Attention & Spatial Representation
-What is Attention?
 Dorsal Stream: Visually guided action
 Attentional capacity largely in dorsal stream-parietal lobe
 William James: father of psychology explains as follows:
 Put all resources into one thing, suppressing other things, and has to have a
conscious component
 Attention can be defined as an internal cognitive process by which one
actively selected environmental information or actively processes
information from internal sources. In more general forms, attention can be
defined as an ability to focus and maintain interest in a given task or idea,
including managing distractions.
 Hemispatial/Spatial Neglect: Pt that is attention deficit (knock out model)
-What is Hemispatial Neglect?
 Impairment in attending to stimuli (or thoughts) on one side of space (usually left space),
not attributable to low-level visual deficits, such as hemianopia (blind pt. on left side,
probably damage on V1)
 Damage is most typically in the right inferior posterior parietal lobe (???)
 Attention is bilateral
 Usually RIGHT damage, LEFT unable to attend
-Behavior Test:
A. Line Bisection Test:
• Pt was asked to bisect a line draw on paper; Hemispatial Neglect pt draw the line far away
from center, towards the right sides. Could because of the pt could only see the right half of
line (Pt with right parietal lobe damage, neglecting the left side of line)
• Pt with left parietal lobe damage: draw line far away from center towards left.
B. Line cross out Test:
 Pt was asked to cross out all the little lines on paper. Pt was only able to cross out lines on the
RIGHT side of paper. Not able to attend the lines on the LEFT side of page.
 Change paper’s orientation to make pt pay more attention on the left side: performance
slightly improved -> Not visual problem. Hard to make them to pay attention on the
impaired side.
C. Drawing Test:
• Pt was asked to copy drawings. Pt was only be able to draw the RIGHT half of everything
• William James attention is a train of thought: thus predict when they imagine, only image the
half. Not be able to draw from memory (???)
• Confusion: Flower petal is half; leaves are complete. Clock number is half; frame is complete.
-> Attention cortex is not operated solely on object recognition system, it reaches out to
other systems.
Imagine Test
• Pt only able to describe the RIGHT side of the imaginary; only be able to tell the RIGHT half of a
consecutive number line. Eat the RIGHT side of plate
Neglect Can Tell Us…
1. Whether attention is multimodal or not…
• Multimodal: Hear rustling in the bushed and see the bushes moving (Evidence of attention
is multimodal: Things can occur together)
-Some patients neglect not only visual stimuli in the left, but also sounds and tactile stimuli ->
Attention is multimodal
•
Extinction: (???)
o Pt has right posterior parietal lobe damage. Only able to attend RIGHT side. Can’t attend
LEFT side. Behavior tests result show he is a pure neglect patient.
o Pure neglect patient: Left: do not see dots / Right: see dots on right / Both: see dots on right
-> Never be able to see / hear on left
o Extinction patient: Left: 100% on left / Right: 0% on the left / Both: 0% on the left.
 Reported see dots on left when show left trail / see dots on right when show right
trail / Both: only see one dots on right but not on left.
 Extinguish LEFT stimuli ONLY when things are presented simultaneously on BOTH
side.
 The presence of right stimuli extinguish the left stimuli, thus patient neglect the left.
Pure Neglect Pt
Left
❌
Right
✔️
Extinction Pt
✔️
✔️
Both presented
Only able see dots
on the right not left
Only able see dots
on the right not left
Use Extinction to ask if attention is multimodal: Vision, Touch, Audition
-Only Audition Test:
• Pt is able to attend tone on right side but not able to attend tone on left side (the same setting
as visual dots)
• Conclusion: Does not tell whether or not attention is multimodal, only tells us may there is an
audition attention system that works the same as the visual attention
-Multimodal Test 1: (left extinction means extinction left stimulus when right is present)
• Audition and vision at same time, Pair visual and sound stimuli together.
• Present dots on left / and tone on right -> left extinction PT only able to hear tone not able to
see dots, right distinguish the left. Vice versa.
• Conclusion: Strong evidence to suggest that attention is multimodal. The attention works as a
large system and reach out to multiple sensory attentions. A general system of attention is
operating across modalities.
-Multimodal Test 2:
 Touch on left: PT able to feel the touch
 Vision on right: PT able to see the dot
 Touch and vision happen simultaneously: Right extinguish left, unable to feel the Left stimuli,
only see the dot
 A general attention system talks to all modality, one damage would cause the other damage
(???)
2. In What Ways We Attend to stuff in space (spatial representation)
 Neglect patients are impaired in attending to one side of space (usually left), but left (or
right) of what?
 TRIP: Q: Is the t in trip on the left or right? A: right side of screen, left side of words.
 It depends on how we represent space.
Spatial representation
 Means of representing the location of an object, object part, etc. Object part in relative to
object is essential for recognizing object.
 According to Miller and Goodale: even ventral stream has location information

We represent the location of objects, objects parts, etc. relative to something: the reference
frame.
 Neglect Patients: Neglect left space, what is space?
Multiple reference frames
 Egocentric (viewer - centered): relative to your eyes, head, or body
o Eye / head / body, all move independently.
o Use eye centered maybe different from head centered
 Allocentric (environment - centered): relative to stuff in environment
 Object - centered: relative to the intrinsic axes of an object.
o Egocentric always play a part in allocentric and object centered
Frame of reference test:
 -Pt shown with trip on computer screen:
 All frame of reference shows TRIP on LEFT
 -We know which frame exists, by knowing neglect pt is able to do two frames but not the rest.
(???)
 Move his eye
o Egocentric retina based is right.
 Move his position as a whole to right
o Allocentric: Room based is right
Patient CS: Left Hemispatial Neglect
Right handed man, worked as salesman (normal intelligence), right-hemisphere stroke at age 66.
Damage to parietal cortex (dark black part, no cortex, a hole). Spoke language comprehension and
production intact. Intact visual fields. -> Study attention, deficit not because of language / visual
deficit
Hypothesis: Has face/object/place recognition intact (ventral stream is intact). Probably has
reaching / attention / OPA (visually guided navigation) problems (dorsal stream). -> Due to
NEGLECT ??? (ventral stream houses in??? and dorsal stream houses in)
Test Results: CS is a left neglect patient
• CS’s line bisection: matches with neglect test, cut the line more on RIGHT. Neglect the left side of
line.
• Line cancellation: cross all RIGHT lines off
• Draw from copy or from memory (train of thoughts): draw a clock with only numbers on
RIGHT; house only right side
• Suffering from LEFT neglect
• Word reading: not attend to the LEFT side of the word, and filled in himself
 Result: Tumble -> Rumble / Picked -> Backed
• Use Patient CS to test the hypothesis frames is true or not, or which frame we have
CS: Frame of reference?
-Control: -> Impaired
• Trip on left of his eye/head/body/screen: reported nothing
• Trip on right of his eye/head/body/screen: see Trip
-✔️Ego-centric:
• Retina-centric
 Control: reported nothing
 Move eye vision: reported TRIP
 Move the eye, PT is normal. The factor moved changed the performance of patients
 Conclusion: Brian represent stuff egocentrically, specially relative to eyes, at least
retina fram
 Head-centric
 Evidence: Neglect stuff on left his head, not right
 Body / trunk-centric, not retina-centric
 The PT after changing eye/head position, still behave impaired
 Then change body position relative to the paper of bisection. Pt impaired performance
on bisecting paper on left of his body and normal on bisecting paper on right of his
body
 Conclusion: Neglect stuff on the left side of his body not on his right
-> All spatial frame is not computed in the same way (???)
-✔️Allocentric: environment, relative to objects in environment
 Pt originally reports seeing world and dice: which on right of his eye/head/body/screen.
Neglecting LEFT.
o -> Conclusion: HAS BODY CENTRIC & ALLOCENTRIC DAMAGE
o Researcher rules out eye and head factor
o To test eye: move eye position, still only see world and dice. -> No improvement
 Evidence of body centric frame damage: Change body position by letting them turn upside down:
o Pt reports seeing the world only
o If it were body only, PT is expected to see the rabbit and world, since they are on the left
side of his body
o Evidence of Allocentric frame exist: because the he cannot see rabbit after lying down,
which is on left side of body and left side of screen.
-✔️Object-centric:
 Perhaps best studied with words because words have an intrinsic spatial orientation
 Most objects do not have a distinct left or right, where as words as a real left
and right
 e.x TRIP: TR on the left of trip, IP on the right of trip
 Essentially two reference frames, beyond retina-centric and allocentric
 Stimulus-Based (stimulus-centered)
 Relative to the word as presented
 Word-based (word-centered)
 Relative to the words in its canonical orientation
A. “HOUND”
• Shown with words “hound”: Egocentric: on the right: ND, on the left: OH
• Stimulus-Based (how the word is exactly presented): on the right: ND,on the left: OH
• Word-Based (how brain vitally presented): on the right: ND, on the left: OH
B. “HOUND” on left side of screen
• Retina centric: on the left: hound, on the right: nothing
• Stimulus based: on the left: HO, on the right: ND (shape presentation)
• Word based: on the left: HO, on the right: ND (identity presentation)
C. “DNOUH” Mirror Image the words
• Shown with words “hound”: Egocentric: on the right: OH, on the left: DN
 neglect ND
• Stimulus-Based (how the word is exactly presented): on the right: OH, on the left: DN
 neglect ND
• Word-Based (how brain vitally presented): on the right: ND, on the left: OH
 neglect OH
Ex
A. HOUND
Left
HO
Right
ND
B. HOUND on left screen
Left
HOUND
Right
C. DUNOH “mirror
image”
Left
Right
DN
OH
Egocentri
c
Stimulus- HO
ND
HO
ND
DN
OH
based
WordHO
ND
HO
ND
HO
ND
based
Stimulus based:
• ROUND: neglect HO, see ND, fill in information
• ROUND: (on right side screen): neglect HO, see ND
• HOUSE: neglect DN, see OH, fill in information
Word based: Uses Intrinsic Access
• ROUND
• ROUND
• ROUND
• No matter round changes relative to the screen position or mirror images. The brain is able
to see word in its intrinsic form.
-Usually damage on right parietal, neglect the left
Researcher then test her with object centric
-Words have intrinsic left and right
• Tower - Answer
• Yellow - Pillow
• Cabin - Robin
 Neglect the left side, and based on the right side, filled in her information
-Pt was asked to fixated at a point on screen, move the word to right side of visual field
• Ruling out the possibility: If she neglect because of egocentric / allocentric: She would say SAKE,
because pt can see the full words, not neglecting anything.
• Sake - Lake
• Hoof – Roof
 Evidence of it is not because of ego centric
-VB: Reading rotated words: up side down
• Only way to distinguish between the two is upside down flipping/mirror imaging (what is
difference), which enables us to tear apart which subset within the object-centric frame. ->
Neglect literally the left side of words
• Stimulus based: brain seeing the word as it is literally presented
 If the is stimulus based: mirror imaged of plant, tnalp NT on the left side of
word. Her answer would neglect NT, and fill in information based on PLA.
 Mirror image / upside down plant (tnalp) - plane TN on left, neglect TN
o Word based stimulus would response: slant, PL on left,
neglect PL
 Mirror image / upside down pear (raep) - pearl RA on left, neglect RA
 Mirror image / upside down score (erocs) - scorn ER on left, neglect ER
• Evidence of her neglect is due to the lack of stimulus based object-centric frame
• Word based: brain flipped the upside down the character to the normal.
Patient neglect on RIGHT: neglect the right side
-Stimulus based frame
• HOUSE
• HOUSE
• SOUND: fill in information based on DN
-Word based frame: fill in information based on HO (left side).
 HOUSE
 HOUSE
 HOUSE
Patient neglect on LEFT:
Stimulus based frame:
• ROUND
• ROUND
• HOUSE: fill in information based HO
Word based: fill in information based on ND
 ROUND
 ROUND
 ROUND
Patient NG: Object-centered (word-centered)
• The opposite of VB, regards neglect side.
• RIGHT neglect 79 years old women
• 8th frade education
• premorbid reading and writing good
• left-hemisphere stroke damaging parietal white matter & basal ganglia -> neglect the right
side
• Intact visual fields
 PASS: Line cancellation test: cancel lines on left, neglect right
 PASS: Draw a clock: put number on left, not on the right side. Able to draw
from memory, with the same neglect number on right
 FAIL: copy image, some imagery are intact, some are not.
-Object centered frame clue:
• She did not neglect the house and apple tree completely (on right side of paper), only neglect
the right side of apple tree / house (tells you???)
-A. Reading word aloud
• Pt has right neglect
• Hound - House, ND on right, neglect ND
• Sprinter - Sprinkle, KLE on right, neglect KLE
• Stripe - Strip, PE on right, neglect PE
B. Present words on left side of screen / visual field. On the left side, according to egocentric, should
not be neglected.
• To rule out the possibility of ego-centric and allocentric frame (how to rule out for
allocentric)
• Frown - From
• Expect - Express
• Allow - Allot
Mental Imagery
Definition
 The ability to represent, transform, and inspect visual information that is retrieved from
memory rather than perceived through the eyes.
o Transform: Rotate apple 90 degree
o Inspect: Zoom in the stem
Purpose
 Remembering the past
o Pt without mental imagery aphantasia
 Predict the future (e.x judge whether the sofa will fit down the stairway on moving way)
 Mental Practice (e.x sports)
 Daydreaming
Mental Imagery
 Most everyone agrees that humans can image mentally
 But scientists / philosophers disagree as to what s happening
 What perceptual / neural systems are engaged?
 Difficult to study
 Very subjective
 Nonetheless has been a hot topic in many fields
 Philosophy
 Psychology
 Neuroscience
Imagery Debate / Theories of Mental Imagery
A. Kosslyn: Depictive Theories (Analog)
-Picture-like (= visual system like): imaging is like seeing it
• If analog: Primary cortex, ventral system (LOC, FFA, PPA) lights up
-Uninterpreted  images, like pictures, can be ambiguous and have multiple meanings
• Rabbit/Duck picture: picture can be ambiguous, so can the mental imagery if indeed it is a
picture
-Determinate  images are the exact match to the picture
• Boat picture: asked to image that boat, imagining will be the exact image that was previously
shown. But if asked detailed question, people may not be able to answer those (not exact
image) (against the depcitive theory )
•
Imagine a star: exact 5 points
-Spatial format  pictures presented spatial information. Pictures have inherently spatial
information
B. Pylyshyn: Propositional Theories (Descriptive)
-Language-like  e.x Delicious / Red / Stem
•
If descriptive: Language area in cortex (not V1) lights up
-Verbal Shadowing  Listen to recording and repeat, interrupt the language ability (???)
-Interpreted  images cannot be ambiguous; symbols tell you everything you need
• Rabbit/Duck picture: Either a duck or a rabbit at the particular moment of us seeing it,
cannot be both, no ambiguity. A symbol duck can only be duck, not a symbol rabbit.
-Indeterminate  images can represent information in an indeterminate, not exact match to the
picture, e.x “many” instead of “four”
• Imagine the Taj Mahal: how many spikes? -> Not all mental imagine is determinate.
• Imagine a penny: don’t remember orientation -> Counter familiarity
-Spatial content  space is described by the symbols, perhaps why we feel like we are seeing it.
Spatial format is context, not format: language depicted location (upright/left). A language tree.
Behavioral Studies
A. Mental Rotation: Kosslyn’s Depictive theory
• Measurements of spatial transformations of the mental models of novel, geometric forms
• Mental Rotation Test  Subjects asked to determine as quickly as possible if they were the
same or different objects: by mentally rotating and match one with another
o Conclusion  Found a strictly linear relationship between angular difference
between the two objects and reaction time.
o Angle of rotation: angle rotated for pic A to match with pic B. As the mental angel of
rotation increases, reaction time becomes longer.
• Picture plane  rotate only on two dimensions
• Depth pairs rotate involve in third dimension
B. Image inspection (image-scanning task): Kosslyn & Colleagues (1978)
• Subjects memorized a fictional map (redraw it) -> to make sure the memory is correct, and
information pulls from it is correct
• Imagine black speck moving from straw hut to well, then press key
o If it is picture depicted, when asked to draw out the route, as the route gets longer, takes
longer time for pencil to draw. It takes longer time for brain to scan the image, and make
the connections between two spots.
o If it is language depicted, e.x the distance between straw hut to well is coded as close /
far. Time to pull out close / far is the same. Not reaction time difference as the route
distance gets longer
• FLAW
o This experiment assumes spatial information is only in picture, NOT in language, the
same with mental rotation task. e.x “In front of” is spatial information in language. (???)
o Language does not have spatial information only picture can show spatial
C. Image inspection (image size task): Kosslyn and colleagues
• It is difficult to perceive parts of an object if its retinal size is small
• Might it also be difficult to discern information in a visual image if its size is small?
o Imagine a goose and an elephant
o Imagine a goose and a fly
• Result Took subjects much longer than to identify a special part of the goose when it was
imagined next to an elephant. Shorter time when it was imagined next to a fly.
o Hold goose as a constant, changes the size of goose by changing its relative size (changing
retinal size) when comparing to elephant or fly
o
o
Make picture small, harder to see the details. The same applies to mental images
Everything happen on vision, happen the same to mental image
Mental rotation / Scanning depictive theories
-Put mental image into perception which is picture depicted
-Visual mental images preserve spatial relations and structural properties
 Time to scan: between two points is proportional to the distance between the points
 Mental Rotation: Time to rotate is proportional to the extent of rotation
-Three evidences:
 Mental rotation
 Time to Scan
 Image Size
-From this type of evidence, researchers have argued that mental imagery taps into the same
neutral representations as perception
How would propositional theory argue against these three evidences?
• Mental Rotation Rotating the language tree to match
• Time to scan Travel on language tree branches takes time too.
Pylyshyn - Propositional account
• Put mental image into cognition, which is language depicted
• Cognition is inherently symbolic (an abstract representation of perceptual input)
• Can be describe previous results: He never said spatial information is not in his theory. But
Krosslyn assumes language does not contain spatial information.
• The information at the same, the difference between the two are how the information are
represented.
-Reinterpreting figures (???)
• Pylyshyn (1973); Chambers & Reisberg (1985)
-Inton Peterson - Experimenter demands
• Experimenter bias: Subjects deduced that experimenters expected scanning times to increases
with distance (???)
• There is no scanning, no 1+1+1
• Cannot be completely ruled out by any existing behavioral study
-Impasse…
• Anderson and Farah argued that behavioral studies alone weren’t enough to distinguish depict
ice from propositional theories
• Turn to brain imaging and / or patients
• Basic idea: if regions of visual cortex that are known to process visual information are also involved
in visual imagery (V1), then strong support for depictive theory.
• Kosslyn: Cognitive scientist, only values behavior studies result. Does not allow at beginning.
Primary Visual Cortex V1: Kosslyn et al (2000)
-Are the same brain areas involved in perception and imaging?
-PET study, specifically testing for visual cortex activation, put radioactive material into person
(invasive). fMRI is preferred because it is not invasive.
• Asked subject to image common objects
• Showed them pictures of the objects beforehand
• Auditory clue triggered which object to image (what is the purpose of sounds)
• Ring the sound for subject to pull out the mental image
-Found V1 (primary visual cortex) to be more activated during imagery than rest
• Person is doing mental imaging vs. subject doing nothing
• Results  Find strong activation in occipital lobe (V1, white area). Don't see significant
activation of the language area (left lobe)
• Conclusion  Mental image uses the same mechanism as seeing the image, support the
depictive hypothesis
-FLAW Imagine vs. Nothing
• Cannot just compare with nothing, a better control
• Attention problem
• Better comparison: Compare the brain image when subjects imaging it and seeing it
Kosslyn et al (1993)
-Purpose  Compared neural activity (PET) during perception and imaging task
-Task  Image the target letter as uppercase and filling the grid
• Does the letter contain the cell with the X when you see F and when you imagine F? (purpose of
asking this question???)
• Match perception with attention, by the only difference is seeing uppercase F.
-Subtracted out neural activity during perception
• Found more activity in early visual cortex during imagery -> supporting depictive theory
• Also found neural activity outside of visual cortex -> Since imaging is harder than perception,
thus the extra cortex may responds to attention / task difficulty. Maybe the whole brain
lights up because tasks are harder.
Consciousness
-Central question for the day: Which statement do you feel more comfortable with?
-“I have a brain” or “I am a brain”
What is consciousness?
-Self-awareness (awake vs. sleeping; coma)
 But isn’t this just another expression for consciousness?
-Having the capability of thought?
• But what are the defining features of thought?
• Ability to adapt to the environment?
• Self-monitoring?
-Having emotions “qualia”
• Does this mean that our “non-emotional” thoughts are not conscious?
Four Questions:
1) Does non-human consciousness exist, and if so how can it be recognized?
2) How does consciousness relate to language?
3) Can consciousness be understood in a way that does not require a dualistic distinction
between mental and physical states or properties? How does a hunk of men give rise to
consciousness?
4) Can it ever be possible for computing machines like computers or robots to be conscious?
-Consciousness is something that is true of the brain, and it involves the control or production of
voluntary actions, and it exerts control, over individual mental processes
• This definition captures some intuitions about what must be true of consciousness, but doesn't
provide any insight into what really drives consciousness
• In other words: consciousness is defined only by what it must involve, not by how it
accomplishes the operations that define it… underscored our near complete lack of
understanding (cant even frame the problem)
-It Involves the brain and awareness
A. The state of being aware of an external object, or something within oneself? Perception
(seeing) and Cognition?
• Sensation: least processing. e.x light sends retina, retina to brain, no interruption
• Perception: some interruption. e.x that’s a face
• Cognition: Memory, executive orders
• Action: More testable for neuroscientist
B. The quality or state of being aware, characterized by sensation and emotion? The feeling of
awareness? “Qualia” (raw feels) - what is feels like to feel pain or to see red.
• More interested to philosopher
A. Perception and Cognition?
Two school of thoughts: Is consciousness a direct consequence of the physical brain?
• Dualism (by Descartes - NO)
• Mind (immaterial; thought) and body (material; sensation) are two different things
• Possible to double existence of a body or physical existence, could all be a dream. But
cannot double existence of your mind
• Sensation is the consequence of body. Thoughts is not a part of body (sensation).
Thought can exist apart from body.
• I think therefore I am. Thought / mind / soul are different from body.
• Inputs are passed on by the sensory organs to the pineal gland in the brain and from there to
the immaterial spirit. While being independent, the sense (perception) and thoughts
(cognition) are communicating via gland
• Sensory/Perception <—(pineal gland)—> Thought (Cognition)
• Some notion of biological foundation for consciousness, but fundamentally a “dualist account”
• According to Descartes: more comfortable with “I have a brain”
-Molism Francis Crick - YES, mind = brain (material)
• We assume so: this is the starting point go most scientific ventures into consciousness
• “Your joys, sorrows, memories… are in fact no more than behavior of a vast assembly of
nerve cells and their associated molecules.” - The Astonishing Hypothesis
• “You are nothing but a pack of neuron”
• Denying “I have a brain”. Support “I am a brain”. There is no immaterial / material difference
o Francis Crick: more comfortable with “I am a brain”
• Brian = handware, Mind = software
Francis Crick: How can we test that you are a brain?
• Two brains communicate through corpse Callosum (CC)
Are you of two minds? Support I am a brain (Two brains)
Language and Consciousness
-Out intuition is that we have a single unified consciousness. But is this reality, or an illusion?
-Split brain patients have the corpus callous severed, usually to alleviate severe epilepsy. Thus, the
lines of communication between the hemispheres are cut, creating two largely independent “brains”
• Recall that the right hemisphere controls the left side of the body, while the left hemisphere
controls the right side of the body
• Each hemisphere also initially gets visual input from the opposite visual field, so possible to
ask a question to each hemisphere separately.
-Question  Do the two split hemispheres now house two separate conscious entities?
-Experiment Setting
•Patients have to be fixated on visual field
•Present FACE (smily image) on right VF, ask patient to say it (language houses in left
hemisphere). ABLE TO DRAW (dorsal stream is aware). Left hemisphere visual cortex sees
a smily face.
-Conclusion / Results 
• Support YOU ARE A BRAIN, can even be two brains. One is not aware of the other.
• Cut corpse Callosum = cut communication, single dissociation
• Right and left V1 is not connect with CC. V1 pass information to V2, and V2 start talking to
CC.
• Suggests that there are competing “yous” inside of you; you have two minds.
• Perhaps we are aware in only one of them (the left hemisphere, cause it has the language
component)
• Left is more aware than right because of the language component
• Don’t know for sure if the right is aware of face, using language as an evidence
Neutral Correlates of Consciousness (NCC)
-Francis Crick pioneered the quest to understand the neutral basis of conscious awareness (or NCC)
• If we are the brain, there must be some brain regions represent consciousness
-Some of the working assumptions that he outlined:
1. There is something to be explained, it is not magic
2. Consciousness awareness has a physical instantiation in the brain. This the assumption of
materialism or physicalism and DENIES dualistic notions of consciousness.
3. Some animal species (ex. nonhuman primates) possess at least some aspects of
consciousness awareness, particularly with regard to sensory experience. Evidence:
Monkey behaves very much as humans would when they are shown certain sensory events.
Animal is conscious as well, because they have a brain
The neuroanatomy of monkeys and humans is very similar
4. Claim 3 is accepted largely as a convenience. Otherwise could not do many experiments.
-Hypothesis  So then what are the neutral correlates of consciousness?
• A particular brain area?
• Multiple brain areas?
• How they are connected?
-Two general approaches to question of what brain area is most closely tied to consciousness
• 1) What happens to perception / behavior without brain area?
• Causal evidence: Knock out brain area
• 2) Examine neutral activity during periods in which perceptual experience fluctuates despite
an unchanging visual input (e.x binocular rivalry).
• Keep the brain area intact, manipulate the experience
• Rabbit duck example. The same visual info but changes the cognition.
• When is awareness identity flipped? What is responsible for that?
1) What happens to perception / behavior without brain area?
Blindsight: Weiskrantz et al. (1974) & Brain, 97, 709-728
-Is consciousness in a particular brain area?
-Individuals who have selective damage to area V1 (via trauma, stroke), or who had V1 removed
surgically, report being blind in the affected part of visual space
• For example, damage to right V1 affects the left visual field
-Visual field in patients who had area V1 in his right hemisphere surgically removed to treat
headaches due to malformed vasculature (vein and arteries). Dashed lines encompass good visual
area (everything else cannot see).
• See everything on the right visual field for both eye, not the left visual field.
• Grey area stands for good area on blind VF
-Blind people not conscious (???)
-Conclusion 
• Patients are still visually processing the information
• fMRI should still show lights up for ventral / dorsal stream (not V1, damaged)
• Selective damage to RIGHT V1, report being blind in LEFT visual field
• However, if these individuals are asked to point to an object or to reach out and grasp an object
(in dorsal stream) in the blind field, they can do so accurately, even though they claims are just
guessing. -> They can visually process the object on blind VF, but are not aware / conscious of it.
• Similarly if they are asked to report on an object in the good RIGHT VF, the simultaneous
presentation of objects in the impaired field can influence those reports.
• A picture of nurse on blind visual filed, they report seeing nothing.
• Then a picture of doctor / dog on good visual field. Good VF is primed to recognize doctor
faster than dog.
• Presentation on impaired VF can affect the decision on intact VF. Brain unconsciously
processed the nurse stimuli, but the patient is not aware of nurse picture.
Result: V1 IS NCC
• Reported to be aware of nothing (blind) -> no visual awareness
• Patients show evidence of visual processing (point correct with blind VF & primed by nurse)
• Dissociating awareness and vision. Knocking out V1 and lost awareness.
How about the ventral stream (or temporal lobe)?
-Circle Image:
• The ventral stream gives rise to our conscious visual experience, while the dorsal stream is not
accessible to perceptual awareness
• Ventral stream - fooled by illusion. Dorsal stream - NOT fooled by illusion.
• Ventral stream IS aware, is fooled. Dorsal is NOT aware, not fooled by the awareness.
• Conclusion: Ventral stream is NCC
-Ventral stream (vision for perception)
• Important for perceiving objects and faces
• Gives rise to consciousness visual experience
• Represents the enduring aspects of objects
-Dorsal stream (vision for action) HOW & Unconscious
• Important for visually guided action (reaching and grasping)
• Not acceptable to consciousness
• Operates online
2) Examine neutral activity during periods in which perceptual experience fluctuates
despite an unchanging visual input
Binocular Rivalry
-Experiment setting:
• Glass: on the screen, the two images are superimposable. On VF, only see one (house / face) at
one time.
• Means of holding stimulus constant, but inducing alternations in the conscious experience of an
observer
• Binocular rivalry is competition between two neutral ensembles as a result of two very
different images coming into the two eyes
• Normally occur two eyes receive virtually identical images, and we see one thing.
• However, when information is incongruent, something very different happened
• Our percept flips back and forth, and thus only aware of one at a time.
• Controlled flip (non-rivalrous): Only green face to one eye, red house to another eye. Brain
never see those two on top of each other, only see one condition at one time. What is being
shown is: one on the top of each other.
 FFA is stronger on the right hemisphere (left on picture). Scene region is on both
hemisphere.
 On average, each interpretation will stay dominate for ~2sec or so
 Generally, the switching of perceived image is beyond voluntary control. Rivalry is out of
control.
-Results 
•
Non-rivalrous
• See green face and then red face, not superimposable on screen.
•
Rivalrous (both present at the same time)
• When Red dotted line is above blue solid line, means the brain is aware of the House
stimuli right now. House wins over face. Aware: when face presented, blue (FFA) is
above red (PPA)
-Conclusion 
•
We found that during rivalry between a face versus a house, face and house selective extra
striate visual area (respectively illustrated in green and red) tightly reflect the observers’
conscious perception not the stimulus itself