Cognitive Neuroscience
and Embodied Intelligence
Attention and
Consciousness
Based on book Cognition, Brain and Consciousness ed. Bernard J. Baars
Janusz A. Starzyk
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Introduction
 Attention and consciousness is brain ability to focus and select
information, and then to perceive and understand it, using it to
think, memorize, recall, feel, plan and act.
 Attentional control mechanism determines what will become
conscious.
 We can say please pay attention but not please be conscious.
 Attentional selection leads to conscious results like eye movement
leads to conscious observation of the event that attracted out
attention.
 Consciousness include immediate perceptual world; inner
speech and visual imagery; traces of present time in memory;
recalling past experiences; feeling pleasure, pain, and
excitement; intentions, expectations, and actions; believes about
yourself and the world; and well defined concepts.
 We are conscious even we do not talk about it: the sight of falling
star, thoughts about our friend, difference in sounds ‘pa’ and ‘ba’.
 We control what we are going to be conscious of.
 We can start to read a book
 We can decide to pay attention to this lecture
 We can think about mother’s birthday
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Consciousness
 According to Bernard J.
Baars
 “Contrary to past beliefs, many
aspects of consciousness are
not untestable at all, as shown
by productive research
traditions on topics like
attention, perception,
psychophysics, problem
solving, thought monitoring,
imagery, dream research, and
so on.“

Figure shows how selective attention selects among
competing inputs.
 The spotlight in the Friston circle of brain hierarchies is guided
by frontal and parietal cortex but it selects visual cortex input. 3
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Consciousness

Polarities between conscious and
unconscious phenomena
Conscious
 1. Explicit cognition
 2. Immediate memory
 3. Novel, informative, and
significant events
 4. Attended information
 5. Focal contents
 6. Declarative memory
(facts, etc.)
 7. Supraliminal stimulation
 8. Effortful tasks
 9. Remembering (recall)
 10. Available memories
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Unconscious
Implicit cognition
Longer term memory
Routine, predictable,
and nonsignificant events
Unattended information
Fringe contents (e.g., familiarity)
Procedural memory
(skills, etc.)
Subliminal stimulation
Spontaneous/automatic tasks
Knowing (recognition)
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Unavailable memories
Consciousness

Polarities between conscious and
unconscious phenomena
Conscious
 11. Strategic control
 12. Grammatical strings
 13. Rehearsed items in
Working Memory
 14. Wakefulness and
dreams (cortical arousal)
 15. Explicit inferences
 16. Episodic memory
(autobiographical)
 17. Autonoetic memory
 18. Intentional learning
 19. Normal vision
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Unconscious
Automatic control
Implicit underlying grammars
Unrehearsed items in
Working Memory
Deep sleep, coma, sedation
(cortical slow waves)
Automatic inferences
Semantic memory
(conceptual knowledge)
Noetic (intellective) memory
Incidental learning
Blindsight (cortical blindness)
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Attention
 The term attention is used when there is a clear voluntary or
executive aspect.
 We ask people to pay attention and they can chose to do so or not
depending on their decision.
 Voluntary attention is involved in preparing and applying
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goal
directed
selection
for
stimuli
and
responses.
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Attention
Voluntary vs stimulus driven attention
 Automatic attention selects relevant stimuli particularly
prominent or unexpected.
 Automatic attention can be captured by human face, intense stimuli
like pain, or unexpected events.
 Selective, attention driven by stimuli is bottom-up.
 Executive, goal-driven attention is top-down.
 In general voluntary and automatic attention are mixed.
 We can train ourselves to respond to telephone ring
 When it rings we pay attention – is it voluntary or automatic?
 Initially it is voluntary, as we are learning to respond to it, later
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Attention
 Attention selects information for cognitive process
 Selection may be shaped by emotion, motivation and
salience and is under some executive control.
 Without flexible, voluntary access control, humans would not
be able to deal with unexpected emergencies or
opportunities.
 We would not be able to change habitual behavior to take
advantage of new opportunities.
 Without stimulus-driven attention we would not be able to
respond quickly to significant events.
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Thus we need both voluntary and automatic attention.
Experiments on attention
 Selective listening
 Subjects were presented
with two streams of speech
one to each ear
 They were instructed to
repeat each word out loud
 People only reported
hearing one of the two
different speech streams
 They selectively listen to a
single stream at a time
 They could switch between
the two
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Experiments on attention
 Visual attention is studied using the flanker task (Posner 1984)
 Subject focuses on the center fixation point – no eye movement allowed.
 The stimuli flashes just outside of the foveal region of maximum
resolution (flank).
 Then a target appears at the site of flank with 80% probability.
 When the target appears at the expected location the response time is
faster than without flank.
 When the target appears at the opposite location than the flank the
response time is slower than no flank.
 Attention network task
 This is a generalization of the flanker task to test three aspects of
attention: alerting, orienting, executive attention.
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Experiments on attention
 Visual search paradigm (Treisman and Gelade 1980)
 This tests stimulus driven attention.
 The red vertical bar pops out automatically in the first image due to
effect of parallel search.
 The same bar on the right hand side requires serial search and it takes
longer.
 Serial search involves voluntary processing by executive regions frontal
lobes and parietal cortex.
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Experiments on attention
 The Stroop color naming test





This tests reaction time to three different color naming cases.
The first one has written text unrelated to colors.
The second one has written text that correlates with colors.
The third one has written text with words different than colors.
While the first two tasks have a similar response time, the third takes
much longer.
 The well practiced skill of reading overwrites the color naming and
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requires executive control to correct the errors.
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Brain basis of attention
 William James wrote
that attention helps to:
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


Perceive
Conceive
Distinguish
Remember
Shorten reaction time
 For example attention to
a location dramatically
improves the accuracy
and speed of detecting
target at this location.
 Attention can be based on internal goals (finding a friend in the
crowd) or external environment (alarm sound, bright colors)
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Brain basis of attention
 An example of attention increased sensitivity:
 The recorded neurons are located in inferotemporal cortex (IT) – area
for object recognition.
 It responds better to some visual objects (flower) than to other.
 Study showed that neuron begins firing in anticipation of the preferred
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stimulus at a higher rate than for non preferred stimulus
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Brain basis of attention
 Brain must constantly
select between competing
inputs.
 Selective attention may
involve a binocular rivalry
when each eye receives
different input.
 Any sources of input that
cannot be integrated into a
single consciously perceive
whole tend to compete
against each other and
require selective attention.
 Prefrontal cortex guides
what is selected.
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Brain basis of attention
neurons
responses to
threat and
neutral faces
 What determines what object the attentional system selects?
 Attention cannot be understood without emotion, motivation,
and prominence.
 Salience maps that are sensitive to prominent events exists in many
regions.
 In visual system salience may be encoded down to V1 area.
 Biologically significant stimuli draw attention.
 Face recognition neurons respond very actively to threat faces. 16
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Brain basis of attention
 Multiple salience maps
has been proposed.
 For example:
 Posterior parietal cortex
controls a visual salience
maps, while
 Prefrontal cortex has a
map for top-down, task
relevant information and
 Superior colliculus has
attentional guidance
system to control the focus
of attention
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Brain basis of attention
 Human may learn to go
against a cue or usual
response.
 For instance he/she
may learn not to
respond to the
telephone ring.
 This involves
executive attention
control as in the
experiment shown on
figure.
 First the subject learns
to follow the cue like in
the flanker test,
 Then the rule changes
and the expected target
appears on the opposite
site of the cue.
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Brain basis of attention
 The executive attention
involve more prefrontal and
parietal regions.
 Figure to the right shows a
similar activation for
executive attention in Stroop
color-naming task
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Brain basis of attention
 Brain areas for
selective attention.
 Voluntary eye movement
is controlled by frontal
eye field.
 The anterior cingulate
plays a major role in
detecting and resolving
conflicting information.
 Right frontal and parietal
regions are control
spatial guidance to
attentional target.
 The pulvinar nuclei of the
thalamus and superior
colliculus provide eye
movement control.
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Brain basis of attention
 Most visible selective
attention is orienting
one’s sensory receptors
towards the object:
looking, sniffing,
listening, or touching.
 Visual selective attention
overlaps brain region for
eye movement control.
 Eye movements are highly selectional skills.
 They are controlled by both cortical and subcortical parts
 The cortical control include frontal and parietal eye fields guided by
explicit goals under control of dorsolateral-prefrontal cortex DL-PFC
 Subcortical control of eye movement is by superior colliculus SC 21
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Brain basis of attention
 In the past, tracking eye
movements required sizable lab
equipment.
 Nowadays this has been
reduced to a backpack size, so
visual attention can be studied
in a natural environment.
 All the brain subcortical regions
that control eye movement
contain visuospatial maps.
 These maps are synchronized
with each other to focus
attention on a selected visual
event.
 There is growing evidence that
the maps are synchronized with
gamma-band rhythms (about 40
Hz)
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Brain basis of attention
 Maintaining attention against distraction requires a significant
effort;
 E.g. trying to study when your roommate plays a loud music
 Shutting out the distracting activity may overload our processing
capability.
 Such shutting out is easier when you do more routine tasks (e.g.
listen to your favorite music).
 Thus mental effort comes from struggle between voluntary (goal
driven) and automatic attention.
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Brain basis of conscious experience
 Conscious cognition is close to
attention, however not identical.
 Useful experimental methods to
study consciousness include:
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Inattentional blindness
Visual backward masking
Change blindness
Attentional blink
Automaticity due to practice
Remembering vs knowing
Conscious vs unconscious word
priming
 You may be aware (conscious) of
reading this text but you may not be
conscious of the touch of your chair,
gravitational forces, background
conversation, your feelings for a
friend, or your major life goals.
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Brain basis of conscious experience
 Consciousness is not just the passive experience of sensory
inputs, but the active involvement and perception. “Self"-related
phenomena such as preference, social cognition, self-recognition,
self-modeling, reflection, and planning all may be central to an
understanding of consciousness.
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Brain basis of conscious experience
 Words may be unconsciously present in your memory before you
bring in a specific meaning.
 When you read that someone likes to fly, you do not bring to your
conscious mind other meanings of this word.
 They are still in your memory, so what mechanism brought the
correct meaning to your mind?
 Research supports that those other meanings were active
unconsciously for a few tenth of a second before your mind
decided on the right one.
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Brain basis of conscious experience
 Experiments compared seen and unseen, novel vs habitual skills,
conscious and unconscious processing of the ambiguous stimuli.
 Binocular rivalry is often used to study conscious vision by
delivering two different images to two the two eyes.
 In the example figure the middle picture disappears due to binocular
rivalry
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Brain basis of conscious experience
 As long as two different inputs cannot be integrated they will rival.
 There are many kinds of binocular rivalry:
 Two different orientations will compete against each other
 Different color patches will rival
 If objects in different eyes are moving in different directions, they will
rival
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 Pictures of faces and objects will rival.
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Brain basis of conscious experience
 The two neighboring inputs can be fused into a single object.
 You will see a 3D effect after fusion.
 Count how many woman’s faces you can see after fusion?
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Brain basis of conscious experience
 Can you see sphinx and pyramids?
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Brain basis of conscious experience
 Binocular rivalry allows comparison between conscious and
unconscious picture.
 Subject is wearing prism goggles so each eye receives different
pictures.
 These two inputs cannot be fused into a single object.
 Unconscious stimulus is still processed by the visual vortex but
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subjects
reports
only
the
conscious
one.
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Brain basis of conscious experience
 Visual backward masking.
 Subjects are presented two faces one after another.
 The smiling face is shown only for 20 msec.
 The brain identifies both stimuli but subject is not aware of the
smiling face.
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Brain basis of conscious experience
 Inattentional blindness.
 Subjects are asked to watch the basketball being tossed between
team players (white-shirted).
 Most subjects are not aware of the gorilla passing by even if it
stands and waves to camera.
 Ball throwing movie:
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Brain basis of conscious experience
 Unconscious processes has been studied in several categories:
 Implicit memory
 Amnesic patient were given a word like ‘assassin’, and could not
recall it later. However given a word fragment like ‘-ss-ss—’ they can
retrieve the correct word
 Implicit learning
 Children do not learn the language by grammatical rules but by
repetitions. The rules are inferred subconsciously.
 Implicit perception
 My occur when perceptual cortex is damaged (damage to V1),
parietal neglect (inability to perceive half of the visual space), face
blindness etc.
 Automacity
 Highly practiced and predictable skills become unconscious.
Automatic process consumes no attentional resources, nor does it
effect ongoing cognitive process or leave trace in the memory.
 Unconscious cognition
 Examples are priming or unconscious period between thinking of
question and realization of the answer.
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Brain basis of conscious experience
 Logothetis (2002) studied visual perception in macaque monkeys.
 They observed brain activities in case of visual rivalry.
 20% of neurons in early
visual regions (V1, V2,
V4) and about 40% in
areas MT and MTS
responded to the
dominant reportable
stimuli and similar % to
non-reportable stimuli.
 However, in object
regions of the brain
(areas IT and STS) 90%
of neurons fired in
response to reported
stimuli and none for nonreportable.
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Brain basis of conscious experience
Comparison of evoked
potentials in conscious
and backward masked
printed words.
Conscious words
maintain activities for
longer period of time
after presentation and
engage more brain
regions.
 Many researchers confirmed that conscious context mobilize frontal
and parietal brain regions.
 Dehaene (2001) used visual backward masking comparing brain
activities to a conscious words to the same words when they were
masked by a pattern.
 They used fMRI and evoked potentials to localize hot spots in the36 brain
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Brain basis of conscious experience
 Results that conscious context activate larger
regions in brain were confirmed by observing
responses of individual neurons, through
electrodes placed in different brain areas.
 Another example is conscious and
unconscious pain in which unconscious pain
barely reached cortex and conscious one
engaged large brain areas.
 While learning new tasks (like walking or
simple games) children are very conscious of
actions, but after they master it and action
becomes more automatic it becomes less
conscious.
 In an experiment with metronome subjects
were supposed to repeat its rhythm by
tapping.
 When rhythm was regular it was quickly
learned and automated with no activation of
executive control and dorsolateral regions.
 When rhythm was distorted randomly within
3% a little more brain activities were observed,
and when it was distorted by 20% a lot.
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Brain basis of conscious experience
Brain synchrony
 Technology allows to observe interactivity of the brain regions.
 Consider a conscious event like pointing to a cup. It involves activation of:
 Visual cortex to detect the cup, identify its size, location, shape and retrieve the
object memory
 Prefrontal, premotor and motor regions to decide to point into a cup, generate a
plan to move a finger, and move appropriate muscles.
 A decision to execute the action from prefrontal cortex, parietal spatial maps,
and triggering the motor action.
 Sensory feedback to check whether the action has been accomplished.
 Each of these steps requires millions of neurons firing in a coordination.
 Gamma activity (40 Hz) is involved in feature binding, theta activity is involved
in episodic retrieval from long-term memory, with rapid moments of synchrony
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between
various
brain
regions.
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Summary
Attention and conscious perception: selection and integration.
 Selective attention seem to be focusing of brain resources on the visual
cortex. In the opposite flow a visual object mobilize cortical regions.
 There is a rapid cycle between attentional selection and conscious
integration with simultaneous activation of parietal and frontal regions.
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Summary
 A neural net architecture
for selective attention
and visual
consciousness.
 Visual information flows
from V1 to areas V2-V4,
an d finally IT where
objects are detected.
 Each area has its
inhibitory neurons to
sharpen differences at
that level.
 Posterior parietal
neurons (PP) bias visual
neurons that detect the
object in that spatial
location.
 Prefrontal neurons in
area 46 are involved in
voluntary attentional
selection.
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Attention and conscious flows.
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