Textbook Notes (363,126)
Canada (158,212)
Psychology (3,263)
PSYC 2390 (118)
Lana Trick (87)
Chapter 1

Chapter 1.docx

11 Pages
Unlock Document

University of Guelph
PSYC 2390
Lana Trick

The Perceptual Process 1/12/2013 2:23:00 PM Intro  Perceptual process is a sequence of processes that work together to determine our experience of + reaction to stimuli in the environment  Four processes w/in the perceptual process: o Stimulus—refers to what is out there in the environment, what we actually pay attention to + what stimulates our receptors o Electricity—refers to the electrical signals that are created by the receptors + transmitted to the brain o Experience and action—refers to our goal—to perceive, recognize + react to the stimuli o Knowledge—refers to knowledge we bring to the perceptual situation  Can have its affect at many different points in the process Stimulus Environmental Stimuli and Attended Stimuli  Both are in the environment  ES is all of the things in our environment that we can potentially perceive  AS is the stimuli that is the centre of attention for a person + changes from moment to moment as attention is shifted from place to place The Stimulus on the Receptors  Stimulus is then transformed into another form which becomes a representation of the stimulus Electricity  Everything we perceive is based on electrical signals in our nervous system which are created in the receptors + transform energy from the environment into electrical signals in the nervous system through a process called transduction Transduction  Transformation of one form of energy into another form of energy  Occurs in the nervous system when energy in the environment is transformed into electrical energy Transmission  Electrical signals activate other neurons, which in turn activate more neurons  These signals travel out of the eye (in vision) + are transmitted to the brain  Transmission is crucial b/c if signals don’t reach the brain there is no perception Processing  As signals are transmitted from the retina to the brain they undergo neural processing which involves interactions between neurons  Signals are relayed through a series of neurons to the brain, which transforms the signal into a perception o Signal that reaches the brain is often transformed so that even though it does represent the original stimulus it is usually very different from the original signal  Transformation that occurs between the receptors + the brain is achieved by neural processing, happens as the signals that originate in the receptors travel through a maze of interconnected pathways between the receptors + the brain + within the brain  In the nervous system the original electrical representation of the stimulus that is created by the receptors is transformed by processing into a new representation of the stimulus in the brain Experience and Action Perception  Perception is conscious sensory experience Recognition  Is our ability to place an object in a category that gives it meaning  Despite seeming similar, research has shown that perception + recognition are separate processes  Visual form agnosia (what Dr. P) suffered from, is an inability to recognize objects while still perceiving parts of the object but not the whole thing Action  Includes motor activities such as moving the head or eyes + locomoting through the environment  Believed to be an important part of the perceptual process b/c of its importance in survival o Some researchers believe that early in evolution of animals the major goal of visual processing was to help the animal control navigation, catch prey, avoid obstacles etc. Knowledge  Any information that the perceiver brings to a situation + can affect a number of the steps in the perceptual process  Rat-man demonstration shows how recently acquired knowledge can influence perception  Bottom-up processing is processing that is based on incoming data o Incoming data always provide the starting point for perception b/c w/out incoming data there is no perception  Top-down processing refers to processing that is based on knowledge  BUP is essential for perception b/c the perceptual process usually begins w/ stimulation of the receptors o TDP can come into play once BUP has triggered the sequence of steps of the perceptual process + both often work together to create perception  As stimuli become more complex the role of TDP increases How to Approach the Study of Perception 1/12/2013 2:23:00 PM Summary  Two different approaches to studying perception: o Psychophysical approach: introduced by Fechner who coined the term psychophysics to refer to the use of quantitative methods to measure relationships between stimuli (physics) + perception (psycho)  Methods are still used today but w/ the inclusion of nonquantitative methods o Physiological approach: involves measuring the relationship between stimuli + physiological processes + between physiological processes + perception  Most often studied using electrical responses in the nervous system as well as studying anatomy or chemical processes  As we use these two methods we will also be concerned w/ how the knowledge, memories + expectations that people bring to situations influence their perceptions o These are called cognitive influences on perception Measuring Perception 1/12/2013 2:23:00 PM Description  When researcher asks a person to describe what they are perceiving or to indicate when a particular perception occurs they are using the phenomenological method o Is a first step in studying perception b/c it describes what we perceive  Can be at a very basic level + are such common observations that we might take them for granted but is where the study of perception begins b/c these are the basic properties that we are seeking to explain Recognition  Occurs when we categorize a stimulus by naming it  Method: procedure for measuring recognition is simple: stimulus is presented + observer indicates what it is o E.g. rat-man demonstration  Describing perceptions using phenomenological method + determining a person’s ability to recognize objects provides info about what a person is perceiving Detecting The Absolute Threshold  Is the smallest amount of stimulus energy necessary to detect a stimulus  Method: 3 basic methods for determining the absolute threshold: method of limits, adjustment + constant stimuli o Method of limits—experimenter presents stimuli in either ascending or descending order  Crossover point is where the observer goes from yes to no in descending trials or no to yes in ascending trials  Actual threshold is determined by averaging the crossover points from all of the results found in both the descending + ascending trials o Method of adjustment—experimenter or observer adjusts the stimulus intensity until the observer can just barely detect it  Differs from limits b/c observer doesn’t say yes or no but instead adjusts the dial until they can just barely perceive the stimulus  Can be conducted many times + the threshold is determined by taking the av
More Less

Related notes for PSYC 2390

Log In


Don't have an account?

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.