Chapter 3, Perception Flashcards
What is perception?
The process of recognizing, organizing, and interpreting information from the senses.
Is perception an exact copy of “the world”
No, it is not an exact copy of the world
Is our perception based on our past experiences and expectations?
Yes, it is based on our past experiences and expectations.
Why has it been so difficult to design a perceiving machine?
- Because of the inverse Projection Problem
- Objects can be hidden or blurred
- Objects look different from different viewpoints
What is the Inverse Projection Problem?
- It refers to the task of determining the object responsible for a particular image on the retina
- It also involves starting with the retina image and then extending outward to the source of that image.
What is Viewpoint Invariance?
The ability to recognize an object from different viewpoints.
- easy for people
- hard for computers
What are the two types of human processing?
- Bottom-up processing
- Top-down processing
What is Bottom-up Processing?
It begins with the sensory receptors and then works up to the brain to identify the object/scene being perceived
What is Top-down Processing?
Begins in the brain then works down to the receptor.
What else happens with Bottom-up processing?
- Perception comes from stimuli in the environment
- Parts are identified and put together, and then recognition occurs
What else happens with Top-down Processing?
- Occurs very quickly
- People actively construct perceptions using information based on expectations and experiences
What is Speech Segmentation?
Knowing when a word begins and ends in speech based on previous experience with the language.
What is the Bottom-up Process for Pain Perception?
The direct pathway model, which is a stimulation of nociceptors
What is the Top-down Process for Pain Perception?
It can be affected by other factors such as expectation, attention, and the Placebo effect
What are some Bottom-up approaches?
- Template Matching Theory
- Feature Approaches
- Recognition-by-Components
What is Template Matching Theory?
it is comparing a stimulus with a set of templates (or specific patterns) that are stored in memory.
- Templates are exact copies
- Identify when a match is made
Do Humans have a tolerance to partial info?
Yes, our perception is fairly good at dealing with partial info, as when objects are degraded or occluded.
Our system has to fill in the gaps when dealing with the incomplete and variable info.
What are some Feature Approaches?
- Pandemonium Model
- the idea- Pattern recognition is a gradual process of evidence accumulation based on a feature-by-feature analysis - A result of hierarchically organized chaos
What is Recognition-by-components?
- We perceive objects by perceiving elementary features
- Objects are recognized when enough info is available to identify objects three-dimensional volumes
What are Geons?
Three-dimensional volumes/ shapes
What else is important for the Recognition-by-Component Theory?
- That object recognition is a matter of separating, analyzing, and recombing features (this occurs for all objects familiar and unfamiliar to us)
- That there are 36 Geons, that are simple shapes combining to form complex shapes. These shapes then look the same no matter the orientation.
How does the Recognition-by-Component work?
At first information about the edges of an object is extracted, then the boundaries of the object are analyzed and then components are determined and matched with object representations in memory.
What are some of the Top-down approaches?
- Helmholtz’s Theory of Unconscious Inference
- Gestalt Theory
- Environmental Regularities
- Bayesian Inference
What is Helmholtz’s Theory of the Unconscious Inference?
It is the theory of how some of our perceptions are the result of unconscious assumptions we make about the environment. We use our knowledge to inform our perceptions