called the pulvinar
when observers receive
instructions to ignore
an irrelevant but
• This disorder is
characterized by a
failure to attend to all
areas of the visual
with damage to the
right hemisphere will
neglect objects or
events occurring in
the left visual field.
• Refers to a supervisory attentional system that inhibits
inappropriate mental representations or responses and
activates appropriate ones.
• It is important in planning, decision making, and other
complex cognitive tasks.
NORMAN and SHALLICE (1986)
• Executive Attention is always needed when:
• Planning or making decisions
• Correcting errors
• The required response is novel or not well-learned
• Conditions are cognitively demanding or dangerous
• An automatic response must be inhibited and overcome.
• When participants perform
the Stroop task in
conditions that permit PET
scans to be taken, a region
in the frontal lobe shows
strong activation. The
anterior cingulate gyrus
in the frontal lobe acts as a
system, inhibiting the
automatic response and
selecting the correct
• The disordered
appears to be in
part related to a
from a disorder
in the inhibitory
capacities of the
FEATURE INTEGRATION THEORY
• Posits that
be followed by
features into a
TREISMAN and GELADE (1980)
• Required observers to detect a target that differed from
distractor items of one dimension, such as color.
• Predicted that the number of distractor items should be
irrelevant to speed of detection if the observer could
automatically recognize all stimulus features in parallel.
• The target
popped out at
• The more
longer it took to
find the target.
• Refers to how the features that are distributed in multiple
brain regions are integrated to result in the perception of a
• Attention may be what binds the features together prior to
• A superthreshold stimulus that is
directly fixated for 200 milliseconds, a
long leisurely glance when attention is
(as usual) locked onto the fixation
point, is simply not seen.
• Provides a compelling, but disturbing,
demonstration that attention is
necessary for binding together features.
• Without attention and the binding that it
supports, perception fails.
• The interval of time after the target is presented when
other stimuli in the series are not perceived.
• This interval seems to be a refractory period following
the encoding of the first stimulus that prevents attending
to the second stimulus.
• Refers to unconscious
perception without attention.