Consciousness Sensation and Perception

Consciousness

Our state of awareness of ourselves and our environment

divided consciousness

Astate of awareness characterized by split attention to two or more tasks or activities performed at the same time

altered state of consciousness

State in which there is a shift in the quality or pattern of awareness of things around us and our thought processes

controlled processing

Explicit thinking that is deliberate, reflective, and conscious

automatic processing

unconscious encoding of incidental information, such as space, time, and frequency, and of well-learned information, such as word meanings

waking consciousness

State in which thoughts, feelings, and sensations are clear, organized, and the person feels alert

circadian rhythm

The biological clock; regular bodily rhythms that occur on a 24-hour cycle

Melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

Suprachiasmatic nucleus (SCN)

A small brain structure that uses input from the retina to synchronize its own rhythm with the daily cycle of light and dark; the body's way of monitoring the change from day to night.

sleep

Periodic, natural loss of consciousness.

Microsleeps

Short, seconds-long periods of sleep that occur in people who have been deprived of sleep.

adaptive theory of sleep

Theory of sleep proposing that animals and humans evolved sleep patterns to avoid predators by sleeping when predators are most active

restorative theory of sleep

The theory that the function of sleep is to restore body and mind

sleep deprivation

A sufficient lack of restorative sleep over a cumulative period so as to cause physical or psychiatric symptoms and affect routine performance or tasks. 7 hours of sleep or less per 24 hours.

R sleep

Stage of sleep in which the eyes move rapidly under the eyelids and the person is typically experiencing a dream (REM)

N sleep

Any of stages of sleep that do not include R-sleep. (Non-REM)

Beta waves (EEG)

Highest frequency, lowest amplitude. Appear during awake states of consciousness and REM sleep.

alpha waves

The relatively slow brain waves of a relaxed, awake state

theta waves

Brain waves indicating the early stages of sleep. "I wasn't sleeping!"

delta waves

The large, slow brain waves associated with deep sleep.

N1 sleep

Theta waves activity begins- muscle tension is lost as well as most awareness of the environment

N2 sleep

Completely lose emotional awareness, theta waves start to show sleep spindles and K-complexes

N3 sleep

Deep Sleep. Slow Wave Sleep.

sleep paralysis

A temporary condition in which somatic nervous system is shut down while sleeping to protect body while dreaming.

REM behavior disorder (RBD)

A sleep disorder in which a person physically acts out a dream

disorder

A disturbance in the normal functioning of the body

Nightmare Disorder

Condition involving frightening dreams that produce awakening

Night terrors

Abrupt awakenings with panic and intense emotional arousal

somnambulism

The condition of walking or performing some other activity without awakening; also known as sleepwalking

insomnia

Recurring problems in falling or staying asleep

sleep apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

sleep paralysis/paradoxical sleep

brainstem blocks messages from motor cortex

sensory receptor cells

specialized cells that convert a specific form of environmental stimuli into neural impulses

Transduction

Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.

Synesthesia

when one kind of sensory stimulus evokes the subjective experience of another

olfactory receptor cells

receive chemicals interpreted as smells

photoreceptor cells

Cells that line the back of the retina and have parts that change shape when they are hit with a photon, allowing them to detect light in a certain part of the visual field. Humans have two main types, rods and cones, and there are three different subtypes of cones.

Proprioception

The cumulative sensory input to the central nervous system from all mechanoreceptors that sense body position and limb movement.

vestibular sense

The sense of body movement including the sense of balance

absolute threshold

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

difference thershold

The minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference

Weber's Law

The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage or ratio (rather than a constant amount)

signal detection theory

Theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Depends on a person's experience, expectations, motivation, and alertness.

Habituation

Decreasing responsiveness with repeated stimulation. We pay less attention to stimuli that is familiar

sensory adaptation

A decrease in sensitivity of sensory receptors to a constant level of stimulation

subliminal stimuli

Stimuli that activate sensory receptors but below the level of conscious awareness

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

bottom-up processing

Perceptual analysis that begins with the sensory receptors and works up to the brain's integration of sensory information

top-down processing

Perceptive onformation processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations

constancy

The tendency to perceive certain objects in the same way regardless of changing angle, distance, or lighting

Gestalt

An organized whole that is perceived as different than the sum of its parts.

Law of Pragnanz

Perceptual organization will always be as regular, simple, and symmetric as possible

figure-ground

The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).

similarity

The tendency to perceive things that look similar to each other as being part of the same group

proximity

The tendency to perceive objects that are close to each other as part of the same grouping

Closure

the tendency we have to fill in gaps to perceive a complete, whole object

Continuity

We perceive smooth, continuous patterns often with movement, rather than discontinuous ones

perceptual set

A readiness and expectation to perceive a stimulus in a particular way based on experiences and/or cultural influences

McGurk Effect

An error in perception that occurs when we misperceive sounds because the audio and visual parts of the speech are mismatched.

linear perspective

A monocular cue for perceiving depth; the more parallel lines converge, the greater their perceived distance.

relative size

A monocular cue for perceiving depth; the smaller retinal image is farther away

overlap (interposition)

The assumption that an object that appears to be blocking part of another object is in front of the second object and closer to the viewer

arial/atmospheric perspective

Creating the illusion of depth of space by fading colors and eliminating detail in objects that are further away.

texture gradient

a gradual change from a coarse distinct texture to a fine, indistinct texture signals increasing distance. Objects far away appear smaller and more densely packed

motion parallax

The perception of motion of objects in which close objects appear to move more quickly than objects that are farther away

accommodation of the lens

Adjustment of the thickness of the lens to focus on objects at different distances

convergence

A binocular cue for perceiving depth; the extent to which the eyes converge inward when looking at an object

binocular disparity

The difference in the retinal images of the two eyes that provides information about depth

hue

The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth

Saturation

Intensity/purity/richness of color

Brightness

The lightness or darkness of reflected light, determined in large part by the light's intensity.

Cornea

The clear tissue that covers the front of the eye

pupil

The adjustable opening in the center of the eye through which light enters

Iris

Ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

lens

The transparent structure behind the pupil that changes shape to help focus images on the retina

Retina

The light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

Fovea

The central focal point in the retina, around which the eye's cones cluster

optic nerve

Carries neural impulses from the eye to the brain the location where it leaves the eye creates our blind spot

blind spot

The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there

activation-synthesis theory

theory that dreams reflect inputs from brain activation originating in the pons, which the forebrain then attempts to weave into a story

information processing theory of dreams

This theory believes that dreams work to transfer what we experienced throughout the day into our memory.

cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

malleus, incus, and stapes/ hammer, anvil, stirrup

the three small bones in the middle ear that relay vibrations of the eardrum to the inner ear

semicurcular canals

Fluid filled canals in the inner ear responsible for our sense of balance.

umami

taste for monosodium glutamate - savory taste

taste buds

sensory organs in the mouth that contain the receptors for taste

Receptors for hearing are located in the \________.

cochlea

Receptors in the skin

cutaneous receptors in the dermis just below the epidermis detect sensations such as pressure, heat, and cold

olfactory bulb

the first brain structure to pick up smell information from the nose

middle ear

the chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea's oval window

inner ear

contains cochlea, semicircular canals, and vestibular sacs

feature detectors

nerve cells in the brain's visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement

Mueller-Lyer Illusion

two horizontal lines of same length, one appears longer because we infer that it is farther away from us