Download Unit IV-Sensation and Perception

Unit IV-Sensation and Perception
Module XVI - Basic Principles of Sensation and Perception
Vocab;
● Selective attention:the focusing of conscious awareness on a particular stimulus
● Change blindness:failing to notice changes in the environment
● Transduction:conversion of one form of energy into another. In sensation, the
transforming of stimulus energies, such as sights, sounds, and smells, into neural
impulses our brain can interpret
● Psychophysics:the study of relationships between the physical characteristics of stimuli,
such as their intensity, and our psychological experience of them
● Absolute threshold:the minimum stimulation needed to detect a particular stimulus 50
percent of the time
● Subliminal:below one's absolute threshold for consciousness awareness
● Priming:the activation, often unconsciously, of certain associations, thus predisposing
one's perception, memory, or response
● 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:diminished sensitivity as a consequence of constant stimulation
Major Learning;
● Sensation is the physical signals; perception is the interpretation of said signals
● Bottom-up begins with sensation and leads to perception. Top-Down begins with prior
experiences and leads to perception
● Humans selectively pay attention and process a limit amount of information. The rest is
blocked out. This leads to in failure to notice changes around us
● Signal Detection theory predicts how humans will detect a faint signal amongst the
background. It relies on the strength of the signal, experience, expectations,and
alertness.
● Humans can be primed, where they process information from signals beyond conscious
detection
● Humans are more likely to notice changes in the environment. A constant stimulus-smell, sound--will become less sensitive
Module XVII - Influences on Perception
● Perceptual set: a mental predisposition to perceive one thing and not another
● Schemas: concepts that organize and allow us to interpret unfamiliar information
● Context effect: a given stimulus may trigger radically different perceptions as a result of
the immediate context
● Extrasensory perception: perception that occurs apart from sensory output including
telepathy, clairvoyance, and precognition
● Parapsychology, the study of paranormal phenomena including ESP and psychokinesis
Module XVIII - Vision
● Wavelength:the distance from one wave peak to the next. Determines the hue of colors
● Amplitude: the height of a wave, determines the the amount of energy in a light or sound
wave, perceived as brightness or loudness
● Rods:retinal receptors that detect black, white, and gray; necessary for peripheral and
night vision where/when cones don't respond
● Cones:retinal receptor cells that are concentrated near the center of the retina (fovea)
and function well with light. They detect fine detail and give rise to color sensations
● Optic nerve:nerve made of ganglion cells that carries neural impulses from the eye to the
brain
● Blind spot:the point at which the optic nerve leaves the eye, creating a "blind spot" where
there are no receptors
● Fovea:the central focal point in the retina, around which the eye's cones cluster
● Parallel processing:the processing of many aspects of a problem simultaneously; the
brain's natural mode of information processing for many functions. Contrasted by step by
step method of conscious processing
● Young-Helmholtz trichromatic theory:the theory that the retina contains three different
color receptors, red, green, blue, that are stimulated in combinations to produce the
perception of color
● opponent-process theory:the theory that opposing retinal processes (red-green, yellowblue, white-black) enable color vision. Causes afterimage.
Major Learning:
● LCIPLRFO: Light -> Cornea -> Iris -> Pupil -> Lens -> Retina -> Fovea -> Optic nerves
● The signal travels to the visual cortex. Feature detectors within the cortex can respond to
specific features--shape, angle, movement--in the visual stimulus.
● Parallel processing allows the brain to analyze an object’s color, form, movement, depth,
and other features at the same time!
Module XIX - Visual Organization and Interpretation
● Gestalt : an organized whole, gestalt psychologists focus on our tendency to integrate
pieces of information into meaningful wholes
● Depth perception:the ability to see objects in three dimensions although the images that
strike the retina are two dimensional
● Binocular cues:depth cues such as retinal disparity that depends on the use of both eyes
● Monocular eyes:depth cues that depends on the use of one eye
● Retinal disparity:a binocular cue for perceiving depth. By comparing images from the
retinas in the two eyes, the brain computes distance - the greater the disparity between
the two images, the closer the object
● Perceptual adaptation:in vision, the ability to adjust to an artificially displaced or even
inverted visual field
Module XX - Hearing
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Middle ear:chamber between eardrum and cochlea where the hammer, anvil,
and stirrup are located.
Cochlea:a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling
through the cochlear fluid trigger nerve impulses
Inner ear:the innermost part of the ear, containing the cochlea, semicircular
canals, and vestibule sacs
Basilar membrane:the membrane with hair cells lining its surface that is rippled
by cochlear fluid motions
Place theory:the theory that links pitches we hear with places in the cochlea's
membrane. Works well with high pitched sounds
Frequency theory : the theory that the rate of nerve impulses traveling the
auditory nerves matches frequency of the tone, enabling us to sense pitch
Volley principle:a combination of place and frequency theory. Neural cells
alternate firing to reach a combined frequency above 1000 waves per second
Locating sounds:we can locate sounds based on the difference in intensity and
time that each ear are stimulated
Module XI - The Other Senses
● Touch: a mix of pressure, warmth, cold, and pain
● Nociceptors: sensory receptors that detect hurtful temperatures, pressures, or chemicals
● Gate-control theory: the theory that the spinal cord contains a neurological “gate” that
blocks pain signals or allows them to pass on to the brain
● Kinesthesia : A system within your body that senses the positioning of individual body
parts
● Vestibular Senses: The sense of balance and positioning of the body
Major learning:
● We can edit our memories of pain so what we remember is not what happened
● We suffer more pain when others around us feel pain
● 5 tastes, sweet, salty, sour, bitter, umami
Unit V- States of Consciousness
Module XXII- Understanding Consciousness & Hypnosis
Vocab;
consciousness : our awareness of ourselves and our environment.
hypnosis : a social interaction in which one person (the hypnotist) suggests to another (the
subject) that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur.
posthypnotic suggestion : suggestion, made during a hypnosis session, to be carried out after
the subject is no longer hypnotized; used by some clinicians to help control undesired
symptoms and behaviors.
dissociation : a split in consciousness, which allows some thoughts and behaviors to occur
simultaneously with others.
Major Learnings;
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After initially claiming consciousness as its area of study in the 19th century,
psychologists abandoned it in the first half of the 20th century, turning instead to the
study of observable behavior because they believed consciousness was too difficult to
study scientifically
Hypnosis does not enhance recall of forgotten events, and may evoke false memories
Hypnosis cannot force people to act against their will, though hypnotized people may
perform unlikely acts
Posthypnotic suggestions have helped people harness their own healing capacity but
have not been effective in treating addiction. Hypnosis can relieve pain.
Many psychologists believe that hypnosis is a form of normal social influence and that
hypnotized people act out the role of “good subject” by following directions given by an
authoritative person (social influence theory).
Other psychologists view hypnosis as a dissociation (divided consciousness theory).
Selective attention may also contribute by blocking attention to certain stimuli.
Module XXIII- Sleep Patterns & Sleep Theories
Vocab;
circadian rhythm : the biological clock; regular bodily rhythms (for example, of temperature and
wakefulness) that occur on a 24-hour cycle.
REM sleep : rapid eye movement sleep; a recurring sleep stage during which vivid dreams
commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except
for minor twitches) but other body systems are active.
alpha waves : the relatively slow brain waves of a relaxed, awake state.
sleep : periodic, natural loss of consciousness—as distinct from unconsciousness resulting from
a coma, general anesthesia, or hibernation.
hallucinations : false sensory experiences, such as seeing something in the absence of an
external visual stimulus.
delta waves : the large, slow brain waves associated with deep sleep.
NREM sleep : non-rapid eye movement sleep; encompasses all sleep stages except for REM
sleep.
suprachiasmatic nucleus (SCN) : a pair of cell clusters in the hypothalamus that controls
circadian rhythm. In response to light, causes the pineal gland to adjust melatonin production,
thus modifying our feelings of sleepiness.
Major Learnings;
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Our bodies have an internal biological clock, roughly synchronized with the 24-hour
cycle of night and day.
The circadian rhythm appears in our daily patterns of body temperature, arousal,
sleeping, and waking. Age and experiences can alter these patterns, resetting our
biological clock.
We cycle through 4 distinct sleep stages about every 90 minutes.
Leaving the alpha waves of the awake, relaxed stage, we descend into the irregular
brain waves from NREM stage 1, often with the sensation of falling or floating.
NREM 2 sleep (most time spent) lasts about 20 minutes and is characterized by sleep
spindles.
NREM 3 lasts about 30 minutes and is characterized by slow delta waves.
About an hour after falling asleep, REM sleep begins
Most dreaming occurs in REM sleep
Our circadian rhythm as well as our age and our body’s production of melatonin
(influenced by SCN) interacts with cultural expectations and individual behaviors to
determine sleeping and waking patterns.
Sleep may have played a protective role in human evolution by keeping people safe
during potentially dangerous periods.
Sleep helps restore and repair damaged neurons.
REM & NREM 2 help strengthen connections that build lasting memories.
During slow-wave sleep, the pituitary gland secretes human growth hormone, which is
necessary for muscle development.
Module XXIV- Sleep Deprivation, Sleep Disorders & Dreams
Vocab;
insomnia : recurring problems in falling or staying asleep.
narcolepsy : a sleep disorder characterized by uncontrollable sleep attacks. The sufferer may
lapse directly into REM sleep, often at inopportune times.
sleep apnea : a sleep disorder characterized by temporary cessations of breathing during sleep
and repeated momentary awakenings.
night terrors : a sleep disorder characterized by high arousal and an appearance of being
terrified; unlike nightmares, night terrors occur during Stage 4 sleep, within two or three hours of
falling asleep, and are seldom remembered.
dream : a sequence of images, emotions, and thoughts passing through a sleeping person's
mind. Dreams are notable for their hallucinatory imagery, discontinuities, and incongruities
manifest content : according to Freud, the remembered story line of a dream (as distinct from its
latent, or hidden, content).
latent content : according to Freud, the underlying meaning of a dream (as distinct from its
manifest content).
REM rebound : the tendency for REM sleep to increase following REM sleep deprivation
(created by repeated awakenings during REM sleep).
Major Learnings;
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Sleep deprivation causes fatigue and irritability, and it impairs concentration,
productivity, and memory consolidation. It can lead to depression, obesity, joint pain, a
suppressed immune system, and slowed performance.
We usually dream of ordinary events and everyday experiences, most involving some
anxiety or misfortune.
Most dreams occur during REM sleep; those that happen during NREM sleep tend to be
vague and fleeting images.
There are five major views of the functions of dreams.
○ Freud’s wish-fulfillment : Dreams provide a psychic “safety valve” with manifest
content acting as a censored version of latent content.
○ Information-processing : Dreams help us sort out the day’s events and
consolidate them in memory.
○ Physiological function : Regular brain stimulation may help develop and preserve
neural pathways in the brain.
○ Neural activation : The brain attempts to make sense of neural static by weaving
it into a storyline.
○ Cognitive development : Dreams reflect the dreamer’s level of development.
Most dream theorists agree that REM sleep and its associated dreams serve and
important function, as shown by the REM rebound that occurs following REM deprivation
in humans and other species.
Module XXV- Psychoactive Drugs
Vocab;
substance use disorder : continued substance craving and use despite significant life disruption
and/or physical risk.
psychoactive drug : a split in consciousness, which allows some thoughts and behaviors to
occur simultaneously with others.
tolerance : the diminishing effect with regular use of the same dose of a drug, requiring the user
to take larger and larger doses before experiencing the drug's effect.
withdrawal : the discomfort and distress that follow discontinuing the use of an addictive drug.
addiction : compulsive drug craving and use, despite adverse consequences.
depressants : drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and
slow body functions.
alcohol use disorder : alcohol use marked by tolerance, withdrawal, and a drive to continue
problematic use.
barbiturates : drugs that depress the activity of the central nervous system, 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, cocaine,
and Ecstasy) 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.
nicotine : a stimulating and highly addictive psychoactive drug in tobacco.
cocaine : a powerful and addictive stimulant, derived from the coca plant, producing temporarily
increased alertness and euphoria.
methamphetamine : a powerfully addictive drug that stimulates the central nervous system, with
speeded-up body functions and associated energy and mood changes; over time, appears to
reduce baseline dopamine levels.
Ecstasy (MDMA) : a synthetic stimulant and mild hallucinogen. Produces euphoria and social
intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons
and to mood and cognition.
hallucinogens : psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions
and evoke sensory images in the absence of sensory input.
LSD : a powerful hallucinogenic drug; also known as acid.
near death experience : an altered state of consciousness reported after a close brush with
death (such as through cardiac arrest); often similar to drug-induced hallucinations.
THC : the major active ingredient in marijuana; triggers a variety of effects, including mild
hallucinations.
Major Learnings;
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Those with a substance use disorder may exhibit impaired control, social disruption,
risky behavior, and the physical effects of tolerance and withdrawal.
Psychoactive drugs alter perceptions and mood.
Alcohol tends to disinhibit, increasing the likelihood that we will act on our impulses,
whether harmful or helpful. It also impairs judgement, disrupts memory processes by
suppressing REM sleep, and reduces self-awareness and self-control.
User expectations strongly influence alcohol’s behavioral effects.
Cocaine gives users a fast high, followed within an hour by a crash. Its risks include
cardiovascular stress and suspiciousness.
Use of methamphetamines may permanently reduce dopamine production.