4.1 Pgs. 137--143

Question 1

Definesensation138 and
perception138.
Distinguish between the two terms. (p. 138)

Answer 1

Sensation — stimulation of sense organs.
Ex— absorption of energy by sensory organs. ie. ears eyes
​
Perception — selection, organization and interpretation of sensory input.
​ex— recognizing best friends face

Distinguish:
​sensation —
Sensory organs absorb information from physical stimuli in the environment.

Perception —
The brain organizes this input and translates it into something meaningful.

Question 2

definepsychophysics.(p. 139)

Answer 2

Psychophysics –the study of how physical stimuli are translated into psychological experience.

Question 3

Definethresholdand
absolute threshold.
Provide and recognize original examples of each. (p. 139)

Answer 3

Threshold — a dividing point between energy levels that do and do not have a detectable effect.

Example: lamps that turn on a certain light level or light level threshold

Absolute Threshold — minimum amount of stimulation an organism can detect.

Example: Smell — one drop of perfume in a six room apartment.

Question 4

How is the absolute threshold typically measured? (p. 139)

Answer 4

absolute threshold is typically measured by varying the degree of intensity of stimuli and the absolute threshold is when the stimulus is detected 50% of the time.

Question 5

What is a just noticeable difference (JND)?
Provide and recognize original examples of different JNDs.
Explain an absolute threshold in terms of a JND.
DefineWeber’s law. (p. 140)

Answer 5

Just Noticable Difference (JND) –the smallest difference in the amount of stimulation that’s specific sense can detect.

Absolute Threshold – I terms of a JND, an absolute Threshold is the JND between null stimulation and any stimulation.

Weber’s Law –the size of a JND is a constant proportion of the size of the initial stimulus.
— as the stimulus increases in magnitude, the JND becomes larger.
​
Criterion, Noise, Detectability

Question 6

DefineFechner’s law.

Explain its ramifications. (p. 140)

Answer 6

Fechner’s Law – the magnitude of a sensory experience in proportional to the number of JNDs that the stimulus causing the experience is above the absolute threshold.
​
Fechner’s Law’s Ramifications – constant increments in stimulus intensity produce smaller and smaller increases in the perceived magnitude of sensation.

Example m: the brightness of a room with 1, 2, or 3 light bulbs lit. Law of Diminishing Returns.
​

Question 7

Describe signal-detection theory
. Definehit
,miss
,false alarm
, andcorrect rejection. (pp. 140-141)

Answer 7

Signal Detection Theory – proposes that the detection of stimuli involves decision processes as well as sensory processes, which are both influenced by a variety of factors besides stimulus intensity.

4 Possible Outcomes of Signal Detection​
1.) Hit — Detecting signals when they are present.
​
2.) Miss — failing to detect signals when they are present.
​
3.) False Alarm — Detecting signals when they are not present.
​
4.)Correct Rejection — Not detecting signal when they are absent.
​

Question 8

What is subliminal perception?

Be able to provide and recognize original examples of the use of subliminal perception for the purpose of advertising.

Does subliminal perception occur?

Should its use be a significant concern? (pp. 141-142)

Answer 8

Subliminal Perception –
The registration of sensory input without conscious awareness.
Example:
General mood while living with pictures of smiling people in environment vs frowning people.

Does Subliminal Perception Occur? –
Yes.
It was doubted in the 60s and 70s but, in the 1980s, more and more evidence came forward on the existence of subliminal perception, especially in the 2000s.

Should its use be a significant concern?
No.
It’s effects are minimal.

Question 9

Definesensory adaptation.

Discuss its importance for detecting changes versus constants in the environment.

Be able to provide and recognize original examples of sensory adaptation. (pp. 142-143)

Answer 9

sensory adaptation–
A gradual decline insensitivity due to prolonged stimulation.

Its impotance for detecting changes versus constants in the environment –
It allows people to ignore the obvious and focus on changes in the environment that may signal threats to safety.

eamples:
Smelling something burning while cooking.
Jumping into a cold lake.

Question 10

List the physical properties of light and the

aspects of visual perception that these properties influence. (p. 143)

Answer 10

Physical Properties of Light:
1.)

Aspects of visual perception that these perperties influence –