Chapter 1: Introduction

Question 1

Sensation

Answer 1

The detection of physical energy by our sense organs. The ability to detect a stimulus and turn it into a private experience.

Question 2

Perception

Answer 2

The act of giving meaning to a detected sensation. Perception doesn’t equal reality.

Question 3

How do we study sensation and perception?

Answer 3

~ Thresholds
~ Scaling
~ Signal detection theory
~ Sensory neuroscience
~ Neuroimaging

Question 4

Stimulus

Answer 4

A thing that evokes a specific functional reaction in an organ or tissue

Question 5

Information

Answer 5

Whatever environmental stimuli we are detecting

Question 6

Gustav Fechner

Answer 6

Founded the field of psychophysics

Question 7

Psychophysics

Answer 7

The science of defining quantitative relationships between sensation/perception (the mind/psycho) and the physical energy (matter, physics) that gives rise to them.

Question 8

Ernst Weber

Answer 8

~ influenced fechner’s work
~ pioneered work in two-point thresholds and just noticeable differences.
~ interested in touch
~ tested the accuracy of our sense of touch by using a device like the compass used to draw circles. Used device to measure the smallest distance between two points that was required for a person to feel touch on two points instead of one (two-point touch threshold).

Question 9

Just noticeable difference

Answer 9

The smallest detectable difference between two stimuli, or the minimum change in a stimulus that enables it to be correctly judged as different from a reference.

Question 10

Weber’s law

Answer 10

The smallest detectable change in a stimulus is a constant proportion of the stimulus level.

Question 11

Fechner’s law

Answer 11

A principle describing the relationship between stimulus magnitude and the resulting sensation magnitude. Logarithmic graph.

Question 12

Absolute threshold

Answer 12

The minimum amount of stimulation necessary for a person to defect a stimulus 50% of the time.

Question 13

How do we measure sensation intensity?

Answer 13

~ method of constant stimuli
~ method of limits
~ method of adjustment
~ magnitude estimation

Question 14

Method of constant stimuli

Answer 14

Many stimuli, ranging from rarely to almost always perceivable are presented one at a time. Participants respond to each presentation. For example, yes, I heard/saw/smelled that. No, I didn’t.

Question 15

Method of limits

Answer 15

The magnitude of a single stimulus or the difference between two stimuli is varied incrementally until the participant responds.

Question 16

Method of adjustment

Answer 16

The participant controls the stimulus rather than the experimenter.

Question 17

Magnitude estimation

Answer 17

The participant assigns values according to the perceived magnitude of the stimuli.

Question 18

Steven’s power law

Answer 18

Sensation magnitude is related to stimulus intensity raised by an exponent. Exponential graph.

Question 19

Signal detection theory

Answer 19

A psychophysical theory that quantifies the response of an observer to the presentation of a signal in the presence of a noise.
~Our perceptions change with changes to the magnitude of the stimulus. Our perceptions also change depending on our current context.