Real Exam 3 Flashcards
What is change blindness
The failure to notice differences between two images of a scene. These differences can be fairly large and important, yet we often fail to perceive them
What would an example of change blindness be?
Look at 2 almost identical pictures but failing to notice the slight differences in them. Spot the difference photos
What is the “gist” of a scene?
it is the core meaning of the overall scene
Why do we only get the ‘gist’ of a scene when first noticing it?
We extract a scene quickly from perceptual elements, we get a ‘gist’ of the scene and ignore the details
What does change perception depend on?
depends on the meaning of a change. if the scenes meaning stays the same we wont notice the change.
What is an example of change perception?
looking at a spot the difference photo. If we see a market place the market place will always be a market place to us regardless of minor changes like pants color etc.
What is attention to action?
paying specific attention to a specific action and ignoring the details going on around it.
What is Saccadic eye movement?
Overt attention shifts where we pay attention to relevant locations to a scene
How many Saccades to we make per second?
3-4 per second
Is the 3-4 saccades per second fast enough to account for scene recognition abilities?
No it is to slow to account for scene recognition.
Can we observe more items in a scene than 3-4 per second
Yes we can…Don’t question it bitch.
What is a covert attention shift?
An attention shift without eye movement
Visual search task results indicate we can process how many objects per second with covert attention shifts?
20-30
What is a scene mosaic?
Attention shifts around a scene faster than eye movements building a collage of objects at locations that make up the scene
What are issues with the scene mosaic idea?
requires a larger working memory load than we have. How do we remember the collage pieces fit together. LARGER THAN 7+2 WORKING MEMORY CAPACITY.
Experimental results indicate that we can identify a scene in less than an eight of a second (125ms). Too fast for putting together a bunch of collage pieces
How fast can we identify a scene?
less than an eight of a second (125 ms)
What is the spatial layout idea?
Perhaps a scene is defined less as a collection of objects at locations and more by its spatial layout.
What would be an example of identifying a scene via spatial layout
enclosed space could mean a room or car, wide open spaces could be a field or ocean.
What is a schema
a rough outline of a scene or situation with placeholders for details. like a farm or classroom
Are specific objects in the schema filled in later or are they recognized later?
Specific objects are recognized later. For example we can tell we are at a farm but won’t fill in that there are cows and chickens (We can also say things are there that weren’t. Just because its a farm we can say there are chickens there even if there weren’t just because chickens fall into our schema of a farm.)
Are we good at recognizing scenes?
Like super good at it brah. We rapidly extract the ‘gist’ of a scene
Are we good at noticing the details of a scene?
No we are really bad at noticing the details in a scene. We have placeholders for things that ought to be there but notice them unless needed.
Recall the primary visual cortex is ____ and ____
Retinotopic (locations close in space are close to the brain)
Contralateral (right visual field processed in left hemispher, LVG [lateral geniculate visual field] in right hemisphere)
Attention could work by increasing sensitivity in a part of the ___ that receives input from the attended location.
V1
What are the two ways to measure brain activity?
Metabolic
Electrical
What test is used to measure metabolic brain activity?
fMRI
What test is used to measure electrical brain activity?
ERP
What is Posner paradigm?
a neuropsychological test often used to assess attention. Formulated by Michael Posner,[1] the task assesses an individual’s ability to perform an attentional shift. It has been used and modified to assess disorders, focal brain injury, and the effects of both on spatial attention.
Are some kinds of objects represented in specific parts of the brain?
Yes for example, faces appear to be represented in a special part of the inferior temporal cortex
T/F if we are attending to a specific kind of object then that part of the brain will be more active.
True
How can we be sure that our brain activity is based on attention and not perception?
If we take an image with a face faded on top of a house and tell particpants to focus on either the face or the house you will get the same results in brain activity location.
What could the individual neurons be doing to create these attention responses?
Response enhancement
Sharper tuning
Altered tuning
All of these mechanisms have been seen
Damage to the ___ ____ ___ causes an inability to attend to contralesional space
Posterior parietal lobe
What is neglect?
The inability to address or recall places or things due to damage of the posterior parietal lobe
What is an example of neglect?
copy the figure or describe your surroundings a person with damage to the posterior parietal lobe will not be able to focus on the right portion of what they are focusing on.
What is not worthy of the Neglect of the Piazza del Duomo of Milan?
Neglect patients were asked to imagine the Piazza and report what they saw. They failed to report contralesional buildings but when asked to visualize where they were from a different spot in the Piazza buildings they could not report previously were reported and buildings but failed in reporting buildings from the last time.
What is the waterfall illusion?
Stare at a waterfall for a while then stare at the still rocks beside it and they will appear to crawl upward
What is the after image of a downward motion?
the after image begins to move up.
What are 4 things the visual system is good at finding?
edges
textures
colors
groups
Sometimes ___ is the best object cue
motion
What is the motion detector model?
Two receptors with adjacent receptive fields (A & B) stimulus enters receptive field of A and then later B (First A fires and then B). Then Motion detector M gets input from A and B. Once A and B have fired then M fires.
What a problems with this motion detector model?
It can’t distinguish between a small bug moving between receptive fields and a large bug in both receptive fields at once. Both will activate A and B which will then activate M
What is the solution to this motion detector model?
Add a ‘delay’ neuron
What does the delay neuron do to fix the motion detector model?
When the bug goes through receptive field A it activates the delay neuron D. this holds the activation of receptive field B. Later B will be activated and when D and B are activated simultaneously motion detection is activated. When this is all strung together we create a motion detection circuit.
Do motion detection circuits actually exist in the brain?
Neural connections exist like the proposed motion detection circuit
What are the neural connections called that make up the proposed motion detection circuit?
Interneurons
Does motion aftereffects demonstrate that there are direction and velocity sensitive neurons?
Yes those are the ones that get fatigued
What is motion perception ambiguity?
Can’t always tell direction of movement
Can perceive movement when there’s neither real nor apparent movement
Can’t always tell whats moving
What are two types of motion?
Real motion - an object moving through space
Apparent motion - not ‘real’ motion but gives perception of motion (waterfall illusion)
What does motion perception depend on?
Proximity (to far no apparent motion)
Speed (to fast no apparent motion)
Too slow (to slow to notice apparent motion)
What is Phi Motion?
Perception of motion without intermediate positions (looks like a single dot jumping back and forth) Happens at fast switch rates (ISIs)
What is Beta Motion?
Perception of motion with intermediate positions (looks like single dots)
Happens at slower ISIs. Perceptual system ‘fills in’ missing in-between stimuli. One dot moving smoothly between locations
What are some examples of apparent motion in daily life
Motion pictures
cartoons
computer animations
How doe motion pictures work? How many pictures are shown per second?
Succession of sequential still photographs shown rapidly. 24 frames per second gives a sensation of smooth motion
How many frames per second to cartoons usually run at?
Usually run at 12 frames per second
What is the correspondence problem?
The motion perception system has to figure out which element at a time T corresponds to which element at a time T+1
If there is no mask the dots correspond diagonally which triggers the diagonal motion detectors more active.
If there is a mask dots correspond vertically which makes the vertical motion detectors more active
What happens when there is input from multiple apertures? What motion direction do dots appear to move?
Dots appear to move diagonally
Someone with lesions near V5 have what?
Akinetopsia
What is Akinetopsia?
Inability to perceive motion
Where are the motion sensitive areas in the brain located?
Medial temporal lobe - area MT AKA V5
Environmental sounds are usually complex or simple tones?
Complex
All complex waves can be represented as a combination of simple sine waves T/F
True
In terms of sine waves, what does approximate and exact mine
Approximate is finite
Exact is infinite
What is Fourier decompisition
The breaking down of complex waveforms into their component sine waves
What is the power spectrum of a sound?
The plot frequency of its amplitude (how slow or fast the wave is and how loud or powerful it is)
What measurement scale is used to measure waveform?
MS (milliseconds)
What measurement scale is used to measure the spectrum?
Hz (hertz)
What are the three parts of the ear?
Outer ear
Middle ear
Inner ear
What does the Pinna do? What is it?
It is the visible ear that funnels sound into the auditory canal.
What is the auditory canal? What does it do?
It is the hole in your ear that sound is funneled into. It amplifies auditory frequency ranges and protects the inner parts of the ear from exposure.