Intro to sensation

Question 1

sensation

Answer 1

To represent the world, we must detect physical energy (stimulus) from the environment and convert it into neural signals,

Question 2

perception

Answer 2

When we select, organize, and interpret our sensations, the process is called perception.

Question 3

Bottom-up Processing

Answer 3

Analysis of the stimulus begins with the sense receptors
and works up to the level of the brain and mind.

Question 4

Top-down Processing

Answer 4

Information processing guided by high-level mental processes as we construct perceptions drawing on our experience and expectations.

Question 5

Absolute Threshold

Answer 5

Minimum stimulation needed to detect a particular stimulus 50% of the time.

Question 6

Difference Threshold

Answer 6

The minimum difference between two stimuli required for detection 50% of the time, also called just noticeable difference (JND).

Question 7

Weber’s Law

Answer 7

The size of the JND is proportional to the intensity of the
stimulus
× if the stimulus intensity is high, the JND will be large (or it will take a bigger change to notice the difference)
× if the stimulus intensity is low, the JND will be smaller (or it will take less of an change to notice the difference)

Question 8

Subliminal Threshold

Answer 8

When stimuli are below one’s absolute threshold for conscious awareness.

Question 9

Signal Detection Theory

Answer 9

Simply put, it states that our thresholds are not absolute – they change.
Predicts how and when we detect the presence of a faint stimulus (signal) amid background noise (other stimulation). Assumes that there is no single absolute threshold and detection depends on: Experience, Expectations, Motivation, Level of Fatigue

Question 10

Sensory Adaptation

Answer 10

Diminished sensitivity as a consequence of constant stimulation.

Like when wearing a band-aid, jewelry, glasses, or getting into a cold pool.

Question 11

Gestalt Psychology

Answer 11

helps us organize information into meaningful
wholes…
but remember…the “whole is different from the sum
of it’s parts”

Question 12

Figure-ground

Answer 12

Organization of the visual field into objects (figures) that stand out from their surroundings (ground).

Question 13

Gestalt Grouping

Answer 13

The whole is more important then the parts .

Question 14

Depth Perception

Answer 14

Depth perception enables us to judge distances. Gibson and Walk
(1960) suggested that human infants (crawling age) have depth
perception. Even new born animals show depth perception.

Question 15

Monocular Cues - Interposition

Answer 15

Objects that occlude (block) other objects tend to be perceived as closer.

Question 16

Monocular Cues

Linear Perspective:

Answer 16

Parallel lines like rail road tracks, appear to converge with distance. The more the lines converge, the greater their
perceived distance.

Question 17

Monocular Cues

Relative Size:

Answer 17

If two objects are similar in size, we perceive one that casts a smaller retinal image as farther away.

Question 18

Monocular Cues

Texture Gradient:

Answer 18

Indistinct (fine) texture signals increasing
distance.

Question 19

Binocular Cues Convergence:

Answer 19

When two eyes move inward (towards the nose) to see near objects, and outward (away from the nose) to see far away objects…object is perceived as closer the more eyes turn inward

Question 20

Binocular Cues

Retinal disparity:

Answer 20

Images from the
two eyes differ…the greater the
difference between the two objects,
the closer the object