Theories of Perception: EQ: How do psychologists attempt to explain how we process information from our senses?

A. What is Perception? Def:A single unified awareness  derived from sensory processes while a stimulus is present. When the information comes from our senses, we must make sense of that information

B. Top Down Perception Def: Aspects of recognition that are guided by higher-level cognitive processes and psychological factors such as expectation Ex: -Logical Thinking -Memory -Organization

Example: Top Down Perception

Example: Top Down Perception

C. Bottom Up Perception Def: Aspects of recognition that depend first upon the information about the stimulus that comes to the brain from the sensory receptors Ex: -touching a new object -Smelling something -Hearing in a conversation -Seeing someone for the first time

Example: Bottom Up Perception

Example: Bottom Up Perception

General Theories of Perception: Computational The Computational approach to perception theorizes that our nervous system uses computations that allow it to translate raw sensations into an experience of reality. This theory is similar to what a computer does. The main weakness of this theory is that it implies we have all the information required to make the computation.

General Theories of Perception: Constructivist The Constructivist approach to perception theorizes that our nervous system uses pieces of information from the senses to create (construct) reality. In this theory, we do not need to have all the information to make a perceptional conclusion However, what if we are wrong???

General Theories of Perception: Ecological The Ecological approach to perception theorizes that we (and other animals) are so well adapted to our environment that we do not need to use higher level thinking skills to perceive the world around us. This theory, of course, has its limitations in the sense that we (humans specifically), often step outside of our ecologically correct environment This severely limits our perceptional abilities

Signal Detection Theory: A mathematical model of psychophysics that theorizes that a person will only report a stimulus when it is near our threshold to detect it. This is similar to absolute threshold theory.

Signal Detection Theory: Sensitivity How sensitive a person’s ability to perceive is based on the individual Since some people are more sensitive than others, they may access more from some senses.

Signal Detection Theory: Response Criterion Our response criterion is the internal process we use to determine if we perceived something or not. The problem is, that we are not always sure Especially if there is little sensory info.