Chapter 5

1. Chapter 5 Sensation

2. The process by which we detect physical energy from the environment and encode it as neural signals. sensation

3. The process by which the brain organizes and interprets sensory information. perception

4. Analysis that begins with the sense receptors and works up to the brain’s integration of sensory information. Bottom-up processing

5. Information processing guided by higher-level mental processes. Top-down processing

6. The study of relationships between the physical characteristics of stimuli and our psychological experience of them. psychophysics

7. The minimum stimulation needed to detect a stimulus 50% of the time. absolute threshold

8. This theory explains precisely how and when we detect the presence of a faint stimulus. Detection depends partly on experience, expectation, motivation, and alertness. signal detection theory

9. A stimulus that is below the absolute threshold for awareness. subliminal

10. The minimum difference in two stimuli that a subject can detect 50% of the time. just noticeable difference (jnd)

11. Whose law states that the just noticeable difference between two stimuli is a constant minimum proportion of the stimulus? Weber’s

12. The decreased sensitivity that occurs with continued exposure to an unchanging stimulus. sensory adaptation

13. In the study of sensation, the process by which receptor cells in the eye, ear, skin, and nose convert environmental stimuli into neural impulses. transduction

14. Refers to the distance from the peak of one light (or sound) wave to the next and gives rise to the perceptual experiences of hue (color) in vision. wavelength

15. The _____ of light and sound is determined by the amplitude of the waves and is experienced as brightness and loudness. intensity

16. The adjustable opening in the eye through which light enters. pupil

17. A ring of muscle tissue that forms the colored part of the eye that controls the diameter of the pupil. iris

18. The transparent structure of the eye behind the pupil that changes shape to focus images on the retina. lens

19. The process by which the lens of the eye changes shape to focus near objects on the retina. accommodation

20. The light-sensitive, multilayered inner surface of the eye that contains the rods and cones, as well as neurons that form the beginning of the optic nerve. retina

21. Visual _____ refers to the sharpness of vision. acuity

22. A condition in which nearby objects are seen clearly but distant objects are blurred because light rays reflecting from them converge in front of the retina. nearsightedness

23. A condition in which distant objects are seen clearly but nearby objects are blurred because light rays reflecting from them strike the retina before converging. farsightedness

24. Visual receptors concentrated in the periphery of the retina - have poor sensitivity, detect black and white, and function well in dim light. rods

25. Visual receptors concentrated in the fovea – have excellent sensitivity, enable color vision, and function best in daylight or bright light. cones

26. Comprised of the axons of retinal ganglion cells, it carries neural impulses from the eye to the brain. optic nerve

27. The region of the retina where the optic nerve leaves the eye. Because there are no rods or cones in this area, there is no vision here. blind spot

28. The retina’s point of central focus. It contains only cones; therefore, images focused on the fovea are the clearest. fovea

29. Located in the visual cortex of the brain, are these nerve cells that selectively respond to specific visual features, such as movement, shape, or angle. Evidently the basis of visual information processing. feature detectors

30. Information processing in which several aspects of a stimulus, such as light or sound, are processed simultaneously. parallel processing

31. This theory maintains that the retina contains red-, green-, and blue-sensitive color receptors that in combination can produce the perception of any color. First stage of color processing. Young-Helmholtz trichromatic (3-color) theory

32. This theory maintains that color vision depends on pairs of opposing retinal processes (red-green, yellow-blue, and white-black). Second stage of color processing. opponent-process theory

33. The perception that familiar objects have consistent color despire changes in illumination that shift the wavelengths they reflect. color constancy

34. Refers to the sense of hearing. audition

35. The number of complete wavelengths that can pass a point in a given time (directly related to wavelength and determines pitch). frequency

36. The chamber between the eardrum and cochlea containing the three bones (hammer, anvil, and stirrup) that concentrate the eardrum’s vibrations on the cochlea’s oval window. middle ear

37. Contains the semicircular canals and the cochlea, which includes the receptors that transduce sound energy into neural impulses. inner ear

38. The coiled, bony, fluid-filled tube of the inner ear where the transduction of sound waves into neural impulses occurs. cochlea

39. The theory of hearing that states that we hear different pitches because sound waves of varioius frequencies trigger activity at different places on the cochlea’s basilar membrane. place theory

40. The theory of hearing that presumes that the rate, or frequency, of nerve impulses in the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch. frequency theory

41. The hearing loss that results from damage in the mechanics of the outer or middle ear, which impairs the conduction of sound waves to the cochlea. conduction hearing loss

42. Nerve deafness – hearing loss caused by damage to the auditory receptors of the cochlea or to the auditory nerve due to disease, aging, or prolonged exposure to ear-splitting noise. Sensorineural hearing loss

43. Melzack and Wall’s theory that maintains that a “gate” in the spinal cord determines whether pain signals are permitted to reach the brain. Neural activity in smallnerve fibers opens the gate; activity in large fibers or information from the brain closes the gate. gate-control theory

44. The principle that one sense may influence another. sensory interaction

45. The sense of the position and movement of the parts of the body. kinesthesis

46. The sense of body movement, position, and balance. vestibular sense