Studied by 12 people
Consciousness
Def: State of being aware of our self, thoughts, and environment
has various levels of awareness
Wakefulness and sleep are two types of consciousness
Awake: highly aware
Asleep: still conscious but lower level of awareness
Sleep
Def: Natural, periodic, recurring state where consciousness is altered
Natural loss of consciousness
undergoes restorative process
even in sleep, brain is active and still has awareness
Circadian Rhythm
Def: Regulates sleep-wake cycle over a 24 hours period
bodies internal clock
regulates sleep, wakefulness, and other bodily functions
functions such as: hormone release, alertness, and body temp
Altered States of Consciousness
Def: Person’s normal state of awareness is modified
Any conditions that differ from normal waking state
Affects awareness and perception
NREM Sleep Stage 1
Def: Lightest stage of sleep, can be awoken easily
occurs when you first fall asleep
alpha waves and hypnagogic sensations (aka hypnic jerk, sensations you imagine that are real)
Lasts 5-10 minutes
Characterized by:
slowed breathing
decreased HR
Mind starts to slow
NREM Sleep Stage 2
Def: Deeper relaxations, largest portion of sleep
theta waves are present
lasts 10-20 minutes per cycle
characterized by:
sleep spindles = bursts of neural activity
decrease in HR and body temperature
more synchronized brain activity
roles:
memory consolidation and blocks external distractions
NREM Sleep Stage 3
Def: Deepest stage of NREM sleep
slow delta waves
lasts approximately 30 minutes
characterized by:
sleep walk/talking
body repairs tissue, bone, and muscles
strengthens immune system
role:
hardest stage to wake
more restorative part of sleep
crucial for physical restoration
REM Sleep (Rapid Eye Movement)
Def: Stage of sleep where dreams occur, the last stage
aka paradoxical sleep
Brain is active but body is relaxed
characterized:
increased brain activity but body is immobilized
rapid eye movement
associated with VIVID dream
Role:
emotion regulation, memory consolidation, and cognitive function
Types of Brain Waves
(used with EEG to visualize the brain waves and patterns)
ALPHA WAVES
prior to NREM Stage 1
Brain waves of relaxed, awake state
Moderate frequency and amplitude
BETA WAVES
stressful situations, not in sleep
used in active thinking, problem solving, etc.
Fastest = high frequency, low amplitude
THETA WAVES
transition from stage 1 to 2 of NREM
light sleep or deep relaxation
lower frequency, higher amplitude
DELTA WAVES
stage 3 NREM to deep sleep
lowest frequency, highest amplitude
REM Rebound
Def: Phenomenon when brain is deprived of REM sleep, it will compensate by increasing amount of REM sleep in subsequent nights
enters REM more quickly and spends more time in the next sleep cycle
natural respond to sleep deprivation
suggests that REM serves essential function = brain prioritizes.
Activation Synthesis Theory
Def: dreams are the brains attempt to make sense of random neural activity
that dreams don’t necessarily have deep meanings, but result from brain trying to make sense of activity by creating dreams
Consolidation Theory
Def: Dreams help process and consolidate memories and strengthen neural connections formed during the day
especially during REM Sleep
organized connections between neurons related to recent experiences
Focus on role of sleep in memory consolidation and learning
Ex: study ap psych notes and during dream, brain organizes the info = helps with recall the next day
Insomnia
Def: Characterized by persistent difficulty falling asleep or staying awake
leads to fatigue and impaired functioning during the day
caused by stress and poor sleeping habits
Narcolepsy
Def: chronic neurological disorder that affects brain’s ability to regulate sleep-wake cycles
causes “sleep attacks” - sudden uncontrollable, episodes of sleep
disrupts normal REM Sleep cycles
linked to deficiency in neurotransmitter hypocretin which regulates wakefulness
symptoms:
muscle weakness, hallucinations, sleep paralysis.
REM Sleep Behaviour disorder
Def: leads to individuals to act out their dream
due to lack of muscle paralysis during REM sleep
example: smo dreams about fighting in sleep and then actually starts fighting the air lol
Sleep apnea
Def: characterized by repeated interuptions in breathing during sleep
breathing repeatedly stops and starts
most common is where airway is blocked
causes:
high blood pressure, disease, heart failure, and more
Somnambulism
Def: person performs complex behaviours while in deep NREM sleep (stage 3)
sleep walk or talking
different from REM Sleep behaviour:
RBD involves dream enactment behavior. The difference between sleepwalking and RBD is subtle, but important: sleepwalking typically takes place in non-REM and transitional stages of sleep, whereas RBD takes place during REM (rapid-eye-movement) sleep.
sensation
def: process which sensory receptors detect physical stimuli from environment and send info to brain for processing
raw data collected by sensory organs before brain interprets it
Absolute threshold
def: minimum level of stimulus intensity needed for person to detect stimulus 50% of the time
for you to experience sensation, need to hit this threshold
aka the second it goes from nothing to something
example:
hearing → can hear watch ticking 20ft away
Sensory adaptation
Def: reduced sensitivity to stimulus after prolonged exposure to it
decreased sensitivity to it over time
allows brain to focus on changed in environment rather than constant stimulus
example: you stop paying attention to feeling of clothing
Just-noticable difference (or difference threshold)
Def: the smallest change between two stimuli that cause people to notice change
just noticeable difference in smallest change in stimuli
greater the intensity = LARGER change needed to detect it
example:
weight of 100 grams → may notice 5g increase
weight of 1kg → 5g change might not be noticeable
difference between absolute threshold and just noticeable difference (sound example)
The absolute threshold for sound, for example, would be the lowest volume level that a person could detect. The just noticeable difference would be the smallest change in volume that a person could sense
Weber’s Law
Def: degree to which stimuli must be different for the difference to be noticed
the JND is constant proportion to original stimulus intensity, rather than fixed amount
related to the JND = calculates for the amount
example:
if notice 1lb increase to 10lb weight, law predicts for 20lb you need 2lb increase to notice difference
sensory interaction
def: principle that one sense can influence another
brain combines input from multiple sensory things to create cohesiveness
example:
how smell can affect taste - stinky tofu
Synesthesia
Def: rare condition which stimulation of one sensory pathway involuntarily triggers another
leads to blended or “crossed” sensory experiences
example:
see colour when listening to music
taste words
Priming
Def: psychological phenomenon which exposure to a stimulus influences person subsequent behavior/perception unconsciously
example:
primed with yellow = more likely to recall yellow objects
Transduction
Def: process which sensory organs convert physical stimuli into neural signals that brain can interpret
allows body to translate environmental stimuli into language brain can understand
example:
retina in eye convert light waves into electrical signals that are sent to the brain
hair in ears transform sounds waves to percieve sound
parts of the eye
Photoreceptors
Def: Specialized cells in retina that respond to light and convert it into electrical signals for the brain to process
There’s two types: Rods and Cones
Travels through optic nerve into the brain to become picture of the world
Rods vs Cones
Rods:
Best in DIM Light = night vision
Detects light but not colour
located in periphery of the retina
ex: see in dark
Cones:
Best in BRIGHT light = enables colour vision
detects colour
concetrated in center of retina (fovea)
ex: distinguish colours of rainbow
Accomodation
Def: process which eye’s lens changes to focus on objects at different distances
when altered leads to far/near sight
example:
book close = lens thicken to focus on near
book far = lens flatten to bring image to focus
Near vs Farsighted
Near:
see things clear up close
Far:
see things clear from far
Trichromatic Theory
def: proposes that retina contains 3 types of cones sensitive to different wavelengths
combines to produce perception of any colour
photoreceptors work in teams of three (red, green, and blue)
able to see colour because combo of three colours
example:
see purple = red and blue stimulated to create perception
Opponent-Process Theory
def: colour perception controlled by opposing pairs of colours
when colour in pair is stimulated, other is inhibited
Explains pheomenon like “afterimage”
stare at red image then look at white = might see green afterimage cuz red-green system in fatigued - rebounds with opposing colour
Colour vision deficiencies
def: involves damage or irregularities to one or more cones or ganglion cells (type of neuron that reciepes visual info from receptors)
when cones in retina don’t function properly
leads to difficulties distringuishing between colours
includes dichromatism and monochromatism
leads to colour blindness
Prospagnosia
deg: results from occipital and temporal lobes = lose ability to recognize faces
aka “face blindness”
neurological disorder
person can recognize frience by voice, hairstyle instead of face
inability to recognize faces even tho other visual processing is still there
Blindsight
def: ability to people who are blind to respond to visual stimuli without percieving them consciously
due to damage to primary cisual cortex in occipital lobe
example: person with blindsigh might avoid obstacle in path even though they did not see it
Sound
def: occurs throuhg movement of air molecules at different wave legnths and amplitudes
pitch and loudness
sound waves vary in wavelengths and amplitude
sound is perception of vibrations throuhg a medium
Wavelenght (aka pitch)
def: distance between consecutive peaks of a sound wave
inversely related to frequancy, which determines pitch
shorter length=high frequency=high pitch
frequency is number of waves that pass given point per second
Amplitude (aka loundess)
def: height of sound wave
determines loundenss/intesnsity
measured in decibels
larger amplitude = louder sound
Sound localization
def: ability to identify the location of sounds in 3d space
process where brain determines origin of sounds, allowing us to identify direction and distance of sounds
example: car on right honks = more intense sound on right/sooner
Place theory
def: theory stating that different frequency stimulate specific places along the basilar membrane in the cochlea
the idea:
high frequency = stimulates base of cochlea
lower frequency = stimulates apex of cochlea
best for explaining HIGHER pitch sounds
Frequency theory
def: theory that frequency of a sound wave is matched by firing rate of auditory nerve
entire basilar membrane vibrates in unison
example: sound wave at 300Hz causes auditory nerve to fire 300 times per second
best for explaing LOWER pitch sounds
struggles to explain high frequency cuz nerons max firing rate is 1000Hz
Volley Theory (extensions of frequency theory)
def: suggests that groups of neurons work together to encode frequency of sound wave
group of neurons fire in staggered manner, allowing them to collectively match frequency of higher pitch sounds
example:
4000hz cant be processed by single neuron fire = multiple neuron fire alternatively to represent frequency
sensorineural deafness
def: hearing loss caused by damage to inner ear or auditory nerve
decline in clarity of loundess and range of sounds
symptoms:
difficulties hearing high pitched sounds
trouble understanding speech in noisy places
causes:
exposure to loud noise over time
Conduction deafness
def: caused by problems in outer/middle ear, preventing sound waves from reaching inner ear
prevents sound from travelling efficiently to inner ear
symptoms:
muffled hearing
sounds seem quieter than they are
causes:
earwax :P
Olfactory system
def: sensory system responsible for SMELL
works by detecting chemical molecules in air and converting them into neural signals
process called transduction
smell bypasses thalumus and go directly to limbic system
why certain smells trigger emotional memories
Pheromones
def: chemical signals released that can influence behaviour
chemical messages for the olfactory system
Gustation
def: sense of taste, which detects chemical compounds in food/drinks
through taste receptors on the tongue
Taste buds
def: tiny sensory organs located on tongue that contains taste receptors
sends signals to brain when they detect certain chemicals in food
Types of tastes (primary taste categories)
Sweet
Sour
Salty
Bitter
Umami
Oleogustus
Taste receptors
Def: special cells in taste buds that detect chemicals from food and send signals to the brain
detects chemical dissolved in saliva
sends signals to brain via the gustatory pathway
Types of tasters
Supertasters
people with more taste buds
Medium Tasters
average number of taste buds
Nontasters
people with fewer taste buds
especially to bitter flavours
INteraction and coordination of chemical senses
def: refers to the way our sense of smell (olfaction) and taste (gustation) work togtehr to create combined perception of flavour
taste = combo of taste and smell
why food taste bland when you can’t smell well
Skin receptors
def: sensory receptors in skin that detects specific types of stimuli
ex: touch, pressure, temp, and pain
Types of skin receptors
Mechanoreceptors
detects pressure, texture, and vibrations
Thermoreceptors
detects changes in temperature
Nociceptors
detects pain
caused by potential/actual tissue damage
structures that process touch
somarosensory cortex
in parietal lobe of brain = processes touch sensations
processes sensory input & maps where it is
Thalamus
brains sensory relay station that sends touch info from body to somatosensory cortex
Processes and complexities of pain
def: pain is body’s way of signaling potential/actual injury
processed through physical and emotional pathways
Nociceptors (in the skin)
detects tissue damage/harmful stimuli → send signal to brain
Thalamus
relays those signals to somatosensory system and limbic system
Gate control theory
def: explains how pain signals are modulated in spinal coord before reaching brain
spinal coord has neurological gate the blocks/allows pain signals
large fibers carrying non-painful stimuli can close gate by inhibiting smaller nerves that contain pain signals
example:
rubbing some spot can reduce pain because non-painful touch signals “close” the gate to the pain signals
Phantom limb sensation
def: perception of sensations in a limb that has been amputed
brain’s sensory map (in somatosensory cortex) still include missing limb
brain can misfire and produce sensation
Vestibular sense
def: sense of balance and spatial orientation, allows for posture and coordination movement
lcoated in inner ear - semicicular canals
detects changes in position of head and body in relation to gravity
example:
when you spin in circles and stop, vesticular sense causes dizziness as floud in semicircular canals keep moving
Semicircular canals
def: three fluid filled tubes in the inner ear that detects rotational movement of the head
located in the inner ear
each canal is oriented in a differnt plane
detects different type of head movement
vertigo
def: sensation of spinning or dizziness caused by issues in the vestibular syste
occurs when brain recieves conflicting signals from vestibular system and other senses
feels like your surrounding are spinning even when you’re standing still
Kinesthetic sense
def: sense of body position and movement, allowing use to be aware of our limbs wihout looking at them
able to touch nose with eyes closed - relies on this sense
