Unformatted text preview:

The Perceiving Mind: Sensation and perceptionSensation vs perceptionSensation: stimulation-detection processOur sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brainPerception: making “sense” of what our senses tell usActive process of organizing the stimulus output & giving it meaningSensory processsystem are designed to extract the information we need to functiontransduction:Psychophysics: studies relations between the physical characteristics of stimuli and sensory capabilitiesSensation is subjective, cant be measuredAbsolute limits of sensitivityDifferences between stimuliStimulus detectionAbsolute threshold: lowest intensity at which a stimulus can be detected 50% of the timeDecision criterion: how certain a person must be that a stimulus is present before they will say they detect itSignal detection theory: concerned with the factors that influence sensory judgmentDepends on factors such a fatigue, expectation, and significance of the stimulusCharacterisitcs of both participants and situations influence decision criterionIncrease rewards for hits or costs for misses results in lower detection thresholdsincrease costs for false alarms results in higher detection thresholdsdifference threshold: smallest threshold between 2 stimuli that people can perceive 50% of the timeWebber’s law: difference threshold is directly proportional to the magnitude of the comparison stimulus with which the comparison is being made.Thresholds- subliminal stimuliA subliminal stimulus is one that is so weak or brief that although it is received by the senses it cannot be perceived consciouslyResearch suggests that subliminal stimuliSubliminal perception can change how we rate itemsSubliminal persuasion is rarely effective in producing large scale changes in our attitudesSensory adaptation: diminishing sensitivity to an unchanging stimulusOccurs in all sensesAllows our senses to pick up changes in the environment that could be important to our survivalSeeing: the visual systemLight( measured in wavelength)Human visible light spectrumBrightness- intensityHue- colorHow light enter the eyeIris- opening that modifies the amount of light permitted through the pupilFocusing light:Cornea-refracts light to focus it on back of eyeLens- changes curvature (accommodation) to refract light onto back of eyeChanging light into neural activityRetina: membrane at back of eyeFovea: center of retina, responsible for acuityReceptor cells- contain photopigments that change on exposure to light:Rods- low levels of lightCones- high acuity, color visionGanglion cells- their axons leave the retina (at the blind spot), forming the optic nerve, which travels to the rest of the brainVisual perception: shape and contourHubel and Wiesel (1960s)- recorded from cat visual cortexFound that different cortical cells respond maximally to different types of stimuliDetecting lines and edged:Simple cells- orientation-specific slits of light in a particularComplex cells-Parts of the eye and visual pathwaysPupil: opening in the center of the irisCornea: clear membrane in front of eyeIris: colored portion, pupillary constriction and dilationVisionYoung-Helmholtz trichromatic theory: Cones are most sensitive to wavelengths corresponding to blue, green, and redProblem with the perception of the color yellowProblem with color afterimagesOpponent-process Theory: 3 types of cones respond to 2 wavelengthsRed-greenBlue-yellowBlack-whiteDual-process- Theory:Combines trichromatic and opponent-process theoryTrichromatic: cones are more sensitive to blue, green, and redOpponent process begin in ganglion cells and beyond (not the cones )Color-deficient vision:Trichormat: normal color visionSensitive to all 3 systemsDichromat: color blind in one of the 3 systemsMonochromat: completely color-blindSensitive onlt to the black-white sysemAnalysis and reconstruction:From the retina, the optic nerveFeature detectors: cells with the primary visual cortex that fire selectively in response to visual stimuli that have specific characteristicsVisual association cortex combines and interpretsPerceptionBottom-up processing: individual elements of the stimulus are combined into a unified perceptionDetection of individual stimuli elements breakdown/analysis of stimuli Combination of interpretation of “whole”Top-down processing: sensory information is interpreted in light of existing knowledge, concepts, ideas and expectationsInterpretation of incoming stimuli… guides analysisContextThe setting or environmental in which we interpret sensory stimuliThe Role of attentionAttentive 2 processes:Focusing on certain stimuliFiltering out other incoming informationStudied experimentally using shadowingInattentional blindness: the failure of unattended stimuli to register in consciousnessStimulus characteristics that affect attention:IntensityNoveltyMovementContrastRepetitionPersonal factors that affect attention:MotivesInterestsThreats to well-beingOrganization and structureGestalt principles: argues that the whole is more than the sum of the partsLaw of similarity: similar elements will be perceived as belonging togetherLaw of proximity: elements that are near each other are likely to be perceived as part of the same configurationLaw of closure: people tend to fill in gaps in incomplete figuresLaw of continuity: people link individual elements together to form a pattern that makes senseFigure-ground relations: the organization of stimuli into foreground figure and a backgroundPsych 101 04/15/2014The Perceiving Mind: Sensation and perception - Sensation vs perception - Sensation: stimulation-detection process o Our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain - Perception: making “sense” of what our senses tell uso Active process of organizing the stimulus output & giving it meaningSensory process- system are designed to extract the information we need to function- transduction:- Psychophysics: studies relations between the physical characteristics of stimuli and sensory capabilitieso Sensation is subjective, cant be measuredo Absolute limits of sensitivityo Differences between stimuli - Stimulus detectiono Absolute threshold: lowest intensity at which a stimulus can be detected 50% of the time o Decision criterion: how certain a person must be that a stimulus is present before they will say they detect it o Signal detection theory:


View Full Document

UW PSYCH 101 - The Perceiving Mind

Download The Perceiving Mind
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view The Perceiving Mind and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view The Perceiving Mind 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?