sensation, perception, and states of consciousness

sensation

input about the physical world obtained by our sensory receptors

perception

process by which the brain interprets, selects, and organizes these sensations

sensory receptors

specialized neurons that respond to specific types of stimuli

sensation has occurred

when sensory information is detected by a sensory receptor

absolute threshold

the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time

mere-exposure effect

merely perceiving a stimulus repeatedly renders it more positive

difference threshold

difference in stimuli required to detect a difference between the stimuli

weber’s law

Ernest Weber discovered that the difference threshold is a constant fraction of the original stimulus and bigger stimuli require larger differences to be noticed

bottom-up processing

perceptions built from sensory input

top-down precessing

interpretaphysical processtion of sensations is influenced by available knowledge, expiriences, and thoughts

sensation processing

physical process

prerception processing

psychological

sensory adaptation

we often don’t perceive stimuli that remain relatively constant over prolonged periods of time

attention

plays a significant role in determining what is sensed versus what is perceived

inattentional blindness

failure to notice something that is completely visible because the person was actively attending to something else and did not pay attention to other things

motivation

detect a meaningful stimulus can shift our ability to discriminate between a true sensory and back round noise

signal detection theory

ability to identrify a stimulus when it is embedded in a distraction backround

eye

the major sensory organ involved in vision

cornea

transparent convering over the eye; barrier between inner eye and outside world

pupil

small opening in the eye through which light passes

iris

colored portion of the eye with muscles that control the pupils size

lens

curved, transparent structure that serves to provide additional focus

retina

the light sensitive lining of the eye; the fovea is a part of this

fovea

in a normal sighted individual, the lens will focus images perfectly on a small indentation in the back of the eye

rods

specialized photoreceptors that work well in low light

cones

specialized photoreceptors that work well in bright condition

optic nerve

carries visual information from the retina to the brain

occipital lobe

processes visual information

blind spot

point where we cannot respond to visual information in that portion of the visual field

depth perception

out ability to perceive spatial relationships in 3-D space

binocular cues

means that we rely on the use of both eyes

binocular desperity

the slightly different view of the world that each of our eyes receives

monocular cues

cues that require only one eye

linear perspective

the fact that we perceive depth when we see 2 parallel lines that seem to converge in an image

sound waves

travel along the auditory canal and strike the tympanic membrane, causing it to vibrate

vibration

results in movement of the 3 ossicles

cochlea

oval window

hair cells

auditory receptor cells

pitch

frequency of a sound wave is associated with our perception of that sounds…

high frequency waves

sound waves perceives as high-pitched

low frequency waves

sound waves are perceived as low-pitched

loudness

is closely associated with amplitude of the sound wave

15 minutes

how long does it take for noise-induced hearing loss to take affect

monaural

one-eared

binaural

two-eared

interaural level difference

refers to the fact that a sound coming from the right side of the body is more intense at your right ear than your left

interaural timing difference

refers to the small difference in the time at which a given sound wave arrives at each ear

deafness

partial or complet

congenital deafness

born without the ability to hear

conductive hearing loss

due to a problem delivering sound energy to the cochlea

sensorineural hearing loss

most common form of hearing loss

meniere’s disease

results in degeneration of inner ear structures that can lead to hearing loss, tinnitus

vertigo

a sense of spinning and increase pressure within the inner ear

cochlear implants

electronic devices that consist of a microphone, a speech processor, and an electrode array that receives incoming sound information and directly stimulates the auditory nerve to transmit information to the brain

taste

gustation

smell

olfaction

taste and smell

chemical senses because both have sensory receptors that respond to molecules in the food we eat and the air we breath

umami

Japanese word that roughly translates to yummy

taste buds

formed by grouping of taste receptor cells with hair-like extensions that protrude into the central pore of the taste bud

olfactory receptor cells

located in a mucous membrane at the top of nose

olfactory bulb

bulb-like structure at the tip of the frontal lobe where the olfactory nerves begin

pain

an unpleasant experience that involves both physical and psychological components

congenital insensitivity to pain

very rare genetic disorder where an individual is born without ability to feel pain

perceptual set

psychological factors that determine how you perceive your environment

gestalt psychology

the whole is different from the sum of its parts

gestalt

pattern

figure-ground relationship

we tend to segment our visual world into fiure and ground

figure

object or person that is the focus of the visual field

ground

backround

proximity

things that are close to one another tend to be grouped together

similarity

things that are alike tend to be grouped together

continuity

we are more likely to perceive continuous smooth flowing lines rather than jagged broken lines closure

closure

we organize our perceptions into complete ogjects rather than as a series or parts

perceptual hypothesis

educated guess used to interpret sensory information

consciousness

our awareness of internal and external stimuli

internal

feeling pain, hinger, thirst, sleepiness, aware of thoughts and emotions

external

seeing light from the sun, feeling warmth of room, hearing voice of a friend

sleep

state marked by relatively low levels of physical activity and reduced sensory awareness that is distinct from periods of rest that occur during wakefulness

wakefulness

characterized by high levels of sensory awareness, thought, and behavior

biological rythym

internal rythms of biological activity

circadian rythm

biological rythym that takes place over a period of aboout 24 hours

biological clock

innate timing device comprised of specific molecules that interact in cells throughout the body

suprachiasmatic nucleus (SCN)

area of the hypthalumus in which the body’s biological clock is located

chronotype

individual differences in circadian patterns of activity indication a propensity to sleep at a certain time

jet lag

collection of symptoms brought on by travel from one time zone to another that results from the mismatch between our internal circadian cycles and our environment

rotating shift work

work schedule that changes from early to late on a daily or weekly basis

sleep debt

result of insufficient sleep on a chronic basis

rapid eye movement

characterized by darting movements of the eyes under closed eyelids

non-rem sleep

subdivided into 3 stages distiguished from eachother and from wakefulness by characteristic patterns of brain waves

Stage 1

transitional phase that occurs between wakfulness and sleep

stage 2

body goes into a state of deep relaxation

stage 3

often refered to as deep sleep/slow-wave sleep because stage is characterized by low frequency, high amplitude delta waves

stage 4

REM sleep - rapid emovements of the eyes

Sigmund Freud

Freud became convinced that dreams represented an opprtunity to gain access to the unconscious

manifest content

the actual content or storyline of a dream

latent content

refers to the hidden meant of a dream

Carl Jung

believed dreams allowed us to tap into the collective unconscious mind

Rosalind Cartwright

sleep and dreaming researcher - believes that dream simply reflect life events that are important to the dreamer

lucid dreams

dreams in which certain aspects of wakefulness are maintained during a dream state

threat simulation theory

suggests that dreaming should be seen as an ancient biological defense mechanism - provide an evolutionary advantage because of their capacity to repeatedly simulate potential threatening events