Sensation and Perception CP Psychology CHAPTER 5 Sensation and Perception Section 5Q2 Mr. Freccia, NHS Glencoe Publishers

The Human Senses 7 Senses: Vision … Hearing …Taste-Smell …Touch/Skin Sensation …Vestibular … Kinesthetic Vision: Light enters the eye through the Pupil, is focused (and inverted) by the Lens, and projected onto the Rods and Cones of the Retina where it is converted to neural impulses and sent through the Optic Nerve (blind spot) to the brain

Sensation & Perception

Sensation & Perception Rods: Very light sensitive, sense black/white, useful for night vision Cones: Concentrated opposite to lens, color sensitive, requires more light Receptors in the Human Eye Cones Rods Number Location in retina Sensitivity in dim light Color sensitive? Yes Low Center 6 million No High Periphery 120 million

Sensation & Perception Trichromatic (three color) Theory three different retinal color receptors red green blue

Sensation & Perception Color Deficiency (color blindness) Some or all of the cones do not function properly (genetic) Color Blindness Test! (Click)

Sensation & Perception Binocular Fusion: The combination of the eye’s two separate images into one Retinal Disparity: The difference between the images sensed by each retina Stereopsis: The ability to see depth as a result of retinal disparity

Sensation & Perception

Sensation & Perception Hearing: Vibration is converted to neural impulses which travel along auditory nerve Decibels measure sound wave intensity (loudness) Pitch measures high/low frequency (in-tune)

noise not only affects hearing it also affects our behavior (stressor) Noise & Stress noise not only affects hearing it also affects our behavior (stressor) noise is especially stressful when unanticipated or uncontrollable A 10 decibel increase results in a ten-fold increase in sound

Sensation & Perception 1 time 10 times 100 1000 32 64 128 256 512 1024 2048 4096 8192 16384 Frequency of tone in waves per second Low Pitch High Amplitude (loudness) required for perception relative to 20-29 year-old group Older people suffer neural hearing loss for higher frequencies/low amplitude 20-29 years old 30-39 years old 40-49 years old 50-59 years old 60 years and up

Sensation & Perception Time delay between ears receiving sound waves contributes to locating its origin Reaches ear later Reaches ear sooner

Sensation & Perception Taste Sensations taste is a “chemical” sense..sweet, sour, salty, bitter Smell smell is also a “chemical” sense precisely how olfactory receptors work is a mystery receptors recognize odors individually Sensory Interaction principle that one sense may influence another the smell of food significantly influences its taste

Sensation & Perception Smell/Taste: Chemicals activate receptors which send signals along olfactory nerve Receptor cells in olfactory membrane Nasal passage Olfactory bulb nerve

Sensation & Perception Olfactory Cortex Located on temporal lobe near taste cortex Linked to areas of memory storage which helps explain smell triggered memories Taste Cortex Olfactory Cortex

Sensation & Perception Bitter Sour Salty Sweet

Sensation & Perception Skin Sensations (Touch) pressure is the only skin sensation with identifiable receptors relationship between warmth, cold, pain remains a mystery when warm/cold receptors are activated together you feel “hot”

Sensation & Perception Vestibular Sense: Three semicircular canals in the ear regulate the sense of balance Kinesthetic Sense: (Kinesthesis) Receptors in muscles, tendons, and joints assist with posture and balance