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

• Capture errors
• Omissions
• Perseverations
• Description errors
• Data-driven errors
• Associative-activation errors
• Loss-of-activation errors

38
Theories of Feature Search

• Feature-integration theory (Triesman, 1986)

39
Theories of Feature Search

• Feature-integration theory (Triesman, 1986)
• Similarity theory (Duncan Humphreys, 1989, 1992)

40
Theories of Feature Search

• Feature-integration theory (Triesman, 1986)
• Similarity theory (Duncan Humphreys, 1989,
  1992)
• Guided search theory (Cave Wolfe, 1990)

41
Theories of Feature Search

• Feature-integration theory (Triesman, 1986)
• Similarity theory (Duncan Humphreys, 1989,
  1992)
• Guided search theory (Cave Wolfe, 1990)
• Movement filter theory (McLeod et al., 1991)

42
Theories of Selective Attention

• Filter theory (Broadbent, 1958)

43
Theories of Selective Attention

• Filter theory (Broadbent, 1958)
• Selective filter theory (Moray, 1959)

44
Theories of Selective Attention

• Filter theory (Broadbent, 1958)
• Selective filter theory (Moray, 1959)
• Attenuation model (Triesman, 1960, 1964)

45
Theories of Selective Attention

• Filter theory (Broadbent, 1958)
• Selective filter theory (Moray, 1959)
• Attenuation model (Triesman, 1960, 1964)
• Late filter model (Deutsch Deutsch, 1963
  Norman, 1968)

46
Theories of Selective Attention

• Filter theory (Broadbent, 1958)
• Selective filter theory (Moray, 1959)
• Attenuation model (Triesman, 1960, 1964)
• Late filter model (Deutsch Deutsch, 1963
  Norman, 1968)
• Neissers synthesis (Neisser, 1967)