Download Unit 5: Consciousness - Bremen High School District 228

Unit 4: Sensation
Sensation: The process by which sensory receptors (in
eye, ear, etc.) receive and are stimulated by stimulus
energies from the environment.
Perception: The process of organizing and interpreting
sensory information, enabling us to recognize
meaningful objects and events.
Bottom-up-processing: Analysis that begins with the
sense receptors and works up to the brain's processing of
the information.
Top-down-processing: Information processing guided
by higher-level processes, such as our expectations.
Absolute Threshold: The minimum stimulation needed
to detect a particular stimulus 50% of the time.
Signal Detection Theory: Predicts how and when we
detect faint stimuli (dependent on experience,
expectations, motivation & fatigue.
Subliminal Stimulation: Stimulation below one's
threshold of conscious awareness. Research reveals a
subtle, fleeting effect on thinking, but no effect on
behavior.
Difference Threshold: The minimum difference
between two stimuli required for detection 50% of the
time. It is also called the just noticeable difference or
JND. It is based on Weber's Law: The difference
threshold is in proportion to the strength of the original
stimulus.
Sensory Adaptation: Our diminishing sensitivity to
unchanging stimuli.
Selective Attention: The focusing of attention on
specific stimuli, while ignoring other stimuli (e.g., the
cocktail party effect).
Transduction: The transforming of stimulus energies
(i.e., light waves, sound waves) into neural impulses.
VISION & LIGHT ENERGY
Wavelength: Distance from the peak of one light or
sound wave to the next. Wavelength determines HUE
or color in vision and Pitch in audition.
Shorter wavelengths are bluish in color, while longer
wavelengths are reddish.
Amplitude: The height of a light or sound wave. It
determines brightness in vision and loudness in
hearing.
THE EYE
Pupil: Adjustable opening in the center of the eye
through which light passes.
Iris: A ring of muscle tissue that forms the colored
part of the eye. It controls the size of the pupil
Lens: The transparent structure behind the pupil that
changes shape (called accommodation) to help focus
images on the retina.
Visual Acuity: The sharpness of vision.
Nearsightedness: Can see nearby objects more
clearly because distant object focus in front of the
retina (eyeball may be too long).
Farsightedness: Can see distant objects more
clearly because nearby objects focus behind the retina
(eyeball may be too short).
Rods & Cones: The receptor cells for
vision. Receptor cells are specialized neurons
designed, in this case, to transduce light energy into
neural impulses.
Rods: detect black, white, & grey. Found mainly in
the periphery of the retina. More than one rod
connects to each bipolar cell. Thus, less light energy
is necessary for them to cause the bipolar cells to
fire. Necessary for NIGHT VISION & PERIPHERAL
VISION.
Cones: Found mainly in the center (fovea) of the
retina. Necessary for COLOR VISION and VISUAL
ACUITY.
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Unit 4: Sensation (cont.)
VISION (cont.)
Light waves stimulate rods & cones which synapse to
bipolar cells, which synapse to ganglion cells. The
axons of the ganglion cells come together to form the
Optic nerves which transmit visual information to the
brain.
Blindspot: The area in the retina where the optic
nerve leaves the back of eye. No rods or cones are
located there, so no vision is possible at that location.
Feature Detectors: Nerve cells in the brain that
respond to specific features of a visual stimulus, such
as shape, angle, or movement.
Parallel Processing: The ability of the brain to
process several aspect of a situation simultaneously.
COLOR VISION
Young-Helmholtz Trichromatic Theory: The theory
that the retina contains three different types of cones-one most sensitive to red, one to blue, and one to
green--which when stimulated in combination can
produce any color. RED, GREEN, & BLUE are the
PRIMARY COLORS OF LIGHT WAVES.
Opponent Process Theory: Theory that opposing
retinal processes (red-green, yellow-blue, & blackwhite) enable color vision. For example some cells
are stimulated by red while inhibited by green; others
are stimulated by yellow, while inhibited by
blue. This helps explain afterimages.
Color constancy: Perceiving familiar objects as
having consistent color, even if changing illumination
alters the wavelength reflected by the object.
Middle Ear: Chamber between the eardrum and the
oval window which contains the ossicles (three tiny
bones--hammer, anvil, & stirrup) which concentrate
the vibrations of the eardrum.
Inner Ear: Contains the cochlea, semicircular canals,
and vestibular sacs.
Cochlea: a coiled, bony, fluid-filled tube through
which sound waves trigger nerve impulses.
Basilar Membrane: Membrane along the center of
the cochlea that contains hair cells (the receptor cells
for sound). Axons from the hair cells for the Auditory
Nerves, which transmit neural impulses to the brain.
PITCH PERCEPTION
Place Theory: Theory that the pitch we hear is
associated with the place where the basilar membrane
is stimulated. Best for explaining high-pitched tones.
Frequency Theory: Theory that the rate of nerve
impulses traveling up the auditory nerve matches the
frequency of the tone we are hearing. Best for
explaining low-pitched tones.
AUDITION
Volley Principle: Helps explain in frequency
Audition: The sense of hearing.
theory how we can hear sounds with a frequency
Frequency: The number of complete wavelengths in greater than 1000 cycles per second. While some
a given period of time. Frequency determines pitch. neurons are "recharging" during the refractory period,
Amplitude: Height of each wavelength--determines others are firing.
loudness.
Conduction Deafness: Caused by damage to the
structures that conduct sound waves through the ear
Sound Localization: Sound waves strike one ear
(eardrum, ossicles).
sooner and with more intensity than the other
Nerve Deafness: Caused by damage to the cochlea's
ear. With this information, the brain can determine the hair cells or the auditory nerve.
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location of the sound.
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Unit 4: Sensation (cont.)
TOUCH
Touch or tactile sense involves a mixture of at least 4
Molecules in the air reach millions of receptor cells in
each nasal cavity. These cells send messages to the
distinct skin senses--pressure, warmth, cold, and
pain. Only pressure has identifiable sense receptors.
COLD + PRESSURE = WETNESS
COLD + WARMTH = HOT
PAIN
Gate-Control-Theory: Theory that the spinal cord
contains a neurological "gate" that blocks pain signals
or allows them to pass. The gate is opened by
stimulation of small nerve fibers and closed by
stimulation of larger fiber or by information coming
from the brain.
TASTE
Taste is the Gustatory Sense.
Taste is a CHEMICAL SENSE and consists of the
four basic tastes of sweet, sour, bitter, & salty. There
may also be a 5th sense called "umami" or a meaty
taste.
olfactory bulb and the olfactory nerve which
transmits the messages to the brain.
BODY POSITION & MOVEMENT
Kinesthesis: The system for sensing the position and
movement of individual body parts. The receptor cells
for kinesthesis are found in our muscles, tendons, &
joints.
Vestibular Sense: The system that monitors the head's
(and thus the body's) position and movement. It is our
sense of equilibrium.
The semicircular canals and vestibular sacs in the
inner ear contain receptors that tell us about our head's
position.
Each bump on the tongue contains over 200 taste
buds. Each bud contains a pore that captures food
molecules. The molecules cause hair-like neurons
within the pores to fire.
Taste Buds reproduce themselves every 2-3 weeks.
Sensory Interaction: The principle that one sense may
be influenced by another, as when the smell of food
influences its taste.
Check out HANDOUTS
SMELL
Smell is the Olfactory Sense.
Smell is also a CHEMICAL SENSE.
Very little is known about the olfactory
sense. However, we are able to detect about 10,000
different odors.
Smells are processed in the temporal lobes of the brain
and in the LIMBIC SYSTEM, which may explain
why certain smells seem to have an emotional
component and can trigger memories.
Unit 7: Perception
Perception: The process of organizing and interpreting Monocular Cues: Distance cues that require the use of
sensory information, enabling us to recognize
one eye only.
meaningful objects and events.
1. Relative Size: If we assume two objects are
about the same size, the one that casts the smaller
retinal image is perceived as being farther away.
Perceptual Organization
Figure-ground Relationship: Our ability to perceive
any object (the figure) as distinct from its surroundings
(the ground).
Visual Capture: The tendency for vision to dominate
the other senses when conflicting information is being
received.
Gestalt Organizational Principles: Gestalt
psychologists emphasize our tendency to integrate
individual pieces of information into a meaningful
whole. To bring order and form to basic visual
sensations, our brains follow certain rules for grouping
stimuli together.
1. Proximity: We group nearby objects and
belonging together.
2. Similarity: Figures similar to each other (i.e., as
in shape or color) are groups together.
3. Continuity: We perceive smooth, continuous
patterns rather than discontinuous ones.
4. Connectedness: When the are uniform and
linked, we perceive spots, lines, or areas as single units.
5. Closure: We fill in gaps to create complete,
whole objects.
2. Interposition (Overlap): If one object partially
blocks another, the one that is partially blocked is
perceived to be farther away.
3. Relative Clarity: Because light from distant
objects must pass through more atmosphere, we
perceive hazy object as being farther away than clear,
distinct objects.
4. Texture Gradient: A gradual change from a
coarse, distinct texture to a fine, indistinct texture
signals increasing distance.
5. Relative Height: We perceive objects higher in
our visual field as being further away.
6. Linear Perspective: Parallel lines (such as
railroad tracks) appear further away as they converge
in the distance.
7. Light & Shadow (relative brightness): Nearby
objects reflect more light. Thus, given two identical
objects, the dimmer one seems further away.
8. Relative Motion (motion parallax): If while
riding in a train you fix your gaze on some object (the
fixation point), objects closer than the fixation point
appear to be moving backward. The nearer an object is
the faster it seems to move. Objects behind the fixation
point appear to be moving with you: The farther away
Depth Perception
the object is from the fixation point, the more slowly it
Visual Cliff: A laboratory device for testing depth
perception in infants. Even when coaxed, infants are appears to move.
Motion Perception
reluctant to venture onto the glass over the cliff.
Binocular Cues: Depth cues that depend on the use of One way we perceive motion is by knowing that if an
object keeps getting bigger, it is probably moving
both of our eyes.
towards us. If an object is shrinking, it is moving away
1. Retinal Disparity: By comparing the two
from us.
slightly different images received on each retina, the
Phi Phenomenon: When two or more adjacent
brain computes the distance of what we are looking
at. The greater the disparity (difference) between the stationary lights blink on and off in quick succession,
we perceive a single light moving. (Lighted signs use
two images, the closer the object.
this phenomenon).
2. Convergence: The extent to which the eyes
Stroboscopic Movement: The brain will interpret a
converge inward when looking at an object. The
rapid series of slightly varying images as continuous
greater the convergence, the closer the object.
movement. By flashing 24 still pictures each second, a
motion picture creates perceived movement.
Unit 7: Perception (cont.)
Perceptual Constancies
Perceiving objects as unchanging (having constant
lightness, color, shape, and size) even when our retinal
images of them change. For example:
Shape Constancy: We perceive the form of familiar
objects as constant even when our retinal images of them
Similarly, Blakemore & Cooper found that kittens
whose vision was restricted to only seeing vertical
lines during a critical period of development, later
could not see horizontal lines.
Perceptual Adaptation: In vision, the ability to
adjust to an artificially displaced or even inverted
change.
Size Constancy: We perceive familiar objects to
maintain a constant size even when their distance from
us changes.
Lightness Constancy: We perceive an object as having
a constant lightness even when its illumination varies.
Some Visual Illusions
visual field.
Perceptual Set: A mental predisposition to perceive
one thing and not another (e.g., seeing the Lock Ness
Monster instead of a piece of driftwood because of
your beliefs).
Context Effects: Any given stimulus may trigger
radically different perceptions depending on the
surrounding environment or circumstances. Culture
may have a great impact on context and perception.
The Ponzo Illusion (in two forms)
Human Factors Psychology: A branch of
psychology that explores how people and machines
interact and how machines and physical environments
can be adapted to human behaviors.
The Ames Room
Extrasensory Perception (ESP)
The controversial claim that perception can occur
apart from sensory input.
Telepathy: Mind to mind communication
Clairvoyance: The sensing of remote events that are
presently occuring.
Precognition: The sensing of future events.
Telekinesis (psychokinesis): Ability to affect objects
with the power of the mind.
Parapsychologists: Psychologists who study
paranormal occurrences, including claims of ESP.
Muller-Lyer Illusion
See HANDOUTS
**Please see your textbook for explanations of these
illusions.
Sensory Deprivation
People blind from birth, who later have their vision
restored, can distinguish figure-ground relationships, can
sense colors, but have great difficulty recognizing
objects that they were familiar with by touch.
Unit 5: Consciousness
Consciousness: Our awareness of ourselves and our
environment.
Biological Rhythms: Periodic physiological
fluctuations.
4. Evolutionary view: Sleeping when it was dark kept us
safe.
DREAM THEORIES
Freudian Theory: Dreams help disguise unconscious
Circadian Rhythm: The biological clock. It involves
regular body rhythms (ex: temperature & sleep) that
occur on a 24-hour cycle.
STAGES OF SLEEP
Stage 1: Alpha waves; hypnogogic hallucinations;
sleep talking; hypnic jerk; slow down of biological
functions (e.g., blood pressure, heart rate, respiration)
& a decrease in temperature.
Stage 2: Waves are slower (see some theta waves);
sleep spindles; K-complexes; sleep talking; biological
functions continue to slow.
Stage 3: Transition stage. See first signs of delta
waves; biological functions continue to slow.
Stage 4: Deep sleep. All delta waves; bedwetting &
sleep walking most likely. Biological functions are at
there lowest.
conflicts and motives.
Manifest Content: According to Freud, the
remembered storyline of a dream.
Latent Content: According to Freud, the
underlying "meaning" of a dream.
Activation-synthesis Theory: Dreams spring from the
mind's relentless effort to make sense of random visual
bursts of electrical activity which originate in the
brainstem and are given their emotional tone as they
pass through the limbic system.
Memory Consolidation Theory: The parts of the brain
active when we learn something are similarly active
later when we sleep and dream.
Brain-Stimulation Theory: Periodic stimulation
during dreaming helps form neural
connections. Especially important in infants.
After stage 4, the sleeper moves back to stages 3,
stage 2, & then into REM sleep.
REM Sleep: Rapid eye movement; dreaming;
erections in males; paralysis. Also called "paradoxical
sleep" because while the person is totally asleep, there
biological function and brain waves appear more like
a person who is awake.
A full sleep-cycle takes about 90 minutes. As the
cycles continue throughout the night, stage 4 sleep
gets shorter and REM sleep gets longer.
SLEEP THEORIES
1. Possibly certain chemicals depleted during the day
are restored during sleep.
2. A build-up of "s-factor" during the day causes sleep
at night.
3. Pituitary gland more active during deep sleep. So,
sleep may be involved in growth process. (Babies and
young people spend more time in deep sleep than
older people).
Regardless, if we don't get enough REM sleep, we will
go into
REM Rebound: The tendency for REM sleep to
increase following a period of REM deprivation.
SLEEP DISORDERS
Insomnia: Recurring problems in falling or staying
asleep.
Narcolepsy: Disorder characterized by uncontrollable
sleep attacks. The sufferer may lapse directly into REM
sleep at inopportune time.
Sleep Apnea: Disorder characterized by temporary
cessation of breathing during sleep and momentary
awakenings throughout the night.
Night Terror: Disorder characterized by high arousal
and an appearance of being terrified. Unlike
nightmares, these occur during stage 4 sleep and are
typically not remembered. NEXT PAGE
Unit 5: Consciousness (cont.)
HYPNOSIS
Hypnosis: A social interaction in which one person
(the hypnotist) suggests to another person (the subject)
that certain perceptions, feelings, thoughts, or
behaviors will spontaneously occur.
Posthypnotic Amnesia: Supposed inability to recall
what one experienced during hypnosis; induced by the
hypnotist's suggestion.
Posthypnotic Suggestion: A suggestion, made during
hypnosis, to be carried out after the subject is no longer
Physical Dependence: A physiological need for a
drug, marked by unpleasant withdrawal symptoms
when the drug is discontinued.
Psychological Dependence: A psychological need to
use a drug, such as to relieve negative emotions.
Psychoactive Drugs
Depressants: Drugs (such as alcohol, barbiturates, and
opiates) that reduce neural activity and slow body
functions.
Barbiturates: drugs that depress the activity of the
hypnotized; used by some clinicians to control
undesired symptoms and behaviors (e.g., eat less, quit
smoking, feel less anxiety, etc.).
Hypnosis does not improve memory. In fact, it is
likely to contaminate our memories. It is, however,
useful in relieving PAIN. Possibly due to dissociation
or a "split in consciousness". While part of the person
is still aware of the pain, the conscious part of the
person is not.
Theories of Hypnosis
1. Divided Consciousness Theory: Suggests that
dissociation occurs during hypnosis. A "split" in
consciousness occurs. "Part" of the person is unaware
of what is occurring, but another "part" is aware. This
part is called:
The Hidden Observer: Hilgard's term describing
a hypnotized person's awareness of experiences, such
as pain, that seem to go unreported during hypnosis.
2. Social Influence Theory: The subject simply
becomes caught up in the "role" of being a hypnotized
person. It involves role-playing, conformity, and
obedience.
DRUGS AND CONSCIOUSNESS
Psychoactive Drug: A chemical substance that alters
perceptions and mood.
Tolerance: The diminishing effect with regular use of
the same dose of a drug; requiring the user to take
larger and larger doses in order to obtain the same
effect.
Withdrawal: The discomfort and distress that follow
discontinuing the use of an addictive drug.
CNS, reducing anxiety but impairing memory and
judgment.
Opiates: Opium and its derivatives (such as
morphine and heroin); they depress neural activity,
temporarily lessening pain and anxiety.
Stimulants: Drugs (such as caffeine, nicotine, and the
more powerful amphetamines and cocaine) that excite
neural activity and speed up body functions.
Amphetamines: Drugs that stimulate neural
activity, causing speeded-up body functions and
associated energy and mood changes.
Ecstasy (MDMA): A synthetic stimulant and mild
hallucinogen. It produces short-term
euphoria. However, it harms serotonin-producing
neurons causing long-term changes in mood and
cognitions.
Hallucinogens: Psychedelic ("mind-altering") drugs,
such as LSD and marijuana, that distort perceptions
and may evoke sensory images in the absence of
sensory input (i.e., hallucinations).
THC: The major active ingredient in marijuana.
NEAR-DEATH EXPERIENCES
Near-death Experience: An altered state of
consciousness reported after a close brush with death
(such as after a cardiac arrest); often similar to druginduced hallucinations.
Monism: The belief that mind and body are different
aspects of the same thing (when the body dies, so does
the mind.
Dualism: The belief that mind and body are two
distinct entities (when the body dies, the mind may
continue to exist).
See HANDOUTS