2. How do psychologists differentiate between sensation and perception?

a. Sensation is the stimulus-detecting process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain.

b. Perception – making sense of what our senses tell us – is the active process of organizing this stimulus input and gives it meaning.

3. What two kinds of sensory capabilities are studied by psychophysics researchers?

e. Psychophysics studies relations between the physical characteristics of stimuli and sensory capabilities.

f. Sensory capability 1; Limits of sensitivity e.g. what is the dimmest light, softest sound, weakest salt solution a human can detect.

g. Differences between stimuli; e.g. what is the smallest difference in brightness, sound, salt solution a human can detect.

4. What is the absolute threshold, and how is it technically defined and measured?

a. Absolute threshold is the lowest intensity at which a stimulus can be detected 50% of the time.

b. The lower the absolute threshold, the greater the sensitivity.

5. Why do signal detection theorists view stimulus detection as a decision? What are the four possible outcomes of such a decision?

a. Signal detection theory is concerned with the factors that influence sensory judgments.

b. Hit > Miss > false alarm > correct rejection

6. What kinds of personal and situational factors influence signal detection decision criteria?

a. Participants can be influenced to become bolder or more conservative by manipulating the rewards and costs for giving correct or incorrect responses e.g. more conservative if Yes is associated with cost of the possibility of false alarm thus resulting in higher detection thresholds.

7. According to research results, what effects do subliminal stimuli have on consumer behaviour, attitudes, and self-improvement outcomes?

a. A subliminal stimulus is one that is so weak or brief that, although it is received by the senses, it cannot be perceived consciously.

b. Very little if any change in behaviour occurred as a result of subliminal stimuli. Change in attitude however brought about different results e.g. positive thinking which created a sense of expectancy.

8. What is the technical definition of a difference threshold? How does Weber’s law help us compare jnd sensitivities in the various senses?

a. The difference threshold is defined as the smallest difference between two stimuli that people can perceive 50% of the time.

b. Weber’s law states that the difference threshold, or jnd, is directly proportional to the magnitude of the stimuli with which the comparison is being made and is expresses as Weber fraction; the smaller the fraction, the greater the sensitivity to differences.

9. What accounts for sensory adaptation? Of what survival value is adaptation?

a. Sensory neurons are engineered to respond to a constant stimulus by decreasing their activity, and the diminishing sensitivity to an unchanging stimulus is called sensory adaptation e.g. background noise is not heard after a while; wrist watch is not felt after wearing it for some time.

b. Adaptation frees our sense from the constant and mundane to pick up informative changes in the environment.

10. How does the lens affect visual acuity, and how does its dysfunction cause the visual problems of myopia and hyperopia?

a. Myopia (nearsightedness) a visual defect in which distant objects appear blurred because their images are focused in front of the retina rather than on it

b. Hyperopia (farsightedness) an abnormal condition of the eye in which vision is better for distant objects than for near objects. It results from the eyeball being too short from front to back, causing images to be focused behind the retina.

11. How are the rods and cones distributed in the retina, and how do they contribute to brightness, perception, colour vision, and visual acuity?

a. Rods function best in dim light thus are primarily black and white receptors. They do not recognize colour sensations. Rods are found throughout the retina except in the fovea, a small area in the centre of the retina that contains only cones.

b. Cones function best in bright light are colour receptors.

c. Visual acuity or ability to see fine detail is greatest when the visual image projects directly onto the fovea.

12. What is transduction, and how does this process occur in the photoreceptors of the eye?

a. The process where characteristics of a stimulus are converted into nerve impulses is called transduction.

b. Rods and cones translate light waves into nerve impulses through the action of protein molecules called photo pigments.

c. The absorption of light by the photo pigments produces a chemical reaction that changes the rate of neurotransmitter release at the receptor’s synapse with the bipolar cells.

13. How is brightness sensitivity in rods and cones affected by the colour spectrum?

a. Rods are far more sensitive that cones under conditions o low illumination.
Rods have greater brightness sensitivity than cones throughout the colour spectrum except at the red end, where rods are relatively insensitive.

Cones are most sensitive to low illumination in the greenish-yellow range of the spectrum.

14. What is the physiological basis for dark adaptation? What are the two components of the dark adaptation curve?

a. The physical and chemical adjustments of the eye, including dilation of the pupil and increased activity of rods in the retina, that makes vision possible in relative darkness.

b. Photo pigment molecules are regenerated and the receptor’s sensitivity increases greatly.

c. Intensity of light to produce vision vs. Time in dark (minutes)

15. Describe the Young-Helmholtz trichromatic theory of colour vision. What kinds of evidence support this theory, and what two phenomena challenge it?

a. According to Young-Helmholtz, there are three colour receptors in the retina.

b. Any colour in the colour spectrum can be produced by some combination of the wavelengths that correspond to the colours blue, green, and red; known as additive colour mixture.

c. Although their theory explained that yellow is produced by activity of red and green receptors, people with red-green colour blindness are able to experience yellow.
Colour afterimage, in which an image in a different colour appears after a colour stimulus has been viewed steadily and then withdrawn.

16. Describe the opponent-process theory. What evidence supports it?

a. The opponent color theory suggests that there are three opponent channels: red versus green, blue versus yellow, and black versus white (luminance), with each responding in an antagonist way. That is, either red or green is perceived and never greenish-red. (Note that although yellow is a mixture of red and green in the RGB color theory; the eye doesn't perceive it as such.)

17. How does the dual-process theory of colour vision combine the trichromatic and opponent-progress theory?

a. Each of the receptors can function in two possible ways, depending on the wavelength of the stimulus. The pattern of activity in the receptors yields our perception of the hue.

18. What are the two major types of colour blindness? How are thy tested?

a. Colour blindness is caused by a deficiency in the red-green, yellow-blue, or both system.

b. Tests of colour-blindness contain sets of coloured dots. Depending on the type of deficit, a colour-blind person cannot recognize certain numbers embedded in the circles.

19. What kinds of feature detectors exist in the visual system? What is meant by parallel processing of sensory information?

a. Groups of neurons within the primary visual cortex are organized to receive and integrate sensory nerve impulses originating in specific regions of the retina.

b. One neuron may fire frequently when a horizontal line is detected while a different neuron may only fire when it detects a vertical line.

c. When a red, white, and green beach ball sails toward you, separate but over lapping modules within the brain simultaneously analyze its colours, shape, distance, and movement by engaging in parallel processing of the information and constructing a unified image.

20. What are the two physical characteristics of sound waves, and which auditory qualities do these characteristics produce?

a. Frequency (Hz) determines pitch (tone)
Amplitude determines intensity (loudness) (db)

21. Describe how the middle and inner ear structures are involved in the auditory transduction process.

a. The transduction system of the ear is made up of tiny bones, membranes, and liquid-filled tubes designed to translate pressure waves into nerve impulses.

b. Sound waves travel into an auditory canal leading to the eardrum, a movable membrane that vibrates in response to the sound waves.

c. Beyond the eardrum is the middle ear, a cavity housing three tiny bones. The vibrating activity of these bones – the hammer, anvils and stirrup – amplifies the sound waves more than 30 times.

d. The inner ear contains the cochlea, a coiled, snail-shaped tube about 3.5 cm in length that is filled with fluid and contains the basilar membrane.

e. Resting on the basilar membrane is the Organ of Corti, which contains thousands of tiny hair which are sound receptors.

22. Describe the frequency and place theories of pitch perception. In what sense are both theories correct?

a. According to the frequency theory of pitch perception, nerve impulses sent to the brain match the frequency of the sound wave.

b. The place theory of pitch perception suggests that the specific point in the cochlea where the fluid wave peaks and most strongly bends the hair cell serves as a frequency coding due.

c. At low frequencies, frequency theory holds true; at higher frequencies, place theory provides the mechanism for coding the pitch of a sound.

23. How does the structure of the auditory system permit humans to localize sounds? What sensory information is used by the brain in localization?

a. The two ears we have play a crucial role in sound localization. The nervous system uses information concerning the time and intensity differences of sounds arriving at the two ears to locate the source of sound in space.

b. Sounds arrive first and loudest at the ear closest to the sound. When the source of the sound is directly in front of us, the sound wave reaches both ears at the same time and at the same intensity.

24. What are the two varieties of deafness, and how do they differ in their physical bases and in possible treatments?

a. Conduction deafness is caused by problems involving the mechanical system that transmits sound waves to the cochlea.

b. Nerve deafness is caused by damaged receptors within the inner ear or damage to the auditory nerve itself, and it cannot be helped by a hearing aid. Exposure to loud sounds is the leading cause.

25. Describe the sensory principles that are applied to create sensory prosthetics for visually and hearing impaired people.

a. Sensory prosthetics produce sensory input that can substitute to some extend, for what cannot be provided by the normal sensory receptors.

b. A device that stimulates the visual cortex directly. When cells in the visual cortex are stimulated electrically, discrete flashes of light called phosphenes are experienced by both sighted and blind people.

c. A prosthetic devise for hearing impaired, called cochlear implant which is a device that can restore hearing in people suffering from nerve deafness. The cochlear implant does not amplify sound. The devise sorts out useful sounds and converts them into electrical impulses. By passing the disabled hair cells in the cochlea and stimulating the auditory nerve directly.

26. Describe the stimuli and receptors involved in gustation and olfaction. Why do researchers sometimes refer to a “common chemical sense”?

a. Gustation is the act or faculty of tasting. Taste buds which are receptors located along the sides and the back of the tongue which detect Sweet, Sour, Salty and Bitter tastes.

b. Olfaction is the act or process of smelling. The receptors for smell are long cells that project through the lining of the upper part of the nasal cavity and into the mucous membrane.

c. Food taken interacts with saliva to form a chemical solution that flows into the taste pore and stimulates the receptors cells.

27. What is menstrual synchrony, and what evidence is there that pheromones are involved?

a. Menstrual synchrony is the tendency of women who live together or are close friends to become more similar in their menstrual cycles.

b. Pheromone is a chemical secreted which influences the behavior or development of others of the same species, often functioning as an attractant of the opposite sex.

28. What four tactile sensations are humans sensitive to? How are these sensations localized, and how are phantom limb sensations produced?

a. Pressure, pain, warmth, cold

b. The amount of cortex devoted to each area of the body is related to that part’s sensitivity.

c. Phantom limb pain felt by an amputee that seems to be located in the missing limb. After amputation of a limb, an amputee continues to have an awareness of it and to experience sensations from it. These phantom limb sensations are also present in children born without a limb, suggesting that perception of our limbs is 'hard-wired' into our brain and that sensations from the limbs become mapped onto these brain networks as we develop.

29. Differentiate between bottom-up and top-down processing of sensory information.

a. In bottom-up processing, the system takes in individual elements of the stimulus and then combines them into a unified perception e.g. reading a sentence; first recognizing each letter, then putting them together in a word.

b. In top-down processing, sensory information is interpreted in the light of existing knowledge, concepts, ideas, and expectations. “Higher order” knowledge is used to interpret the meaning of the words read.

30. What two complimentary processes occur in attention?

a. Focusing on certain stimuli

b. Filtering out other incoming information

31. Describe the results of shadowing experiments in relation to attentional capabilities

a. Shadowing experiments demonstrate that we cannot attend completely to more than one thing at a time. But we can shift our attention rapidly back and forth between the two messages, drawing on our general knowledge to fill in the gaps.

32. What stimulus and personal characteristics influence attention?

a. Stimuli that attract our attention include intensity, novelty, movement, contrast, and repetition. Internal factors such as interest, act as filters and influence what we notice and what not.

33. How does our tendency to separate figure and ground contribute to perception?

a. Figure-ground refers to humans' ability to separate elements based upon contrast. We tend to organize stimuli into a central or foreground figure and a background.

34. Define and give examples of the four Gestalt laws of perceptual organization.

a. Similarity > Proximity > Closure > Continuity

35. In what sense is perception a kind of hypothesis testing? What is the role of perceptual schemas in this process?

a. Perception is an attempt to make sense of stimulus input and causes us to search for the “best” interpretation of sensory information.

b. The perceptual system actively searches its gigantic library of internal schemas for the interpretation that best fits the sensory data.

36. What is a perceptual set? What factors can create such sets? How did the Vincennes incident illustrate this concept? How is it involved in perceiving people?

a. Perceptual set is a readiness to perceive stimuli in a particular way.

b. Two groups are getting different information about something e.g. a person. After meeting or listening to that person, the information given to the two groups is ‘absorbed’ in their critique of the speaker.

c. The perception that the plane was a war plane and that it was descending toward the ship fit the crew’s expectations and fears, and what they experienced at that moment become “reality”.

37. What are the nature and adaptive value of perceptual constancies?

a. Perceptual constancies allow us to recognize familiar stimuli under varying conditions e.g. shape sounds, size, and illumination.

38. Identify eight monocular cues for distance and depth. (requires only one eye)

a. Light and shadow
b. Linear perspective
c. Interposition
d. Height in the horizontal plane
e. Texture
f. Clarity
g. Relative size
h. Motion parallax; (Closer objects appear to move faster than objects far away)

39. Describe two binocular cues. (Requires two eyes)

a. View Master: Each eye sees a slightly different image
b. Convergence: Provided by feedback from the muscles that turn your eyes inward to view a near object. (Cross eyed)

40. What is the primary cue for motion perception? How is stroboscopic movement used in motion pictures and television?

a. The primary cue for perceiving motion is the movement of stimulus across the retina.

b. Stroboscopic movement is an illusory movement produces when a light is briefly flashed in darkness and then, a few milliseconds later, another light is flashed nearby. Movie projectors are working similar in that a still image or frame is advanced, a light is sent through for a very short time; the next image or frame is advanced and so on giving the illusion that the pictures are moving.

41. In what sense is an illusion a false perceptual hypothesis? In what ways are constancies and context involved in producing visual illusions?

a. Illusions are compelling but incorrect perceptions
b. Most visual illusions can be attributed to perceptual constancies that ordinarily help us to perceive more accurately e.g. size constancies result in part from our ability to use distance cues to judge the size of objects.

42. How do endorphins exert their effects on pain perception?

a. Endorphins exert some of their pain-killing effects by inhibiting the release of neurotransmitters involved in the synaptic transmission of pain impulses from the spinal cord to the brain.

43. How do researchers determine whether endorphins underlie the analgesic effects of a procedure such as acupuncture or hypnosis?

a. In acupuncture the needles that are being inserted into the skin produce an analgesic (a medication capable of reducing or eliminating pain) effect by stimulating the release of endorphins.

44. What is stress-induced analgesia, and what is its adaptive value? How do we know if endorphins play a role in it?

a. Stress induced analgesia is a reduction of perceived pain in a stressful situation e.g. accident where pain is not perceived until much later, giving the individual opportunities to escape the situation and get out of a life threatening situation.

b. The release of Endorphins is part of the body’s natural response to stress..

45. Can endorphins have negative effects on the body?

a. Continuous high release of endorphins cause however the immune system not to work correctly

46. What evidence is there that cultural learning, beliefs, and personality factors influence pain perception?

a. Pain is perceived and endured differently in various cultures.

47. What evidence is there that cultural factors can influence picture interpretations, constancies, and susceptibility it illusions?

a. The culture one grows up in, determine how we see things.