Sensation and Perception

Question 1

Sensation

Answer 1

is the conversion of signals (auditory, physical, electromagnetic) to electrical signals in the nervous system

Question 2

Perception

Answer 2

processing of sensory info to make sense of its significance

Question 3

Sensory Receptors (photoreceptors, hair cells, nociceptors etc)

Answer 3

nerves that respond to sensory stimuli and trigger electrical signals. associated with sensory ganglia (collections of cell bodies outside the CNS) and transmit to projection areas in the brain (for further analysis)

Question 4

Threshold

Answer 4

absolute minimum that causes change in signal transduction

Question 5

Absolute Threshold

Answer 5

minimum amount of stimulus needed to be detected by sensory system

Question 6

Threshold of conscious perception

Answer 6

minimum amount of stimulus needed so that it will be brought into perception (awareness)

Question 7

Difference Threshold or JND

Answer 7

minimum difference needed in two things before it becomes noticeable

Question 8

Weber’s Law

Answer 8

jnd for stimulus is proportional to the magnitude of the stimulus

Question 9

Signal Detection Theory

Answer 9

refers to the effects of nonsensory factors such as experiences, motives and expectations on the perception of stimuli. insight into response bias. experiment has 4 outcomes-hit, miss, false alarm, correct rejection

Question 10

Eye parts

Answer 10

Cornea- filters incoming light
Iris- has constrictor and dilator pupillae which open and close pupil
Lens- refracts incoming light
rods- BW vision
cones- color vision
sclera and choroid- support eye

Question 11

Visual Pathway

Answer 11

lens–>retina–>rods and cones–>bipolar cells–>ganglion cells–>horizontal and amacrine cells–>optic nerve –>optic chiasm–>optic tract–>Lateral geniculate nucleus of thalamus –> occipital lobe
- also goes to superior collicular for startle reflex

Question 12

Parallel Processing

Answer 12

all senses use this. combine info regarding shape(by parvocellular cells- high spatial resolution and low temporal resolution ), color (by cones) and motion(by magnocellular cells) to sense object
- happens without much conscious thought

Question 12

Parallel Procession

Answer 12

all senses use this. combine info regarding shape(by parvocellular cells- high spatial resolution and low temporal resolution ), color (by cones) and motion(by magnocellular cells) to sense object

Question 13

Auditory pathway

Answer 13

cochlea–>vestibularcochlear nerve –> medial geniculate nuclei in thymus–> auditory cortex in temporal lobe
- also goes to inferior collicular for startle reflex

Question 14

Membranous Labyrinth Components

Answer 14

cochlea- sound detection
semicircular canals- rotational acceleration, balance
saccule and utricle- linear acceleration, motion and orientation

Question 15

Olfactory Pathway

Answer 15

olfactory nerves–> olfactory bulb –> olfactory tract –> limbic system

Question 16

Somatosensation

Answer 16

pressure
pain
temperature
vibration

Question 17

two point threshold

Answer 17

minimum distance necessary between two points of stimulation before its felt as two distinct stimuli

Question 18

physiological zero

Answer 18

normal temp of skin to which objects are compared to determine if they are cold or hot

Question 19

gate theory of pain

Answer 19

pain sensation is reduced when other somatosensory signals are present

Question 20

Bottom up processing

Answer 20

data driven. Taking sensory information and assembling and integrating it. slower but less prone to mistakes

Question 21

Top down processing

Answer 21

conceptually driven. recognizing an object based on memory and expectation with little attention to detail. faster but more mistakes

Question 22

Gestalt Principles

Answer 22

ways brain can figure out what an incomplete picture is

Question 23

Gestalt Laws

Answer 23

Proximity- things close to ne another are perceived as a unit
similarity- similar objects are grouped together
good continuation- elements following same pathway are grouped together
closure- when space is enclosed by group of lines it is perceived as closed line
pragnanz- perceptual organization will always be simple, regular and symmetric
subjective contours- edges or shapes that are not actually present can be implied by surrounding objects

Question 24

Place theory

Answer 24

place theory posits that one is able to hear different pitches because different sound waves trigger activity at different places along the cochlea’s basilar membrane

Question 25

Highest density of rods and cones

Answer 25

fovea is the part of the retina that contains a high density of cones for daytime vision, whereas, the periphery of the retina contains a high density of rods which are more photosensitive and can detect dim light

Question 26

Trichromatic theory (young- Helmholtz)

Answer 26

we see colours because of the combined activity of the three different cones we have

Question 27

opponent process theory

Answer 27

color info from cones is combined in such a way that we see pairs of color- black/white, blue/yellow, red/green. can’t see no two pairs at the same time

Question 28

opponent process theory

Answer 28

color info from cones is combined in such a way that we see pairs of color- black/white, blue/yellow, red/green. can’t see no two pairs at the same time