Ch 3. Perceptions Flashcards
Describe the difference between bottom up processing and top-down processing.
But in the processing is when the environmental energy stimulates the receptors from the eye to the brain for example.
Processing that originates in the brain is called top-down processing-, for example perception involves factors such as persons knowledge of environment and expectations people bring to the perceptual situation
Explain the three different reasons why it would be difficult to design a perceiving machine and explain.
A stimuli on the receptors is ambiguous for example the task of determining an object responsible for particular image on the retina is called the inverse projection problem because it involves starting with the retinal image and extending of the rays from the eye.
Objects can be hidden or blurred
Different point of view
Who came up with the likelihood principle? define likelihood principle and define unconscious inference.
Helmholtz contributions was based on his realization that the image on the retina is ambiguous.
His answer to how perceptual systems decide a pattern was the likelihood principle which states that we perceive object that is most likely to have caused the pattern of stimuli we have received this judgment of what is most likely to occur is by a process called unconscious inference in with your perceptions is just results of unconscious assumptions are inferences.
A gestalt psychologists named Max Wertheimer was on vacation when he discovered what with a stroboscope, the mechanical device to create an illusion of movement by rapidly alternately to slightly different pictures?
He discovered the principle behind the illusion of movement created by the stroboscope which is called apparent movement because of the movement is perceive nothing is actually moving.
There is a flash on and off and there is a period of darkness and the second light flashing on and off.
What were the two conclusions Wertheimer drew from the phenomenon of apparent movement and how is this related to the principles of perceptual organization?
His first conclusion was that apparent movement cannot be explained by sensation because there’s nothing in the dark space between the flashing lights.
Second conclusion became one of the basic principles of the Gestalt psychology the whole is different than the sum of its parts. This conclusion follows from the fact that the perceptual system creates the perception of movement from stationary images.
That idea let them to propose a number of principles of perceptual organization to explain the way elements a group together to create larger objects.
What are gestalt principles of perceptual organization?
The principle of good continuation and seen with the rope and Crystal.
Pragnanz or good figure it states every stimulus pattern as seen in such a way that the resulting structure is a simple as possible.
Similarity the principle similarity were similar things appear to be grouped together is a striking example of grouping my similarity of color refer back to the columns of exes and owes and why we see them as columns.
What is the difference of physical regularities and semantic regularities?
Physical regularities such as vertical and horizontal orientation which are perceived more easily. Light from above assumption is also a regularity. Our mind is trying to make sense if it’s environment.
Semantic regularities are basically seeing a object picturing an object on long with the functions that are carried out a different scenes. For example when asked to picture a lion you might picture line in the Safari this is called scene schema.
Explain the Bayesian inference. Whose ideas is this in line with?
Thomas bayes proposed that our estimate of probability of an outcome is determined by two factors number: 1) prior probability or simply the prior which is our initial belief about the probability of an outcome. 2) the extent to which the available evidence is consistent with the outcome called the likelihood of the outcome.
Ex) mary’s priors for three types of health problems include having a cold a heartburn or lung disease lung disease is unlikely. Her friend Charles has a bad cough she guesses that the three possible causes can be heartburn her lung disease. Her research concludes that he may have a cold disease but his symptoms don’t include heartburn. This additional information which is the likelihood is combined with Mary’s prior to produce the conclusion that Charles probably just has a cold.
It reinstates Helmholtz idea that we perceive what is most likely to have created the stimulation we have received in terms of probabilities.
What does the approaches of helmholtz, regularities and bayes all have in common? Why is gestalt approach different? Who is top-down processing and who is the bottom up processing?
That we use data about the environment gathered through past experiences in proceeding to determine what is out there therefore top-down processing is very important part to these approaches.
Gestalt psychologists emphasize the idea that the principles of organization or built-in and although perception is affected by experience the built in principles can override experience there by assigning bottom up processing a central role in perception
What did we learn from Greeble experiment?
Those demonstrations of experience dependent plasticity in kittens in humans show that the brains functioning can be tuned to operate best within a specific environment that is continued exposure to things that occur regularly can cause neurons to become adapted to respond best to these regularities. If you look at it this way it’s not unreasonable to say neurons can reflect knowledge about properties of the environment.
What does perception action have to do with brain ablation and neuropsychology define.
Brain ablation is the study of the effect of removing parts of the brain and your psychology is the study of behavior of people with brain damage. They’re connected when trying to identify a connection between perceiving objects and interacting with them. (The link between perception and action)
Match object discrimination and landmark discrimination to the specific brain part and indicate whether it is a where or what pathway.
When a part of the Temporel lobe is removed there is an issue with object discrimination which indicates that the pathway leading from the striate cortex to the temporal lobe is the what pathway.
Monkeys who had their parietal lobes removed had difficulty solving the landmark discrimination problem, this indicates that the pathway leading from the striate cortex to Parietel lobe is the where pathway
Describe where the perception pathway is and where the action pathway is.
Milner and Goodale suggested that the pathway from the visual cortex to the temporal lobe which was damaged in subject DF’s brain is called the perception pathway.
The pathway from the visual cortex to The parietal lobe is called the action pathway.
The perception pathway corresponds to the what in the action pathway correspond to the where.
What is distributed representation?
It is the idea that specific cognitive functions activate different parts of the brain.
Explain Principle of Good continuation.
Points when connected are seen as smooth lines that belong together. Also objects that overlap.
Top down example
Bottom up example
Top down- Spectogram, how we identify how one word stops and ends even when words are continuous.
Bottom up- mind over matter is an example. Pain could be stopped by distraction.
What is the binding problem?
The binding problem deals w how features that are processes in parallel are bound to that unique percept.
What is tms and how is it used?
Transcranial magnetic stimulation is a wand that generates electromagnetic field and depending on power of stimulus will either activate or disrupt neural activity.
