Human G&D/S&P (Psych Chapter 3 + 4)

Transducers

devices that convert one kind of energy into another

the main function of our sensory organs

-takes a type of physical energy and turns it into neuron activity

Sensations

a sensory impression; the process of detecting physical energies with the sensory organs

(Receiving signals)

Perception

the mental process of organizing sensations into meaningful patterns

(Organizing and interpreting signals)

Psychophysics

the study of how various forms of energy (light waves, sound waves, chemicals, temperature) can be measured and how it’s related to different aspects of the sensory experience (brightness, loudness)

Absolute Threshold

the lowest level of stimulation that can be detected 50% of the time

Subliminal messaging

messages or actions with a hidden subtext to subconsciously make a person think a certain way or about a certain thing

not proved effective; however, when features we are evaluating are addressed, they may be effective.

Sensory Adaptation

a decrease in sensory response to an unchanging stimulus

(getting used to certain sensory receptors (smell) over time as fewer nerve impulses are sent to the brain as same reception is detected multiple times)

Weber’s Law

the proportion of change is more important than the absolute value of change

(Although there may be what is considered a great change in things such as sound, if said sound was already at a high level, this difference may not play the same impact as it would’ve at if the sound was originally at a lower level)

Difference Thresholds

• when you notice the change

• the amount in difference

Sensory Prosthetics

video cameras translate light into electrical impulses that directly stimulate the visual cortex which results in basic visual experiences.

Sensory Analysis

the separation of sensory information into important elements.

Perceptual features

basic elements of a stimulus such as lines, shapes, edges, and colors

Blakemore & Cooper (1970)

proved that sensitivity to perceptual features is influenced by experiences in early life

(through the experiment where kittens were raised in a room with only vertical stripes or horizontal stripes)

Attention

link between sensation, perception, & experiences

DIRECTS, SELECTS, ALLOCATES, REGULATES

Multitasking Problem - Error

more likely to make mistakes, miss important information

Multitasking Problem - Stress

task switching creates internal stress, knowing that you might/did miss something

Multitasking Problem - Switch Cost

it takes time to reorient between tasks

Multitasking Problem - No Real Multitasking

it is really just task switching or task toggling

Waves

What does light travel in?

Wavelength

perceived as color

Amplitude

perceived as brightness in vision

encoded as loudness or intensity in hearing

Sclera

whites of your eyes

Cornea

thin layer that lets light in (clear)

Lots of nerve endings, but no blood vessels

How many nerve endings and blood vessels does the cornea have

Iris

a muscle that can contract (colored part)

extremely unique (more differentiating than our fingerprint)

Pupil

the hole in our iris

Cateract

can make eyes look milky white, build up of proteins

Vitreous body

fluid in our eyes (jelly-like substance)

Lens

a hard structure, held in place with muscles & allows for contracting which allows for things to come in and out

Retina

uses rods and cones to break down lights

Fovea centralis

best point of focus/vision

Optic nerve

“ponytail” of all the nerves

Optic disc

nerves exit eye to go to brain through this

Rods

for viewing dim light with no color

Cones

for viewing bright light with color (sharp images)

Rods & Cones

visual receptors located within the retina that contain pigments broken down by light energy

Rods

Which are more sensitive to light - rods or cones?

(excel at seeing dim light)

Periphery of retina (peripheral vision)

Where are there more rods - periphery of retina or fovea?

(which can view dim light better?)

3

How many cones is perception of color based on?

(total number of types of cones as well)

Opponent Process Theory of Color Vision

proposes the existence of “opposing” red-green, blue-yellow, & black-white channels.

(Our brain essentially matches those colors in pairs)

Colorblindness

the inability to distinguish 2 or more shades in the color spectrum

Monochromats

• total color blindness

• black-and-white world

• Individuals either have only rods or only one kind of functioning cone

Dichromats

individuals have trouble distinguishing red from green because they only have 2 function cones

(inherited and can mostly see blue and yellow)

Dark Adaptation

increased retinal sensitivity

Rhodopsin

light-sensitive visual pigment in rods

Frequency

encoded as pitch in hearing

Ultrasounds

above the range of human hearing (20,000 Hz)

(jewelry or teeth cleaning)

Infrasound

frequencies below the range of human hearing (less than 20 Hz)

• used by animals and marine mammals

• effective in water

• can cause dizziness, nausea, uncontrolled bowl movements, etc. in humans

Process of the Cochlea

Vibrations in the ossicles → Waves in the vestibular canal fluid → Movement of hair cells

Pinna

• collects and focuses sounds like a funnel

• localize sounds (above or below head)

• part of outer ear

Auditory Canal

sounds collected by pinna are channeled through here

(ends at the tympanic membrane)

(part of outer ear)

Tympanic membrane

• eardrum

• boundary between outer and middle ear

Ossicles

• series of 3 tiny bones

  • malleus, incus, stapes

• occupies the gap between the tympanic membrane and the oval window

• amplifies sound energy

• air from outer & middle ear → fluid in inner ear

Inner Ear

• contains two sets of fluid-filled cavities

  • vestibular system

  • cochlea

Cochlea

• filled with a fluid called paralymph

• contains specialized receptor cells that respond to vibrations transmitted

• part of inner ear

Oval Window

sound waves are pushed from the ossicles into the cochlea through here

Basilar Membrane

contains hair cells that are displaced from vibrations

Auditory Pathway

Auditory Nerve → Medulla → Midbrain → Thalamus → Temporal Lobe

Primary auditory cortex

• located in the temporal lobe

• conducts first basic analysis of the wavelengths & amplitudes of incoming information

Midbrain

• used for the reflexive responses to sound

• used for sound localization

Decibels

measurement value of the loudness of sound

Cochlear Implants

• bypass hair cells to stimulate auditory nerves directly

• wires from a microphone carry electrical signals to an external coil → a matching coil underneath skin picks up such signals and carries them to cochlea

Somatosensation

Bodily sensations coming from skin, muscles, & joints

• somatosensory cortex

• touch, pressure, temperature

• position & movement

• pain signals

Free nerve endings

sense temperature and pain

Endorphins

reduce pain by helping to close gates in spinal cord (gates allow painful nerve impulses to the brain)

Vestibular System

• sensitive to position/movement, acceleration, & rotational movements/gravity

• contains otolith organs

• stimulates hair-like receptor cells

Semicircular canals

sensory organs for balance

Smell Pathway

Olfactory Nerve → Olfactory Bulb → Frontal Lobe

Olfaction

receptors located in a thin layer of cells within the nasal cavity

responsible for producing the mucus surrounding the receptors

Taste Pathway

Mouth & Tongue → Medulla → Thalamus → Parietal Lobe

Taste/Gustation

• purpose: protect us from eating poisonous or spoiled food and to attract us to food that boost our survival chances

• 4 main categories: sweet, sour, salty, bitter

• 5th type: umami - savory/meaty

Taste Buds

extend tiny hair like cilia into the saliva that interact with dissolved taste stimuli & transduce resulting information into neural signals

Top-down processing

context and preexisting knowledge are used to rapidly organize features into a meaningful whole

(broad → detailed)

Bottom-Up processing

begin with small sensory units (features) & build upward to a complete perception

(detailed → broad)

Figure-Ground

• Gestalt Principle

• when we perceive a stimulus, we visually pull the figure part of the stimulus forward while visually pushing backward the background

(queen elizabeth and king phillip vase)

Similarity and Proximity

• Gestalt principle

• we usually group together objects by how similar their features are or how close they are to each other

Continuity

• Gestalt principle

• the tendency towards simplicity and continuity

Closure

• Gestalt principle

• tendency to complete a figure

Common Region

• Gestalt Principle

• tendency for items in a region to be seen as a group

Linear Perspective

• Depth Perception

• Monocular Cues

• thinking that we are looking far into the distance, even when we are viewing a painting or drawing on a flat surface

(road drawing)

Relative Size

• Depth Perception

• Monocular Cues

• the more distant an object, the smaller its image will be on the retina

Interposition

• Depth Perception

• Monocular Cue

• Our brain automatically understands that objects we see more of are in the front as opposed to objects we see less that are in the back

• overlapping

(horse image)

Light & Shadow

• Depth Perception

• Monocular Cue

• when light is on top, our brains register it as moving towards us

• when dark is on top, our brains register it as moving away from us

Texture Gradient

• Depth Perception

• Monocular Cue

• As things move further away, texture seems finer

Aerial Perspective

• Depth Perception

• Monocular Cue

• things that are closer to us are more in focus and clear

• things farther away from us are hazier

Motion Parallax

• Depth Perception

• Monocular Cue

• In a moving vehicle, objects closer to us appear to move past us much quicker than those farther away

(“the moon is following me”)

Convergence

• Depth Perception

• Binocular Cue

• The degree to which the eyes turn in to focus on a close object

Retinal Disparity

• Depth Perception

• Binocular Cue

• The difference in the apparent position of an object as seen by the left & right retinas

Perceptual Constancies

tendency to perceive objects as the same even when their physical characteristics change

(size, shape, brightness, color)

Size Constancy

perceive objects as remaining the same size even when their images on the retina continually grow and shrink

Shape constancy

perceive an object as retaining its same shape even though when you view it from different angles, its shape is continually changing its image on your retina

Brightness constancy

perceive brightness as remaining the same in changing illumination

Color constancy

perceive colors as remaining stable despite differences in lighting

Müller-Lyer illusion

optical illusion where two lines of the same length appear to be of different lengths

-two arrows, one with arrows and the other with inverted arrows

Ponzo Illusion

Two lines of the same length appear to be different as they are placed in front of lines gradually getting smaller

Illusion

a perceptual experience in which you perceive an image as being so strangely distorted that, in reality, it cannot and does not exist

-created by manipulating the perceptual cues so that your brain can no longer correctly interpret space, size, and depth cues

Multisensory Perception

our sensory experiences co-occur with another sensory system

-See and Hear

-Taste and Smell

McGurk Effect

an auditory-visual illusion that illustrates how perceivers merge information for speech sounds across the senses.

For example, when we hear the sound “ba” while seeing the face of a person articulate “ga,” many adults perceive the sound “da,” a third sound which is a blend of the two.

Telepathy

• Extrasensory Perception

• the ability to transfer one’s thoughts to another or to read the thoughts of another

Precognition

• Extrasensory Perception

• the ability to foretell events