Psych Questions, Module 16

Why is it that after wearing shoes for a while, you cease to notice them (until questions like this draw your attention back to them)?

The shoes provide constant stimulation. Sensory adaptation allows us to focus on changing stimuli.

Sensation is to ( ) as perception is to ( ). a. absolute threshold; difference threshold b. bottom-up processing; top-down processing c. interpretation; detection d. grouping; priming

b

Weber's law states that for a difference to be perceived, two stimuli must differ by: a. a fixed or constant energy amount. b. a constant minimum percentage. c. a constantly changing amount. d. more than 7 percent.

b

Sensory adaptation helps us focus on: a. visual stimuli. b. auditory stimuli. c. constant features of the environment. d. informative changes in the environment.

d

The process by which we organize and interpret sensory information is called ( ).

perception

Does perceptual set involve bottom-up or top-down processing? Why?

It involves top-down processing. Our perceptual set influences our interpretation of stimuli based on our experiences, assumptions, and expectations.

How do our expectations, contexts, motivation, and emotions influence our perceptions?

Perceptual set is a mental predisposition that functions as a lens through which we perceive the world. Our learned concepts (schemas) prime us to organize and interpret ambiguous stimuli in certain ways. Our physical and emotional context, as well as our motivation, can create expectations and color our interpretation of events and behaviors.

Another term for difference threshold is the ( ).

just noticeable difference

What is the function of sensory adaptation?

Sensory adaptation (our diminished sensitivity to constant or routine odors, sounds, and touches) focuses our attention on informative changes in our environment.

What three steps are basic to all our sensory systems?

Our senses (1) receive sensory stimulation (often using specialized receptor cells); (2) transform that stimulation into neural impulses; and (3) deliver the neural information to the brain. Transduction is the process of converting one form of energy into another.

What is the rough distinction between sensation and perception?

Sensation is the bottom-up process by which our sensory receptors and our nervous system receive and represent stimuli. Perception is the top-down process in which our brain creates meaning by organizing and interpreting what our senses detect.

Using sound as your example, explain how these concepts differ: absolute threshold, subliminal stimulation, and difference threshold.

Absolute threshold is the minimum stimulation needed to detect a particular stimulus (such as the sound of an approaching bike on the sidewalk behind us) 50 percent of the time. Subliminal stimulation happens when, without our awareness, our sensory system processes a stimulus (when it is below our absolute threshold). A difference threshold is the minimum difference needed to distinguish between two stimuli (such as the sound of a bike versus a runner coming up behind you).

How do absolute thresholds and difference thresholds differ, and what effect, if any, do stimuli below the absolute threshold have on us?

Our absolute threshold for any stimulus is the minimum stimulation necessary for us to be consciously aware of it 50 percent of the time. Signal detection theory predicts how and when we will detect a faint stimulus amid background noise. Individual absolute thresholds vary, depending on the strength of the signal and also on our experience, expectations, motivation, and alertness. Our difference threshold (also called just noticeable difference, or jnd) is the difference we can discern between two stimuli 50 percent of the time. Weber's law states that two stimuli must differ by a constant minimum percentage (not a constant amount) to be perceived as different. Priming shows that we process some information from stimuli below our absolute threshold for conscious awareness.

What are sensation and perception? What do we mean by bottom-up processing and top-down processing?

Sensation is the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. Perception is the process of organizing and interpreting this information, enabling recognition of meaningful events. Sensation and perception are actually parts of one continuous process. Bottom-up processing is sensory analysis that begins at the entry level, with information flowing from the sensory receptors to the brain. Top- down processing is information processing guided by high-level mental processes, as when we construct perceptions by filtering information through our experience and expectations.

Does subliminal sensation enable subliminal persuasion?

Subliminal stimuli are those that are too weak to detect 50 percent of the time. While subliminal sensation is a fact, such sensations are too fleeting to enable exploitation with subliminal messages: There is no powerful, enduring effect.

Our perceptual set influences what we perceive. This mental tendency reflects our: a. experiences, assumptions, and expectations. b. sensory adaptation. c. priming ability. d. difference thresholds.

a

Subliminal stimuli are: a. too weak to be processed by the brain. b. consciously perceived more than 50 percent of the time. c. strong enough to affect our behavior at least 50 percent of the time. d. below our absolute threshold for conscious awareness.

d