Psychophysics

Question 1

What is perception?

Answer 1

A psychological process: the act of organizing and interpreting sensory experience.

Question 2

What is sensory adaptation?

Answer 2

Process by which our sensitivity diminishes when an object constantly stimulates our senses.

Question 3

What is transduction?

Answer 3

The conversion of physical info into neural info.

Question 4

What is psychophysics?

Answer 4

The study of how people psychologically perceive physical stimuli (e.g. light, sound waves, touch).

Question 5

What is absolute threshold?

Answer 5

The lowest intensity level of a stimulus a person can detect half of the time.

Question 6

What is signal detection theory?

Answer 6

Viewpoint that both stimulus intensity and decision-making processes are involved in the detection of a stimulus.

Question 7

What is difference threshold?

Answer 7

Smallest amount of change between two stimuli that a person can detect half of the time.

Question 8

What is Weber’s law?

Answer 8

The finding that the size of a just noticeable difference is a constant fraction of the intensity of the stimulus.

Question 9

What is bottom-up processing?

Answer 9

Assembling a perceptual experience from its basic elements.

Question 10

What is top-down processing?

Answer 10

Perception of the whole based on our experience and expectations, which guide our perception of smaller elemental features of a stimulus.

Question 11

What is perceptual set?

Answer 11

Effect of frame of mind on perception.

Question 12

What is a cornea?

Answer 12

Clear hard covering that protects the lens of the eye.

Question 13

What is a lens?

Answer 13

Structure behind the pupil; bends light rays that enter eye to focus images on retina.

Question 14

What is a pupil?

Answer 14

Opening in the iris through which light enters eye.

Question 15

What is an iris?

Answer 15

Muscle that forms coloured part of eye; adjusts pupil to regulate amount of light that enters eye.

Question 16

What is a retina?

Answer 16

Thin layer of nerve tissue that lines back of eye.

Question 17

What are photoreceptors?

Answer 17

Cells in retina (called rods and cones) that convert light energy into nerve energy; they are transducers.

Question 18

What are ganglion cells?

Answer 18

Retinal cell that carries visual info from the eye to the brain; their axons make up optic nerve.

Question 19

What are bipolar cells?

Answer 19

Retinal cell that links photoreceptors with ganglion cells.

Question 20

What are horizontal cells?

Answer 20

Retinal cells responsible for modulating activity at photoreceptor-bipolar cell synapse.

Question 21

What are amacrine cells?

Answer 21

Retinal cells responsible for modulating activity at bipolar-ganglion cell synapse.

Question 22

What are rods?

Answer 22

Photoreceptors that function in low illumination and play key role in night vision.

Question 23

What are cones?

Answer 23

Photoreceptors responsible for colour vision; most functional in bright light.

Question 24

What is a fovea?

Answer 24

Spot on back of retina that contains highest concentration of cones; place of clearest vision.

Question 25

What is rhodopsin?

Answer 25

Light-sensitive protein responsible for transduction in rods

Question 26

What are photopsins?

Answer 26

Light-sensitive proteins responsible for transduction in cones.

Question 27

What is the optic chiasm?

Answer 27

Point at which strands of optic nerve from half of each eye cross over to opposite side of brain.

Question 28

What are Gestalt’s Laws of Grouping?

Answer 28

Similarity; continuity; proximity; closure.

Question 29

What is the tympanic membrane?

Answer 29

The eardrum.

Question 30

What makes up the middle ear, and what do they do?

Answer 30

Hammer, anvil, and stirrup. Amplify waves 20 times compared to when they entered ear.

Question 31

What makes up the inner ear, and what do they do?

Answer 31

Semicircular canals - maintain balance.

Cochlea - bony tube; site of transduction in auditory system. Contains basilar membrane, which contains hair cells - transduce sound vibrations into neural impulses.

Question 32

What is the range of human hearing?

Answer 32

20-20,000 Hz

Question 33

What are bodily senses?

Answer 33

Senses based in skin, body, membrane surfaces.

Question 34

What are mechanoreceptors?

Answer 34

Receptor cells in skin; sensitive to different tactile qualities such as shapes, vibrations, etc.

Question 35

What are olfactory sensory neurons?

Answer 35

Sensory receptors for smell; reside high up inside nose.

Question 36

What is the purpose of cilia in the nose?

Answer 36

Convert chemical info in odour molecules into neural impulses.

Question 37

What is the olfactory bulb?

Answer 37

Forebrain structure that sends info either directly to smell-processing areas in cortex or indirectly to cortex by way of the thalamus.

Question 38

Where are the olfactory cortexes located?

Answer 38

Primary in the temporal lobe; secondary in the frontal lobe.

Question 39

What are taste buds?

Answer 39

Structures inside papillae that contain taste receptor cells (sensory receptors).

Question 40

What are papillae?

Answer 40

Textured structures on surface of tongue that contain taste buds.

Question 41

What is sensation?

Answer 41

A physical process: the stimulation of our sense organs by features of the outer world.