For unlimited access to Textbook Notes, a Class+ subscription is required.
CHAPTER 4 –
ROLES OF KNOWLEDGE IN COGNITION
Knowledge – is often thought of as constituting particular bodies of facts, techniques, and
procedures that cultures develop.
Ex knowledge of a guitar
KNOWLEDGE is information about the world that is stored in memory, ranging from
everyday to the formal. Can also be further defined as info about world that is true, that
you have justification for believing, and that is coherent
Bulk of your knowledge is mundane knowledge.
Knowledge is very important for any mental process!!
Without knowledge you would be unable to categorize things!!!! And lose its meaning!!
The whole point of categorization is to allow you to draw inferences, to allow you to
derive information not explicitly present in a single member of a category but available
because of knowledge of the characteristics of the group or groups to which it belongs.
So categorization can allow you to draw inferences about a certain object!!! If no
knowledge, then no inferences can be made!!!
Also, no knowledge means no appropriate action. If you do know or cannot assign any
meaning to a situation or an object (when no knowledge present), than you cannot
perform appropriate actions accordingly.
Without knowledge, you also cannot complete partial perception. Ex if an object is
blocking part of your name, you would perceive of it as not ur name, without knowledge.
But with knowledge, you would understand that part of ur name is hidden by the object in
front of it.
SOOOO .. Knowledge affects perception. Knowledge also affects attention, if you lack
knowledge, then you would not be able to focus your attention on the proper place.
The ability of understanding language requires knowledge, if no knowledge, then cannot
understand and understand the meaning behind what the other person is saying.
Without knowledge, cannot judge, not perform transitivity (ex if X is louder than Y, and
Y is louder than Z, then X is louder than Z). Transitivity is but one example of the many
ways in which knowledge enables sophisticated thought. Knowledge underlies virtually
every form that THOUGHT takes… ex decision making, planning, problem solving etc
So knowledge imp for categorization, action, inference, perception, attention, memory,
language and thought!!!!!!!!!!!!!!
Without knowledge, you’d simply by registering images of the scene passively like a
REPRESENTATIONS AND THEIR FORMATS
Knowledge relies on representations.
A REPRESENTATION is a physical state ( such as marks on a page, magnetic fields in a
computer, or neural connections in a brain) that stands for an object, event, or concept.
Representations also carry information about what they stand for.
MEMORIES AND REPRESENTATIONS
The Intentionality Criterion a representation must be constructed intentionally to stand
for something else.
Your brain stores information automatically, even when you are not trying to fix it in
Some information is stored consciously as well as unconsciously. You have the
unconscious goal of storing information about experience, INDEPENDENt of your
conscious goals of storing information about experience.
The intentionality criterion is met because the brain at an unconscious level has the
design feature of storing information about experiences of the world to stand for those
experiences. The intention to capture information is built into the brain system, whether
or not you consciously direct each memory.
The Information- Carrying Criterion a representation must carry information about
what it stands for. Ex you carry information of an object and describe the object to
someone without it being present in front of you. So ur memory of the object carries
information about it.
Since it carries information, it can allow you to categorize and make inferences from it
THEREFORE, representations lay the groundwork for knowledge!!!!
Once the brain intentionally establishes memories that carry information about the world,
all sorts of sophisticated cognitive abilities become possible.
FOUR POSSIBLE FORMATS FOR REPRESENTATIONS
Format – refers to the type of its code. Format not only refers to the elements that make
up a representation and how these elements are arranged, but also relies on characteristics
of the processes that operate on them to extract information.
Representation can be
1. modality specific – may make use of perceptual or motor systems
2. amodal – residing outside of perceptual and motor modalities.
MODALITY – SPECIFIC REPRESENTATIONS: IMAGES
An image has three elements
1. a spatiotemporal window a photograph does not capture everything in a scene,
but only part of it which is within a spatiotemporal window (ex an image in a
photo can only display a pic that is taken at a certain perspective, and not
everything in a scene would be captured in a single pic… so any image is defined
to some extent by its spatiotemporal window)
2. storage units image contains an array of storage units (like pixels of a digital
camera) in a grid. Each storage unit is sensitive to the light hitting on it. Each
storage unit also has a spatiotemporal window, it captures only the info within a
bounded spatial and temporal region.
3. stored information Each storage unit gives us information of the light
intensity at visible wavelengths. The collective information of the light intensity
AND light wavelength gives us the stored information
These 3 elements (spatiotemporal window, storage units, and stored information), taken
together, determines the images CONTENT
Much scientific evidence supports the presence of images in the human brain. In an
experiment on a monkey, found that the pattern of brain activation on the brains surface
roughly depicts the shape of the stimulus. The reason is that the cortex of early visual
processing areas is laid out somewhat like the pixels of a digital image and responds
similarily. When neurons arranged in this manner fire, the pattern of activation forms a
topographical map – their spatial layout in the brain is analogous to the layout of space in
Much research has shown that visual images are represented partly in the brains
OCCIPITAL lobes, and that the brain represents these images topographically.
Because visual images are represented in the occipital lobes, removing the right occipital
lobe should reduce image size by one-half.
***Not only have mental images been found in the visual system, they have also been
found in the motor system, and in the auditory system
In an experiment, asked participants to construct mental images while performing a task.
If the participants actually constructed mental images, then these images should have
perceptual qualitites, such as color, shape, size etc. They indeed found that participants
had constructed mental images having perceptual qualities.
Brain images differ significantly from those taken by a camera. Brain images are NOT as
continuous and complete as photographs. The failur to be aware of changing stimuli in
the visual field indicates that peoples perceptual images do not have uniform level of
detail; some areas are not as well represented as others. Visual attention appears to be
responsible for this unevenness
So much behavioural evidence has also accumulated for mental images