Class Notes (837,981)
Canada (510,607)
Psychology (4,227)
PSY345H5 (172)
Lecture 4

Lecture 4.docx

6 Pages
Unlock Document

Stuart Kamenetsky

PSY280 –Perception Test - Lecture contents are imp - No equations - Understand key equations from lecture 1 and 2 - Key terms - Check your understanding part of textbook Lecture 4 Visual Object Recognition - Recognize an object by its shape and size - Key feature: shape Image clutter complicates or - Clutter: many of the objects are partially visible or occluded - Visual info is incomplete but not hard to determine what the whole object is - We are exposed to enormous variety of objects everyday in social and natural environments - Brain is the most powerful processer - There are so many objects sometimes that makes it taxing for the brain Variety of the same object - Can recognize that it belongs to the same category (Tree) Viewpoints - An object is seen from many different viewpoints - Can still recognize an object even if the viewpoint changes Object recognition is robust - Occulusion - Despite the oddity of the objects, the size doesn’t affect the reconigition of it - Surprising and unsettling aspect of the painting Object recog. Is a 2 part process Visual Science – how to move from light and dots to a complex scene with objects and events - Perceptual Organization o The segregated various parts of visual system to extract various objects o Once it has been identified, o Look at the colorful wooden bars picture – segregate various bars quite effortlessly o How? o These numbers show that there are many portions – how to tease the various scenes The various components of perceptual organization Hypercolumns - an edge is presented within the visual field and out of that, the pattern will tell the brain the orientation and contour in that location Picture of a house amidst some trees - Can identify the various objects that make up the scene - How? o First have to appreciate the convex edge that is a part of the house or the mountains o But to figure it out you have to make the connections o Have to decipher between the peaks and points o Identify which is front figure, ground etc – have to find a way to connect the edges - Uniform connectedness - Perceptual Grouping o Combine and tease out various object - Perceptual Interpolaton - Matching o What kind of object is it o Matched to some representation and recognize when match is successdul Local Edge extraction Luminous gradient for bottom square bordered by an edge - There are also curved edges, concave – 90 deg angle, convex Partitioning the scene into regions of uniform connectedness’ following local edge extraction is not enough - Brightness is a pysholkogical construct, lumionous is a physical measurement Uniform connectedness – the same colors have the same lumionous - Wokrs with simple situation The picture of the bowls are complex because there are SHADOWS, GRADIENTS, - IF YOU USE THE PRINCIPLE OF UNIFORM CONNECTNESS, you would use b - It’s good as a first step but it needs a lot more to arrive at (d) The first step is to connect uniform parts but harder with a complex scene Figure Ground organization - Edge is boundary - Who owns the egde (border ownership) - Carried out by number of rules for border ownership - It can be ambigious The picture - Do they belong to the white or black part - Cannot perceive both at the same time - Border ownership is not a trivial process Surroundness / Size - Can think that the figure at the front is a black board with a whole in it - Or that its black all around the white shape - Then will grant ownership to the smaller object - Attribute the ownership of the edges to the smaller object Symmetry - Two logical possibilities - Can attribute ownership to the black edges - Usually think that b) is the main picture because of sym
More Less

Related notes for PSY345H5

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.