1. Psychology 100:12 Chapter 5 Sensation & Perception Part II

2. Outline Basic Sensory Processes Olfaction and gustation Touch Audition Study Question: Label diagrams of the following structures: The Ear, The Eye, The Tongue, Haptic Nerves, etc.

3. Ramachadrin From: A journey to the center of your mind

4. Sensation Signal detection theory –Human judgement and the absolute threshold > E.g., A radar operator during 9/11/01 versus a radar operator today > Sensation vs. decision > Discriminating a signal + noise from noise alone > Lax (yea-sayer) and strict (nea-sayer) criterion  E.g., Hits and false alarms on a true-false test Sensation

5. Signal detection theory - Payoff matrices MissHit Correct rejection False alarm Response YesNo Stimulus On Off Sensation

6. Signal detection theory - Gullible student (Lax; yea-sayer) 10 %90 % 40 %60 % Response TrueFalse Test Item True False Sensation

7. Signal detection theory - Skeptical student (strict; nay-sayer) 40 %60 % 90 %10 % Response TrueFalse Test Item True False Sensation

8. Signal detection theory – The Receiver Operator Characteristic Bias vs. Sensitivity Hit Rate False Alarm Rate 1.0.5 1.0.5 Strict Lax Sensation

9. The simplified view Bitter Sour Salt Sweet Sensation Taste –Qualitative information: > Sour  H+ ions block K+ channels > Sweet  Receptors that bind glucose > Salty  amiloride-sensitive Na+ channel > Bitter (G-Protein related) > Umami  metabotropic glutamate receptor (mGluR4) Gustation Sensation Gustation

10. Other Taste sensations –Temperature – False temperature > Cool (mint)  Heat (capsaicin) –Astringency (tannins) – Fat  CD36 receptor Gustation

11. Taste buds http://www.cf.ac.uk/biosi/staff/jacob/teaching/sensory/taste.html Sensation Gustation

12. Taste buds –Range: 500 - 10,000 > Normal  200 Fungiform + 1280 foliate + 2200 circumvallate = 3680 > Individual differences  Non-tasters (25%) 117 papillae per cm 2  Normal (50%) 127 papillae per cm 2  Super-tasters 165 papillae per cm 2 Sensation Gustation

13. Sense of smell –Olfactory Epithelium: thin layer of tissue containing the olfactory receptors – Olfactory Bulb: the brain center for smell. – Vomeronasal organs: respond to pheromones > E.g., menstrual synchronization SensationThe skin Olfaction

14. Skin Sensations: –Pressure –Warmth –Cold –Pain Other Candidates –Vibration, tickle and itch Haptic senses

15. Pain –Types of Pain fibers >A-Delta fibers: Convey the sharp immediate pain of injury. > C fibers: Convey slow, dull, burning pain that lingers after injury. Haptic senses

16. Pain –Gate control theory > There is a gateway for pain located in the midbrain. > The periaqueductal gray (PAG) contains neurons that inhibit cells carrying pain signals to the brain. > Role of Endorphins Ronald Melzack Haptic senses

17. Low High Compression Sensation Hearing –The physical stimulus >The quantitative element: Amount of compression (sound pressure). > We hear loudness, measured in decibels. Sensation Audition

18. > The qualitative element: Frequency of compression waves. >We hear pitch SoftLoud Quantitative Qualitative Low High Sensation Audition

19. Sensation The Ear Sensation Audition

20. Sensation Audition

21. Transduction in the chochlea Sensation Audition

22. Sensation Coding for pitch –Place theory >Frequency is determined by the place on the basilar membrane where there is maximal vibrational amplitude. >Two forms of deafness  Conduction  Nerve –Problems with place theory –Coding for time (frequency theory) Sensation Audition