percpetion 351 Flashcards
what is percpetion
experience resulting from the stimulation of senses
basic characteristics of perception
can change due to added info
its a process
rule baed sequential stages
relies of past experince
connected to action
diff between percpetion and sensation
sesnations - receiving stim energies from environment
percpetion - interperating sensory info - applying meaning to it
the human perceptual system uses two types of information
enviornmental energy stimulating receptors
knowledge and expectations the observer brings to the situation
what is the bottom up theory of perception
Direct Perception Theory
percpetions come from stim in environment
parts are identified then we can recognize it
what is the top down perception theory
Constructive Percpetion Theory
people actively construct percpetions using info based on expectations
bottum processing starts with _
top down processing starts with _
bottum up – starts with senses, assembles and integrates sensory info, fit puzzle pieces together
top down - starts with brain - relies on past experience and expectations to figure it out, looks at compkete puzzle and thinking if it realtes to things you have seen in past - schema driven
whats a shema
mental molds we pour experience into
relying on past knowledge and experince of the world
what is Biederman’s RBC theory
is it top down or bottom up
Recogntion by Components
theory of Geons. fit those puzzle peices together
bottum up
4 aspects of geons that make them a good tool
how many are there
Discriminability - easily to tell apart
Resistant to Visual Noise
Invariance - recognizable no matter hte texture, markings,
Distinctiveness - there are 36
bottum up evidence supporting RBC
we are able to recognize objects from geon combos
priming studies - airplane example
viewpoint invariance studies - blender example
is the following rules top down or bottum up
we make inferneces based on context
like surrounding elements of visual scene (apple on ground vs platter)
knowledge and expectations on the past
Top Down Processing
stroop effect is example of TD or BU
top down
words in diff colours
what is HemHoltz’s theory of Unconcsious Inference
top down or bottum up
what principle does he mention
our perceptiosn result from unconscious assumtpions we make about the enviornment
we infer much of what we know about the world
Likelihood Principle - we perceive world in way that is most likely based on past experiences
draws on past experiences to unconsisuly fill in the gaps
top down
what are the Gestalt Laws
bu or td
mind groups patterns according to laws of perceptual organization
heuristics based on waht usually happens in the environment - fast
‘whole is greater than the sum of its parts’
Bottum Up
what is the PHI Phenomenon
the reason animation creates a look of motion
skeleton dance
what is the gestalt law of perceptual organization
law of good contnuation
lines tend to be seen as following the smoothest path
what is the gestalt law of perceptual organization
law of simplicity and good figure
every stimulus pattern is seen so teh resulting strucutre is as simple as possible
olympic flags
what is the gestalt law of Similarity
similar things appear grouped together
what is the gestalt law of Proximity
nearby objects appear grouped together
what is the gestalt law of Closure
seperate elements will tend to be grouped to form closed figures
circle with holes in some parts
what is the gestalt law of Familiartiy
things are more likely to form groups if the groups appear familiar or meaninful
forest has eyes painting
what are environmental regularities
td or bu
2 common properties we look out for are
common physical properties of an environment we expect to see learned form expereince
top down
the 2 common properties we look for are physical - light form colour and semantic - looking for the meaning or purpose or function
physical environmental regualrities
what is oblique effect
we perceive verticals & horizontals easier than other orientations
physical environmental regualrities
light from above assumptin
we assume light comes from above because that is most common
we perceive shadows as information about depth and distance
Sematnic environmental regualrities -
the meaning of a given scene is related to waht happens within that scene
Sem Regularities are the characteristics associated with functions carried out in diff types of scenes
Scene Schema - doctors office example
how does the Bayesian Inference Theorem Work
H = Hypothesis
E= Evidence (observation)
P(H) - Prior Probability
how likely is the hypothesis before considering the evidence
P(H|E) - Posterior Prob - how likely is hypothesis H given the evidence E
P(E|H) - posterier
divided by
P(E)
= likelihood
how likely is the evidence E, given hypothesis H, compared to how likely the evidence E is overall
single double dissocation test in Monkeys - they gave them what 2 tasks in this experiment
Object Discrimination - monkey’s job to pick correct shape - tells us about making choices on WHAT we see
Landmark Discrimination - asked to put food in the well closer to cylinder, choices about WHERE something is located
WHAT and WHERE
Single and Double Diss in Monkey’s
gave monkey brain lesion in Temporal Lobe
it did well on _ task and poor on _ task
monkeys performed poorer on Object Discrimination tasks - hard to pick correct shape
But no effect on the landmark task - knew where it was, not what it was
single dissociaton
Single and Double Diss in Monkey’s
gave monkey brain lesion in Parietal Lobe
it did well on _ task and poor on _ task
Found monkeys performed worse on Landmark task
But could do the object discrimination task
what is the double diss in the monkey what and where study
because a lesion in the temporal lobe imparied them on the WHAT task but not the where task
and a lesion in Parietal lobe impaired them on the WHERE task but not the what task
where is the where pathway
along Parietal Lobe, Dorsal Pathway
where is the WHAT pathway
takes same visual info from Occipital lobe, processed along Ventral pathway, into Temporal Lobe
parietal lobe does what - monkey
process object’s location in relation to the viewer
temporal lobe does what - monkey
object and visual identification and recognition
patient DF is used to demonstrate a single dissocaiton - waht is their brain damage, what task could they do, what ability did they lose?
part of their **Temporal and Occipital Lobe were damaged **
could perceive objects see them but could not recognize them
couldnt draw apple in front of them if asked to,
if asked to draw an apple from memory they could
how did DF do when performing the mail slot activity
DF could not line up the card with the slot
she could mail the card, but not line it up, as she was unable to perceive the Slot
did DF have damage to the WHAT or WHERE path
df had damage in the WHAT pathway
‘dorsal failure’
what syndrome is an exmaple of damage in the WHERE pathway
balint’s syndrome
what is Balint’s Syndrome cause
what do they see when looking at a forest
lack of coordination between visual inputs and movements
unable to complete visually guided tasks like maling card in slot
can not follow objects with thier eyes - have to turn whole head to see
can not see the forest, can see the individual trees
what are the causes of Balint’s Syndrome
strokes - swelling in pareital region
brain lesions
alzheimers
head trauma
in balin’t syndrome - ___ of object is impared but ___ of object is not
nagivation of where an object is is Imapiredl but identification of the object is not
why are DF and Balint’s a Double Diss
Balint’s = damage to Dorsal/WHERE path
can identify objects but can not navigate/facilitate movement through space. pareital lobe damage
DF = damage to Ventral/WHAT path, can not perceive/identify objects they see, but can faciliate movement through space. temporal lobe damage
more specifically what brain part is damaged in balint’s
Bilateral Posterior Parietal Damage
posterior = back of head
what is the ebbinghaus illusion?
circles in the middle surrounded by other cirlces make them look bigger or smaller than they are (bigger if surrounded by small cirlces, smaller if surrounded by big cirlces)
perceputaly diff, physically identical
the reverse Ebbinghaus illusion makes the circles look the same sizes when they are diff sizes
what did we learn when measuring a hand’s grasp appeture
meaning our __ path was fooled but our __ was not
even tho we perceive 2 cirlces as same size, our aperture does change to pick up the larger circle
What pathway was fooled, the Where pathway was not
what do we see in the Ponzo Illusion
graph behind image makes us perceive line 2 as bigger than line 1 - but they are same size
describe Ventral pathway
what is it responsible for
its hte W—- path
has the same Sensory info going from Occipital Lobe to the Temporal Lobe
responsible for Visual Perception of what we think we see
WHAT (why)
describe Dorsal pathway
what is it responsible for
its hte W—- path
has the same Sensory info gong from the Occipital Lobe to being processed by Parietal Lobe
responsible for ‘vision for action’
WHERE (how)
where in the brain are the Frotnal Pareital Occipital and Temporal Lobes
frontal - front of brain
Parietal - top middle
Temporal - bottom middle
Occipital - back of brain
how does Percpetion facilitate Action?
- hint - 2 ways
Initially perception informs us what to act on and how to act on it
during our performance of actions, perception provides feedback on progress and success, making adjustments if need be
how does Action facilitate Perception?
moving to get a different POV of an object, aiding in Percpetion
We take in sensory info from our environment - parts can be identified and put together, and then recognition occurs -
We also rely on past experience and knowledge to inform our perceptions -
which is top down which is bottom up
We take in sensory info from our environment - parts can be identified and put together, and then recognition occurs - Bottom Up - processing
We also rely on past experience and knowledge to inform our perceptions - uses both top down and bottom up processes
how is cogntion involved in the Percpetion Action Cogntion cycle
We can also inform our cognitions, our actions adjust for what’s really in the environment - not what we perceive
we learn in part by physically interacting with the world around us and perceive the results -
this informs our cognition,
This kind of weird cycle continues. When feedback is informative and immediate we update our schemes to incorporate new info.
So our cognition is influenced by both perception and action
defintion of Affordances
when we see an object
we think of any possible action an indiviudal can do with that object
MUG - grasp it, lift it, sip it, clean it
Those actions are Afforded by this object
Objects contain visual features (we see) also properties we can’t see like how to interact, so our perceptual system is not based only on what the physical object is, based on what we see and what we can do with it
affordance test - on computer screen we see
- a +
- then blank screen
- image of object (beer mug)
- hand signal
what if the effect of this study
what makes us react slower or faster to these trials
the picture of how we are supposed to respond influences us wehther it is Congruent or Incongruent (proper way to interact or not)
incongrunet - grabbing frying pan like we would a mug
we are faster if hand signal is Congruent, and slower if it is InCongruent
the ventral path involves the ___ lobe
the dorsal path involves the ____ lobe
the ventral path involves the Temporal lobe
the dorsal path involves the Parietal lobe
what is the inverse projection problem
image is on the retine - and our percpetual system determines what object out there created the image
people’s ability to recognize an object even wen seen from diff viewpoints is called
Viewpoint Invariance
ability to tell when one word ends and the other begins is
Speech Segmentation
we learn _______ likelihood that one sound will follow another within a word -
Transitional Probabilities
process of learning about transitional probabilities and about other characteristics of language is called
Statistical Learning
hemholtzs realized that the image on the retina is ambiguous - what does this mean
a particular pattern of stimulation on the retina can be caused by a large number of objects in the environment
illusioin of movement created by a stroboscope is called
Apparent Movement
what are mirror neurons
neurons that respond both when a monkey observes someone else grasping an object such as food on a tray and when the monkey itself grasps the food
called mirror neurons because the neuron’s response to watching the experimenter grasp an object is similar to the response that would occur if the monkey were performing the same action.
what is the Size Weight Illusion
When a person is presented with two similar objects, such as two cubes, that are the same weight but different sizes, the larger one seems lighter when they are lifted together. One explanation for this is that we predict that larger objects will be heavier than smaller objects, because objects of the same type typically get heavier as they get larger
