BehSci GR1 Sleep and Sensation

Circadian rhythm

as morning nears, body temp rises, peaks during the day, dips in the early afternoon, and dropped into the evening

sleep tendencies

-Night owls - around 20 years old, more smart and creative
-Morning types - we gradually shift to be morning types around the early 20s, typically do better in school, take more initiative, punctual, less depressed

Sleep

The brains cortex stops communicating
-1/3 of our lives, 25 years

90 minute sleep cycle

from N1 (10 mins), to N2 (20 mins), to N3 (30 mins), back up through N2 (20 mins), and then to REM (10 mins)
-Each cycle that passes, N3 gets shorter and disappears, REM and N2 get longer, N1 only occurs once, at very beginning

N1

Experience sensory that occurs without stimulus, called hypnogogic or hypnic sensations, falling or floating weightlessly
-Theta Waves and alpha waves

N2

Periodic sleep spindles: bursts of rapid, rhythmic brain activity, aids memory processing
-easy to wake
-emits theta waves and sleep spindles

N3

brain emits large, slow, delta waves, hard to wake, children wet their bed @ end of this stage

REM

Brain waves are rapid and saw toothed, heart rate rises, breathing is rapid and irregular, every 30 seconds eyes dart around behind eyelids, which signal the beginning of a dream, sexually aroused during REM as well
-cortex is very awake, but brainstem blocks the signals to the body, so body is paralyzed and is hard to wake

Dreams

An emotion, story-like, hallucinatory event, occurs during REM, 1500 dreams 600 hrs per year
-only usually recall dreams if woken near or during REM sleep, because dream is in short term memory

lights and sleep

bright lights affect our sleepiness, they activate our sensitive retinal proteins, signals the suprachiasmatic nucleus to decrease production of melatonin, the sleep hormone
-late night screen interaction as well affects quality and duration

5 reasons we need sleep

-Sleep protects: night contains historical dangers
-Helps us recuperate: body + brain heals, reorganizes, immune system reset
-Restores and rebuilds our faded memories of the days experiences
-Sleep feeds creative thinking: "sleeping on it" works
-Sleep supports your growth: muscle development, improves athletic ability

Sleep deprivation

-brain keeps sleep debt counter for 2 weeks
-5 or less hours, 70-80% higher chance of suicide and depression
-causes weight gain, increasing hunger hormone while decreasing hunger supressing hormone
-increased cortisol, stress hormone
-decreases lifespan

Insomnia

ongoing difficulty falling or staying asleep, 1 in 5

Narcolepsy

sudden attack of overwhelming sleepiness, 1 in 2000

Sleep apnea

stopping breathing repeatedly while sleeping, 1 in 20

sleepwalking and talking

few serious concerns, rarely any memory, occurs during N3

night terrors

as we age, increasingly rare, appearing terrified and talking nonsense

Bottom up processing

sensation, enables sensory system to detect movement and senses

top down processing

interpreting the senses you detect, perception, influenced by our motivation, emotions, and exceptions

transduction

converts the outside information input given to the senses, transform that stimuli into neural impulses that our brain can understand

Electromagnetic spectrum

we see from 400-700nm, just a thin slice of the spectrum, ROY G BIV, from highest to lowest
-we dont actually see the color red, but we perceive the electromagnetic energy the visual system receives as red

light wave amplitude

-The height of the waves
-determines the intensity of the light, with influences brightness

Cornea

enters though the cornea, which bends the light and helps in focus

Pupil

light passes through the pupil, which is constricted by the iris, depending on the intensity of the light

Iris

constricts on basis of intensity and emotion
-constricts when disgusted, dilate when feeling amorous or trusting

Lens

focuses the light onto the retina, changing thickness and curvature to accommodate distance.

Retina

multilayered tissue lining the back of the eyeball, rods and cones at the very back, which translate their stimuli to bipolar cells, which then stimulate ganglion cells. the axons of the ganglion cells form the optic nerve

myopia

nearsightedness, lens focuses light on an place which is too far from the retina

cones

cluster around the center of the retina, called the fovea, low sensitivity in low light, high color and detail detection

rods

scattered around the peripheral of the retina, high sensitivity at night, low color and detail detection, peripheral vision, good at detecting motion

Optic Chiasm

the optic nerves from each eye cross as they relay to the thalamus at the opposite side, creates x-shaped optic chiasm

Young-Helmholtz trichromatic theory

we have three types of color receptors, each corresponding to one of the primary colors of red, blue, and green, various colors stimulate each of these receptors at a certain intensity, causing us to see colors that are combinations of red, green, and blue

opponent-processing 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

Our hearing capabilities

Our hearing abilities are so incredible, that if they were any more sensitive we could hear the collision of air molecules

how hearing works

the ear detects pressure changes from the air molecules vibrating via sound waves, wavelength and frequency are inversely related, and determine the pitch that we hear

Decibels

-Db is a measurement of intensity
-0 Db is the threshold for hearing
-every 10 Db increase, the intensity of the sound increases 10 fold

Eardrum

detects the sound waves via pressure sensing in the ear canal

Middle Ear

The middle ear is made up of a tiny piston of three bones which translate the vibrations from the eardrum to the cochlea

Cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses
-vibrations jostle the fluid inside, causing ripples inside the basilar membrane, which bends the hair cells that line the inside of the cochlea
-these hair cells are connected to nerve cells, whose axons converge into the auditory nerve
-hairs have frequencies that they specialize in detecting

sensorineural hearing loss

damage to the cochlea hair receptors or auditory nerve, you can hear sound but have trouble discerning what is being said

conduction hearing loss

damage to the eardrum or middle ear bones, mechanical system of the ear

kinesthesia

your body's sense of its own location and movement

proprioceptors

monitor the position and movement of skeletal muscles and joints, enables kinesthesia

vestibular sense

monitors you heads (and thus body's) position and movement with:
-semicircular canals: filled with fluid, maintain balance and coordination
-vestibular sacs: calcium crystal filled, these organs stimulate hair like receptors when a sudden movement is detected, sends signal straight to cerebellum
these organs act as gyroscopes and accelerometers for you body

hearing loss ranges

80 dB for 8 hours
85 dB for 4 hours
90 dB for 2 hours
95 dB for 1 hour
100 dB for 20-30 min

Perceptual set

a set of mental tendencies and assumptions that affect top-down processing, series of beliefs, ideas, and experiences that influence your perception
-Hear what we expect to hear
-see what we expect to see
-a "mind over our mind"

concepts and schemas

pre-formed expectations that organize and interpret new information

Motives

motives give us energy towards a certain mental agenda, like context, they bias interpretations of neutral stimuli
-desirable people appear closer
-closeness can increase desirability

Emotions

Emotions also influence perception
-when we're hungry, we find larger bodies more attractive

other-race affect

Trouble recognizing the faces of other races, "they all look alike" is not bigotry but biology

fundamental attribution error

the tendency for observers, when analyzing another's behavior, to underestimate the impact of the situation and to overestimate the impact of personal disposition

Eye's blind spot

where the axons of the ganglion cells converge into the optic nerve and begin to travel back into the skull, there is a blind spot with no receptors that our brains top-down processing fills

Brain waves during sleep

-Alpha waves: Awake, relaxed, about to fall asleep, also during REM
-Beta waves: similar to when awake, more rapid and alert than alpha waves
-Gamma waves: similar to when awake, very alert and mindful, more so than beta waves