Psychology: An Introduction Benjamin Lahey 11th Edition Slides by Kimberly Foreman 2008 McGraw-Hill Co., Inc. All rights reserved

Sensation and Perception Chapter Five: Sensation and Perception 2008 McGraw-Hill Co., Inc. All rights reserved

Sensation: Receiving Sensory Messages What messages can be received? - stimulus: any aspect of the world that influences behavior or conscious experience Virtually anything that can excite receptor cells can be a stimulus. 2008 McGraw-Hill Co., Inc. All rights reserved

Sensation: Receiving Sensory Messages (cont.) Transduction: - translating messages for the brain - translation of energy in the environment into neural impulses - transduced by sensory receptor cells 2008 McGraw-Hill Co., Inc. All rights reserved

Sensation: Receiving Sensory Messages (cont.) Sensory limits: how strong must messages be? - absolute threshold: - smallest magnitude of a stimulus that can be detected - difference threshold: - smallest difference between two stimuli that can be detected half the time 2008 McGraw-Hill Co., Inc. All rights reserved

Sensation: Receiving Sensory Messages (cont.) Sensory limits: how strong must messages be (cont.)? - sensory adaptation: - when a stimulus is continuously present or repeated at short intervals, the sensation becomes gradually weaker - psychophysics: - specialty area that studies sensory limits, sensory adaptation and related topics - Weber’s law 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light Light: - electromagnetic radiation - includes radio waves and X rays - only a small portion is visible waves that vary in frequency and intensity - intensity = brightness - wavelength = hue 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) The eye: - cornea - iris - pupil - lens - ciliary muscle 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) The eye (cont.): how does it work? - retina: - rods - cones - fovea 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) The eye (cont.): How does it work? - optic nerve - blind spot - optic chiasm 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) Dark and light adaptation: - dark adaptation: - in darkness, the rods and cones are not sensitive enough to be stimulated by the low-intensity light; they begin to gain sensitivity by making a fresh supply of the chemicals used in light reception - light adaptation: - when suddenly exposed to intense light, the visual circuits are overloaded 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) Color vision: - trichromatic theory: - 3 kinds of cones that respond to either red, green or blue range 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) Color vision (cont.): - opponent process theory: two kinds of color- processing mechanisms respond in opposite ways to the two pairs of complementary colors 2008 McGraw-Hill Co., Inc. All rights reserved

Vision: Sensing Light (cont.) Color blindness: - genetic defect - partial color blindness: - 8% of males - 1% of females 2008 McGraw-Hill Co., Inc. All rights reserved

Hearing: Sensing Sound Waves - audition - sound waves - frequency of cycles: - Hertz (Hz) - intensity: - decibel (db) - timbre 2008 McGraw-Hill Co., Inc. All rights reserved

Hearing: Sensing Sound Waves (cont.) The ear: - outer ear: - pinna - external auditory canal - middle ear: - eardrum hammer, anvil, stirrup 2008 McGraw-Hill Co., Inc. All rights reserved

Hearing: Sensing Sound Waves (cont.) The ear (cont.): - inner ear: - oval window - cochlea - round window - basilar membrane - organ of Corti 2008 McGraw-Hill Co., Inc. All rights reserved

Body Senses Orientation and movement: - vestibular organ: semicircular canals: - saccule - utricle - kinesthetic sense: - kinesthetic receptors: - cupula 2008 McGraw-Hill Co., Inc. All rights reserved

Body Senses (cont.) Skin senses: pressure four types of receptors: - free nerve endings - basket cells - tactile discs - specialized end bulbs - sensitivity: - Braille 2008 McGraw-Hill Co., Inc. All rights reserved

Body Senses (cont.) Skin senses (cont.): - temperature: - hot: - cold: - intense heat stimulates both warm and cold receptors - cold: - generally responsive only to cold temperatures 2008 McGraw-Hill Co., Inc. All rights reserved

Body Senses (cont.) Pain: - nociceptors: - pain gates: - brain stem - spinal cord - peripheral pain receptors 2008 McGraw-Hill Co., Inc. All rights reserved

Body Senses (cont.) Pain (cont.): - brain stem: - gate-control theory - spinal cord - peripheral: - regulation of pain - phantom limbs 2008 McGraw-Hill Co., Inc. All rights reserved

Chemical Senses Taste: - 10,000 taste buds - papillae: - sweetness - sourness - saltiness - bitterness - fattiness 2008 McGraw-Hill Co., Inc. All rights reserved

Chemical Senses (cont.) Smell: - olfactory epithelium - impacts taste 2008 McGraw-Hill Co., Inc. All rights reserved

Chemical Senses (cont.) The pheromone detection: - important roles in regulation of reproductive behavior - released in sweat, saliva or urine - can influence human reproductive cycles 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages Visual perception: - perceptual organization - figure-ground - continuity - proximity - similarity - closure 2008 McGraw-Hill Co., Inc. All rights reserved

Figure-Ground 2008 McGraw-Hill Co., Inc. All rights reserved

Continuity 2008 McGraw-Hill Co., Inc. All rights reserved

Proximity 2008 McGraw-Hill Co., Inc. All rights reserved

Similarity 2008 McGraw-Hill Co., Inc. All rights reserved

Closure 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Visual perception (cont.): - perceptual constancy: - brightness constancy - color constancy - size constancy - shape constancy 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Visual perception (cont.): - depth perception: - monocular cues: - texture gradient - linear perspective - superposition - shadowing - speed of movement - aerial perspective - accommodation - vertical position 2008 McGraw-Hill Co., Inc. All rights reserved

Texture Gradient 2008 McGraw-Hill Co., Inc. All rights reserved

Shadowing 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Visual perception (cont.): - depth perception (cont.): - binocular cues: - convergence: - eyes must angle inward for a near object - retinal disparity: - difference between the images on the two retinas 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Visual perception (cont.): - visual illusions: - Ponzo - Zollner - Muller-Lyer - Ames room - Poggendorf 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Visual perception (cont.): - color perception: - interpreted in the brain using contextual clues 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Multisensory perception: integration and interpretation of information from multiple senses at the same time 2008 McGraw-Hill Co., Inc. All rights reserved

Perception: Interpreting Sensory Messages (cont.) Motivation, emotion and perception: - emotions strongly influence perception - no simple one-to-one relation between the physical stimulus and what one perceives 2008 McGraw-Hill Co., Inc. All rights reserved