AP psych part 2 unit 1

consciousness 

awareness of ourselves and environment 

• sense of emotions, sensations and choices 

Cognitive neuroscience

interdisciplinary study of the brain activity linked with our mental processes

Dual processing

information simultaneously processed on separate conscious and unconscious tracks

where does parallel processing happen 

unconscious mind 

parallel processing

processing multiple aspects of a stimulus or problem simultaneously

where does sequential processing happen

conscious mind

sequential processing

processing one aspect of a stimulus or problem at a time

• new info and problem solving 

sleep

natural loss of consciousness 

Circadian Rhythm

biological clock and regular bodily rhythms that occur on a 24 hour cycle

Alpha waves

relatively slow brain waves of a relaxed, awake state

when does alpha happen

before you sleep

Stage 1 of sleep cycle

• irregular brain waves

• slowed breathing

• resembling hallucinations

• hypnagogic sensations

hypnagogic sensations

Body may jerk or may have feeling of floating weightlessly or feeling of falling

Stage 2 of sleep cycle 

• relax more deeply, abt 20 min

• sleep spindles - rapid rhythmic brainwave

Stage 3 sleep cycle

• deep sleep stage

• delta waves

• hard for you be awake

• 30 min

delta waves

large slow brain waves associated with deep sleep

what is NREM sleep 

stage 1, 2 and 3 

what happens after stage 3 of sleep cycle

you go back to stage 2 of sleep cylce and then go into 10 min of REM

REM sleep

“rapid eye movement”

• brain waves rapid like stage one

• 20-25% total sleep

how is rem sleep diff than stage 1 

• heart rate rises

• breathing becomes rapid 

• eyes move rapidly 

• dreams

Paradoxical Sleep

• REM = “paradoxical sleep”

• Brain is highly active

• Body stays calm/inactive

how long does a sleep cycle last

abt 90 min

what happens to motor cortex in REM

• motor cortex active

• BRAINSTEM blocks movement —> temporary paralysis

suprachiasmatic nucleus 

cell cluster in the hypothalamus that causes pineal gland to decrease its production of melatonin in the morning and increase in the evening 

melatonin

sleep inducing hormone

what does sleep protect from

from evolutionary perspective, keeps safe from dangerous periods of wandering in the dark

what does sleep help us recuperate 

restore and repair brain tissue, gives neurons a rest  

how does sleep make memories

restores and builds our fading memories from the day, strengths neural connections

how does sleep feed creative thinking

become more insightful after sleep, solve problems easier

how does sleep play role in growth process 

during sleep pituitary gland releases a growth hormone 

sleep loss can be correlated with

• Depression and irritability

• Depressed immune system

• Suppressed immune system to fight of infections

• Increased weight gain

• Increases ghrelin and decreases leptin

• Makes you look older

• high blood pressure, impaired memory, and more accidents

insomnia

recurring problems in falling or staying asleep

• cant fall asleep or always waking up during sleep

• chronic tiredness, depression and hypertension (high blood pressure)

narcolepsy 

uncontrollable and sudden attacks of sleepiness

• falls asleep at random 

• lasts short times likes 5 min 

• accompanied by loss of muscle tension, dangerous to engage in actions like driving 

sleep apnea

stopping of breathing during sleep and repeated momentary awakenings

• can happen over 100 times

• usually NOT aware have it OR waking up in the night

• increased tiredness, obesity, and depression

sleepwalking

complex motor activity in stage 3 of sleep

• not harmful and usually in children

Rem sleep behavior disorder 

sleep disorder in which normal REM paralysis does not happen but 

• twitching 

• talking 

• kicking 

occurs, acting out ones dream 

dreams

sequence of images, emotions, thoughts passing through a sleeping person’s mind

why do we dream

• file away memories —> help sift, sort and fix the day’s experience in our memory

• devolp and preserve neural pathways —> believed that it helps devolp neuron and neural network

• make sense of neural static

• reflect cognitive development —> see dreams as a part of brain maturation and cognitive development

activation synthesis theory

random neural activity and our brain attempts to make sense of it when we dream

sensation

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

perception

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

bottom up processing 

using our sensory recpetors and works up to the brains higher levels of processing by integrating the sensory information 

top down processing

information process guided by higher level mental processes, as when we construct perceptions drawing on our experience and expectations

transduction

converts stimulus energy into neural impulses

• receive sensory input

• transform it into neural impulses

• send it to the brain

Psychophysics

physical properties of stimuli (like intensity) relate to our psychological experience of them

Thresholds

minimum level of stimulus intensity required to be consciously aware of the stimulus

absolute threshold

minimum stimulation needed to detect a particular stimulus 50% of time

subliminal 

stimulus you can not detect 50% of the time

signal detection theory

-detect faint stimulus in a background of other stimulation

says there is no fixed absolute threshold

detection depends on factors like experience, expectations, motivation and alertness

difference threshold

• minimum difference between two stimuli needed to notice a change 50% of the time

• small changes are more easily at low intensities than high ones

  • 40—>45 more noticeable 90—>95

Weber’s law 

principle that two stimuli must differ by a constant proportion (percentage) not constant amount 

• lights differ by 8% and weights 2% to notice change

sensory adaptation

• constant stimulation causes your sensitivity to decrease

• Example: bad smell fades after a few minutes

• Helps us ignore unimportant background stimuli and focus on changes in our environment.

why do eyes take in light energy

to convert neural signals

wavelength 

distance between peaks —> determines color 

amplitude

height of the wave which determines intensity

cornea

• Clear outer layer

• Protects the eye

• Bends light to start focusing the image
  

pupil 

• Dark, adjustable opening where light enters

• Works like a camera aperture—more or less light depending on conditions

iris

• Colored ring of muscle around pupil

• Controls pupil size

• Dilates (opens) in low light or when excited

• Constricts (closes) in bright light or when calm

• Helps regulate how much light reaches the retina so images aren’t too bright or too dim

lens

• Behind the pupil

• Focuses light onto the retina

• Changes shape to keep images clear
  

accommodation 

lens changes shape to focus near vs. far objects on the retina

retina

• Light-sensitive inner surface of the eye

• Contains rods and cones (receptor cells)

• First place where neural processing of visual info begins

rods

• outer retina

• Sense black, white, gray

• Work best in low light

• night vision + peripheral vision
  

cones

• Concentrated in fovea (center of retina)

• Detect color and fine detail

• Work best in daylight / bright conditions

bipolar and ganglion cells

Light signal travels to bipolar cells, then to ganglion cells

blind spot

• Where the optic nerve leaves the eye

• No rods/cones there → no vision in that tiny point

Retina to Visual Cortex

• Each part of the retina sends visual info to a matching spot in the visual cortex (occipital lobe)

Optic Chiasm

Optic nerves cross at the optic chiasm (X-shaped structure)

Visual Info Crossing

half the info from each eye goes to the opposite side of the brain

optic nerve formation

• Ganglion cell axons bundle together

• These bundled axons form the optic nerve

Optic Nerve Function

Optic nerve = carries neural messages from the eye to the brain

brain pathway 

• Visual info travels to the thalamus

• Then sent to the visual cortex (occipital lobe)

Young-Helmholtz Trichromatic Theory

• Retina has 3 color receptors: red, green, blue.

• All colors are seen by combining activity from those three receptors.

• Yellow is perceived when red + green receptors are activated together
  
  

when does colorblindness happen

when one receptor type is missing or not working.

flaws in Trichromatic Theory

• People missing red + green receptors (red–green colorblind) can still see yellow, which shouldn’t happen if yellow is only a mix of red + green.
  

• Yellow looks like a pure, unique color—not like a blended one (unlike purple, which clearly feels like red + blue mixed).

Opponent-Process Theory

• Color vision is controlled by opposing pairs:

  • Red ↔ Green

  • Yellow ↔ Blue

  • White ↔ Black

• one color in a pair is activated, the other is suppressed

afterimages

• Stare at green → green sensor tire → when image is gone, the opponent (red) shows up.

• Same idea for black→white and yellow→blue

Two stages of current understanding of color vision 

1. Stage 1: Trichromatic

   • Retina has red, green, and blue cones.

   • Each responds in different amounts to light wavelengths.
     

2. Stage 2: Opponent-Process

• Cone signals are sent to opponent-process cells (red–green, yellow–blue, white–black) for final color perception

feature detection

• Nerve cells in the occipital lobe (visual cortex)

• Respond to specific features: shape, line, angle, movement

processing complex patterns

• Feature detectors send info to other areas of the visual cortex

• Allows the brain to recognize more complex patterns

parallel processing

• The brain processes multiple features at once (not one at a time).

• visual scene gets split into color, motion, form, and depth simultaneously.

• All pieces processed together —> one complete perception.

Audition

• the sense or act of hearing

• ear transforms the vibrating air into nerve impulses which our brain decodes as sound

amplitude in sound 

 loudness; height of sound wave determines how loud

frequency

length of the sound wave, which determines pitch

pitch

tone of a sound in high or low

how is sound measured 

decibels (dB)

0 dB = absolute threshold for hearing.
Every +10 dB = 10× increase in sound intensity

Outer ear

auditory canal that funnels sound waves to the eardrum and middle ear

Includes the pinna (your ear)

Middle Ear

Eardrum – membrane that vibrates when sound waves go into ear

three tiny bones in the middle ear known as ossicles

vibrate and trigger the cochlea in the inner ear

Inner Ear

• Innermost part of the ear.

Includes the cochlea, semicircular canals, and vestibular sacs.

Cochlea

• Snail-shaped, fluid-filled tube in the inner ear.

Sound waves move the fluid → triggers nerve impulses sent to the brain

How Sound Becomes Neural Signals

• Sound waves vibrate the fluid in the cochlea.

• This makes the basilar membrane ripple → bends hair cells.

• Hair cell movement creates neural impulses.

• These impulses travel through the auditory nerve → thalamus → auditory cortex in the temporal lobe.

hearing loss

• Damage to cochlea, hair cells, or auditory neurons

• Can hear sounds but have trouble understanding speech

• Causes: disease, aging, loud music

what are devices for hearing loss

Cochlear implant: converts sound → electrical signals → stimulates auditory nerve via electrodes in cochlea

condition hearing loss

• Hearing loss caused by damage to the eardrum or ossicles 

• Loss of ability for these to vibrate and  reach cochlea

loudness

• Softer sounds → only a few hair cells

• Louder sounds → more hair cells also respond 

• depends on the number of activated hair cells

place theory

theory that links the pitch we heart with place where the cochlea’s membrane is stimulated 

frequency theory 

theory that rate of nerve impulses traveling up the auditory nerve matches the frequency of tone 

volley theory

neural cells can alternate firing. By firing in rapid succesion → achieved combined frequency above 1000 waves per second

how can we determine location of sound 

• Sounds strike one ear sooner and more intensely than the other, allowing us to locate the sound

Touch 

sensitivity to pressure on the skin 

Somatosensation

general term for four classes of tactile sensations

• Touch

• Pressure 

• Cold 

• Pain