AP Psychology Unit 1 Biological Bases of Behavior (2024/2025) Part 2 (1.5 Sleep and 1.6 Sensation)

Sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

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.

Absolute Threshold

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

just noticeable difference

difference in stimuli required to detect a difference between the stimuli

Sensory adaptation

diminished sensitivity as a consequence of constant stimulation

Weber's Law

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

Sensory interaction

the principle that one sense may influence another, as when the smell of food influences its taste

Synesthesia

describing one kind of sensation in terms of another ("a loud color", "a sweet sound")

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

Blind Spot

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

Visual nerve

carries the visual impulse out the back of the eye and into the brain for further processing.

Lens

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

Accommodation

the process by which the eye's lens changes shape to focus near or far objects on the retina

Nearsightedness

a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina

Farsightedness

a condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina

Photoreceptors

Specialized light-sensitive neurons in the retina that convert light into neural impulses; includes rods and cones

Rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don't respond

Cones

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

Trichromatic theory

theory of color vision that proposes three types of cones: red, blue, and green

Opponent-Process theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green

Afterimages

images that occur when a visual sensation persists for a brief time even after the original stimulus is removed

Ganglion Cells

In the retina, the specialized neurons that connect to the bipolar cells; the bundled axons of the ganglion cells form the optic nerve.

Dichromatism

partial color blindness in which the eye contains only two types of cone photopigment instead of the typical three:

Monochramatism

partial color blindness in which the eye contains only one type of cone photopigment instead of the typical three

Prosopagnosia

inability to recognize faces

Blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

Wavelength

the distance from the peak of one light or sound wave to the peak of the next.

Pitch

a tone's experienced highness or lowness; depends on frequency

Amplitude

the intensity or amount of energy of a wave, reflected in the height of the wave; determines a sound's loudness.

loudness

a sound's intensity

Pitch perception

the aspect of hearing that allows us to tell how high or low a given tone is

Place theory

in hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated

Volley theory

a theory that proposes that our brain decodes pitch by noticing the frequency at which groups of hair cells on the basilar membrane are firing

Sound localization

the process by which the location of sound is determined

conduction deafness

An inability to hear resulting from damage to structures of the middle or inner ear.

sensorineural deafness

deafness that results from damage to the auditory nerve

Olfactory system

the sensory system for smell

Thalamus

for all senses except olfaction, the information from the sensory neurons necessarily passes through this before reaching the primary sensory cortex.

Pheromones

Chemical signals released by an animal that communicate information and affect the behavior of other animals of the same species.

Gustation

sense of taste

Sweet, sour, salty, bitter, umami

5 taste sensations

oleogustus

the taste of fat

taste receptors

chemical receptors on the tongue that decode molecules of food or drink to identify them

supertasters

people with heightened sensitivity to all tastes and mouth sensations

medium tasters

50% of people have this level of taste sensitivity

nontasters

people who cannot detect bitter compounds except at very high concentrations

sensory interaction

the principle that one sense may influence another, as when the smell of food influences its taste

warm/cold receptors

Thermoreceptors detect temperature. Cold receptors are more numerous in the skin, and warm receptors are more numerous in deep tissue.

gate control theory

the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain.

phantom limb

perceived sensation, following amputation of a limb, that the limb still exists

vestibular sense

the sense of body movement and position, including the sense of balance

semicircular canals

three canals within the inner ear that contain specialized receptor cells that generate nerve impulses with body movement

kinesthesis

the system for sensing the position and movement of individual body parts

consciousness

our awareness of ourselves and our environment

circadian rhythm

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

jet lag

a period of discomfort and inefficiency while your internal clock is out of phase with your new surroundings

shift work & circadian rhythm

- as shift work is sometimes opposite to 'regular' hours, getting a full 8 hours sleep is hard

- fixed shifts are better for s/w cycle, but rotating night shifts generally better for social life and mental health

NREM stage 1 sleep

relaxation begins; EEG shows alpha waves; arousal is easy

NREM Stage 2

Irregular EEG with sleep spindles (short high-amplitude bursts); arousal is more difficult

NREM Stage 3

sleep deepens; theta and delta waves appear; vital signs decline

REM Sleep

a stage of sleep characterized by rapid eye movements and a high level of brain activity

activation-synthesis theory

a theory of dreaming; this theory proposes that the brain tries to make sense of random brain activity that occurs during sleep by synthesizing the activity with stored memories

Consolidation of sleep theory

Sleep aids in the consolidation or formation of memories and learning

memory consolidation

the gradual, physical process of converting new long-term memories to stable, enduring memory codes

REM Rebound

increased amounts of REM sleep after being deprived of REM sleep on earlier nights

Restoration of resources

evolutionary theory of sleep holds that sleep is essential for restoration of resources that are expended during the demands of day-to-day life.

Insomnia

recurring problems in falling or staying asleep

Narcolepsy

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

REM sleep behavior disorder

a neurological disorder in which the person does not become paralyzed during REM sleep and thus acts out dreams

Sleep Apnea

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

somnambulism

sleepwalking