MCAT Psychology/Sociology Ch 11 Sensation, Perception, and Cognition

Mechanoreceptors

Mechanoreceptors

Respond to mechanical stim, such as Pacinian corpuscles. These are pressure sensors located deep within the skin shaped like and onion. Another important one is the auditory hair cell found in the coclea of the inner ear that detects vibrations. Vestibular hair cells found in the innter ear detect acceleration and positon

Chemoreceptors:

respond to chemicals. Gustatory receptors are taste buds

Nociceptors:

v are pain receptors stimulated by tissue injury, similar to a nerve ending. Referred pain occurs when nerves cross paths with somatic afferents from the skin

Electromagnetic Receptors:

v are stimulated by electromagenetic waves. Rods and cones (photoreceptors) in humans.

Stimulus Modality

Type of stimulus

Stimulus Location:

v communicated by the receptive field of the sensory receoptor sending the signal

Stimulus Intensity:

v Coded by the frequency of action potential

Stimulus Duration

Tonic receptors dire action potentials as long as the stimulus continues, but can be adaptable. Phasic receptors only fire action potentials when the stimulus begins, and do not explicitly communicate the duration of the stimulus.

Muscle Spindle

Detects how much your muscles is stretched out

Golgi tendon Organs:

Montior tension in the joints

Joint Capsule Receptors

Measure pressure, tension, and movement in the joints

5 Tastes

v Sweet, Salty, Sour, Bitter, Umami

Nasopharynx

v : Nasal Cavity

Outer Ear

Auricle, External Auditory Canal

Middle Ear:

Tympanic membrane, ossicles, malleus, incus, and stapes

Inner Ear

Cochlea, semicircular canals, utricle, and accule

Sound to Hearing

v sound waves, auricle, external auditory canal, tympanic membrane, malleus, incus, stapes, oval window, perilymph, endolymph, basilar membrane, auditory hair cells, tectorial membrane, neurotransmitters, brain, perception

Loudness:

Amplitude of the vibration

Pitch

Which regions of the basilar membrane vibrate

Auditory Cortex

v Where sound stimuli are processed

Visual Pathway

Cones, bipolar neurons, ganglion, optic nerve, optic chiasm, optic tract, lateral genicular nuclei, optic radiations, occipital lobes

Rods:

black and white, also pull off night vision

Cones

v color

Retinal

: vitamin A derived molecule that starts with many trans double bonds and one cis bond that keep the sodium channels open keeping the cell depolarized. Absorbing a photon makes retinal all-trans and closes the channels and polarizes the cell

Emmetropia

: Normal vision in reference to curve of the retina

Myopia:

v too much refraction at the lens or an abnormally long eyeball results in a focal length that is too short (nearsightedness)

Hyperopia:

v Too little refraction or an abnormally short eyeball reslting in a focal length that is too long (farsightedness)

Feature Decection Theory:

different areas of the brain are activated depending on what type of information is being processed

Parallel Processing:

Many aspects of the stimulus are interpreted simultaneously instead of stepwise to mitigate delay

Depth Perception:

Ability to see objects in three dimensions despite the fact that images are imposed on the retinal in only two dimensions

Binouclar Cues:

are depth cues that depend on information received from both eyes and are most important for perceiving depth when objects are close by

Retinal Disparity:

v The brain compares the images on both retina to create the image that we see. The greater the difference or disparity between the two images on the retina, the shorter the image is to the observer

Convergence:

is another binociul;ar cue that describes the extent to which the eyes turn inward when looking at an object, the greater the angle of convergence or inward strain the closer the object it (going cross eyed)

Monocular Cues

v Depth cuse that depend on information that is available to either eye alone. Cant rely on both eyes for images really far away so need this

Relative Size:

Smallest image cast on the retinal appears to be more idstant

Interposiiton

v If one object blocks the view of another, we perceive it as closer

Relative Clairty

Hazy objects are further away than clear, sharp objects

Texture Gradient

A change from a corase distinct texture to a fine, indistinct texture indicates increasing distance

Relative Height

v Objects higher in the visual field are farther away

Realive Motion

v Stable objects appear to move while we are moving. Objects nearby move faster than those far away.

Light and Shadow

Closer objects reflect more light than distant objects. The dimmer of two objects will seem more far away

Difference Threshold:

Minimum noticeable difference between any two sensory stimuli

Webers Law:

v Two stimuli must differ by a constant proportion in order for their difference to be perciptable. For objects in humans, they must differ in weight by 2% to be noticlable

Signal Detection Theory:

v Predicts how and when someone will detect the presence of a given sensory stimulus amongst the rest of the stuff

Gestalt

v Word for parts, has come to mean an organized whole is perceived more than the sum of its indicuial parts

Emergence

v We identify the whole and then the parts of an image

Multistablility

Ambigous images bounce back and fort in appearance

Proximity

Things near each other seemed to be group together

Continuity

v We percinves smooth, continuous lines and forms rather than a disjoinetd one

Law of Closure

We will perceive things as a complete logical entity and fill the gaps

Law of Common Fate

v : Objects moving in the same direction of in sync are perceived as a group or unit

Law of Connectedness:

v Things that are joined or linked or grouped are perceived as connected

Bottom Up Processing

Begins with the sensort receptors and works up to the integration going on in the brain

Top Down Processing

v When the brain applies epeirnce and expectations to interpret sensoty information

Attended Channel

The one you are actually paying attention to

Unattended Channel:

v The one you aren't listening to

Donald Broadbent:

v thought the brain as a processing system with aa limited capacity and souldt to map the steps out

Broadbent Filter Mosdel of Selective Attention

Information is taken through a sensory buffer then put through a selective filter that goes to processing

Anee Triesman's Attenuation Model:

Tries to account for the cocktail party effect, where you can hear your name or something amidst a loud party. IN this mode, the unattended message is instead attenuated when put into the higher level processing

Information_processing Models:

v Focusis on what happens between the ears

Jean Piaget:

v One of the first developmental psychologists who astudied contiive development in children

Assimilation:

conforming experiences to our existing schemas

Accomodation

: adjusting schemas to take into account the new experiences

Sensorimotor Stage:

v Birth to age 2. Babes and young infants experince the world through touching, mouthing, and grasping to learn about object permemeance, the understanding that things exist when out of sight

Preoperational Stage:

v ages 2-7. Children learn that tings can be represented through symbols such as words and images. They are egocentric, meaning that they do no understand that others have different perspectives

Concrete Operational Stage

v Ages 7 to 11. Children learn to think logically about concrete events. They learn about conservation, that quantity remains the same shape despite the change in shape

Formal Operational Stage

v 12 through adulthood. People learn about abstract reasoning and moral reasoning

Recall:

v getting information without any clues

Recognition

getting information with clues

Agnosia

v Inability to recognize obejcts through sensory mechanisms despite them still working

Conformation Bias

tendency to search only for information that confirms out preconceived thinking, rather than information that might not support it

Fixation

Unable to see the problem from a fresh perspective

Mental Set:

tendency to fixate on solutions that worked in the past that may not apply to the current situation

Funcitonal Fixedness:

v A tendency to perceive the functions of objects as unchanging.

Belief Bias

: The tendenct to judge arguments based on what one believes about their conclusions rather than on wether they use sound logic.

Belief Perseverance

v : A tendency to cling to beliefs despite the presence of contrary evidence

Consciousness:

Defined as the awareness that we have of ourselves, our internal states, and the environment

Retiuclar Formation

v Structure in the brainstem that control alertness and arousal

Polysomonography:

Consists of and EEG, and EMG, and EOG that measure physiological processes during sleep

Alpha Waves

v When a person is sleepy but relaxed, the EEG will shoe alpha waves with low amplitudes and high frequencies (8-12 Hz). Thesse are the first indicatior that a person is ready to drift off to sleep

Beta Waves

v show during times of alert, focused, and active consciousness. Lower amplitudes than alpha waves but higher frequencies (12.5 Hz and 30 Hz)

Stage 1 Sleep

the first stage of non-REM sleep. EEG is dominated by theta waves (3-7 Hz). EOG shows slow rolling eye movements and EMG has moderate activity. Person becomes less responsive to stimuli and has feleeting thoughts

Stage 2 Sleep

Theta waves are now intermixed with K complexes and sleep spindles

K Complex:

v Duration of a half second and is large and slow and occurs amongst the theta waves

Sleep Spindles

bursts of waves in the 12-14 Hz and last only ½ to a full seocnd

Stages 3 and 4 Sleep

v : Persontransitons into a slow waeve sleep. These have high amplitude and low frequency delta waves with frequencies of 0.5-3Hz and is the deepest satages of sleep. This is when thre is no eye movement and growth hormones are released

REM Sleep

v Characterized by bursts of quick eye movements. EEG measures waves that are closested to beta waves. However, you see more sawtooth waves that are low intensity and have variable frequency (16-25 Hz). Generally when dreams occur

Paradoxical Sleep

v There is no skeletal muscle movement when in REM sleep, despite that they are physiologically awake.

Circaidian Rhythm

v Biological clock. Waxing and waning of alertness throughout a 24 hour cycle

REM rebound

v missing REM sleep for one night tends to intensify it the next chance it can occur

Manifest Content

v The subject matter of dreams

Latent Content:

v unconcscious drives and wishes that are difficult to express

Activation Synthesis Theory:

dreams are byproduces of brain activation during REM Sleep, meaning that dreams are far from purposeful

Dyssomnias:

Abnormailites in the amount, quality, or timing of sleep

Insomnia:

v Difficulty falling or staying asleep. Drugs and or relaxation can help

Narcolepsy:

v Periodic, overwhelming sleepiness during waking periods that usually last less than 5 minutes

Sleep Apnea:

v disorder that causes people ito intermittently stop breaking during sleep, which results in waking after a minute or so without air

Somnambulsim:

: Sleepwalking. Occurs during stage 3 during the first third of the night. There could be genetic predispositions for this

Night Terrors:

Also occur during stage 3, and may be characterized by a person sitting up, walking around, appearing terrified, but non of it is ever recalled

Hypnotism:

a social interaction which a hypnotist can create false memories in someone but cannot force them to do extreme things they wouldn't normally do