Sensation

process of detecting, converting, and transmitting raw sensory information from the external and internal environments to the brain.—begins in sense organs (eyes, ears, nose, tongue, skin, internal body tissues)—follows a bottom-up processing model (data driven)

Perception

process of selecting, organizing, and interpreting sensory info into meaningful patterns.—from stimuli (light, mechanical pressure, chemical molecules)—follows top-down processing (conceptually driven)

Transduction

Converting a receptor’s energy into neural impulses that are sent on to the brain

Eye converts light, ear converts sound

Coding

Converting sensory inputs into different sensations

Sensory reduction

Filtering and analyzing incoming sensations before sending a neural message to the cortex

Psychophysics

studies the link between the physical characteristics of stimuli and our sensory experience of them.—how the strength or intensity of a stimulus affects an observer

Absolute Threshold

minimum amount of a stimulus needed that an observer can reliably detect

1. Cornea

2. Pupil

3. Iris

4. Lens

5. Retina

6. Optical Nerve

1. Normal Eye

2. Nearsightedness-myopia

3. Farsightedness-hyperopia

1. Pinna

2. Ossicles

3. Stapes

4. Cochlea

5. Auditory Nerve

6. Tympanic Membrane

7. External Ear (Ear Cannal)

Minimum difference needed to notice a stimulus change—AKA just noticeable difference

Decreased sensitivity due to repeated or constant stimulation

            -Endorphins released can be mistaken for sensory adaptation to pain

How often a light or sound wave cycles

 respond to light intensity controlling the amount of light that enters the eye

at the back of the eye and contains special light-sensitive cells

detect shades of gray and are responsible for peripheral and dim light vision-slow to adapt

-120 mil in each eye

-located at outer eye

-detect movement and location

-low light threshold

located near center of the eye and are responsible for color and fine detail vision; most sensitive in brightly lit conditions-quickly adapting

                                                  tiny pit in the center of the retina filled with cones; responsible for sharp vision

                                                            point where the optic nerve leaves the eye; contains no receptors for vision

 lens becomes less flexible making focusing on nearby objects difficult

Opponent-Process Theory:

MODERN: Color is processed in a trichromatic fashion at the level of the retina (in the cones) and in an opponent fashion at the level of the optic nerve and the thalamus

Explains that pitch perception is linked to the particular spot on the cochlea’s basilar membrane that is most stimulated

Explains that pitch perception occurs when the nerve impulses sent to the brain match the frequency of the sound wave

Middle-ear deafness resulting from problems with transferring sound waves to the inner ear

5 major taste sensations

1. sweet

2. sour

3. salty

4. bitter

5. umami (delicious/savory)---glutamate (protein)

1.      Touch/pressure

2.      Temperature-no “hot” receptor--cross-activated with cold receptor

3.      Pain-detected in spinal cord first

Vestibular Sense

sense of body orientation and position with respect to gravity and space (balance)

-tells cerebellum where head is

-uses semi-circular canals filled with lymphatic fluid

Kinesthesia/Kinesthetic Sense

bodily posture and orientation as well as movement

                        -receptors found throughout muscles, joints, and tendons

-Vision tends to override sense

-body is illusion constructed in mind

Selection

sort out important messages—choosing where to direct our attention

Selective attention

filtering out and attending to  only important sensory messages

Feature detectors

specialized neurons in the brain that respond only to certain sensory info

-filters out unused features and keeps recognized features to form object

Organization

selected info is organized into patterns and principles that will help us understand the world.

Gestalt Law

Law of Figure/Ground

tend to distinguish between figure and background, only focusing on the figure

-when you perceive figure, background is ignored

Law of Proximity

Objects that are physically close together are grouped together

objects that continue a pattern are grouped together

-Straight lines continue to be straight and curved continue to be curved

the tendency to see a finished unit from an incomplete stimulus

Law of Similarity

similar objects are grouped together

Perceptual Constancies

• tendency for the environment to be perceived as remaining the same even with changes in sensory input
• Size-mind corrects for distance
• Shape-perceive as same shape regardless of angle
• Color-mind corrects color for lighting conditions
• Brightness-need to see where image begins and ends to have a brighness constancy (shadows)

Depth Perception

• Ability to perceive three-dimensional space and to accurately judge distance

Binocular cues

• visual input from two eyes that allows perception of depth or distance

Retinal disparity

• separation of the eyes that causes different images to fall on each retina

Convergence

• the closer the object, the more the eyes turn inward

Monocular cues

• visual input from a single eye alone that contributes to perception of depth or distance

Linear perspective

• parallel lines converge as they recede into the distance

Interposition

• objects that obscure or overlap other objects are perceived as closer

What is happening with blindsight?

Graham's example

One pathway of vision is damaged-one path to visual cortex to consciously see, one to the brain stem-then to higher brain

Graham-visual cortex is damaged, does not see consciously, but detects movement

Visual neglect

Peggy's Example

Damage to portion of parietal lobe (where things are)

Peggy has left visual neglect, unaware of the left side of the world.  She would only draw the right side of a flower

Capgras delusion

David's example

message does not reach Amygdala -no emotions evoked when visual message is sent

David thought that family and own apartment was not his.

Did not occur with auditory cues because there is a separate auditory pathway to the amygdala

Temporal lobe epilepsy

John's Example

"Electrical storm" in temporal lobe-over firing of neural messages, which makes connections to amygdala stronger

John felt that he was omnipotent because everything was very emotionally significant

Red Cones-detect long wavelengths

Green Cones-medium wavelengths

Blue Cones-short wavelengths

Red=100%, Green=100%: Yellow

Sound:

Sense-Perceive

Sense: Amplitude

Perceive loudness

Sense: frequency

Perceive: pitch

As you move, objects closer to you appear to move past you more quickly than farther objects

-if one eye, this is best depth perception to use

 Theory that the pain sensations are processed and altered by the mechanisms within the spinal cord—When we are soothed by endorphins or distracted by competition or fear, our experience of pain can be greatly diminished

Relative Size:

Texture gradient:

Aerial perspective:

Light and shadow:

Relative height:

1.      Perceptual Adaptation:

1.      Perceptual Set (expectancies):

1.      Frame of reference:  

perceptions of people, objects, or situations are affected by the frame of reference

ignores familiarity

-unconscious response out of habit

 -expectations and familiarity tell you what you are supposed to see, what makes sense

EX-Paris in the the spring

brain pays more attention to changes in the environment than to stimuli that stay or remain constant—occurs in the brain

-filter out meaningless noise

-this is the perception

-cocktail party effect

-unconscious mind goes throuh filtered info

-This is what is sensed

-lunch line effect

-done simultaneously with filtering

difference

-each eye sees different image/different point of view

Controlled Process:

Consciousness:

Alternate States of consciousness:

Mental states, other than ordinary waking consciousness, found during sleep, dreaming, psychoactive drug use, hypnosis, etc

Automatic Processes:

Require minimal attention (walking and talking, listening while daydreaming. Unconscious-familiar tasks.  Can be done in parallel with other tasks

Subconscious: 

No Awareness: 

Circadian Rhythm:

Biological changes that occur on a 24 hour cycle

·         Regulated by suprachiasmatic nucleus in hypothalamus

·         Suprachiasmatic nucleus receives light info from eyes

*if no environmental signals, runs on 25h cycle

Sleep Deprivation:

Disruptions in circadian cycles

·         Symptoms mimic stress

·         Mood alterations

·         Decreased self-esteem

·         Reduced concentration and motivation

·         Increased irritability

·         Lapses in attention

·         Reduced motor skills

·         Increased cortisol

1. concentration impaired

2. vigilance impared

3. reaction time impaired

4. coordination impaired

*can repair to 100% after 1 good sleep

Hypnagogic state:

STAGE 1 SLEEP

Breathing becomes more regular

Heart rate slows

Blood pressure decreases

Theta waves

-not consciously aware, can be easily awaken

STAGE 2 SLEEP

-Short bursts of rapid, high-amplitude brain waves-AKA sleep spindles

-Become less responsive to outside world

-K-Complex (like delta waves)-short bursts of high aplitude, low frequency waves-transition to stage 3-no brain processing

-deeper sleep

STAGE 3 & 4  

   Low frequency, high-amplitude delta waves

·         Hard to awaken

·         Stage 4 where bed-wetting and sleepwalking occur

1. Awake

2. Stage 1

3. Stage 2

4. Stage 3

5. Stage 5

6. REM

a. alpha (at rest) and beta waves (more active)

b. theta waves

c. sleep spindle

d. k-complex

e. delta waves

f. 50% or more delta waves

g. REM

REM SLEEP

    Fast wave activity: Low amp; high frequency-similar to awake waves

·         Irregular breath and pulse

·         Genital arousal

·         Occurs only in higher intelligent mammals

·         The greater the total amount of sleep, the greater the percentage in REM

1. Rapid eye movements

2. muscle atonia

3. genital arousal

4.dreaming

5. theta waves (matches stage 1)

Evolutionary/circadian theory:

Sleep evolved to conserve energy and as protection from predators; also serves as part of the circadian cycle.

Repair/restoration theory:

Psychoanalytic/Psychodynamic view

main purpose of dreams is to express our hidden desires and conflicts. 

-dreams are meaningful communication from unconscious

·         Manifest content

·         Latent content

-the true, unconscious meaning of a dream

Biological View:

·         Activation-synthesis Hypothesis: 

-dreams are by-products of random stimulation of brain cells;--brain is active during REM

-the brain attempts to synthesize this activity into coherent patterns known as dreams--explain

Cognitive View:

SLEEP DISORDERS

1.      Insomnia

 2.      Sleep Apnea

3.      Narcolepsy

a.      Cataplexy

 4.      Parasomnias

1.      Insomnia: 

1.      Sleep Apnea

1.      Narcolepsy

Cataplexy

a) Nightmares: 

b) Night terrors:

a) consciuously aware, REM, muscle atonia, might remember--anxiety arousing dreams generally occurring near the end of the sleep cycle, during REM

b) deep sleep panic attack, completely unconscious, do not remember, no muscle atonia---Abrupt awakening from sleep accompanied by intense physiological arousal and feelings of panic

electroencephalogram-measures electric potential

-high amplitude=LESS activity

-low amplitude=MORE activity

sleep paralyisis-happens in REM

NOT in stage 3/4