Attention Processes

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Attention Processes

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Attention Processes 'the focusing of awareness on a narrow range of stimuli ... Selective filter theory (Moray, 1959) Attenuation model (Triesman, 1960, 1964) ... – PowerPoint PPT presentation

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Title: Attention Processes

1
Attention Processes
the focusing of awareness on a narrow range of
stimuli or events, and the ability to sustain
and shift that focus.
2
Attention

It not possible to focus or attend to all of the
stimuli impinging on us from our internal and
external world at the same time.
Therefore we selectively attend to information.
Often times the information we attend to has to
do with changes in our internal or external
world.
As with our basic sensory systems we tend to
adapt to the usual or normal and notice the novel
or unusual.
Attention is applied selectively, events that are
important to survival usually have priority

3
Attention

Attention is the means by which we actively
process a limited amount of information from the
enormous amount of information available through
our senses, our stored memories, and our other
cognitive processes
Attention is not a unitary process! There are
multiple processes that are defined under the
label of attention.
At least four basic types factors that appear to
be involved in attention.
These include (the name of the factor is in
parenthesis)
ENCODING-The ability to encode information
(Mnemonic/Numerical)
FLEXIBILITY-The ability to shift attentional
focus from one point to another (Shift).
VIGILANCE-The ability to sustain attention over
time (Sustain)
PERCEPTUAL/MOTOR RESPONSE-The ability to focus on
a stimulus and execute a motor response
(Focus-execute).

4
Neuropsychological Evidence

Neuropsychological evidence indicates that there
are a variety of functions that may be linked to
attention
The ability to select stimuli for processing
The ability to focus attention
The ability to sustain attention or maintain
vigilance
The ability to shift focus of attention
The ability to modulate the intensity of
attention
The ability to avoid being distracted

5
Functions of Attention

Divided attention
Vigilance and signal detection
Search
Selective attention

6
The relationship between Attention Consciousness

Attention is the first process necessary for the
transfer of information. It also is the process
that selects information for conscious thought.
However conscious processing capacity is very
limited, therefore attention simultaneously
prohibits other information from reaching
consciousness.
Consciousness includes both the feeling of
awareness and the content of awareness, some of
which may be under the focus of attention
We know that unattended information still
activates the sensory receptors, and thus must
appear on the sensory register. But what happens
to it? (decay from the register because it was
not selected? Does it get processed at all? Can
it affect behavior later?).
Although unattended information does seem to get
processed to a certain degree it does not appear
to be able to affect behavior without our
knowledge!
Studies on subliminal perception (perception
without awareness) seem to indicate that our
behavior cannot be influenced by information
below the threshold of awareness and hidden in
advertising or other messages (e.g. study tapes).

7
More on Consciousness

Consciousness is the awareness of internal
external stimuli and it includes the following
characteristics.
Your awareness of external events
Your awareness of your internal sensations
Your awareness of yourself as a unique being
having the above listed sensations (self
awareness).
Your awareness of thoughts about these
experiences.

Consciousness is your ability to monitor yourself
and your environment so that percepts, memories,
and thoughts are represented in awareness such
that you have the ability to control yourself.

8
Attention, Consciousness, evolution

Animals like simple worms have a limited sensory
capacity, and an equally limited repertoire of
behaviors, animals like dogs have a much more
sophisticated sensory capacity and a
corresponding increase in behavioral options.
Primates (including humans) have gone much
farther, thus we see that as sensory and motor
capacity increase, so does the problems of
selecting which behaviors to use.
Furthermore, as the brain expands, memory
increases, providing yet another variable in both
stimulus interpretation and response selection.
Most importantly as the number of sensory
channels increase, there is a need to correlate
the different inputs into a single reality
One way to explain these evolutionary changes is
to posit that as the brain expands to increase
sensory-motor capacity, so does the process of
attention.
The clear implication is that consciousness is
not a dichotomous phenomenon, there is a gradual
evolutionary increase in consciousness, that is
correlated with the ability to organize sensory
and motor capacity.

9
Historical Theories of Consciousness

The contents of your consciousness are always
changing, rarely if ever does it come to a
complete standstill!

William James, the father of American Psychology
coined the term stream of consciousness to
refer to the ever changing nature of your
conscious experiences.
If you could record the conscious experience you
would have a pattern that fluctuated at a rapid
pace with vary little apparent order.
10
Historical Theories of Consciousness Variations
in Levels of Awareness Sigmund Freud

Freud argued that there were different levels of
consciousness, and that the stream of
consciousness has depth.
He argued that much of peoples drives and
motivations came from unconscious needs, wishes
and conflicts that lie beneath the surface of the
conscious awareness.
In other words consciousness is not an all or
none affair, conscious and unconscious processes
are qualitatively different levels of awareness.
Freud was the first to recognize this phenomenon
but modern theorists now routinely discuss
different levels of consciousness.

11
Experimental Evidence for Variations in Levels of
Awareness Selective Awareness
Studies of selective awareness have continued to
reinforce the theory that there are qualitatively
different levels of awareness. Not all of our
actions are carried out at a conscious level

Anesthesia studies (e.g. reporting data while
under anesthesia).
Sleep studies (e.g. responding to tasks while
asleep).
Selective responding (e.g. parents responses to
infants selective responses while driving).
Selective Attention (The Broadbent Studies).
The cocktail party effect.
Automaticity dissociation

12
The Role of Attention in Memory

The definition of attention is the focusing of
awareness on a narrow range of stimuli or
events.
On important function of memory is the selection
of input.
Attention is crucial for getting information into
memory if you intend to remember it at a later
time.
Although information can enter memory in the
absence of focused attention it can be very
difficult to consciously retrieve without
attending to it.
Attention is likened to a filter that allows
some information into conscious awareness while
screening out the rest.
The question is at what stage does the filter
operate?

13
Early Cognitive Models of Attention
14
Early Research on Attention

Our ability to behave consistently and rationally
depends on selecting information from the
environment which maintains continuity in meaning
with what has occurred before!
That means we must select some information off
the sensory registry for further processing and
exclude extraneous information.
A major focus of early research in attention has
been to localize the process of attention in the
pattern recognition process.
That is, does the decision to further process or
respond to sensory information occur prior to
activating the meaning of that information.
Do we completely block out the unattended
material, or do we process the meaning of the
material before deciding to ignore it (e.g. the
cocktail party effect)?
How do we select what to attend to?

15
Selective Attention

Early selection vs. late selection models of
attention.

16
Filter Models of attention Early Selection

Filter models address the question of where
meaning is assigned to information.
Early selection models assume that only 1 stream
of information is allowed to reach the stage of
meaningful processing. Unattended information is
actively filtered or blocked early in processing.
These models assume that attention operates early
in the information processing sequence.
This would prevent extraneous information from
competing for the highly limited resources for
higher order processing.
Two early selection models of attention are the
Switch Model (Broadbent, 1958), and the Filter
Attenuator Model (1964).

17
Filter Models of attention Switch Model

Attention operates like a switch, directing input
into one message or input channel or the other.
The message is then fully analyzed for meaning
and available to consciousness.
The switch is an all or none system so any
additional messages are completely blocked and
will decay off the sensory register.
Attention is attracted and maintained by the
sensory or physical characteristics of a message
(e.g. identified characteristics like formant
information in speech continue the data stream).

This model was examined using Dichotic Listening
Shadowing Studies.
18
Filter Models of attention Filter Attenuator
Model

Filter attenuation model was a modification of
switch model.
This models suggests that attention operates like
an attenuator, that is it allows gradations of
information through, it is not all or none.
Attention, is a matter of degree, that is
simultaneously some of the information in the
unattended message gets through to pattern
recognition
This model also assumes that changes in physical
cues attract the attenuator BUT some of the
meaning of the previous message filters back and
influences attention (e.g. both sensory
semantic information)

Note this model still assumes that attentional
filtering occurs at the sensory memory level. The
attenuator allows for some attention to multiple
messages BUT it does not allow for any long term
effect of unattended information! Behavior is
influenced ONLY by conscious content.
19
Problems for early Selection Models

While moving from switch models to attenuator
models allows for the processing of multiple
inputs and increases the number of activities
that can be performed it still presents a
problem.
The analysis selection of sensory signals seems
to require recognition of information before it
is processed. How can we sift through various
sources of information for continuity of meaning
without checking the meaning of ALL sources?
It is logical to assume that all sensory input
activates a meaningful representation and
selective attention is a matter of choosing which
input to respond to.
These models are know as late selection models of
attention.

20
Filter Models of attention Late Selection

In contrast to the assumption that information is
filtered or blocked prior to input, all
information is assumed to activate its long term
memory representation
e.g. All information is recognized
However, the human system is assumed to be
limited in the ability to organize a response to
all of the sensory input.
We are not able to concentrate al all activated
information, therefore we must select some
fraction of that information to respond to.
What about unconscious processing of the
unattended information
Semantic priming studies using masking seem to
indicate that the meaning of information is
activated at an unconscious level.
This indicates that attention operates after
after pattern recognition, but attention also
selects among activated meanings and allows only
a limited amount of information to enter
consciousness

Shadowing and testing for content, immediate
testing
Shadowing testing for targets at intervals in
both ears (Treisman Geffen, 1967)
Semantic priming with the lexical decision task.
Increased speed to related words that follow the
prime
21
Differences Between Early Late Selection Models

The major difference between early and late
selection theories revolves around unconscious
processing.
However both theories agree that any long term
effects from unconscious processing of
information is impossible (e.g. late selection
Rapid decay, early selection no processing).

22
Capacity Models of Attention

Capacity models assume that our psychological
resources are finite, we have only a limited
amount of resources to devote to task
performance.
Different tasks require different amounts of this
capacity, and the higher the requirements the
lower the number of simultaneous tasks that you
can perform
Capacity models of attention propose that
attention is the process of allocating resources
of capacity to various inputs.

23
An Example of a Capacity Model

In this capacity model (Kahneman, 1973),
attention is controlled by 4 factors
Enduring dispositions (things that grab attention
in an involuntary way, e.g. your name or motion)
Momentary intentions (under conscious control
like shifting your gaze)
Evaluations of delay (what you want to do) with
the rule that if activities require more than
your capacity you will perform some delay some.
Arousal (varies with the state of arousal)
Secondary technique studies are used to study
capacity models (easy/hard anagrams reaction
time, easy/hard sentence completion Reaction
time e.g. Tyler, Hertel, McCallum, Ellis, 1979)

24
Notes about Capacity Models of Attention

Some tasks require more attention than others
some tasks are automatic and require less
attention resources
Automatic processes occur without intent
Automatic processes are not available for
conscious monitoring
Automatic processes do not require any of our
limited conscious capacity

25
Cognitive Neuroscience Approaches

Posners (1995) anterior frontal lobe and
posterior parietal lobe identifications
ERP approaches
Psychopharmacological approaches

26
Cognitive Neuroscience Evidence for Different
Attention Systems

At least three such attentional networks, for
alerting (achieving and maintaining an alert
state in preparation for coming stimuli),
orienting (selectively focusing on one or a few
items out of many candidate ones), and executive
control (monitoring and resolving conflicts in
planning, decision-making, error detection, and
overcoming habitual actions), have been
identified. Considerable functional neuroimaging
evidence has shown activities of these areas
highly correlate with the essential functions of
attention.

27
Neuroscience evidence

Attention seems to enhance or amplify neural
signals responsible for coding a particular
feature of an object.
This appears, based on PET EEG evidence, to
occur early in the information processing
sequence.

28
Attention Systems

A sketch of the three attentional networks. The
alerting network consists of the frontal and
parietal cortical regions particularly of the
right hemisphere. The orienting network consists
of parts of the superior and inferior parietal
lobe, frontal eye fields and such subcortical
areas as the superior colliculus of the midbrain
and the pulvinar and reticular nucleus of the
thalamus. The executive control network includes
the midline frontal areas (especially the
anterior cingulate cortex, or ACC), lateral
prefrontal cortex, and the basal ganglia.

29
ERP and attention

ERP Responses during a sustained attention task
in infants.
This slide demonstrates that the ability to
sustain attention is well developed early in

30
ERP and attention

Brain activity during attentive states and
inattentive states, with presentations of novel
familiar stimuli.

31
Evidence for Preconscious Processing

Priming
Tip-of-the-tongue phenomenon

32
Controlled versus Automatic Processes

Automatic processes no conscious control
Controlled processes conscious control

33
An example of Automatic Processing The Stroop
Color/Word Test
34
Instructions for the Stroop Test
In the next slide, you will see 3 columns with
words that are printed in different colors. Start
with Column One, read DOWN each column and name
all of the colors you see. Then move on to Column
Two, and finish up with Column Three. Remember,
don't name the words, name the colors of the
words.
35
The Stroop Effect

Column 1 Column 2 Column 3
Food Red Blue
Game Green Yellow
Book Yellow Red
Street Blue Green

Which Column Took longer to Read? Column
1 Column 2 Column3 Why Does This Happen???
36
Why

The Stroop effect occurs because word meaning
appears to be processed first and then interferes
with color naming.
Word meaning is automatically processed and
cannot be ignored, so this demonstration will
work even if you know what is going to happen!

37
Slips Associated with Automatic Processes