Sensation vs Perception

● Sensation is the detection of physical stimuli by your sensory organs. ○ It happens first ○ Your eyes, ears, nose, tongue, and skin detect information in front of the environment ○ Example: light enters your eye ● Perception is the interpretation of that sensory information by the brain ○ It is a cognitive process ○ Your brain gives meaning to what you sensed ○ Example: Your brain recognizes the light as your friends face

backward masking

refers to playing a recording backwards. Psychologists use it to show that

expectation influences perception.

app: if someone tells you “you’ll hear the words ‘God loves you’ “

.. your brains starts searching for

those words. Even though the sounds are random, expectations cause people to “hear” the

suggested message.

transduction

the process of converting physical energy into electrical signals the nervous system can understand.

wavelength (frequency)

determines Hue (color)

amplitude

determines Brightness

purity

determines how rich or vivid a color looks

sound characteristics

determines pitch

amplitude (hearing)

determines loudness

purity (timbre)

determines sound quality

cornea

clear outer covering of the eye. function that protects the eye and begins focusing incoming light

pupil

the black opening in the center of the eye, it allows light into the eye

iris

colored part of the eye, controls pupil size and therefore how much light enters

lens

focuses light into the retina, changes shape to focus on objects near or far

retina

light sensitive layer lining the back of the eye, contains rods and cones, light is converted into nerve impulses hear

photoreceptors

cells that detects light, there are two types, rods and cones

fovea

small center of the retina that’s responsible for sharp vision and visual acuity

blind spot

area where the optic nerve exits the eye, contains no photoreceptors and anything that lands here can’t be seen

optic nerve

carries visual information from the retina to the brain

rods vs cones

rods work best in dim light functions night vision, peripheral vision can detect movement not color and cones work best in bright light and functions in color vision, fine detail, sharp vision and mostly located in the fovea

trichromatic theory (Helmholtz)

states that humans have three kinds of cones. each responds best to red, green, blue. all colors are created by combining activity from three cone types

opponent-process theory (Hering)

states that color works in opposing pairs (red vs green, blue vs yellow, and black vs white)

Pinna (auricle)

the visible outer part of the ear. Functions: collects sound waves,

funnels them into the ear canal

ear canal

a tube that carries sound waves toward the eardrum

Tympanic membrane

eardrum

a thin membrane that vibrates when sound waves hit it.

Its vibrations begin the process of hearing

hammer (malleus)

first middle ear bone, receives vibrations from the eardrum

anvil (incus)

second middle ear bone, passes vibrations from the hammer to the stirrup

stirrup (stapes)

smallest bone in the body, transfers vibrations to the oval window

oval window

a membrane that separates the middle ear from the inner ear. When the

stirrup pushes on it, fluid inside the cochlea begins to move

cochlea

a spiral shaped, fluid filled structure in the inner ear. Its movement causes the

basilar membrane to vibrate

basilar membrane

located inside the cochlea. Different sound frequencies cause

different parts of this membrane to vibrate, these vibrations bend the hair cells

hair cells

sensory receptors for hearing. It converts vibrations into electrical nerve

impulses

Auditory nerve

carries electrical signals from the cochlea to the brain where sound is interpreted

umami

savory or meaty taste

vestibular sense

tells us balance, head movement, and body position in space. It

helps us stay upright

semicircular canals

part of the vestibular organs in the inner ear. They detect head

movement, rotation, and balance. Problems with these canals can cause dizziness or

motion sickness

kinesthetic sense

also called proprioception. It tells you where your body parts are

and how your limbs are moving. Example: you can touch your nose with your eyes

closed because of proprioception

experience and expectations in perception

perception is not just based on sensory

input. Your brain also uses previous experiences, expectations and knowledge to

interpret information. This is called top down processing

consciousness

our subjective awareness of the world among us, our thoughts, our

bodies, and our mental experiences. In simple terms, it is everything you are aware of

experiencing at any given moment

circadian rhythms

your body's natural 24 hour biological clock . It regulates many

body functions including sleep, wakefulness, body temperature, and hormone release.

Your circadian rhythm helps determine when you feel sleepy and when you feel alert

suprachiasmatic nucleus (scn)

considered the body's master biological clock

located in the hypothalamus. Function: controls your circadian rhythm by helping regulate sleep and wake cycles. As the day becomes darker, the SCN signals the body

to prepare for sleep

pineal gland

small gland in the brain. Its main job is to release melatonin

melatonin

hormone that promotes sleep. It increases at night and decreases during

the day. As melatonin increases, you begin to feel sleepy

seasonal affective disorder

type of depression that occurs during certain

times of the year, usually winter. This is because during winter there is less sunlight, the

SCN receives less light information and melatonin production remains higher for longer

jet lag

occurs when you travel across multiple time zones. Your internal biological

clock is still operating according to your previous time zone. As a result your sleep

schedule is disrupted, fatigue occurs, and alertness decreases. Your circadian rhythm

needs time to adjust to the new schedule

eeg

measures brain waves

eog

measures eye movements

emg

measures muscle activity

Non-REM Sleep

characterized by little or no eye movement and less dreaming than REM

sleep. It includes 3 stages.

REM-sleep

stage where eyes move rapidly , most vivd dreaming occurs and brain becomes highly active

REM Rebound

when a person is deprived of REM sleep, the body compensates later by spending more time in REM sleep than usual

Delta waves

slow waves, person is difficult to wake ups during this stage and body performs important restorative functions

sleep paralysis

during REM sleep the body experiences temporary muscle paralysis sometimes a person wakes up before this paralysis has ended. the person is awake , aware of surrounding and unable to move