AP Psych Notes
Thresholds: Absolute and Difference
Signal detection theory
Subliminal stimulation – can we perceive stimuli below our threshold?
YES – Why??
Can we be affected by Subliminal stimulation?
YES – Priming
Difference Threshold = Just noticeable Difference (JND)
The minimum difference a person can detect between 2 stimuli 50% of the time
Light 8%
Weight 2%
Tone 3%
Hearing 5%
Sensory Transduction – conversion of one form of energy into another (stimuli = nerve impulse)
Light energy – phototransduction
turning light into sensory impulse
Electromagnetic Spectrum
There are three main parts to light energy
WAVELENGTH = HUE/COLOR
Hue (color) is determined by the wavelength (distance from peak to peak)
Short is blue
Long is red
Vision – The Retina
The light sensitive inner surface of the eye that contains the rods and cones, in addition to the Bi-Polar and Ganglion cells
Rods: Receptors for black/white/grey, necessary for night vision, used in peripheral vision, approximately 120 million
Cones: receptors for fine detail and color, function in daylight and Well-Lit areas, concentrated in center of retina, approximately 6 million
Rods and cones trigger a chemical reaction which activates Bi-polar cells which in turn trigger the ganglion cells.
Axons from the ganglion cells form the optic nerve, which carries information from the thalamus and then to the occipital lobe
As the optic nerve leaves the eye it creates a Blindspot
Fovea – central point in the retina around which the cones cluster, no rods here
Vision – Visual Acuity
Nearsightedness – distant objects are focused in front of the retina = blurry; Nearby objects clear
Farsightedness – nearby objects reach retina before the image can focus = blurry; far away objects are clear
Color Vision – Person with normal color vision can distinguish over 7 million different shades of color
Human color vision is Tri-Chromatic = depends on three types of color cones
Young Helmholtz theory: three types of cones give rise to one basic color and that all colors are deviation of these three
Short - Blue
Medium - Green
Long – Red
Lack of functioning in red or green color cones for most people
8% of men and 0.3% of women
Paternally passed genetic trait (dad to daughter to son)
Subtractive and additive color mixing
When you add pigments – you subtract wavelengths = Black
When you add Light waves – you add wavelengths = White
Opponent Process theory of color
Idea that we process four primary colors combined in pairs of red-green, blue-yellow and black, white; explains after images
Hearing
Acoustic transduction – turning soundwaves into neural impulses
Sound Waves
Amplitude = Loudness
Greater Amplitude = louder
Wavelength = frequency = pitch
Long waves = low frequency = low pitch
Short waves = high frequency = high pitch
Sound is measured in decibels:
Threshold for hearing is 0
Prolonged exposure to 85+ decibels can result in deafness
Parts of the Ear
Outer Ear – Pinna and Auditory Canal
Recieves and channels the sound waves to the eardrum which then vibrates in response
These vibrations set the middle ear in motion
Middle Ear – 3 bones
Hammer (malleus)
Anvil (incus)
Stirrup (stapes)
Movement of these bones transmits vibrations to the oval window which connects the middle ear to the inner ear
Hearing – parts of the Ear
Inner Ear
Cochlea – snail shaped structure filled with fluid contains the hair cells (basilar membrane) that connects to the Organ of Corti
Organ of Corti – are the auditory receptors that transduce sound waves into neural impulses that will be processed by the auditory cortex
Hearing – How do we perceive pitch
Place theory – links pitch with the place where the cochlea's membrane is stimulated
Frequency Theory – Rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone
Hearing – Types of Hearing Loss
Conduction hearing loss: hearing loss caused by damage to the mechanical structures of the ear that conduct sound waves to the cochlea normally damage to the eardrum or bones)
Sensorineural Hearing Loss: hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerve; also called nerve deafness
Touch
Touch is a mix of four distinct senses
Pressure – Mechanoreceptors
Warmth – thermoreceptors
Cold – thermoreceptors
Pain – nociceptors (vary per person)
Only pressure has identifiable receptors; all other skin sensations are variations of the four senses
Touch and Pain:
Pain signals something is wrong; usually with skin or tissue
Some people live with chronic pain (physical)
Anxiety, lack of sleep, poor coping skills = higher pain
Touch and Pain:
Pain is influenced through biological, social-cultural and psychological factors
Biological = spinal cord/brain interpretation
Social-cultural = Prescence of others/empathy/cultural expectations
Psychological = attention to pain/learning and expectation of pain and relief
Touch and Pain Control
Gate control theory of pain
Our spinal cord acts like a gate that either blocks pain (closed) or allowed it to be sensed/perceived (open)
Small nerve fibers transmit pain; large nerve fibers transmit other sensory input
To stop small nerve fibers, activate large nerve fibers
Examples: rub a bruise/run cut under cold water
Gustation – the sense of Taste
Taste buds are receptors in the mouth; located on the tongue
Papillae – located within bumps on the tongue
Taste buds are replaced every few weeks
Taste can change
Buds decrease with age
Saliva helps break down food and releases chemicals called Tastants which interact with taste buds
Five Tastes – Sweet, sour, salty, bitter, umami
Olfaction – The sense of smell
Olfactory Epithelium – receptors cells located I the nasal cavity; over 5 million of them
Odor molecules are sent to the Olfactory bulb at the base of the brain where it is detected as smell
Smell serves two purposes
Detect odor
Communicate aggression
Aggression – primarily animals
Animals respond to pheromones = certain odor = specific message
Sense of smell depends on the chemicals emitted by the substance, which are absorbed by the receptor cells
Estimated over 100 different smells
The nerves from the Olfactory Bulb do not go to the thalamus like all other senses
Rather the connect to the brain at the Amygdala and Hippocampus (limbic system)
Why some smell evokes strong memories
Body Position and Movement
Vestibular sense – tells how the body is oriented in space
Based on the Head’s position
3 semicircular canals in the inner ear provide feedback to the brain about the body’s position and equilibrium (balance)
Vision will impact
Messages go to cerebellum
Kinesthesis – gives feedback about the position and movement of specific body parts
Muscles and joints
Perception
Uses both bottom up and top-down processing
Attention
Need to pay attention to “perceive”
Selective Attention: what you are paying attention to; ignoring other information
Selective Listening/Hearing: focus on one voice in a crowd
Cocktail party effect: will hear your name in & amongst others
Divided Attention
It takes time to switch your attention
In attentional Blindness: Failure to see something because your focus is elsewhere
Did You see?
Change blindness: fail to notice a switch in people
Change Deafness: don’t notice a change in person talking
Change Blindness: don’t notice change in pictures
Perception
Form perception
Figure ground: perceiving objects separate from the ground- can be reversible
Gestalt: (means WHOLE) and refers to our tendency to integrate pieces of information into meaningful wholes
Group information into coherent groups in various ways:
Also use closure: using top-down processing we will fill in “gaps”
Depth Perception
Allows you to judge distance
Visual cliff Experiment (Gibson and Walk)
Confirmed that infants learn to fear heights and are not born with the fear as was once thought
Monocular cues – images that come from one eye
Relative size: far off objects produce smaller retinal images than nearby object of the same size
Relative clarity: we perceive hazy images as farther away than clear images
Texture gradient: change in surface area texture helps give an idea of distance; objects farther away seem more densely packed
Relative height: we perceive objects that are higher in our field of vision to be farther away than those that are lower
Linear perspective: parallel lines appear to converge in the distance. The more lines that converge the greater the distance perceived
Light and shadow: dimmer objects appear farther away based on the amount of light reflected by an object (nearer = more light)
Unit 5: Cognition
Part 1: Memory (modules 31-33)
Memory: your accumulated knowledge that is processed, stores and retrieved
Flashbulb Memory: a clear memory of an emotionally significant even or moment (like you took a picture)
*Memory can be wrong…
How we process information into memory:
Encoding – getting information into our brain
Storage – retain that information
Retrieval – get the information back out
Atkinson-Shiffrin 3 stage processing Model of Memory
Sensory memory: immediate, brief recording of sensory information
Duration of ¼ - 3 seconds
If you “select” to pay attention to something it moves to short term memory
Short Term memory: memory that holds a few items briefly; before the information is lost (20 seconds)
Contemporary psychologists prefer to call this working memory
Idea is that you must keep rehearsing the information before it can be moved to long term memory
Long term memory: Relatively permanent and limitless storehouse of the memory system
Includes knowledge, skills, experiences
Some information skips first 2 stages and goes directly to long term
Encoding: What we Encode
Encode meaning
Semantic Encoding – what it means; produces better recognition later
Visual Encoding - Appearance of the letters
Imagery: Mental picture
Acoustic Encoding – Rhymes with
Mnemonics – jingles that help you remember information is processed more if it is also deemed relevant to the person (self-reference effect)
Organizing Information for Encoding
Chunking: organizing material into familiar, manageable units; we often do this automatically
Acronyms – ROY G BIV, HOMES
Numbers also: Phone #, SS #
Hierarchies: dividing info into logical levels (outlines)
Automatic Processing (happens unconsciously)
Space: where info is located
Time: “memorize” the sequence of the day (“retrace your steps”)
Frequency: keep track of how many times things happen
Practice: meaning of words, pictures
Effortful Processing (require attention and effort)
Herman Ebbinghaus
Rehearsal: Conscious Repetition
Ebbinghaus stated: the amount remembered depends on the amount of time spent learning
Rehearsal Phenomenon
Next in line effect: focus on our own performance and often fail to remember what the person right in front of us said
Spacing Effect: retain info better when it is distributed over time (spaced learning vs cramming)
Serial Position effect: our ability to recall the information at the beginning and end of a list
Primacy effect: retain info at the beginning better
Regency effect: retain info at the end better (attributed to sensory or STM)
Storage: Retaining Information (Sensory Memory)
Iconic Memory: momentary sensory memory of visual stimuli; photographic or picture image memory only lasts ¼-½ second
Eidetic Memory (photographic) - rare; more likely people have a good memory – more common when young, tends to fade in teens
Echoic Memory: momentary sensory memory of auditory stimuli
If attention is elsewhere, sounds and words can still be recalled within 3-4 seconds
“What did you say”
Short-Term/Working Memory
Short term memory tends to be encoded in auditory format = you talking to yourself (aloud or in your head)
Without active processing, STM last about 20 sec.
In 1956 George Miller confirmed STM is 7 items (+, -) 2 items
Encoding strategies allow for more to be stored (chucking and rehearsal)
Long term memory
Estimated that humans do not use anywhere near the full capacity of their brains
Must also consider what is available versus what is accessible
Memory is stored all over (Association Areas)
Do see synaptic changes w/ memory creation = LTP: Long Term Potentiation
Long Term Potentiation (LTP)
An increase in a synapse’s firing potential after brief, rapid stimulation
Drug companies are using this info to create drugs that help boost LTP and thus memory for Alzheimer's patients
Scientists have also discovered that when learning occurs, more serotonin is released into the synaptic cleft
Suffering a head injury (lose consciousness) interrupts LTP thus memory is not created
Storage of Long-Term Memories
Two types of LTM; Implicit and Explicit
Implicit memory (Non-Declarative/Procedural Memory)
Memory of how to do something
Processed by cerebellum
Memory of skills – motor skills, habits and any reflexive actions that have been conditioned
Explicit Memory
Memory of facts/experiences that you consciously know and can declare
Processed in Hippocampus
Two Types: Episodic and Semantic
Episodic – events experienced
Semantic – facts and general knowledge
Retrieval: Getting info out
Recall – ability to retrieve info already learned (fill in blank test)
Recognition – Identify info previously learned (multiple choice questions)
Relearning – once you have learned something you will probably relearn it much more quickly (cumulative tests)
Retrieval Cues: associations formed at the time of encoding that can help you “remember” information
Can be visual, words, sounds, experiences
To effectively retrieve memory, you first must activate the neurons that connect to the memory – PRIMING
Usually happens unconsciously (just remember)
Priming predisposes you down certain line of thought
Context Effects
Putting yourself into the context in which you experienced something will help you remember it more
Deja-Vu – sense that you have experienced something before
Typically, skeptical in Psych
Retrieval Cues probably subconsciously triggered memories From a past experience (you may or may not be conscious of experiencing)
Being over tired or stressed = correlation
Forgetting
Seven Sins of memory – Daniel Schacter (1999)
Absent Mindedness: Inattention to detail = failure to encode
Transience: storage decay over time = unused info/facts
Blocking: inaccessibility if stored info = tip of tongue phenomena
Distortion
Misattribution: confusing the source of info believing you have seen or heard something you haven’t
Suggestibility: lingering effects of misinformation = false memories
Bias: current knowledge and beliefs distort our memories of past events
Intrusion
Persistence: unwanted memories you cannot get rid of or stop thinking about = interruption of memory (PTSD)
Encoding Failure
Failure to get info in
Must pay attention to it
Age can impact; encode slower
Retrieval Failure
Interference: earning some items may interfere with retrieval of information when its similar
Proactive Interference – prior on new
Retroactive Interference – New on old
Learning an hour before bed is good – interference is limited