ap psych unit 1 - biology

consciousness

the state of being aware and able to perceive one’s thoughts, feelings, sensations, and surroundings

involves various levels, from alert wakefulness to altered states such as sleep or meditation

awareness of oneself and environment

circadian rhythm

natural, internal process that regulates the sleep-wake cycle and repeats every 24 hours

altered by natural light/darkness

jet lag

temporary disruption of the body’s circadian rhythm due to rapid travel across multiple time zones

can result in fatigue, sleep disturbances, difficulty concentration

shift work

employment schedules that require working outside of typical daytime hours, often disrupting the body’s natural circadian rhythm

can lead to sleep disturbances and other issues

NREM stage 1

first stage of sleep, characterized by drifting in/out of sleep, lasts a few minutes

aka hypnagogic stage

brain waves slow down, muscles relax, individuals experience hypnic jerks

NREM stage 2

second stage of sleep, characterized by light sleep, lasts ≈ 20 mins

brain waves slow further, sleep spindles and k-complexes appear

NREM stage 3

third stage of sleep, deepest sleep, characterized by presence of delta waves

restoration of resources period, helps mental & physical wellness

REM sleep

fourth stage of sleep, characterized by rapid eye movement, vivid dreams, muscle paralysis; lasts 90 mins

associated with increased brain activity, plays a role in memory consolidations & emotional processing

REM rebound

phenomenon where the body increases time spent in REM after period of REM deprivation

occurs as a compensatory response to lack of REM, results in more intense & frequent REM episodes 

activation synthesis (dreams)

theory proposing that dreams are the result of random neural activity in the brainstem during REM sleep, which is then interpreted and synthesized by the cerebral cortex onto a narrative

consolidation theory (dreams)

theory suggesting that dreams play a role in memory consolidation and processing

during REM sleep, brain organizes and integrates info acquired in the day

more accepted theory because REM sleep is important

insomnia

sleep disorder characterized by difficulty falling/staying asleep or experiencing restorative sleep

leads to daytime impairments such as fatigue, mood swings, decreased cognitive function

can be caused by stress/anxiety

narcolepsy

sleep disorder characterized by excessive daytime sleepiness and sudden episodes of muscle weakness, sleep paralysis, and hallucinations

often fixed with medication

sleep apnea

sleep disorder characterized by pauses in breathing or shallow breathing, leading to disrupted sleep patterns, daytime fatigue, and other health issues

common in older and obese people

solved by a cpap machine

REM sleep behavior disorder

sleep disorder characterized by individuals physically acting out their dreams during REM sleep, potentially causing injury to themselves/others

occurs due to a loss of muscle paralysis

somnambulism

sleep disorder characterized by walking or performing other activities during sleep, aka sleepwalking

occurs during NREM sleep stages (usually NREM 3)

often caused by higher fevers in small children, typically grown out of

psychoactive drugs

substances that alter brain function, changing perception, mood, consciousness, cognition, or behavior; acts on the CNA

4 categories: stimulants, depressants, hallucinogens, opioids

agonists

substances that bind to neurotransmitter receptors and mimic their effects

antagonists

substances that bind to neurotransmitter receptors without activating them, instead block their effects

reuptake inhibitors

medications that block the reabsorption of neurotransmitters by the sending neuron → increases concentration of neurotransmitters in the synaptic cleft + their effects

ex: ssri (serotonin reuptake inhibitor) used to cure depression

stimulants

drugs that increase neural activity and arousal → heightened awareness, energy, attention

ex: caffeine, methamphetamines, cocaine, mdma, nicotine, ephedrine

caffeine

natural stimulants found in coffee, tea, and some sodas

acts on the CNS, increases alertness and reduces fatigue by blocking the neurotransmitter adenosine

nicotine

tobacco products that deliver highly addictive nicotine

ex: cigarettes, chewing tobacco, pipes

leading cause of preventable death in the USA

cocaine

powerful stimulant derived from coca, increases neural activity → euphoria, increased energy and alertness

blocks reuptake of dopamine, serotonin, norepinephrine, decreases appetite

highly addictive

depressants

drugs that slow down neural activity and bodily functions; induces relaxation, sedation, can lower inhibitions

ex: alcohol, benzodiazapine

alcohol

depressant drug that slows neural activity in the CNS

can impair judgement, coordination, cognitive function → euphoria, relaxation, high doses = intoxication

hallucinogens

drugs that alter perception, mood, cognitive processes → hallucinations or profound changes in consciousness

ex: lsd, pcp, mdma, psilocybin (mushrooms)

marijuana

mild hallucinogen derived from cannabis, contains THC (alters mood, perception, cognition)

affects relaxation, altered perception of time, heightened sensory experience

amplifies color, sound, taste, smell

opioids

psychoactive drugs that act on opioid receptors in the brain and body, producing pain relief, euphoria, sedation

extremely addictive

ex: morphine, codeine, oxycodone, fentanyl

heroin

highly addictive opioid derived from morphine; produces intense euphoria, pain relief, sedation by binding to pain receptors in the brain

usually shot up in the arms, starts with morphine prescription for legitimate reason

tolerance

condition where increasing amounts of a psychoactive substance are needed to achieve the same effects

occurs due to brain’s adaptation to the drug → reduced sensitivity over time

withdrawal

onset of symptoms when a person stops using a psychoactive substance after a prolonged use

symptoms can include physical discomfort, psychological distress, and craving for the drug

addiction

chronic brain disorder characterized by compulsive drug seeking and use, despite harmful effects

involves changed in brain structure and function → loss of control of consumption

parallel processing

operates at an implicit and unconscious level, takes care of routine business

sequential processing

operates at a conscious level, best for solving new problems that require attention

dual processing

when sequential and parallel processing occur at the same time

affects perception, memory, attitude, and other cognitions

sensation

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

five senses

perception

process of organizing and interpreting sensory information to make sense of the world

involves the brain’s interpretation of sensory inputs, which can be influenced by past experiences, expectations, and context

transduction

conversion of sensory stimuli into neural impulses that can be understood by the brain

transformation of physical energy into electrochemical signals, enabling brain to interpret and perceive sensory information

locations:

• vision - retina

• hearing - cochlea

• olfactory - olfactory epithelium

• taste - taste buds

• touch - all receptors in the skin

absolute threshold

minimum amount of stimuli required for a stimulus to be detected by a sensory system

represents the point at which a stimulus becomes noticeable at least 50% of the time

just noticeable difference

smallest change in a stimulus that can be detected by someone 50% of the time

minimal difference needed for someone to perceive that a change has occurred

weber’s law

the perceived difference in a stimulus must be proportional to the original intensity of the stimulus

bigger something is → more change required to perceive a difference

sensory adaptation

process by which sensory receptors become less responsive to constant stimuli over time

ex: getting used to the scent of parent’s cooking

synesthesia

condition in which a stimulus of one sensory pathway leads to automatic, involuntary experiences in another sensory pathway

ex: hearing colors

retina

the light-sensitive inner surface of the eye containing photoreceptor cells that convert light into neural signals

at the back of the eye

rods

photoreceptor cells in the retina responsible for vision in low-light conditions and detecting motion

provide black and white vision, are highly sensitive to light → allow to see in the dark

manage peripheral vision, around 120 million

cones

photoreceptor cells in the retina responsible for color vision and details in bright light

enables the perceiving of colors and fine visual details (reading or distinguishing between hues)

6-7 million

fovea

central area of the retina, responsible for sharp, central vision

contains high concentrations of cones (no rods)

blind spot

area on the retina where the optic nerve exits the eye, lacking photoreceptor cells

spot where vision is absent and there are no light sensitive cells present

ganglion cells

neurons in the retina that receive visual information from bipolar cells and transmit it to the brain via the optic nerve

play a crucial role in processing visual signals and relaying them to the brain

lens

transparent & flexible structure in the eye that focuses light onto the retina, adjusts its shape to help the eye properly refract light → enables clear vision at different distances

accommodation

process by which the lens changes its shape to focus on objects at different distances (changes the curvatures)

nearsightedness

common vision conditions where close objects appear clear, but far objects appear blurry

happens when the eyeball is too long or the cornea is too curved → light focuses in front of the retina

farsightedness

vision condition where distant objects appear clear, but close objects appear blurry

happens when the eyeball is too short or the cornea is too flat → light focuses behind the retina

trichomatic theory

theory proposing that color vision is based on 3 types of cone receptors, each sensitive to different wavelengths of light

brain combines signals from these cones to create the perception of a wide range of colors

colors: red, green, blue

opponent process theory

theory proposing that color vision is based on pairs of opposing color processes; afterimages supports this theory

pairs:

• red - green

• blue - yellow

• black - white

afterimages

visual sensations that persist after a stimulus is removed

occur due to temporary stimulation of cone cells in the retina → brief perception of complementary images

dichromatism

type of colorblind where an individual only has 2 types of functioning cones

results in difficulty distringuishing between colors, especially red-green

monochromatism

rare colorblindness where an individual has 1 type of functioning cone cells or none at all

results in an inability to perceive color

blindsight

phenomenon where people with damage to their visual cortex (blind) can respond to visual stimuli without consciously perceiving them

suggests that some visual processing can occur unconsciously, bypassing traditional pathways in the brain

prosopagnosia

aka face blindness, neurological condition characterized by an inability to recognize familiar faces (including own) despite intact vision and intellect

wavelength

distance between sound wave peaks

shorter length = higher pitch; longer length = lower pitch

transduction (ear)

occurs in the cochlea, where hair cells convert sound vibrations into electrical signals that are sent to the brain

amplitude

measure of the intensity (loudness) of a sound wave, represented by the height of its peaks

greater amplitude = louder; lower amplitude = softer 

pitch perception

brain’s interpretation of the frequency of sound waves, determining whether a sound is high or low in tone

high frequency = high pitch; low frequency = low pitch

place theory

theory of pitch perception that different parts of the inner ear detect different sound frequencies

higher pitches sensed at the entrance, lower pitches sensed at near the inner ear

frequency theory

theory of pitch perception that the frequency of a sound wave directly corresponds to the rate at which auditory nerve fibers fire

higher frequency = faster firing; lower frequency = slower firing

volley theory

theory of pitch perception that groups of auditory neurons fire in rapid successions to encode the frequency of sounds above 1000 hertz

allows brain to perceive pitches that exceed firing rate of individual neurons

sound localization

the brain’s ability to determine location of sound source in space, relies on cues 

ex: difference in arrival times and intensity between ears + spectral cues to accurate locate sound

conduction deafness

hearing impairment caused by problems with the outer/middle ear, such as damage to the ear canal, eardrum, or middle ear bones

typically results in difficulty hearing soft sounds and is treated medically, is temporary

sensorineural deafness

hearing loss caused by damage to the inner ear or auditory nerve, resulting in an inability to hearing soft sounds and understanding speech

causes: loud noise, aging, medical conditions

is permanent, cochlea (hairs in ear) are damaged

sensory interaction

the principle that one sense can influence another, demonstrates how senses work together to create overall perceptions of thr world

ex: smell affects taste

olfactory system

responsible for smell; special receptors in the nose detect smells and send signals to the brain via the olfactory nerve → thalamus helps process information and identify orders

unique because it goes to the limbic system (primitive brain)

pheromones

chemical substances released by animals (including humans) that trigger social or behavioral responses in others of the same species

play a role in communication, mating, territorial marking

gustation

sense of taste; involving receptors on the tongue that detect different flavors

taste receptors: specialized cells located on the tongue that detect different tastes

tastes: sweet, sour, salty, bitter, umami, oleogustus?

supertasters

people highly sensitive to taste, experiencing flavors more intensely (especially bitterness)

medium tasters

people with an average sensitivity to taste, experiencing flavors modestly

nontasters

people less sensitive to taste, experiencing taste less intensely than others

warm/cold receptors

specialized neurons in the skin that detect changes in temperature, help perceive and regulate body temperature

warm receptors respond to temperature increases & cold receptors respond to temperature decreases

pain

not a sensation, but an emotional response to stimuli

has biopsychosocial causes/effects

people can experience pain while others feel thrill or arousal (ex getting a tattoo)

gate control theory

proposal that pain experience is modulated by a neural gate in the spinal cord

gate can open to allow pain signals to be transmitted or close to block them

phantom limb

sensation of pain/other feelings in a missing limb

occurs due to the brain’s continued perception of the limb even though it is not there

can range from tingling to intense pain and result from plasticity processing in the somatosensory cortex post-amputation

vestibular sense

sense of the body, orientation and movement, including balance and spatial awareness

relies on receptors in the inner ear that detect changes in the head position and movement, helping to maintain stability

semicircular canals

fluid filled structures in the inner ear that detect rotational movements of the head

play a crucial role in vestibular sense, send signals to the brain about head movements

vertigo occurs because the fluid does not move → brain is unaware of the position

kinesthesis

sense of body movement and position, including the awareness of muscle and joint sensations; allows to perceive and control body movements

bottom up processing

enables the sensory system to detect lines, colors, angles, etc

perception (step 1)

top down processing

interprets what senses detect

sensation (step 2)

optic chiasm

each half of eye’s information arrives in the opposite side of the brain

nocieptors

detect harmful temperatues, chemicals, pressures

placebos

diminish the CNS attention and response to painful experiences

proprioceptors

position and motion sensors in muscles, joints, tendons; enable kinesthesis

embodied cognition

influence of bodily sensations, gestures, and other states on cognitive preferences/judgements

McGurk effect

see one thing + hear another = perceive combination

evolutionary psychology

the study of how psychological traits become more evolved over time to enhance survival and reproductive success

natural selection

how organisms with traits better suited to their environment are more likely to survive, reproduce, and pass on traits

evolved over time in response to environmental pressures

nature

genes, inherited/genetic traits that influence an individual’s psychological development, traits, behavior, and cognitive abilities

nurture

environment, the environmental influences of experiences that shape one’s psychological development, behavior, and cognitive abilities

twin studies

examines similarities and differences between identical and fraternal twins to assess relative influence of genetics and environment on traits and behavior

adoption studies

examines similarities and differences between adopted kids and their biological versus adoptive parents to assess the impact of genetics versus environment on traits and behavior

family studies

analyzes similarities and differences between family members (parents and siblings) to understand the interplay of genetics and environment in traits and behaviors