Chapter 2—Sensation and Perception

Question 1

Sensation

Answer 1

Provides the raw signal, communicating information, entering the nervous system through receptors in the Peripheral Nervous System

Information is sent to the Central Nervous System by action potentials and neurotransmitters

Question 2

Perception

Answer 2

Processing of information obtained from sensation

Question 3

Sensory Receptors

Answer 3

Neurons that trigger electrical signals in response to stimuli from the environment

Communicate modality (type of stimulus), location (where stimulus is coming from), intensity (frequency of action potentials), and duration (how long stimulus lasts) to the Central Nervous System

Divided into exteroceptors, which respond to stimuli from the outside world, and interoceptors, which respond to internal stimuli

Question 4

Hair Cells

Answer 4

Sensory receptors that respond to movement of fluid in the inner ear

Function in hearing

Question 5

Olfactory Receptors

Answer 5

Sensory receptors that respond to volatile compounds in the air

Function in smell

Question 6

Osmoreceptors

Answer 6

Sensory receptors that respond to the osmolarity of blood in the body

Function in water homeostasis in the body

Question 7

Nociceptors

Answer 7

Sensory receptors that respond to painful stimuli

Function in somatosensation (touch)

Question 8

Photoreceptors

Answer 8

Sensory receptors that respond to the visible spectrum of the electromagnetic waves

Function in sight

Question 9

Taste Receptors

Answer 9

Sensory receptors that respond to dissolved compounds in substances

Function in taste

Question 10

Threshold

Answer 10

Minimum amount of stimulus required to deliver a difference in perception

Question 11

Absolute Threshold

Answer 11

Minimum amount of stimulus energy that is needed to activate a sensory system

Threshold of sensation, not perception

Question 12

Threshold of Conscious Perception

Answer 12

Minimum amount of stimulus energy that is needed for a signal to be sent to the Central Nervous System and perceived

Question 13

Difference Threshold

Answer 13

Minimum difference in magnitude between two different stimuli before the difference can be perceived

Follows Weber’s Law—the change in magnitude of a stimulus that will make it noticeable is a constant ratio of the magnitude of the original stimulus

Question 14

Cones

Answer 14

Photoreceptors of the eye that perceive color and fine detail

Question 15

Rods

Answer 15

Photoreceptors of the eye that allow for the perception of light and dark

Have no involvement in color vision, but permit humans to see in reduced lighting

Question 16

Macula

Answer 16

Central region of the retina

Contains a high concentration of cones

Question 17

Fovea

Answer 17

Central point of the macula where vision is most clear and acute

Contains no rods

Question 18

Optic Disk

Answer 18

Area where the optic nerve leaves the eye

Contains no photoreceptors (cones or rods), meaning it is a blind spot

Question 19

Perception of Light—Pathway

Answer 19

Photoreceptors —> Synapse with Bipolar cells —> Synapse with Ganglion cells —> Optic Nerve —> Occipital Lobe

Question 20

Parallel Processing

Answer 20

Ability to analyze and combine several pieces of information regarding color, motion, and shape simultaneously

How the brain is able to create a cohesive image of the world

Question 21

Feature Detection Theory

Answer 21

Explains why different areas of the brain are activated when a person is looking at different things

Question 22

Parvocellular Cells

Answer 22

Detect shape

Have high spatial resolution, allow us to see very fine detail of a stationary object; do not work with fast-moving objects because they have low temporal resolution

Allows for us to see the full three-dimensional shape of the object and differentiate it from its background (boundaries of the object are clearly seen)

Question 23

Magnocellular Cells

Answer 23

Detect motion

Have high temporal resolution and low spatial resolution, meaning the detail of an object is lessened when it is in motion