Sensation and Perception

Question 1

What is the difference between sensation and perception

Answer 1

Sensation is the detection of physical stimuli located outside the mind. While perception is the selection, organization and interpretation of sensations.

Question 2

What is Psychophysics and what perspective did it directly come from? what are the two types of thresholds measured through psychophysics and how are they graphed?

Answer 2

Psychophysics is the physical stimuli in relation to the subjective experience. Came from the signal detection theory

Question 3

what are the two types of thresholds measured through psychophysics and how are they graphed?

Answer 3

1. Absolute threshold: The minimal amount of physical stimulus that generates a conscious experience. Represented as a s curve
2. Difference threshold: the minimal amount of change of a physical stimulus to create a just noticeable difference(JND)
   Represented as a logarithmic curve- all are exponential

Question 4

3. What is signal detection theory?

Answer 4

Signal detection theory- nothing is ever sensed in isolation(background noise)

Question 5

Webers Law

Answer 5

Not a consistent amount but it’s a consistent proportion

Question 6

When attempting to detect a stimulus, what are the four possible outcomes (i.e. based on the presence or absence of the stimulus and on whether or not the subject thinks they have detected, or not, the stimulus)?

Answer 6

1. Signal is there, person detects it(hit)
2. Signal is not there, person detects it(false alarm)
   3.Signal is there, person does not detect it(miss)
3. Signal is not there, person does not detect it(correct rejection)

Question 7

4. For all senses, what is the physical stimulus and how do the attributes of the physical stimulus relate to features of our conscious perception? (e.g. what about the physical stimulus is encoded as color?). For some, this may be unknown, but you need to know that we don’t know.

Answer 7

This is done by the use of many implicit(unconscious) rules for how to combine sensory info, or how to infer something new about the world based on the simple senses. If there is an excitatory effect and if there is inputs of colors

Question 8

What are sensory receptor cells?

Answer 8

Cells that detect stimuli from the world that is processed in the brain.

Question 9

Sight

Answer 9

Photo receptors found in the retina

Question 10

Hearing

Answer 10

Hair cells found in the cochlea

Question 11

Taste

Answer 11

taste receptors founds in the taste buds of papillae

Question 12

Smell

Answer 12

olfactory receptors found in the olfactory epithelium

Question 13

5. Touch

Answer 13

warm and cold receptors embedded in the skin and pressure receptors found at the base of hair follicles

Question 14

How is color perceived

Answer 14

Color is perceived for survival to associate reds with fruits to discrimate from vegetation such as grass

Question 15

b. Trichromatic theory

Answer 15

relates color perception to cone receptions based on three colors blue(s cones), green(m cones) and red( L cones).

Question 16

c. Opponent process theory :

Answer 16

The idea that perception is skewed based on color because the ganglion cells in the retina receive excitatory input from one type of cone and inhibitory input from another type.

Question 17

8. What is the idea about perception that comes from the Gestalt perspective (discussed in class).

Answer 17

a. Gestalt memory is all about context. The idea is that the whole is greater than its parts.

Question 18

i. Proximity

Answer 18

Close figures are grouped as an object

Question 19

ii. Similarity:

Answer 19

Similar figures are grouped in an object

Question 20

Continuity:

Answer 20

Intersecting lines are interpreted as continuous

Question 21

iv. Closure:

Answer 21

Figures with gaps are interpreted as complete

Question 22

v. Illusory contours:

Answer 22

: contours are perceived even when they do not exist.

Question 23

What cues gives rise to depth perception and which one perceives size

Answer 23

1.Binocular depth perception causes binocular disparity which is the difference in the location of an object as seen by the left and right eyes
2. Monocular depth perception is related to perception of size relative size associates objects in the distance as smaller opposed to an object close. Familiar size is where objects with familiarity can be inferred how far they are.

Question 24

How is motion detected?

Answer 24

It is inferred.

Question 25

Reconsider Perception: what is the role? Consider the statement “we are inferring what is out there by analyzing small attributes of the physical world”

Answer 25

Your conscious perception is the product of this process and represents what the mind guesses. ? Perception is analysis taking small info from the real world and inferring small attributes.

Question 26

What are the two types of pain receptors, and pain fibers that carry information to the brain?

Answer 26

a. Temperature and pressure nocireceptors. Fast fibers are myelinated and convey pain immediately to the brain. While slow fibers are unmyelinated fibers that convey pain slowly to the the brain and is perceived as chronic.

Question 27

What is the Gate-Control theory of Pain?

Answer 27

We experience pain when pain receptors are activated and a neural gate in the spinal cord allows the signals through the brain

Question 28

As discussed in class, what is the relationship between the amount of information that we actually detect from our environment and the amount of information in our perception (this is true for all senses)? Shattered world?

Answer 28

Takes the set of sensations and break them into small pieces and perception includes takes all those pieces together and creating a conscious image but there is more that we sense so we must infer what must be out there