Chapter 4: Sensation and Perception

15.Describe monocular and binocular cues that enable depth perception.

Binocular cues - visual input from two eyes that allows perception of depth or distance. Monocular cues - visual input from a single eye alone that contributes to perception of depth or distance.

8.Identify the different parts of the auditory system from a diagram and describe the function of each.

Cochlea - the fluid-filled, coiled tube in the inner ear that contains the receptors for hearing. Pinna - the outer ear, auditory canal, and eardrum structures which funnel sound waves to the middle ear. Ossicles - (hammer, anvil, and stirrup) capture vibrations from the tympanic membrane then the stirrup hits the oval window. Hair cells - communicate with the auditory nerve, which sends neural impulses to the brain. Tympanic membrane - ear drum captures sound waves.

16.Define constancy and identify an example of how it applies to size, shape, and brightness.

Constancy is the ability to retain an unchanging perception of an object despite changes in the sensory input. Size Constancy: our perceptions of the size of objects are constant even though the size of the object on the retina vary with distance. Shape Constancy: the ability to recognize visual stimuli from many different angles as the same. Brightness Constancy: we perceive the relative brightness of objects to remain the same under different conditions of illumination.

17.Understand how context influences perception.

Context influence on perception is part of the top-down processing based off our knowledge and expectations.

4.Identify the different parts of the visual system from a diagram of the eye and describe the function of each.

Cornea - helps protect the eye and focus incoming light rays. Optic nerve - consists of axons of the ganglion cells, then carries the message on to the brain. Retina - the light-sensitive inner surface of the back of the eye, which contains the receptor cells for vision (rods and cones). Optic disk (blind spot) - the point at which the optic nerve leaves the eye, which contains no receptor cells for vision - thus creating a "blind spot." Fovea - a tiny pit in the center of the retina that is densely filled with cones; it is responsible for sharp vision. Iris - allow the pupil to dilate or constrict in response to light intensity or emotional factors. Pupil - a small adjustable opening. Lens - focuses incoming light into an image on the light-sensitive retina, located on the back surface of the fluid-filled eyeball.

7.Correctly order the structures involved in vision, from light entering the eye through the occipital lobe.

Cornea, pupil, iris, lens, retina, fovea, rods, cones, and optic nerve.

6.Describe the function of feature detectors on the visual system.

Feature detectors: neurons in the visual cortex respond to specific features; shape; angle; movement.

13.Define perceptual parsing. What are the two primary pieces of the visual field that are parsed to achieve perceptual organization?

Perceptual parsing - our visual system divides everything we see into components. The most important aspect of perceptual parsing is dividing what we see into the figure and ground.

9.Correctly order the structures involved in audition (hearing), from sound entering the pinna through the temporal lobe.

Pinna, tympanic membrane, Ossicles (hammer, anvil, stirrup), oval window, cochlea, basilar membrane, hair cells, auditory nerve, temporal lobe.

10.Define pitch and loudness, noting the units of measurement for each.

Pitch is measured in Hertz; the frequency of sound waves determines pitch. Loudness of a sound is measured in decibels, the force of sound waves on the ear determines loudness.

11.Contrast the two different theories for how pitch is interpreted by the auditory system. Which is correct?

Place Theory - different locations on the cochlea are stimulated by different pitches. Frequency Theory - pitch is sensed based on the firing rate of the auditory nerve. Both.

14.Identify and describe the following perceptual grouping processes suggested by Gestalt psychologists.

Proximity: elements that are near each other tend to be perceived as part of the same configuration. Similarity: when parts of a configuration are perceived to be similar, they will be perceived as belonging together. Closure: people perceive objects as being whole when they are not complete. Continuity: people link elements together that forms a continuous pattern that makes sense.

5.Contrast rods and cones with respect to location, function, and density.

Rods - transduce information about black, white, and gray, and are denser in the periphery of the retina. Cones - transduce information about color and fine detail, and are concentrated in the center of the fovea.

1.Contrast sensation with perception.

Sensation deals with our sense organs receiving information and sending it to the brain. Perception is when the brain takes the sensory information and interpret the information.

3.Define the different methods for reducing sensory information: sensory reduction, selective attention, habituation and sensory adaptation.

Sensory reduction: analyzing and filter incoming sensations before sending a neural message to the cortex Selective attention: attending only to "important" sensory information by filtering out sensory information that is interpreted to be "unimportant" Habituation: pattern of decreased response to stimuli after frequently repeated exposure Sensory adaptation: the process by which receptor cells become less sensitive due to constant stimulation.

2.Define transduction.

The process whereby sensory receptors covert stimuli into neural impulses to be sent to the brain (for example, transforming light waves into neural impulses.)

12.Contrast top-down processing and bottom-up processing.

Top-down processing is using model, ideas, and expectations to interpret sensory information. Bottom-up processing is taking sensory information and then assembling and integrating it.

blind spot

the point at which the optic nerve leaves the eye, which contains no receptors cells for vision - thus creating a "blind spot."