Textbook Notes (368,150)
Canada (161,680)
Psychology (1,418)
PSYC 212 (49)
Chapter 1

Chapter 1.doc

17 Pages
Unlock Document

PSYC 212
Remy Allard

Fundamentals of Sensory PerceptionChapter OnePrinciples of Perceptual MeasurementIntensity of light is measured with a device that is called radiometeroSpecifies the intensity in a set of unitsPsychological events evoke an appreciation for physical stimulusPerceptionprivate experiencePerceived intensity of sensationsA Scientific basis of perceptual measurementMust be scientific with experimental procedures to study perception to establish a quantifiable relationship between two variablesphysical stimulus and perceptual impressionHow biological operations within nature of brainhow it processes information lead to sensation and perceptionQuantitative relationshipsadvantageousoProvides an estimate of the perceptual quality of a stimulus in numerical termsoie new perfumestesting its aromatic acceptance by the publicapply a set of experimental procedures to numerically index it impact on the sense of smelluse to provide a meaningful comparison with the perceptual impression made by other perfumesoAllows for comparisons within other stimulioAllow for comparisons among individuals and speciesMathematical descriptors of the systemCrossmodal comparisoncomparison amongst different sensory modalities to see if similarities existRelationship between perception and physical stimulusoEarly experimentalists looked for a general formula to describe all sensory systemsWhat kind of function could relate physical intensity of a stimulus to its perceived magnitudeTheres an increasing relationship but in which way does it increaseLinearfor any given increase in physical intensity there is a certain increment in the perceived intensity oConstant proportion of increaseoConstant slopeExponentialperceived sensation intensity changes very slowly at low values of physical intensityoAfter a certain point function takes offoSmall changes in stimulus intensity produce a dramatic increase in perceptionoSlope progressively increases with physical intensityLogarithmic functionslope very large at the beginning so perceived intensities can dramatically change with small stimulus intensity changesoEffect diminishesfunction tails off at higher stimulus intensitieisoDecreasing slope over entire rangeoTwo approaches to obtaining precise relationship between physicalperceptualAsk human subjects to rate the perceived intensity of a stimulus sound at different physical intensitiesGraph stimulus intensity vs sensation magnitudeMeasure of the smallest change in stimulus input to cause a just discriminable change in sensationMathematical relationship between physicalperceptual qualities to be established by obtaining 2 basic characteristicsdescriptions of the functionB Classical PsychophysicsFunctions will not start at 0 because we do not detect very low levels of stimulus intensityPhysical stimulus present biological elements involved in capturing stimulustransforming it to a sensory experienceAbsolute thresholdthe intensity once it has reached its minimum levelSubthresholdstimulus intensities below the pointSuprathresholdwhere sensation takes placeMust determine where slope changes as a function of physical intensityMust plot other points as well in order to see the changeDifference thresholdknowing how a small change in stimulus intensity is required to produce a discriminable change in sensationoCan help estimate how the slope changes in suprathreshold levelsGerman physicist Gustav Fechner 1860determine the relationship between mind and bodyestablish guiding principleexperimental methods to be used in psychophysics1 Psychophysical methods3 general methods by Fechner to obtain absolutedifference thresholdsomethod of adjustmenthuman subject told simply to adjust the physical intensity of the stimulus until its barely detectableinitial intensity set abovebelow the threshold and its changed until just perceptiblesensation disappearsadvantagesquick engages subjectdisadvantagessubject has an idea of what the next stimulus is like in comparison to the one beforeomethod of limitspreferable if speed is not an issueprovides more reliable estimatessubjected presented with a stimulus whose intensity is chosen from an ascendingdescending seriesif ascendingintensity of stimulus set at subthreshold value
More Less

Related notes for PSYC 212

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.