Test 3 ReviewChapter 6- Thresholdso Absolute thresholds are the minimum stimulation necessary to detect a stimuli 50 percent of the timeo Subliminal stimuli occur when information processing occurs automatically and off the screen of our conscious mind These can have noticeable effects on our consciouso Difference threshold is the minimum difference a person can detect between any two stimuli half the time Depends on the size or strength of the stimuli Weber’s law says that two stimuli must differ in a constant proportion, not a constant amount- Sensory Adaptation – diminishing sensitivity to unchanging stimuluso Nerve cells fire less frequently after constant exposure to stimuluso Allows us to focus on informative changes in our environment- The eyeo Process of vision Light enters eye through cornea which bends light It then passes through the pupil which is controlled by the iris muscle Behind the pupil, a lens focuses incoming light rays on the retina- The retina consists of rods and coneso Cones are for details and rods are on peripherals The optic nerve carries information to brain- Visual Information Processingo Different parts of the brain respond to different types of object viewedo Parallel processing: the brain divides a visual scene among sub dimensionssuch as: color, movement, form and depth- Color Visiono Cones are responsible for color visiono Color resident in our brains; light waves don’t emit coloro Retina has three types of color receptors Red, green and blueo Opponent-processes: opposing retinal processes (red-green, yellow-blue, white-black) enable color visiono Color vision occurs in two stages The retina’s cones for red, green, and blue respond in varying degrees to different color stimuli The cones’ signals are then processed by the nervous system’s opponent-process cells- Hearingo The brain interprets loudness from the number of activated hair cells- Toucho Only pressure has identifiable receptorso Other skin sensations are variations of the basic four (pressure, warmth, cold and pain)o Important sensors in joints, tendons, bones, and ears enable sense of the position and movement of body partso Vestibular sense is the sense of body movement and position, including balance- Paino There are different nociceptors (sensory receptors that detect hurtful temperatures, pressure or chemicals) that trigger paino Pain can be effected by physiological and biological influences Pain can often be ignored People overlook a pain’s duration- People remember pain at its peak and at its endo Pain can be perceived when others are feeling paino Being given fake pain killers cause the brain to produce real ones- Tasteo Five sensations: sweet, salty, sour, bitter, and umamio Taste receptors reproduce every two weekso As you grow older, the number of taste buds decreaseo Expectations influence brain’s response- Smello Olfactory receptor cells allow us to smello Preferences for smells are often learned- Perceptual Organizationo When given a cluster of sensations, people typically organize them into a gestalt (whole or form)o Figure and ground When we see things, we see them as a figure against a backgroundo Grouping Proximity- we group nearby figures together Similarity- we group similar figures together Continuity- we perceive smooth, continuous patterns Connectedness- We see things that are uniform and linked Closure- We fill in gaps to create a complete, whole objecto Depth perception Depth perception is an innate ability People perceive vertical dimensions as longer than identical horizontal dimensionso Perceptual Constancy Shape constancy- we perceive the form of familiar object as constant even while our retinal image of it changes (moving door) Size constancy- we perceive objects as having a constant size, evenwhile our distance from them varies Lightness constancy- We perceive an object as having a constant lightness even while its illumination varies Color constancy- as light changes, we still perceive the same color- Surroundings determine the color we seeo Perceptual Interpretation Experience allows us to recognize faces and objects- Vision is a partly acquired sense There is a critical period during infancy for normal sensory and perceptual developmento Perceptual Adaptation Senses adapt quickly when disoriented – especially visiono Perceptual Set Mental predispositions that greatly influences what we perceive Perception is both innate and learnedChapter 7- How we learno Successful adaptation requires both nature and nurtureo Conditioning is the process of learning associations In classical conditioning, we learn to associate two stimuli and thusto anticipate events- Watson and Pavlov were proponents of this- It is a basic form of learning by which all organisms adapt to their environment  In operant conditioning, we learn to associate a behavior and its consequence and thus to repeat acts followed by good resultso Conditioning Conditioned = learned; unconditioned = unlearned Acquisition- When one links a neutral stimulus and an unconditioned stimulus, so that the neutral stimulus begins triggering the conditioned response- Higher-order conditioning- occurs when pairing a neutral stimulus with a conditioned stimulus Extinction and Spontaneous Recovery- Extinction is the diminished response that occurs when the conditioned stimulus no longer signals an impending unconditioned stimulus- Spontaneous recovery is the reappearance of a (weakened) conditioned response after a pause – after the pause the conditioned response can come back Generalization – the tendency for stimuli similar to a conditioned stimulus to elicit similar responses Discrimination is the learned ability to distinguish between a conditioned stimulus and other irrelevant stimuli Biological predispositions- Organisms can be conditioned mainly to things that contribute to their survivalo They are predisposed to learn associations that help them adapto Operant Conditioning Shaping behavior – think of petting a dog after it does a trick- Successive approximations – reward responses that are ever-closer to the final desired behavior, and ignore all other responses- Reinforcer- any event that strengthens a preceding responseo Negative reinforcement- strengthens a response by reducing or removing something undesirable (such as pressing snooze on an alarm clock) It