1. SENSATION AND PERCEPTION Chapter 8

2. SENSATION  Any aspect or a change in the environment to which an organism responds = Stimulus  Sensation = any time a stimulus activates a receptor

3. RECEPTOR Sense organs that detect changes in heat, light, sound, pressure, etc. Sense organs that detect changes in heat, light, sound, pressure, etc.

4. PERCEPTION Sensations may be combined with others and/or past experiences Sensations may be combined with others and/or past experiences Perception = the organization of sensory information into meaningful experiences Perception = the organization of sensory information into meaningful experiences

5. THRESHOLD How much stimulus or energy is required for a person to sense or experience the stimulus How much stimulus or energy is required for a person to sense or experience the stimulus Each person has their own threshold Each person has their own threshold Absolute threshold – the weakest of smallest amount of stimulus to produce a sensation Absolute threshold – the weakest of smallest amount of stimulus to produce a sensation

6. DIFFERENCE THRESHOLD The minimum amount of difference a person can detect between 2 stimuli The minimum amount of difference a person can detect between 2 stimuli Weber’s Law – the larger or stronger a stimulus, the larger the change required for a person to notice it Weber’s Law – the larger or stronger a stimulus, the larger the change required for a person to notice it Ex: Adding 5 lbs to a 100 lb weight vs adding 100 lbs to a 5 lb weight Ex: Adding 5 lbs to a 100 lb weight vs adding 100 lbs to a 5 lb weight

7. SENSORY ADAPTATION Responsive to changes in environment Responsive to changes in environment Ex: darkened room, cold water vs hot, etc. Ex: darkened room, cold water vs hot, etc. Adaptations can also help you cope with certain stimuli Adaptations can also help you cope with certain stimuli Ex: ticking clock, street noise, odors Ex: ticking clock, street noise, odors

8. SIGNAL-DETECTION THEORY The relations between motivation, sensitivity, and decision making in detecting the presence or absence of a stimulus The relations between motivation, sensitivity, and decision making in detecting the presence or absence of a stimulus Ex: study while the tv or radio is playing Ex: study while the tv or radio is playing

9. PERCEPTION The brain receives information from the senses and organizes and interprets it into meaningful experiences-unconsciously The brain receives information from the senses and organizes and interprets it into meaningful experiences-unconsciously

10. GESTALT The brain creates whole structures out of bits and pieces of information we take in from the environment The brain creates whole structures out of bits and pieces of information we take in from the environment The “whole picture” is called – Gestalt The “whole picture” is called – Gestalt (German word meaning “pattern” or “configuration”) (German word meaning “pattern” or “configuration”)

11. GESTALT PRINCIPLES See figure 8.12 pg. 224 See figure 8.12 pg. 224

12. FIGURE-GROUND PERCEPTION The ability to discriminate properly between a figure and its background The ability to discriminate properly between a figure and its background Ex: pick out a person’s voice in a crowd Ex: pick out a person’s voice in a crowd

13. PERCEPTUAL INFERENCE Filling in the gaps based on cues and information we get or perceive Filling in the gaps based on cues and information we get or perceive Ex: going up a steep hill that “disappears” over the top, we assume the road will continue on the other side Ex: going up a steep hill that “disappears” over the top, we assume the road will continue on the other side

14. PERCEIVE Perceiving is learned Perceiving is learned Influenced by our needs, beliefs, and expectations Influenced by our needs, beliefs, and expectations Ex: experiment with hungry people - Ex: experiment with hungry people - *faster at identifying food-related words when words are flashed in front of them *faster at identifying food-related words when words are flashed in front of them

15. SUBLIMINAL PERCEPTION Subliminal messages – brief auditory or visual messages presented below threshold Subliminal messages – brief auditory or visual messages presented below threshold Less than 50% chance they are perceived Less than 50% chance they are perceived Ex: movie theaters subliminal messages about coke and popcorn (1/3000 of sec every 5 sec) Ex: movie theaters subliminal messages about coke and popcorn (1/3000 of sec every 5 sec)

16. DEPTH PERCEPTION Monocular – cues that can be used with the single eye Monocular – cues that can be used with the single eye Cues: relative ht., Interposition (overlapping of images), light and shadows, Cues: relative ht., Interposition (overlapping of images), light and shadows, texture-density, linear, and relative motion texture-density, linear, and relative motion Binocular – cues that depend on existence or movement of both eyes Binocular – cues that depend on existence or movement of both eyes

17. CONSTANCY The ability to perceive an object in the same way regardless of size, shape, brightness, or color The ability to perceive an object in the same way regardless of size, shape, brightness, or color

18. ILLUSIONS Incorrect perceptions Incorrect perceptions Created when perceptual cues are distorted so that our brains cannot correctly interpret space, size and depth cues Created when perceptual cues are distorted so that our brains cannot correctly interpret space, size and depth cues

19. EXTRASENSORY PERCEPTION (ESP) Receiving information about the world through channels other than the normal senses Receiving information about the world through channels other than the normal senses Hotly debated Hotly debated Studied since the 1900’s Studied since the 1900’s Not consistent results in experiments Not consistent results in experiments

20. TYPES OF ESP Clairvoyance – no sensory input Clairvoyance – no sensory input Telepathy – reading minds or transferring thoughts Telepathy – reading minds or transferring thoughts Psychokinesis – moving objects mentally Psychokinesis – moving objects mentally Precognition – ability to foretell events Precognition – ability to foretell events