Sensation I. Basic Concepts II. Characteristics of Sensory Systems III. The Visual System
Sensation The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. (from text) In other words The process of converting physical stimuli (light, sound, heat, pressure, etc ) into the language of the brain (action potentials & neurotransmitter release). Also known as transduction Strongly associated with bottom-up processing: analysis strongly shaped by sensory receptors.
Important Thresholds Absolute Threshold: The smallest possible amount of a stimulus that can be detected half (50%) of the time. Difference Threshold: The smallest possible difference between two stimuli that can be detected half (50%) of the time.
Some Questions to Consider. Would you notice a change of $10,000 in your bank account? Would everyone notice a change of $10,000 in their bank accounts?
Weber s Law The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant minimum amount).
Two Theories of Color Vision Trichromatic Theory blue, green, & red sensors Opponent Process Theory Blue-yellow, red-green, & black-white sensors
Some Unusual Quotes N is sort of rubbery smooth, L is sort of the consistency of watery paint Letters also have vague personalities, but not as strongly as numerals do. The letter A is blue, B is red, C is a kind of light gray, D is orange I hear a note by one of the fellows in the band and it s one color. I hear the same note played by someone else and it s a different color. When I hear sustained musical tones, I see just about the same colors that you do, but I see them in textures. Basically, I taste words.
Synesthesia The perceptual experience of one sense that is evoked by another sense. For the typical person: A B C D E For someone with synesthesia: A B C D E
Perception I. Review II. Important Points about Perception III. Object Perception IV. Depth & Distance Perception V. Illusions
I. Review Sensation: The process of converting physical stimuli into the language of the brain. Example: converting photons of light into nerve impulses Perception: The process of integrating, organizing, and interpreting sensory information. Example: recognizing the pattern of light that corresponds to the face of a friend
Bottom-Up versus Top-Down Bottom-Up Processing: Information processing that is strongly shaped by adding up the inputs of sensory receptors. Top-Down Processing: Information processing that is strongly shaped by higher level mental processes (such as expectations or beliefs).
II. Important Points about Perception Perceptual systems often misperceive the world Perceptions are strongly influenced by context Perceptions are strongly influenced by beliefs and expectations
Do you see the woman?
III. Object Perception
Figure-Ground Relationship
This lecture is brought to you by
Gestalt Laws of Perceptual Grouping We perceive as belonging together objects that.. are close to each other (proximity). are similar to each other (similarity). are physically touching each other (connectedness). form continuous lines, curves, or patterns (continuity/good continuation) We also tend to perceive objects as more complete than they really are (closure).
Depth Cues Monocular depth cues only require one eye Binocular depth cues require two eyes
Monocular Depth Cues
Relative Size
Texture Gradient
Interposition
Relative Clarity
Relative Height
Relative Motion
Relative Motion Example 1 Example 2
Linear Perspective
Light & Shadow
Binocular Depth Cues Convergence Retinal/Binocular Disparity
IV. Illusions
Illusions
States of Consciousness I. Introduction II. Circadian Rhythms III. Sleep IV. Dreams
I. Introduction
II. Circadian Rhythms
The SCN (Suprachiasmatic Nucleus)
Other factors that follow circadian rhythms Immune system activity Medication effectiveness Tooth enamel Hearing, vision, taste, & smell sensitivity Pollen & dust sensitivity Pain sensitivity
III. Sleep
Sleep Myths (or at Least Half-Truths) We sleep to rest our brains We sleep to rest our bodies Sleep is a unitary state (all sleep is the same) Sleep is primarily a function of the environment (sleepy/boring places put you to sleep)
EEG & brain waves Measuring Sleep
Dreams Dream Theories Freudian Dream Theory: dreams allow unconscious wish fulfillment Activation Synthesis Theory: dreams represent the higher brain s (cerebral cortex s) attempt to interpret random signals from the lower brain
4/21/2004
Learning I. Introduction II. Classical Conditioning III. Operant Conditioning IV. Cognition & Learning V. Observational Learning
II. Classical Conditioning
Classical Conditioning & Bear the Dog Presentation of a tofu hotdog Salivates Say the phrase, Tofu Pup? Salivates
Unbeknownst to most students of psychology, Pavlov s first experiment was to ring a bell and cause his dog to attack Freud s cat.
Office clip
III. Operant Conditioning
Variable -ratio Fixedratio Fixedinterval Variable -interval Student receives $50 for every 5 classes s/he attends. reinforce after specific number of correct responses Student receives $50 after s/he attends an average (sometimes more, sometimes less) of 5 classes reinforce after an average number of correct responses Student receives $50 every week (payday is constant e.g., Friday) reinforce 1 st correct response after a specific amount of time has passed Student receives $50 about every week (payday varies e.g., Thursday, Friday, Monday, etc ) reinforce 1 st correct response after an average amount of time has passed
IV. Cognition and Learning
Cognitive Maps
Cognitive Maps
Latent Learning
Latent Learning
V. Observational Learning
V. Observational Learning
Bandura s Bobo Doll Study Illustrated the distinction between learning and performing Showed it is possible to learn but not perform