Title NOTES - SENSATION & PERCEPTION.pdf ✅

1 | P a g e SENSATION AND PERCEPTION SENSATION − Detects physical energy from environment − Encodes as neutral signals PERCEPTION − Select, organize, and interpret sensations PROSOPAGNOSIA − Condition; losing temporal lobe (inability to recognize faces) CONDITION FOR SENSORY AWARENESS 1. Stimulation of sensory receptor 2. Presence of receptor cells in each sense organ 3. Stimulus converted as electrochemical impulses (transduction) THRESHOLDS − Divide line what energy can be detected/not ABSOLUTE THRESHOLD − Minimal amount of energy that can produce sensation DIFFERENCE THRESHOLD − Minimum difference in magnitude of two stimuli present SIGNAL-DETECTION THEORY − Perceive sensory stimuli/difference between two signal FACTORS: − Intensity of signal − Quality of person’s biological sensory system − Psychological factor: motivation, expectation, learning SENSITIZATION − Non-associative learning process − Increased responsiveness to stimulus (complementary habituation) − Increase responsiveness/behavior due to exposure of strong stimulus DESENSITIZATION − Becoming less sensitive to stimulation SYSTEMATIC DESENSITIZATION − Behavioral treatment technique − Gradually exposed to an anxiety-producing stimulus
2 | P a g e SENSATION AND PERCEPTION THE SENSORY SYSTEM 1. THE VISION EYE − Receptor organ of vision − Sensitive to light waves − Pulses of electromagnetic energy (wat strikes our eyes) THREE PHYSICAL CHARACTERISTICS OF LIGHT (BY SENSORY EXPERIENCES) 1. Wavelength- distance from one wave (pink, green) 2. Intensity- amount of energy in light waves; brightness 3. Saturation- extent light contains only one wavelength > many; purity/richness of color CORNEA − Transparent protective structure − Light ray pass through PUPIL − Light rays enter IRIS − Adjustments made − Varies on light condition − Colored part of eye LENS − Light rays pass after pupil RETINA − Clear structure; adjust to focus on objects − Postage stamp − 2 types of light & sensitive receptor cell (6.5 cones; 100 million rods) ANATOMY OF HUMAN EYE VISUAL PROBLEMS 1. Visual Acuity- sharpness of vision/discriminate usual details a) Nearsightedness/Myopia- seeing nearby than distant objects b) Farsighted/Hyperopia- distant than nearby objects 2. Presbyopia- brittleness of lens; age 38-46 3. Strabismus- cross-eyed visual disorder; eye can’t focus on one point at same time
3 | P a g e SENSATION AND PERCEPTION 4. Astigmatism- abnormal curvature lens; image indistinct/distorted 5. Color Blindness- monochromats & sensitive to light-dark only THEORIES OF COLOR VISION ➢ TRICHROMATIC THEORY − Three types of cones − Respond to red, green, blue − Thomas Young (British scientist) − Early 1800s − Any color from visible spectrum by varying interactions of light − Herman von Helmholtz (eye have 3 diff types of photoreceptors/cones) ➢ OPPONENT-PROCESS THEORY − Edward Hering Theory − 3 types but not red, green, blue − Afterimages − Red-green-blue-yellow (perceive different brightness from light to dark) 2. THE HEARING HUMAN EAR − Sensing auditory stimulation/hearing − Capture sound waves, vibrate in sympathy, transmit info to brain THREE MAJOR PARTS OF HUMAN EAR 1. Outer Ear- funnel sound wave to eardrum (thin; vibrates in response to sound waves; transmits to middle & inner ear) 2. Middle Ear- eardrum & 3 small bones (hammer, anvil, stirrup); amplifier (increase magnitude of air pressure) STIRRUP- attached to another vibrating membrane (oval window) 3. Inner Ear COCHLEA- bony tube; snail shape; 2 long membranes that divide to 3 fluid filled chambers BASILAR MEMBRANE- coiled within cochlea ORGAN OF CORTI- command post; attached to basilar membrane PSYCHOLOGICAL DIMENSIONS OF SOUND 1. Pitch- frequency/number of cycles per second; unit hertz (9h2) − Greater number of cycles = higher pitch 2. Loudness- height/amplitude of sound waves; higher amplitude = louder sound 3. Consonant- combination of pleasant tones 4. Overtones- highly pitch sound; contribute to quality/richness/timbre AUDITORY PROBLEMS 1. Conduction Deafness- damage middle ear (eardrum/3 bones) 2. Sensory-neural Deafness- inner ear; loss of hair cells; more sensitive to sounds 3. Stimulation Deafness- exposure to very loud sounds; ringing sensation = hair cells might damaged 3. SMELL AND TASTE: CHEMICAL SENSES **smell + taste = partners for life
4 | P a g e SENSATION AND PERCEPTION ANOSMIA − Smell blindness − Nose sensitive to various basic odors (flowery, misty, etc) PAPILLAE − Sensory receptors for taste − Small burps on tongue AGEUSIA − Disorder of taste − Eating hot food > scrape tongue > loss of taste − Taste cells renewal every week DIAGRAM OF NOSE DIAGRAM OF TONGUE 4. THE SKIN SENSES SKIN − Largest organ − 5 kinds of sensations: touch, pressure, warmth, cold, pain THREE LAYERS: 1. Epidermis (outer layer) 2. Dermis (intermediate layer) 3. Subcutaneous Adipose Tissue (deep layer) TOUCH AND PRESSURE TWO-POINT TOUCH THRESHOLD − Asses sensitivity to pressure