SENSATION & PERCEPTION

1. SENSATION & PERCEPTION TRY THIS: Iti soft envotre alized howcom plext heproces sofrea ding is. Afe wsim plerear range mentscan ah veyoucomp lete lucon fused. &

2. WHY IS THAT SO CONFUSING? - Info must be organized in ways that are meaningful to our senses. - All sensory info is organized into a meaningful whole by perception. PHYSICAL CHANGES IN THE ENVIRONMENT TRIGGER SENSORY ACTIVITY

3. FOR EXAMPLE:A SMELL 1. ODERANT MOLECULES: STIMULATION 2. OLFACTORY RECEPTORS ACTIVATE: RECEPTION 3. ACTION POTENTIAL SENT: TRANSDUCTION 4. NERVE IMPULSE GIVEN MEANING BY THE BRAIN: CODING KNOW THIS ORDER!!!!

4. THRESHOLDHOW MUCH OF A STIMULUS IS NEEDED TO PRODUCE A SENSATION ABSOLUTE THRESHOLD: - THE SMALLEST AMOUNT OF ENERGY THAT WILL PRODUCE A SENSATION - DIFFERS FROM PERSON TO PERSON DIFFERENCE THRESHOLD: - THE SMALLEST CHANGE IN A STIMULUS THAT WILL PRODUCE A CHANGE IN SENSATION - WHEN DOES HOT BECOME COOL BECOME COLD? Weber’s Law = The larger/stronger the stimulus, the greater the change required to realize a difference 1 light bulb vs. 1 in a 1000 light bulbs

5. SENSORY ADAPTATION - OUR SENSORY SYSTEM IS “TUNED” TO DETECT CHANGES • WE ARE MOST RESPONSIVE TO INCREASES AND DECREASES • NEW EVENTS - SENSES WILL ADAPT TO A CONSTANT LEVEL OF STIMULATION (GET USED TO), THEN WILL RESPOND ONLY TO CHANGES

6. SIGNAL DETECTION THEORY WHAT IS IT? - STUDY OF THE CORRELATION BETWEEN MOTIVATION, SENSITIVITY AND SENSATION - MOTIVATION IS NEEDED FOR DETECTION TO OCCUR

7. THE 6SENSES • VISION • HEARING • TASTE • SMELL • TOUCH • I SEE DEAD PEOPLE (OOPS, SORRY) • BALANCE (2 TYPES) - VESTIBULAR - KINESTHETIC EACH TYPE OF SENSORY RECEPTOR TAKES SOME SORT OF EXTERNAL STIMULUS:

8. VISION (IGNORE THIS ONE PART) KNOW THESE PARTS (IGNORE THIS ONE PART)

9. EYE STRUCTURES KNOW THESE PARTS, AND WHAT THEY DO Kindergarten cop, Humor, Funny, Mashups, Prank Calls, Sound Bite PUPIL – OPENING THAT ALLOWS LIGHT IN, DOES NOT CHANGE SIZE IRIS – “COLORED” AREA – THIS CHANGES SIZE IN RESPONSE TO LIGHT LENS – ADJUSTS THICKNESS TO FOCUS LIGHT ON THE RETINA CILIARY MUSCLE – FOCUSES THE LENS FAR OBJECT FOCUS NEAR OBJECT FOCUS

10. EYE STRUCTURES KNOW THESE PARTS, AND WHAT THEY DO Kindergarten cop, Humor, Funny, Mashups, Prank Calls, Sound Bite RETINA – REAR SURFACE OF THE EYE LINED WITH VISUAL RECEPTORS FOVEA – “FOCAL POINT” FOUND ON THE MACULA SPECIALIZEDFOR ACUTE VISION FOVEA = LATIN FOR “PIT” FUN FOVEA FACT RAPTORS HAVE 2 BLIND SPOT – POINT ON THE RETINA WHERE THE OPTIC NERVE AND BLOOD VESSELS ENTER THE EYE = NO VISUAL RECEPTORS!!!!!

11. VISUAL RECEPTORS LOCATED ON THE RETINA – BOTH CONTAIN PHOTOPIGMENT, A LIGHT SENSATIVE CHEMICAL DERIVED FROM VITAMIN “A” (CAROTINE) FOUND IN RODS – MOVEMENT& GREYS - MOST ABUNDANT IN THE PERIPHERY OF THE RETINA - ACTIVE IN DIM LIGHT CONES – COLOR – MOST ABUNDANT IN AND AROUND THE FOVEA - ACTIVE IN BRIGHT LIGHT

12. COLOR VISION 3 TYPES OF CONES: SHORT WAVE = BLUES MEDIUM WAVE = GREENS & YELLOWS LONG WAVE = YELLOWS & REDS THE VISUAL SPECTRUM OF LIGHT =

13. 2 COLOR VISION THEORIES TRICHROMATICTHEORY: (YOUNG – HELMHOLTZ) - BASED ON 3 DIFFERENT SIZED CONES - RATIO OF CONE ACTIVITY = COLOR • WHEN ALL 3 ARE = YOU SEE WHITE OPPONENTPROCESS THEORY: - BASED ON NEGATIVE COLOR AFTER IMAGE - RESULTS FROM FATIGUE OF CONES - ONE COLOR ACTIVATES A CONE, WHILE THE OTHER INHIBITS THE CONE

14. PROPERTIES OF VISION DEPTH PERCEPTION: - IS DUE TO STEREOSCOPIC VISION; WHAT 2 EYES SEE AND THE BRAIN PROCESSES MOTION PERCEPTION: - IS DUE TO THE BRAIN RECOGNIZING THAT RECEPTOR CELLS ARE FIRING IN SEQUENCE - LOCATED IN THE TEMPORAL LOBE - DAMAGE CREATES MOTION BLINDNESS VISUAL ATTENTION:IT TAKES ABOUT 1/3 SEC. TO SHIFT

15. THE BLIND THE BLIND SPOT THE BLIND SPOT SIZE VARIES FROM PERSON TO PERSON GLAUCOMA CAN INCREASE THE SIZE OF THE BLIND

16. AND YOU THOUGHT YOU HAD EYE PROBLEMS?

17. VISIONDISORDERS • PRESBYOPIA: • GRADUAL LOSS OF LENS ELASTICITY DUE TO AGE • - NEAR POINT RECEDES AND ACCOMIDATION LOWERS • - READING BECOMES DIFFICULT • - CORRECTED WITH CONVEX LENS OR BIFOCALS

18. VISIONDISORDERS CATARACTS: - THE LENS BECOMES OPAQUE DUE TO THE PROTEINS IN THE LENS “CLUMPING” TOGETHER - THIS CLOUDY APPEARANCE PREVENTS LIGHT FROM REACHING THE RETINA - TREATED BY SURGICAL REMOVAL AND STRONG EYEGLASSES THREE TYPES: SUBCAPSULAR = BACK OF LENS NUCLEAR = CENTER OF LENS CORTICAL = CORTEX OF THE LENS

19. VISIONDISORDERS MYOPIA: NEARSIGHTEDNESS (YOU CAN SEE CLOSE UP) - EYEBALL IS ABNORMALLY LONG - IMAGE FOCUSES IN FRONT OF THE RETINA - CORRECTED WITH A CONCAVE LENS

20. VISIONDISORDERS HYPEROPIA: FARSIGHTEDNESS (YOU CAN SEE FAR) - EYEBALL IS ABNORMALLY SHORT - IMAGE FOCUSES BEHIND THE RETINA - CORRECTED WITH A CONVEX LENS

21. VISIONDISORDERS ASTIGMATISM: KINDA NEED GLASSES KINDA NOT - EYEBALL IS NORMALLY SHAPED - IMPERFECTIONS MAY EXIST IN THE LENS OR CORNEA - NOT ALL OF THE LIGHT RAYS CONVERGE AT THE RIGHT SPOT ON THE RETINA - A PARTIALLY “FUZZY” IMAGE IS FORMED, CAUSING EYE STRAIN, HEADACHES, AND LIGHT SENSATIVITY

22. VISIONDISORDERS AMBLIOPIA: LAZY EYE (USUALLY DIAGNOSED IN KIDS) - CHILD IGNORES VISION IN ONE EYE - SOMETIMES CHILD EVEN NEGLECTS TO FOCUS THAT EYE - TREATMENT – WEAR A PATCH OVER THE ACTIVE EYE • STRABISMUS: EYE MISALIGNMENT • DO NOT DEVELOP STEREOSCOPIC DEPTH PERCEPTION • NOT EVEN AFTER SURGERY!