PSYC1020_1.ppt YES OF COUSE NINYO TANAN KAY

YES

1. 
PSYC 1020PSYC 1020
Sensing and Perceiving ISensing and Perceiving I
Sense ModalitiesSense Modalities
PsychophysicsPsychophysics
Light, Eye & BrainLight, Eye & Brain
Internet : http: // www.psy.uq.edu.auInternet : http: // www.psy.uq.edu.au
Dr. Jack Broerse Dr. Jack Broerse

2. Visual elaborationVisual elaboration
Visual sensationVisual sensation
(visual cortex)(visual cortex)
Skin sensationSkin sensation
Auditory Auditory
sensationsensation
MovementMovement
Conscious elaboration
& thought
Perceptual Perceptual
judgementjudgement
Body sensationBody sensation
(cerebellum)(cerebellum)
Sensing States & Events:Sensing States & Events:
External versus InternalExternal versus Internal

3. External States & EventsExternal States & Events
Sweet
Salty
Sour
Bitter
Taste & SmellTaste & Smell
Skin SensesSkin Senses
Touch, Temperature,
Pressure, Pain
VisionVision
AuditionAudition
Hue, Brightness,
Saturation (Density)
Volume, Frequency,
Tonal Quality (Density)
Flowery
Fruity
Spicy
Burned
Putrid
Resinous

4. ?
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Extrasensory Perception:Extrasensory Perception:
Phenomena in Science or Pseudoscience? Phenomena in Science or Pseudoscience?
!

5. Extrasensory Perception:Extrasensory Perception:
Charles Darwin’s ScepticismCharles Darwin’s Scepticism
Thought Transference (1870s)Thought Transference (1870s)
For:For:
Alfred Russel Wallace Alfred Russel Wallace
Against:Against:
Charles DarwinCharles Darwin
Thomas H. HuxleyThomas H. Huxley
(see Scientific American,(see Scientific American,
October, 1996).October, 1996).

6. Internal States & EventsInternal States & Events
Proprioception & KinaesthesisProprioception & Kinaesthesis
Sensations of body/limb/muscleSensations of body/limb/muscle
position & movementposition & movement
InteroceptionInteroception
Vague sensations of internal organs &Vague sensations of internal organs &
deep paindeep pain

7. Psychophysics & MeasurementPsychophysics & Measurement
Stimulus to Conscious ExperienceStimulus to Conscious Experience
Psychophysical Relationship Psychophysical Relationship

8. Classical PsychophysicsClassical Psychophysics
Absolute ThresholdsAbsolute Thresholds
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Detection Threshold (Limen) Detection Threshold (Limen)
Vision A candle flame at 60 km on clear dark night
Hearing A watch ticking at 6 m in quiet conditions
Touch Wing of a bee falling on your cheek from 1cm
Smell One eye drop of perfume in 3-room appartment
Taste One teaspoon sugar in 10 litres water

9. Difference ThresholdsDifference Thresholds
Just Noticeable Differences (JND)Just Noticeable Differences (JND)
L L
LL
11
LL
22 + + L L
LL
2 2
LL
1 1 + + L L wherewhere
WEBER’s LAW WEBER’s LAW LL
LL
Constant Constant
Discriminations: Same vs DifferentDiscriminations: Same vs Different

10. Thresholds & DecisionsThresholds & Decisions
Signal Detection Theory (SDT)Signal Detection Theory (SDT)
Stimulus RealityStimulus Reality
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Same/PresentSame/Present Diff/AbsentDiff/Absent
Same/PresentSame/Present
Diff/AbsentDiff/Absent
HITHIT
FALSEFALSE
ALARMALARM
MISSMISS
CORRECTCORRECT
REJECTIONREJECTION
Hits – False AlarmsHits – False Alarms
SensitivitySensitivityDecision CriterionDecision Criterionvsvs
Key WordsKey Words

11. Subliminal Perception?Subliminal Perception?
A case study for SDTA case study for SDT
Perceptual DefencePerceptual Defence
MotivationMotivationMental SetMental Set
Key WordsKey Words

12. Subliminal Perception?Subliminal Perception?
A case study for SDTA case study for SDT
Perceptual DefencePerceptual Defence
MotivationMotivationMental SetMental Set
Key WordsKey Words

13. The Stimulus for VisionThe Stimulus for Vision
Electromagnetic RadiationElectromagnetic Radiation
Frequency= 1/Frequency= 1/
Wavelength (Wavelength ())
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Visible Visible LightLight Spectrum 400 – 700 nanometres (10 Spectrum 400 – 700 nanometres (10
-9-9
m) m)
 = 10 = 10
1515
mm
 = 10 = 10
77
mm –10 –10
1313
mm

14. The EyeThe Eye
Anatomy & Physiology Anatomy & Physiology
Retina (photosensitive rods & cones)
Fovea (central vision)
Lens
Cornea
Blind Spot
Pupil
Iris
Optic Nerve
++
Approx. 9 cm at normal viewing distance

15. Retinal Rods and ConesRetinal Rods and Cones
Sensitivity & Dark AdaptationSensitivity & Dark Adaptation
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Wavelength (nm) Wavelength (nm)
Minutes in Dark Minutes in Dark
1.01.0
2.02.0
4.04.0
3.03.0
5.05.0
6.06.0
7.07.0
1.01.0
2.02.0
4.04.0
3.03.0
5.05.0
6.06.0
400400500500600600700700
RodsRods
ConesCones
300 x300 x
1010202030304040 5050
ConesCones
RodsRods

16. Visual Cortex
Brodmann Areas 17, 18, 19
Corpus Callosum Thalamus
Cerebellum
Retina to BrainRetina to Brain
Central Visual Pathway Central Visual Pathway

17. Basic Visual Functions:Basic Visual Functions:
Everyday Tests of Visual AcuityEveryday Tests of Visual Acuity
E
RKF
VMWXL
Snellen ChartSnellen Chart
Landolt ‘C’Landolt ‘C’
BN
E
C

18. Enmetropic (normal acuity)Enmetropic (normal acuity)
Myopic (nearsightedness)Myopic (nearsightedness)
Hyperopic (farsightedness)Hyperopic (farsightedness)
Astigmatic (Blurring in some axis)Astigmatic (Blurring in some axis)
Presbyopic (Accomodation problems)Presbyopic (Accomodation problems)
Optical Disorders:Optical Disorders:
Focussing the imageFocussing the image