sensory processes

Question 1

an input about the physical world obtained by our sensory receptors
- activation of sense organs, stimulated by physical energy

Answer 1

sensation

Question 2

the process by which the brain selects, organizes and interprets stimuli coming form the environment

Answer 2

perception

Question 3

stimulus

Answer 3

any passing source of physical energy that produces a response in a sense organ

Question 4

psychophysics

Answer 4

science studying the relationships between the physical world obtained by our sensory receptors

Question 5

absolute threshold

Answer 5

the smallest intensity of the stimulus that is necessary for it to be detected

Question 6

difference threshold

Answer 6

the smallest intensity change needed to detect a difference between 2 stimuli (JND)

Question 7

JND

Answer 7

just noticeable difference

Question 8

Weber’s fraction (k)

Answer 8

it’s a constant, the intensity by which the standard must be increased to be noticed (Ai) is proportional to the intensity of the standard (Ss)

• K = Ai / Ss

Question 9

3 ways individuals are passive receivers

Answer 9

1. evaluate and estimate the stimulus
2. adapt their sensation to the environment
3. decide to or not to report the difference detected

Question 10

Steven’s law

Answer 10

had subjects do an estimate of magnitude: discovered the relationship between perceived magnitude and the intensity of stimulus is a power function

Question 11

sensory adaptation

Answer 11

phenomenon in which the sensory capacity DECREASES with long exposure to the same stimulus

Question 12

signal detection

Answer 12

considers the influence of a subject’s decision making on the presence of stimulus
- hit, miss, false alarm, correct rejection

Question 13

image forming system consists of:

Answer 13

1. cornea
2. lens
3. pupil

Question 14

two types of photoreceptor cells in retina

Answer 14

1. cones
2. rods

Question 15

cones

Answer 15

particularly in BRIGHT light situations light sensitive, responsible for detailed focus and colour

Question 16

rods

Answer 16

thin and cylindrical
activated in LOW light, highly sensitive to light, colourless results

Question 17

fovea

Answer 17

depression in the inner retinal surface (1.5 mm)
- photoreceptor layer is entirely cones and for maximum visual activity

Question 18

role of the fovea

Answer 18

to see details in an object we move our eyes so that the object is projected by the fovea
- receptors are plentiful and closely packer = higher resolution

Question 19

steps from eye to brain

Answer 19

1. photoreceptor pick up visual signals because they detect light
2. the bipolar cells receive info from receptors and send the info to the ganglion cells
3. ganglion cells collect and synthesise info coming from bipolar cells
4. info is sent from the back of the eye to the brain through ganglion axons, called optic nerve

Question 20

blind spot

Answer 20

area where the optic nerve leaves the eye, so it has NO receptors

Question 21

optic chiasm

Answer 21

point of conduction between 2 optic nerves, where they cross before making their way to the brain

Question 22

primary visual area (BA 17)

Answer 22

located in occipital lobe in correspondence to the calcanne fissure

Question 23

features extraction

Answer 23

in visual cortices there are specialized cells for the detection of lines oriented in a certain way (single cell recording)

Question 24

ventral way (visual message to brain)

Answer 24

occipital lobe to temporal lobe
dedicated to the perception of attributes of an object, such as a shape, size and orientation (what is is)

Question 25

dorsal way (visual message to brain)

Answer 25

analyses position of objects in space (where it is)

Question 26

trichromatic theory

Answer 26

3 types of cones, each of which responds preferentially to a range of wavelength (blue/violet; green; yellow/red)

Question 27

colour blindness

Answer 27

supports trichromatic theory: genetic disorder that determines inability to see RED or GREEN colour

Question 28

opponent colour theory

Answer 28

receptors are linked in pairs and work in opposition to each other - yellowish greens exist but reddish greens don't

Question 29

sound

Answer 29

movement air molecules caused by a source of vibration

Question 30

from ear to brain steps

Answer 30

1. enters from outer ear 2. proceeds inside the auditory canal 3. reaches the eardrum 4. vibrations pass to the middle ear 5. internal ear transforms sound into energy to send to brain

Question 31

taut membrane that vibrates with passage of sound

Answer 31

eardrum

Question 32

cochlea (inner ear)

Answer 32

spiral-shaped tube that contains fluid capable of vibrating in presence of sound

Question 33

what happens to sound in internal ear

Answer 33

Sound waves are transduced into electrical impulses that the brain can interpret as individual frequencies of sound

Question 34

basilar membrane

Answer 34

the main mechanical element of the inner ear - crosses central part into the upper and lower cavity

Question 35

hair cells

Answer 35

if moved by vibrations entering the cochlea, they send message to brain (sensory cells)

Question 36

4 sound features

Answer 36

1. frequency 2. pitch 3. amplitude 4. loudness

Question 37

resonance-place theory (sound)

Answer 37

different areas of the basilar membrane respond to different types of frequencies

Question 38

temporal theory (sound)

Answer 38

the sound wave causes basilar membrane to vibrate and the rate of vibration determines the rate of impulses of nerve fibres in auditory nerve

Question 39

semicircular canals

Answer 39

three tubes containing liquid that moves inside them when the head moves, signalling rotation or angular movement

Question 40

otoliths

Answer 40

crystals that signal forward, backward, up and down movements along with the force of gravity - register gravity and linear acceleration

Question 41

olfaction

Answer 41

sense of smell

Question 42

olfaction steps

Answer 42

1. molecules of a substance enter the nasal canal 2. molecules meet the olfactory cells 3. through the fibres, the signal reaches the olfactory bulb located under the frontal lobes and connected with the olfactory cortex inside the temporal lobe (memory)

Question 43

gustation

Answer 43

allows qualitative evaluation of a substance based on flavour

Question 44

receptive cells in gustation

Answer 44

taste buds (10 000)

Question 45

how many tactile receptors does the each cm of skin have?

Answer 45

130

Question 46

3 types of somatic sensitivities (touch)

Answer 46

1. meccanoceptive (pressure) 2. thermal (temp) 3. dolorific (pain)

Question 47

has an evolutionary projection function

Answer 47

pain

Question 48

phasic pain

Answer 48

sharp and brief

Question 49

tonic pain

Answer 49

dull and long

Question 50

"gate control" theory

Answer 50

specific receptors in spinal cord connected to parts of the brain - when receptors are activated they open gate and the sensation of pain is experienced

Question 51

how can the gate be closed (pain)

Answer 51

1. competition between stimuli 2. psychological factos

Question 52

pain reduction: distraction method

Answer 52

tested on wounded soldiers with the use of virtual reality and worked

Question 53

touch and vision

Answer 53

increased sensitivity when we see the part of the body affected (rubber hand theory)

Question 54

vision and gustation

Answer 54

food appearance affects its palatability

Question 55

vison and audition

Answer 55

mouth movements affect what we hear - Mc Gurk effect

Question 56

synesthesia

Answer 56

2 is green and 3 is red - produces responses in more than one system

Question 57

2 theories on synesthesia

Answer 57

1. psycholinguistic theory 2. neurogical theory

Question 58

neurogical theory

Answer 58

synesthesia - activation effect of this ancestral perceptual system (poor inhibition between sensory areas)

Question 59

psycholinguistic theory

Answer 59

activations of different sensory modalities evoke coherent emotional response