-
Adaption
- the decreasing response of the sense organs, the more they are exposed to a
- continuous level of stimulation
-
Sensations versus perception
- Relatively meaningless bits of information that result
- when the brain processes electrical signals that come from sense organs.
-
Perceptions
- meaningful sensory experiences that result after the brain combines hundreds
- of sensations.The eyes, ears, nose, skin, and tongue are complex, miniaturized, living sense organs that automatically gather information about
- your environment
-
Transduction
- a process in which a sense organ changes, or transforms, physical energy into
- electrical signals that become neural impulses, which may be sent to the brain
- for processing.
-
Stimulus:light waves
- Invisible –too short: Wavelengthsthat are too short we cannot see such as gamma rays, x-rays, and ultravioletrays.
- Visible –just right§ The visiblespectrum is the segment of electromagnetic energy that we can see because these
-
1. The Eyes (vision) structure and function
Eyes perform 2 separate processes –
- First:
- gather and focus light into precise area in the back of the eye.
- - Second: the
- area absorbs and transforms light waves into electrical impulses. This process
- is called transduction.
-
(Chapter 7)
Consciousness:
Refers to different levels of awareness of one’s thoughts and feelings. It may include creating images in one’s mind, following one’s thoughts processes, or having unique emotional experiences.
-
1. The continuum of consciousness:
- Refers to a wide range of experiences, from being acutely aware and alert to being totally
- unaware and unresponsive.
-
Controlled processes
- activities that require full awareness, alertness, and concentration to reach some goal. The focused
- attention required in carrying out controlled processes usually interferes with
- the execution of other ongoing activities
- Exp: talking on the phone while drivingities.
-
Automatic process:
- Are activities
- that that require little awareness, take minimal attention, and do not
- interfere with other ongoing activities?
- § Exp: eating
- an apple while reading
-
Day dreaming:
- Is an
- activity that requires a low level of awareness, often occurs during automatic
- processes, and involves fantasizing of daydreaming while awake?
-
Altered states of consciousness:
- Results from
- using any number of procedures – such as meditation, psychoactive drugs,
- hypnosis, or sleep deprivation – to produce an awareness that differs from
- normal consciousness.
- § Exp: using
- meditation to focus attention on a single image or thought.
-
Sleep:
- Consist of
- five different stages that involve different levels of awareness, consciousness,
- and responsiveness, as well as different levels of physiological arousal. The
- deepest state of sleep boarders on unconsciousness.
- § An 8-hour
- sleep may seem like one continuous state but it has composed of different
- states of body arousal.
-
Dreaming:
- Is a unique
- state of consciousness in which we are asleep but experience a variety of
- astonishing visual, auditory, and tactical images, often connected in strange
- ways and often connected in strange ways and often in color. People blind from
- birth have only auditory or tactical dreams
-
Unconsciousness
Which canresult from disease, trauma, and a blow to the head, or general medicalanesthesia, results in total lack of sensory awareness and complete loss ofresponsiveness to one’s environment.§ Exp: aboxer in a fight getting knocked out.
-
Implicit or no declarative memory:
- Means learning
- without awareness, such as occurs in emotional situations or in acquiring
- habits. We are unaware of such learning, which can influence our conscious
- feelings, thoughts, and behaviors.
- § Exp: you can’t
- describe why your complex motor movements your feet make as they walk down the
- stairs because such motor memories are stored in implicit memory, which you are
- unaware of and cannot voluntarily recall.
-
Biological clocks:
- Internal timing
- devices that are genetically set to regulate various physiological responses
- for different periods.
-
A circadian rhythm:
- Refers to a
- biological clock that is genetically programmed to regulate physiological
- responses within a time period of 24 hours (about one day)
- § Resetting you,
- circadian clock is important because it is set for 24-hour long day. In the
- morning when sunlight hits your eyes it stimulates light detecting cells in the
- eyes retina. These cells are not involved in seeing, they send electrical
- signals it the brain’s circadian clock and reset it by about 18 minutes each
- day.
- § Problems:
- if your circadian clock is not reset each day, it may result in problems
- getting to sleep, getting over jet lag, and adjusting to working the night
- shift.
-
The Suprachiasmatic nucleus:
- One of the
- many groups of cells that make up the hypothalamus, which lies in the lower
- middle of the brain. The supruchiasmatic nucleus is a sophisticated biological clock
- that regulates a number of circadian rhythms, including the sleep-wake cycle.
- Because this nucleus receives direct input from the eyes, the supriachiasmatic
- cells are highly responsive to changes in the light.
-
The interval timing clock:
- Can be started and stoped like a stopwatch,
- gauges the passage of seconds, minutes, or hours and helps people and animals
- time their movements, such as knowing when to start or stop doing some
- activity(taking a 1 hour nap and actually waking up and hour later). The interval
- timing clock is located in a part of the brain known as the basal ganglia.
-
The food-entrainable circadian clock(AKA the
midnight snack clock)
- Regulates eating paterns in people and animals
- and might be responsible for late nigh eating in people. Thus, obese people,
- many of whom eat more than half their calories at night, may have an
- abnormality in their clock, which is located in the hypothalamus.
-
Jet lag
- is the experiencce of fatigue, lack of concentration, and reduced cognitive skills that occures when ravelers biological circadian clacks are out of step or synchronized with the external clock times at their new locations.
- - generally it takes about one day to reset your circadian clcok for each hour of time change.
-
light therapy
is the use of bright artificial light to reset circadian clocks and to combat the insomnia and drowsiness that plague shift workers and jet-lag sufferers. It also helps people with sleeping disordersin wich the body fails to stay in time with the external enviroment.
-
Module 5
- Sensation
- THREE DEFINITONS
- Adaptation:
- the decreasing response of the sense organs, the more they are exposed to a continuous level of stimulation
- Sensation versus perception:
- relatively meaningless bits of information that result when the brain processes electrical signals that come from the sense organs
- perceptions:
- meaningful sensory experiences that result after the brain combines hundreds of sensations
- THREE DEFINITONS (CONT.)
- eyes, ears, nose, skin, and tongue are complex, miniaturized, living sense organs that automatically gather information about your environment
- Transduction:
- process in which a sense organ changes, or transforms, physical energy into electrical signals that become neural impulses, which may be sent to the brain for processing
- EYE: VISION
- Structure and function
- eyes perform two separate processes
- first: gather and focus light into precise area in the back of eye
- second: area absorbs and transforms light waves into electrical impulses
- process called transduction
-
EYE: VISION (CONT.)
- Stimulus: Light Waves
- Invisible�too short
- wave lengths too short
- gamma rays, x-rays, ultraviolet rays
- Visible�just right
- Visible spectrum
- Particular segment of electromagnetic energy that we can see because these waves are the right length to stimulate receptors in the eye
- Invisible�too long
- wave lengths longer
- Radar, FM, TV, shortwave, AM
-
EYE: VISION (CONT.)
- EYE: VISION (CONT.)
- Structure and function
- Vision: 7 steps
- Image reversed
- Light waves
- Cornea
- Pupil
- Iris
- Lens
- Retina
-
EYE: VISION (CONT.)
- Structure and function
- Image reversed
- In the back of the eye, objects appear upside down.
- somehow the brain turns the objects right side up
- Light waves
- light waves are changed from broad beams to narrow, focused ones
-
EYE: VISION (CONT.)
- Structure and function
- Cornea
- rounded, transparent covering over the front of your eye
- Pupil
- round opening at the front of the eye that allows light waves to pass into the eye�s interior
-
EYE: VISION (CONT.)
- Structure and function
- Iris
- circular muscle that surrounds the pupil and controls the amount of light entering the eye
- Lens
- transparent, oval structure whose curved surface bends and focuses light waves into an even narrower beam
-
EYE: VISION (CONT.)
- Structure and function
- Retina
- located at the very back of the eyeball, is a thin film that contains cells that are extremely sensitive to light
- light sensitive cells, called photoreceptors, begin the process of transduction by absorbing light waves
-
EYE: VISION (CONT.)
- EYE: VISION (CONT.)
- Retina:
- three layers of cells
- back layer contains two kinds of photoreceptors that begin the process of transduction
- change light waves into electrical signals
- rod located primarily in the periphery
- cone located primarily in the center of the retina called the fovea
-
EYE: VISION (CONT.)
- rods:
- photoreceptor that contain a single chemical, called rhodopsin
- activated by small amounts of light
- very light sensitive
- allow us to see in dim light
- see only black, white and shades of gray
-
EYE: VISION (CONT.)
- cones:
- photoreceptors that contain three chemicals called opsins
- activated in bright light
- allow us to see color
- cones are wired individually to neighboring cells
- allows us to see fine detail
-
EYE: VISION (CONT.)
- EYE: VISION (CONT.)
- Visual pathways: Eye to brain
- Optic nerve
- Primary visual cortex
- Visual association areas
- EYE: VISION (CONT.)
- EYE: VISION (CONT.)
- Visual pathways: eye to brain
- Optic nerve
- nerve impulses flow through the optic nerve as it exits from the back of the eye
- the exit point is the �blind spot�
- the optic nerves partially cross and pass through the thalamus
- the thalamus relays impulses to the back of the occipital lobe in the right and left hemisphere
- EYE: VISION (CONT.)
- Visual pathways: eye to brain
- Primary visual cortex
- the back of the occipital lobes is where primary visual cortex transforms nerve impulses into simple visual sensations
- Visual association areas
- the primary visual cortex sends simple visual sensations to neighboring association areas
-
EYE: VISION (CONT.)
- Color Vision
- Trichromatic theory
- three different kinds of cones in the retina
- each cone contains one of the three different light-sensitive chemicals, called opsins
- each of the three opsins is most responsive to wavelengths that correspond to each of the three primary colors
- blue, green, red
- all colors can be mixed from these primary colors
-
EYE: VISION (CONT.)
- Opponent-Process Theory
- Afterimage
- visual sensation that continues after the original stimulus is removed
- ganglion cells in retina and PERCEPTUAL THRESHOLDS
- Subliminal stimulus
- has an intensity that gives a person less than a 50% chance of detecting the stimulus
-
breast cancer
- accuracy problems
- looking for ways to lower the threshold for detecting cancerous tumors and thus save patients
- recently, use of digital mammograms (allows for images to be enhanced or magnified) is better in detecting cancerous tumors in women
-
PERCEPTUAL THRESHOLDS (CONT.)
- E. H. Weber
- worked on the problem of how we judge whether a stimulus, such as loud music, has increased or decreased in intensity
- concept of just noticeable difference (JND)
- refers to the smallest increase or decrease in the intensity of a stimulus that a person is able to detect
- Weber�s law
- The increase in intensity of a stimulus needed to produce a just noticeable difference grows in proportion to the intensity of the initial stimulus.
-
SENSATION VERSUS PERCEPTION
- Basic Differences
- Sensations
- our first awareness of some outside stimulus
- outside stimulus activates sensory receptors, which in turn produce electrical signals that are transformed by the brain into meaningless bits of information
- Perceptions
- the experience we have after our brain assembles and combines thousands of individual sensations into a meaningful pattern or image
-
SENSATION VERSUS PERCEPTION (CONT.)
- Changing sensation into perception
- Stimulus
- change of energy in the environment, such as light waves, sound waves, mechanical pressure, or chemicals
- Transduction
- change physical energy into electrical signals
- electrical signals are changed into impulses that travel into the brain
- Brain
- impulses from senses first go to different primary areas of the brain
-
SENSATION VERSUS PERCEPTION (CONT.)
- Changing sensation into perception
- brain: association areas
- sensation impulses are sent to the appropriate association area in the brain
- Personalized perceptions
- each of us has a unique set of personal experiences, emotions, and memories that are automatically added to our perceptions by other areas of the brain
- RULES OF ORGANIZATION
- Structuralist versus Gestalt psychologists
- Structuralists
- believed that you add together hundreds of basic elements to form complex perceptions
- Gestaltists
- believe our brains follow a set of rules that specify how individual elements are to be organized into a meaningful pattern, or perception
-
RULES OF ORGANIZATION (CONT.)
- Organizational rules
- rules of organization: identified by Gestalt psychologists
- specify how our brains combine and organize individual pieces or elements into a meaningful perception
- Figure-ground
- states: in organizing stimuli, we tend to automatically distinguish between a figure and a ground
- Similarity
- states: in organizing stimuli, we group together elements that appear similar
- RULES OF ORGANIZATION (CONT.)
-
Closure
- states: in organizing stimuli, we tend to fill in any missing parts of a figure and see the figure as complete
- Proximity
- states: in organizing stimuli, we group together objects that are physically close to one another
- Simplicity
- states: stimuli are organized in the simplest way possible
- Continuity
- states: in organizing stimuli, we tend to favor the smooth or continuous paths when interpreting a series of points or lines
- PERCEPTUAL CONSTANCY
-
Size, shape, brightness & color constancy
- Size constancy
- refers to our tendency to perceive objects as remaining the same size even when their images on the retina are continually growing or shrinking
- Shape constancy
- refers to our tendency to perceive an object as retaining its same shape even though when we view it from different angles, its shape is continually changing its image on the retina
- PERCEPTUAL CONSTANCY (CONT.)
-
Size, shape, brightness & color constancy
- Brightness constancy
- refers to the tendency to perceive brightness as remaining the same in changing illumination
- Color constancy
- refers to the tendency to perceive colors as remaining stable despite differences in lighting
- DEPTH PERCEPTION
-
Binocular (two eyes) depth cues
- Depth perception
- refers to the ability of your eye and brain to add a third dimension, depth, to all visual perceptions, even though images projected on the retina are in only two dimensions, height, and width
- Binocular depth cues
- depends on the movement of both eyes
- Convergence
- refers to a binocular cue for depth perception based on signals sent from muscles that turn the eyes
- DEPTH PERCEPTION
- DEPTH PERCEPTION (CONT.)
-
Retinal disparity
- refers to a binocular depth cue that depends on the distance between the eyes
- DEPTH PERCEPTION (CONT.)
- DEPTH PERCEPTION (CONT.)
-
Monocular depth cues
- produced by signals from a single eye
- Linear perspective
- monocular depth cue that results as parallel lines come together, converge, in the distance
- Relative size
- monocular depth cue that results when we expect two objects to be the same size and they are not
- Interposition
- monocular depth cue that comes into play when objects overlap
-
-
Monocular depth cues
- Light and shadow
- monocular depth cues where brightly lit objects appear closer, while objects in shadows appear farther away
- Texture gradient
- monocular depth cue in which areas with sharp, detailed texture are interpreted as being closer and those with less sharpness and poorer detail are perceived as more distant
- DEPTH PERCEPTION (CONT.)
-
Monocular depth cues
- Atmospheric perspective
- monocular depth cue that is created by the presence of dust, smog, clouds, or water vapor
- Motion parallax
- monocular depth cue based on the speed of moving objects
- ILLUSIONS
-
Strange perceptions
- Illusion
- a perceptual experience in which you perceive an image as being so strangely distorted that, in reality, it cannot and does not exist
- Impossible figure
- perceptual experience in which a drawing seems to defy basic geometric laws
- ILLUSIONS (CONT.)
- SUBLIMINAL PERCEPTION
- Subliminal Message
- brief auditory or visual message that is presented below the absolute threshold
- means that there is less than a 50% chance that the message will be perceived
- Self-fulfilling prophecies
- involve having strong beliefs about changing some behavior and then acting, unknowingly, to change that behavior
- EXTRASENSORY PERCEPTION
-
Definition
- a group of psychic experiences that involve perceiving or sending information (images) outside normal sensory processes or channels
- Four general abilities
- telepathy
- ability to transfer one�s thoughts to another or to read the thoughts of others
- precognition
- ability to foretell events
- EXTRASENSORY PERCEPTION (CONT.)
-
Clairvoyance
- ability to perceive events or objects that are out of sight
- Psychokinesis
- ability to exert mind over matter; moving objects
- Believing in ESP
- recent Gallup polls report 41% of adult Americans believe in ESP
- 31% believe in communication between minds without the use of regular senses
- 21% believe they can communicate mentally with someone who has died
- 55% believe in psychics
-
cells in thalamus respond to two pairs of colors�red-green and blue-yellow
- when excited, respond to one color of the pair
- when inhibited, respond to complementary pair
-
EYE: VISION (CONT.)
- Color Blindness
- inability to distinguished two or more shades in the color spectrum
- Monochromatic:
- total color blindness
- black and white
- result of only rods and one kind of functioning cone
- Dichromatic:
- trouble distinguishing red from green
- two kinds of cones
- inherited genetic defect
- mostly in males
- See mostly shades of green
-
EAR: AUDITION
- Stimulus:
- Sound waves
- stimuli for hearing (audition)
- ripples of different sizes
- sound waves travel through space with varying heights and frequency
- Height
- distance from the bottom to the top of a sound wave
- called amplitude
- Frequency
- number of sound waves occurring within one second
-
EAR: AUDITION (CONT.)
- Loudness
- subjective experience of a sound�s intensity
- brain calculates loudness from specific physical energy (amplitude of sound waves)
- Pitch
- subjective experience of a sound being high or low
- brain calculates from specific physical stimuli
- speed or frequency of sound waves
- measured in cycles (how many sound waves in one second)
-
-
Measuring sound waves
- decibel: unit to measure loudness
- threshold for hearing:
- 0 decibels (no sound)
- 140 decibels (pain and permanent hearing loss)
-
EAR: AUDITION (CONT.)
EAR: AUDITION (CONT.)
-
Outer, middle, and inner ear
- Outer ear
- consists of three structures
- external ear
- auditory canal
- tympanic membrane
-
EAR: AUDITION (CONT.)
- Outer, middle, and inner ear
- Outer ear
- external ear
- oval shaped structure that protrudes from the side of the head
- function
- pick up sound waves and then send them down the auditory canal
-
EAR: AUDITION (CONT.)
- Outer, middle, and inner ear
- Outer ear
- auditory canal
- long tube that funnels sound waves down its length so that the waves strike the tympanic membrane (ear drum)
-
EAR: AUDITION (CONT.)
- Outer, middle, and inner ear
- Outer ear
- tympanic membrane
- taut, thin structure commonly called the eardrum
- Sound waves strike the tympanic membrane and cause it to vibrate
-
EAR: AUDITION (CONT.)
- EAR: AUDITION (CONT.)
- Outer, middle, and inner ear
- Middle ear
- bony cavity sealed at each end by membranes.
- the membranes are connected by three tiny bones called ossicles
- hammer, anvil and stirrup
- hammer is attached to the back of the tympanic membrane
- anvil receives vibrations from the hammer
- stirrup makes the connection to the oval window (end membrane)
-
EAR: AUDITION (CONT.)
- Outer, middle, and inner ear
- Inner ear
- contains two structures sealed by bone
- cochlea: involved in hearing
- vestibular system: involved in balance
-
EAR: AUDITION (CONT.)
- Cochlea
- bony coiled exterior that resembles a snail�s shell
- contains receptors for hearing
- function is transduction
- transforms vibrations into nerve impulses that are sent to the brain for processing into auditory information
-
EAR: AUDITION (CONT.)
- EAR: AUDITION (CONT.)
- Auditory brain areas
- sensations and perceptions
- two step process occurs after the nerve impulses reach the brain
- primary auditory cortex
- top edge of temporal lobe
- transforms nerve impulses into basic auditory sensations
- auditory association area
- combines meaningless auditory sensations into perceptions, which are meaningful melodies, songs, words, or sentences
-
VESTIBULAR SYSTEM: BALANCE
- Position and balance
- vestibular system is located above the cochlea in the inner ear
- includes semicircular canals
- bony arches set at different angles
- each semicircular canal is filled with fluid that moves in response to movements of your head
- canals have hair cells that respond to the fluid movement
- function of vestibular system
- include sensing the position of the head, keeping the head upright, and maintaining balance
- CHEMICAL SENSES
- Taste
- chemical sense because the stimuli are various chemicals
- tongue
- surface of the tongue
- taste buds
-
CHEMICAL SENSES (CONT.)
- Tongue
- Five basic tastes
- sweet
- salty
- sour
- bitter
- umami: meaty-cheesy taste
-
CHEMICAL SENSES (CONT.)
- Surface of the tongue
- chemicals, which are the stimuli for taste, break down into molecules
- molecules mix with saliva and run into narrow trenches on the surface of the tongue
- molecules then stimulate the taste buds
-
CHEMICAL SENSES (CONT.)
- Taste buds
- shaped like miniature onions
- receptors for taste
- chemicals dissolved in saliva activate taste buds
- produce nerve impulses that reach areas of the brain�s parietal lobe
- brain transforms impulses into sensations of taste
- Flavor
- combination of taste and smell
-
CHEMICAL SENSES (CONT.)
- CHEMICAL SENSES (CONT.)
- Smell, or olfaction
- Steps for olfaction
- Stimulus
- Olfactory cells
- Sensation and memories
- Functions of olfaction
-
CHEMICAL SENSES (CONT.)
- CHEMICAL SENSES (CONT.)
- Smell, or olfaction
- Stimulus
- we smell volatile substances
- volatile substances are released molecules in the air at room temperature
- example:
- skunk spray, perfumes, warm brownies; not glass or steel
-
CHEMICAL SENSES (CONT.)
- Smell, or olfaction
- Olfactory cells
- receptors for smell are located in a I-inch-square patch of tissue in the uppermost part of the nasal passages.
- olfactory cells are covered in mucus
- which dissolve volatile molecules and stimulate the cells
- the cells trigger nerve impulses that travel to the brain
- which interprets the impulses as different smells
-
-
Smell, or olfaction
- Sensations and memories
- nerve impulses travel to the olfactory bulb
- impulses are relayed to the primary olfactory cortex
- cortex transforms nerve impulses into olfactory sensations
- can identify as many as 10,000 different odors
- we stop smelling our deodorants or perfumes because of decreased responding
- called adaptation
-
CHEMICAL SENSES (CONT.)
- Smell, or olfaction
- Functions of olfaction
- one function: to intensify the taste of food
- second function: to warn of potentially dangerous foods
- third function: elicit strong memories; emotional feelings
-
TOUCH
- Touch
- includes pressure, temperature, and pain
-
TOUCH (CONT.)
- TOUCH (CONT.)
- Receptors in the skin
- skin
- hair receptors
- free nerve endings
- Pacinian corpuscle
- TOUCH (CONT.)
- Skin
- outermost layer
- thin film of dead cells containing no receptors
- just below, are first receptors which look like groups of threadlike extensions
- middle and fatty layer
- variety of receptors with different shapes and functions
- some are hair receptors
-
TOUCH (CONT.)
- Hair receptors
- free nerve endings wrapped around the base of each hair follicle
- hair follicles fire with a burst of activity when first bent
- if hair remains bent for a period of time, the receptors will cease firing
- sensory adaptation
- example: wearing a watch
-
TOUCH (CONT.)
- Free nerve endings
- near bottom of the outer layer of skin
- have nothing protecting or surrounding them
- Pacinian corpuscle
- in fatty layer of skin
- largest touch sensor
- highly sensitive to touch
- responds to vibration and adapts very quickly
-
TOUCH (CONT.)
- Brain areas
- somatosensory cortex
- located in the parietal lobe
- transforms nerve impulses into sensations of touch temperature, and pain
-
PAIN
- What causes pain?
- pain: unpleasant sensory and emotional experience that may result from tissue damage, one�s thoughts or beliefs, or environmental stressors
- pain results from many different stimuli
-
PAIN (CONT.)
- PAIN (CONT.)
- How does the mind stop pain?
- gate control theory of pain
- nonpainful nerve impulses compete with pain impulses in trying to reach the brain
- creates a bottleneck or neutral gate
- shifting attention or rubbing an injured area decreases the passage of painful impulses
- result: pain is dulled
-
PAIN (CONT.)
- Endorphins
- chemicals produced by the brain and secreted in response to injury or severe physical or psychological stress
- pain reducing properties of endorphins are similar to those of morphine
- brain produces endorphins in situations that evoke great fear, anxiety, stress or bodily injury as well as intense aerobic activity
-
PAIN (CONT.)
- Dread
- connected to pain centers in brain
- not the act itself that people fear
- time waiting before event causes dread
-
Acupuncture
trained practitioners insert thin needles into various points on the body’s surface and then manually twirls or electrically stimulates the needlesafter 10-20 minutes of stimulation, patients often report a reduction in various kinds of pain
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