Ap psych Unit 1 topic 1.6 (sensation)

Sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

our senses

receive sensory stimulation, transform stimulation into neural impulses, and deliver neural info to our brain

sensory interaction

the principle that one sense may influence another, as when the smell of food influences its taste

synesthesia

when one kind of sensory stimulus evokes the subjective experience of another. like tasting colors for example

absolute threshold

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time

weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)

sensory adaptation

tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging

sensory habituation

brain stops paying attention to/noticing sensory info

selective attention

the ability to focus on only one stimulus from among all sensory input

our eyes and how vision works

our eyes

-receive light energy

-transduce it into a neural message

-deliver message to brain

color depends on wavelength

-brightness(intensity) of light depends on amplitude

-saturation depends on the wavelength and varying heights

saturation

higher the saturation, the more pure the color is and vice versa

Cornea

The clear tissue that covers the front of the eye

pupil

the adjustable opening in the center of the eye through which light enters

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

visual accommodation

the change in the thickness of the lens as the eye focuses on objects that are far away or close

retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

why are visual stimuli projected onto the retina upside down?

-provides peripheral vision

-allows us to see things bigger than our eyes (no tunnel vision)

chemical reactions in rods/cones

-triggered by light energy

-triggers bipolar cells

-bipolar cell transmission activates ganglion cells

cones

retinal receptor cells that are concentrated in the fovea and function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

-in all other parts of retina

-detects the brightness of light

trichromatic theory

theory of color vision that proposes three types of cones: red, blue, and green combine to form different colors

Hering's opponent-process theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

-explains afterimage effect

monochromatism

the inability to distinguish colors; also known as color blindness (only black and white)

dichromatism

A type of color blindness where one of the three basic color mechanisms is absent or not functioning.(one set of cones faulty or missing)

prosopagnosia

face blindness

blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

sound waves

a longitudinal wave consisting of compressions

-pitch: frequency

-volume: amplitude

-timbre: purity

Pinna

the visible part of the ear

middle ear

the chamber between the eardrum and cochlea contains three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window (contains ossicles)

inner ear

contains cochlea, semicircular canals, and vestibular sacs

how we hear

sound waves through ear->vibrations in eardrum->bones of middle ear amplify the vibrations->transmit them to cochlea->basilar membrane->movement of cilia->on the organ of corti (transduction)->cilia->auditory nerve->thalamus->temporal lobe

sensorineural hearing loss

nerve deafness (damage to nerves)

conduction hearing loss

damage to ear structure that transmits sound waves

place theory

how we hear high pitched sounds

entire length of cochlear duct

frequency theory

how we hear low pitches

sound lands on specific particular spot/place on basilar membrane

volley principle

combination of place and frequency theories

locating sounds

one ear receives sound waves faster and harder which allows for brain to figure out where its coming from.

Taste

chemical sense

-mix of 6 basic taste sensations (sweet, sour, salty, bitter, umami, Oleogustus)

taste buds

bump on tongue: papilla/papillae --> each bud has a pore --> taste receptor cells --> antenna like hairs

expectations influence taste

water experiment

tasting variations in humans

supertasters, medium tasters, non-tasters

Smell

-no basic sensation

-chemical sense

-only sense that doesn't go through the thalamus

-processed through prefrontal cortex and then brain

-triggers memories the most

how we smell

-Olfactory nerves directly connect to the olfactory bulb in the brain, which is actually the enlarged ending of the olfactory cortex at the front of the brain.

-Axons from the olfactory bulb form the olfactory tract.

-These neural pathways project to different brain areas, including the temporal lobe and structures in the limbic system.

-The projections to the temporal lobe are part of the neural pathway involved in conscious recognition of smells; projections to limbic system are thought to regulate emotional response to odors.

-Olfactory function declines with age and some diseases.

odor molecules

they trigger memories the most

Touch

-4 basic sensations (heat,cold,pressure,pain)

types of skin

hairy skin (contains hair cells-detect movement and pressure)

glabrous cells (no hair, more sensitive)

pain reflects

bottom-up sensations (such as input from nociceptors, the sensory receptors that detect hurtful temperatures, pressure, or chemicals) and top-down processes (such as experience, attention, and culture).

gate control theory of pain

a theory of pain perception based on the idea that signals arriving from pain receptors in the body can be stopped, or gated, by interneurons in the spinal cord via feedback from two directions

phantom limb syndrome

the perception of sensations, including pain, in a limb that has been amputated because the brain is so used to having information from that body part

kinesthesia

our movement sense - our system for sensing the position and movement of individual body parts and for spatial awareness

vestibular sense

sense of balance

-vestibular sacs and semicircular canals