chapter 4 sicology

the meaningful interpretation of sensory information by the brain

perception

the conversion of physical energy into neural signal

transduction

various parts of the eye that allow us to focus, detect, and transduce light energy into neural signals

visual anatomy

the path to and in the brain where neural processing occurs (follows transduction)

visual pathway

ability of the brain to interpret differences in wavelengths as differences in color

color perception

ability to see the world in three dimensions despite the two-dimensional nature of images and our retinas

depth perception

ability to identify objects based on their shapes

form perception

the misperception of physical reality

illusion

false sensory perceptions

hallucinations

parts of the ear needed for hearing and the pathway responsible for transferring sound information to the brain

auditory system

process by which the brain interprets and makes meaning of incoming auditory information

auditory perception

parts of the nose and the pathway that transfer olfactory information to the brain

olfactory system

structures and neural pathways involved in taste

gustatory system

touch and pain

tactile senses

kinesthetic and vestibular senses

body senses

process of bringing together information from multiple sensory systems

sensory integration

light waves are seen, sound waves are heard, mechanical energy is felt through our skin, and chemical molecules are tasted and smelled

energy forms

specialized cells that detect the physical energy from the environment and convert it into electrical impulses

sensory receptors

the smallest stimulus intensity that can be detected

absolute threshold

the smallest possible difference between two stimuli that can be detected 50% of the time

difference threshold

difference threshold in any given situation is proportional to the intensity of the original stimulus

Weber's Law

occurs after sensory receptors are exposed to a constant stimulus after a period of time, they stop sending neural signals to the brain

sensory adaptation

processing information at level of sensory receptors first, then putting together bits of information to form a whole perception

bottom-up processing

processing information and stimuli as a whole, then applying our experiences and expectations to generate a perception

top-down processing

a portion of the electromagnetic spectrum that can be detected by the sensory receptors in our eyes

light waves

a hole in the middle of ring-shaped muscle (iris) that can expand and contract to regulate the amount of light that enters the eye

pupil

structure that focuses light as it enters the eye

lens

a thin membrane that contains the sensory receptors where transduction takes place

retina

sensory receptor cells in the retina; rods and cones

photoreceptors

photoreceptors that are sensitive to low levels of light, allow us to see at night

rods

photoreceptors that are activated by daytime brightness, allow us to see color, and are specialized for acuity

cones

point of central focus on the retina, contains only cones

fovea

small section of retina without rods or cones, bundle of nerve fibers that leave the retina to form the optic nerve

optic disc

lack of photoreceptors in the optic disc where vision is not perceived

blind spot

special neurons that collect neural signals from photoreceptors and pass them forward to ganglion cells

bipolar cells

receives visual data from a hundred or more rods, integrating the data into one signal

ganglion cells

large nerve formed by axons of all ganglion cells in each retina, nerves exit eyes and merge together at the optic chiasm

optic nerve

point at which some nerve fibers from each eye cross to the other hemisphere of the brain, and some nerve fibers remain on the same side of the brain

optic chiasm

forebrain structure; processes all sensory information except smell, and then relays the information to higher brain areas in the cerebral cortex

thalamus

final brain destination for analysis and interpretation of visual information

visual cortex

theory that suggests that color vision results from the action of three different types of cones

trichromatic theory

theory that suggests that ganglion cells respond to neural signals in terms of opposing (on-off) pairs of colors

opponent-process theory

depth perception cues that require the use of both eyes

binocular cues

cues that require a single eye to judge the distance of objects

monocular cues

organizing tactics used to form perceptions of groups of stimuli

Gestalt principles

perceiving familiar objects as unchanging

perceptual constancy

a tendency to perceive our environment from a particular frame of reference

perceptual set

mechanical energy form sensed by the ears

sound waves

external structure that collects and funnels sound waves into the ear canal

outer ear

tightly stretched structure at the end of the ear canal, vibrates in time with sound waves

eardrum

amplifies sound waves, contains three small bones

middle ear

begins with the oval window and contains the cochlea

inner ear

a fluid-filled tube of the inner ear where transduction takes place

cochlea

membrane that runs the length of the cochlea, embedded with hair cells

basilar membrane

sensory receptors for the auditory system, bend in response to vibrations, transduction occurs

hair cells

structure where neural signals are sent to the brain from the cochlea

auditory nerve

region of the brain where sound stimuli are processed and interpreted

auditory cortex

different amplitudes of sound waves, loudness

volume

complex mixes of different sound waves with a distinctive quality

timbre

sound wavelength which can be perceived

frequency

highness or lowness of sound, a function of frequency

pitch

theory that explains how frequency of a sound wave is translated into pitch - the vibration of the basilar membrane matches the frequency of the sound wave that entered the ear

frequency theory

theory that states that different frequencies result in maximal excitation of hair cells at different locations along the basilar membrane

place theory

chemical molecules floating in the air which we smell or dissolved in the saliva which we taste

chemical energy

tiny molecules of substances that have been released into the air

odorants

tiny neurons in the olfactory epithelium of the nasal cavity, where odorants bind and result in transduction - olfactory axons then travel through bone to olfactory bulb

olfactory receptor cells

area of the brain which collects information and passes it on to other brain areas for processing in the limbic system

olfactory bulb

area of the cerebral cortex that processes olfactory information

olfactory cortex

located beneath the cerebral cortex, forebrain structures that play a critical role in regulating emotion or feelings

limbic system

chemical molecules dissolved in your saliva

tastants

sensory receptors in the mouth

taste buds

energy form sensed by the skin through several types of specialized touch receptors

mechanical energy

transduce mechanical energy into neural signals

touch receptors

brain area in parietal lobe that receives information from touch receptors located in specific locations of the body

somatosensory cortex

free nerve endings that recognize pain

nociceptors

theory that explains how variations in pain perception can be altered by various psychological and situational influences

gate-control theory

sense of the location and position of body parts

kinesthetic sense

sensory receptors for kinesthetic sense, located in muscles and joints and transduce mechanical energy into neural signals

proprioceptors

sense of balance, change of position or motion, the body automatically compensates in order to stay upright and balanced

vestibular sense

structure in inner ear, sensory organ for the vestibular system, gravitational pull of fluid is transduced into neural signal

semicircular canals

structure in inner ear, sensory organ for the vestibular system, gravitational pull of fluid is transduced into neural signal that provides information about movement, direction, and gravity

vestibular sacs

the brain has trouble receiving and processing sensory information into appropriate responses

sensory processing disorder

sensing stimuli in the environment

detection

decoding stimuli from the language of their environmental energy form to the language the brain can understand

translation

processing stimuli by the brain in order to make it meaningful

interpretation

the detection of information from the environment

sensation