AP Psych- Unit 3 (Sensation and Perception)

Sensation

Process by which our sensory receptors and nervous system nrecieve and represent stimulus from environment

Transduction

Conversion of one form of energy into another receiving sensory info, transform stimulus into neural impulse, deliver neural info to our brain

Absolute Threshold

The min. level of sensory stimulation to detect stimulation 50% of the time, when stimulation becomes noticeable

Signal Detection Theory

Predicts when we will detect weak signals

Webler’s Law

Just noticeable difference between 2 stimulus is a constant proportion, as intensity increases, amount of change increases to notice

Just Noticeable Difference

The smallest amount of change in stimulus that a person can detect at least 50% of the time

Sensory Adaptation

Decreased sensitivity to change after constant stimulation, less sentivite (cold room)

Bottom- Up Processing

Info processing that begins with sensory receptors and work up to brain integration of sensory info, no expectations

Top-Down processing

Info processing aided by higher level mental processes, make perceptions based on our experiences and expectations

Prosopagnosia

Condition that impaires the ability to recognize faces, face blindness, left hemisphere

Blindsight

Individual w/damage to visual cortex can still progress and respond to visual stimuli w/o being aware of it

Visual Adaptation

The brain ability to adjust to changes in sensory input, causing new or constant sensations other than be perceived as less intense over time

Wavelength

Distance from peak o flight/sound wave to the peak of the next one

Intensity

Amount of energy in wave, determined by amplitude (height)

Retina

Light sensitive back of eye, receptor rods and cones, where transduction happens

Fovea

Central focus point in retina, visual acuity is highest, clusters of cones

Rods

Retinal receipts that detect black, white, and gray: sensitive to movement, retina outer region

Cones

Rental receptors near center of retina that function in daylight/well-lit conditions, fine detail and color

Cone Responses

Light energy triggers chemical charges, spark neural signals in nearby bipolar cells, activate ganglion cells

Photoreceptors

Specialized cells in the retina that convert light into electrical signals that the brain can interpret as vision

Bipolar Cells

Neurons in the retina that trasnmit visual signals from photoreceptors to ganglion cells

Ganglion Cells

Neurons in the retina that transmit visual info to the brain through the optic nerve

Optic nerve

Sensory nerve that carries visual info from the retina to the brain

Blindspot

Optic nerve leaves eye, creating blind spit with no receptors

Cornea

Eyes clear, protective outer layer, light enters and bends to help provide focus

Pupil

Adjustable opening in center of the eye, light enters

Iris

Ring of muscle tissue that forms that forms the colored portion of the eye, controls pupil size

Lens

Transparent structure behind pupil that changes shape to help focus images in retina

Accommodation

Process by which the eyes lessen change shape to focus images near or far

Nearsightedness

When light focuses in front of retina instead of on it, distant objects are blurry

Farsightedness

Distant objects clear but near objects are blurry

Trichromatic Proces Theory

Eye has 3 types of cones: red (long wv), green (medium wv), blue (short wv), activated in diff degrees

Opponent Proces Theory

Opposing retinal processes enables color vision (red-green, blue-yellow, white-black)

Damage to cones

Causes color blindness and central vision problems

Damage to ganglion

Peripheral vision loss

Dichromatism

Can only perceive 2 of 3 primary colors

Monochromatism

Sees all colors as shades of gray, black, and white

Amplitude

Measurement of a sound waves strength = loudness

Wavelength

Distance between 2 peaks of a sound wave

Sound localization

Ability to identify the location of a sound source by using subtle differences in how sound reaches each ear

Place Theory

We hear different pitched b/c different sound waves trigger activity at different places on cochlea’s basilr membrane, high pitched not low

Frequency Theory

Brain reads pitch by monitoring the frequency of neural impulses traveling up the auditory nerve

Volley Principle

Have groups of neurons fire in a staggered pattern for a higher frequency, collective firing

Sensrionerual Hearing Loss

Damage to cochlea receptors

Conduction Hearing Loss

Damage to mechanical system

Olfactory Cilia

Hair-like structures in nose that detect smells by binding to airborne odor molecules in nasal mucus

Olfactory bulb

Neural structure in the vertebrae forebrain responsible for processing smell

Pheremones

Olfactory chemical messages, serve as attraction tool

Gustatory Receptors

Tastebuds on top and side of tongue, 200+ pore that catches food chemicals

Basic Tastes

Sweet, Sour, Salty, Bitter, Unami, Oleogustus

Sensory Interaction

One sense may influence another, as when the smell of food influences its taste

Supertaster

Individual with a weighted sense of taste, sensible to bitterness

Medium Taster

Average sensitivity to taste

Gate Control Theory

Spinal cord contains gate that controls transmission of pain messages

Phantom Limb Sensation

Common experience where you feel sensation in the missing limb as if it were still present

Hot

Specialized nerve endings in the skin detect increase in temp

Vestibular Snese

Balance sense, body movement and position

Kinestheic Sense

Movement sense, position and moment of body parts

Synesthesia

Brain circuits for 2 or more senses become joined

Perceptual Set

Mental predisposition to perceive one thing as another

Schemas

organize and interpret unfamiliar info

Attention

Cognitive process of selectively focusing on and processing specific info stimulus

Selective Attetnion

Specific process of focusing on a single stimulus from a a multitude of competitng stimuli

Cocktail Party Effect

Ability to attend to only once voice within a sea of many

Inattentional blindness

Failing to see objects when our attention is directed elsewhere

Change Blindness

Failing to notice changes in environment

Clousre

Gestalt, we fill in gaps to create a complete, whole object

Figure Ground

Gestalt, orgnaization of visual field into objects that stand out from their surrounds

Proximity

Gestalt, Group nearby figures together

Similarity

Gestalt, group objects according to how similar they are

Visual Cliff Experiment

Lab device for testing depth perception

Binocular cues

a depth cue, use of 2 eyes

Retinal Disparity

Comparing images from 2ceys, compute distance

Convergence

Cue to nearby objects distances, combine images

Relative size

objects appear smaller are farther away, same size

Texture Gradient

Close=high level of detail

Linear Perspective

Parallel lines appear to converge as they get farther away

Size Constancy

Perceiving an object as the same size even when its images on the retina changes

Color Constancy

Perceiving familiar objects as having a consistent color, even under different lighting conditions

Shape constancy

Recognizing na object as having the same shape even when viewed from different angles

Motion Constancy

Perceiving stationary objects as still, even if our own movement causes their retinal image to shift

Stroboscopic Motion

Readily flashing still images appear to move smoothly

Phi Phenomenon

Adjacent lights blink on and off in quick succession, single moving light

Autokinetic Effect

stationary light in a dark room appears to move b/c of eye movement

Apparent motion

illusion of movement when no actual motion occurs