Textbook Notes (368,875)
Canada (162,227)
York University (12,886)
Psychology (3,584)
PSYC 1010 (1,086)

Psychology Unit 2

62 Pages
Unlock Document

PSYC 1010
Jennifer Steele

Psychology Test 2 NotesChapter 4 Sensation and PerceptionPsychophysics Basic concepts and IssuesoStudy of how physical stimuli are translated into psychological experienceoThresholds looking for limitsSensation begins with stimulusFechner what is weakest detectable stimulus for any sensationThreshold dividing point between energy levels that do and do not have detectable effects light turning on when it gets darkAbsolute threshold for specific types of sensory input is the minimum amount of stimulation that an organism can detectno absolute but rather response gradually increasesabsolute thresholdstimulus intensity detected 50 of the timeoWeighing the Difference The JNDFechner interested in peoples sensitivity to difference between stimuliJNDjust noticeable difference smallest difference in the amount of stimulation that a specific sense can detectVaries by senseWebers law strength size of a JND is constant proportion of the initial stimulus called webers fractionPsychophysical ScalingFechner used JND as unit of measurementFechners lawmagnitude of sensory experience is proportional to the number of JNDs stimulus is above the absolute thresholdSignal detection theoryDetection of stimuli involves decision and sensory processesinfluenced by various factorsoCan be altered by noiseIrrelevant stimuli in environmentPerception without awarenessSubliminal perception registration of sensory input without conscious awarenessoShowing popcorn advertisements in moviesDeals with subliminal messagingSensory AdaptionGradual decline in sensitivity due to prolonged stimulationAllows people to ignore constants and focus on changes in environmentPossibly sculptured by natural selectionOur Sense of Sight The visual systemoThe Stimulus LightLight electromagnetic radiationVary in amplitude and in wavelengthsAmplitudebrightness wavelengthcolourUsually mix of several wavelengthsoThe Eye A living Optical InstrumentEyes have 2 main purposesChannel light to retinaHouse the retinaLight enters through corneaCornealens form upside down image on retinaLens is transparent eye structure that focus the light rays falling on the retinaCapable of adjustmentsWhen curvature of lens adjusts to alter visual focusLens get fatround when focus on close objectGet flat when focus on far objectNear sightedness focus of light from distant object falls short of retinaLenscornea bends light too mucheye ball too longFar sightedness light from close objects behind the retina eye ball too shortEye can make adjustments to alter the amount of light reaching the retinaIriscolored ring surrounding pupilPupil opening regulates amount of light passing into the rear chamber of eyeoIf pupil constrictsless light but sharper imageoIf pupil dilatesmore light but less sharpoConstricts in bright light dilates in dim lightEyes in constant motionReferred to as saccadesoEssential to good visionoShows subconscious interestsoThe Retina The brain Envoy in the EyeNeural tissue lining the inside back surface of the eyeAbsorbs light processes images sends visual information to brainoAxons run from retina to the brainConverge at optic diskHole in the retina where the optic nerve fibres exit the eyeoBlind spotVisual Receptors Rods and ConesRetina has a lot of receptor cellsIn the inner most layer of the retinaoOnly 10 of light reaches here2 types of receptorsrods and conesoMore rods than conesCones specialized visual receptors that play key role in day light vision and colour visionoHandle day time vision bright light dazzles rods
More Less

Related notes for PSYC 1010

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.