Exam 2 Review (11/3) Flashcards
Sensation
the detection of physical energy by sense organs (by cells in eye, nose, ear, skin, and tongue)
Transduction
Conversion of stimulus to electrical signal
Perception
the brain’s interpretation of raw sensory input
What do sensation and perception do?
Sensation gathers info from the external world, and perception helps us make sense of the info
Absolute threshold
the smallest amount of stimulus we can detect at least 50% of the time
Just noticeable difference (JND)
the smallest change we can detect in stimulus strength
Sensory adaption
a decrease in the noticeability of a stimulus over time
- happens at the sensory receptor level (e.g. candle scent)
True or False: our perceptual experience is a direct translation of sensory input
- False
We use more than just sensory input to make sense of the world
perception = sensory input+past perceptions+context+guesses
we need this, partly, bc the sensory input isn’t always clear or complete
Signal-to-noise ratio
sometimes the stimulus is unclear so our brain makes its best guess
Perceptual constancy
the process by which we perceive stimuli consistently across varying conditions
Shape constancy
where an object is perceived as having the same shape when viewed at different angles (e.g. door)
Color constancy
our ability to perceive colors as relatively constant over varying illuminations (light sources)
Visible light
wavelength: 400nm - 700 nm of light
Pupil
a hole that allows light into the eye
Iris
colored part, muscle that controls pupil
Cornea
outside covering that helps protect and focus light
lens
a disc that focuses light on the back of the eye
- lens inverts the image as it focuses it
Retina
membrane on the back of the eye containing sensory receptors
Optic nerve
transmits visual signals to the rest of the brain
Fovea
area of the retina where light is focused
Why care about fovea?
light focused on the fovea controls how well you see
Myopia
nearsighted: light focuses too soon
Hyperopia
farsighted: light focuses too late
Visual System
- the eye
- photoreceptors
- color vision
Visual Perception
top-down/ bottom-up processing, feature integration theory
Photoreceptors
- located in the retina
- visual sensory receptors (two types: cones, rods)
- rods and cones connect to ganglion cells
Cones
- sense bright light and color, work best in bright light
- cones are connected at fovea (very high acuity)
Rods
- sense dim light, become oversaturated in bright light
- rods are concentrated in the periphery (low acuity, might improve night vision, need time to recover if exposed to too much light, dark adaption takes approx 30 minutes)
Ganglion cells
- carry visual info from eye to brain
- form optic nerve
- blind spot: filled in through brain’s perception/ guesses
Color vision
- light (sunlight) has all wavelengths in it
- some wavelengths are absorbed by surfaces, others are reflected
Reflected Light
–> color
- subtractive vs. additive color mixing
Subtractive color mixing
mixing pigment absorbs more light (looks darker) –> color
Additive color mixing
mixing colored lights gives off more light (gets brighter) –> light
Trichromatic theory of color vision
- idea that color vision is based on three primary colors: blue, green, red
- 3 types of cones: tuned to respond to blue, green, red
- patterns of activity between different cones types allows us to see all possible colors
Color blindness
- occurs when one cone is missing
- called dichromatic vision
- 5% of men and 0.25 % of women are color blind
Opponent process theory of color vision
- we perceive things in terms of opponent color pairs
- ganglion cells pool incoming info from cones
(send one signal about the color to the brain) - explains afterimages
(cones get oversaturated, we see opposite color)
Visual Perception
Bottom-up processing
Top-down processing
Bottom-up processing
Processing that’s driven primarily by sensory input
- perceiving an object based on its edges
Top-down processing
Processing driven primarily by concepts, beliefs, or expectations
- object + context
Feature Integration theory
- Describes what happens in your brain after photoreceptors take all the visuals into the brain
- objects are made up of features our cells detect separately
- (color, shape, etc) The brain must detect these features and integrate them into a whole object
- Feature – integration theory says these occur separately
- Feature detection involves parallel processing
(all features can be sensed at once) - Feature integration involves Serial Processing (we can only put one thing together at a time)
- (each object feature must be integrated one at a time)
–>(puzzles, you can see all the pieces at once, but you can only place on epiece in at a time)
How does your brain decide what an object is?
Gestalt Principles of Grouping: cues that help us group features or parts into whole objects
Proximity
physically close things are grouped
Similarity
similar things are grouped
Good continuation
continuous things are grouped
Closure
Gaps in borders are ignored to form a whole
Symmetry
Symmetrical things are grouped
Figure-ground
Foreground is grouped
Common motion
things that move together are grouped
Depth perception
- ability to see in 3-D
- monocular cues
- binocular cues
Monocular Depth cues
(cues that require input from just one eye)
Relative size
distant objects look smaller
Texture gradient
texture of distant object is less clear
Interposition
closer objects block further ones
Linear perspective
Lines converge over distance
Height in plane
distant objects appear higher
Light and shadow
shadows cue 3D shapes
Motion parallax
further things pass by slower
Binocular Depth Cues (BD)
(Cues that require input from both eyes)
- Binocular disparity: difference in retinal images
Binocular Depth Cues (BC)
(slight difference in view from each eye)
- Binocular convergence: difference in visual angle
Perceptual illusions
A lot of our perceptions are based on:
- expectations
- maintaining continuity
Sperling Experiment
- showed a series of letters for a fraction of a second, subjects were able to recognize at least some letters
- no one reported all letters and reported letters varied
- (we can see all the info, but it fades too quickly)/ partial report technique
- we can sense all info present, but do not have enough time to attended to all of it
- stuff that’s not attended to is forgotten
- separate sensory memory for each type of sense
Iconic memory
- visual sensory memory
- last < 1 second
- Inattentional blindness
Echoic memory
- auditory, sensory memory
- lasts a few seconds
- cocktail party effect
Short term memory
- working memory
- area of consciousness
- attention: transfers information from sensory memory to short-term memory
- short duration and small capacity
Rehearsal
Maintains information in STM
STM capacity
7+/-2 pieces of information
STM loss
- decay: fade away
- Interference: loss of information due to competition with other information
Retroactive interference
new information inhibits old information
Proactive interference
old information inhibits new information
Chunking
combining bits of information into meaningful groups
Sound
mechanical vibrations
Pitch
property of sound that corresponds to the frequency of the wave (measured in hertz)
Longer wavelength
low- frequency sound
Shorter wavelength
high- frequency sound
Outer-ear
- pinna
- ear canal
Function: funnels sound waves onto the eardrum
Middle-ear
- eardrum
- ossicles (hamer, anvil, stirrup)
Function: transmits a frequency of sound wave from the eardrum to the inner ear
Inner-ear
- semicircular canals (verstibular organ)
-cochlea
Function: converts vibration of sound waves into neural activity (transduction)
Transduction: Cochlea
organ of corti and basilar membrane: contains hair cells
Hair cells
- perform auditory transduction
- fluid in the cochlea bend cilia, causing hair cells to fire action potentials
Place theory
different regions of the basilar membrane allow you to hear different frequencies
STM Capacity
+7/-2 pieces of information
STM Chunking
- combining bits of information into meaningful groups
- Experts use chunking to remember complex information
- Chess board experiment
Experts chunked locations into meaningful patterns
Recalled more when patterns were realistic
Maintenance rehearsal
repeating information to keep it in STM
Elaborative rehearsal
linking information in a meaningful way to improve STM
Levels-of-processing model
- the more deeply we process info, the better we remember it
- Semantic processing is best
Long-term Memory
Our permanent store of information
* Includes facts, skills, experiences
* Long duration and unlimited capacity
LTM vs STM
The order of the word matters for how well we remember it
* Serial position curve: people have generally better memory for words at the beginning and end of the list
Primacy effect
tendency to remember words from the beginning of the list
- Word gets encoded into LTM
Recency effect
the tendency to remember words from the end of the list
- Word is still stored in STM
Types of LTM
- Explicit memory
- Implicit memory
Explicit memory
conscious memories we recall intentionally
o Semantic memory: knowledge of facts
o Episodic memory: autobiographical memory
Implicit memory
unconscious memories we do not reflect on deliberately
o Procedural memory: memory of how to do things, including motor skills and habits
o Priming memory
o Conditioning memory – classical conditioning
o Habituation memory
How do we get info into LTM?
Encoding: a mechanism that transfers information from STM to LTM
Things that help to encode:
o Maintenance rehearsal
o Elaborative rehearsal – why care about it?
- For the test
Best ways to study:
Don’t highlight or copy, take notes in your own words
Ask yourself f questions as you read or study
Come up with examples that apply to you
Teach a friend
Retrieval
a mechanism that transfers information from LTM to STM
o What helps?
- Encoding specificity: we remember info better under the conditions present at learning
Context-dependent learning
we recall information better in the same place we learned it
o Godden and Baddeley – 1975
o Scuba divers learned lists of words on land or underwater
o Tested in the same or opposite environment
o Remembered best when tested under the same conditions
State-dependent learning
we recall information better in the same cognitive state we learned it in
o Psychological state (mind)
o Physiological state (body)
Memory Fallibility
- memory isn’t perfect
- memory is a reconstruction
–> memory+context+other experiences+typicality
–> memories may shift with time
Flashbulb memories
extremely vivid and detailed memories
- Feel special, stand out to us
- Important or tragic events
–> 9/11, JFK assassination
challenger explosion, etc.
- Thought to be photographic in
detail. immune to decay
But..
- Tests find major distortions in these
memories over time
–>Just like reqular memories,
carry same reconstructive
nature and distortion
- There’s nothing special about
flashbulb memories. They’re
reconstructions too.
Even though they feel special
False memories
memories for events that never happened
- Elizabeth Loftus
* Famous for studying false memory
* 3 words to describe human memory
- Suggestive
- Subjective
- Malleable
False memories can be formed in
therapy
- Suppressed memories
recovered through therapy?? - Feel very real
- Can be very damaging
Lost-in-the-mall experiment: - Told participants they had been lost in the mall as a child. later asked them to recall the event
- People formed memories of events that never occurred
- Called parents, asked them to list and describe events that happened to you as a child
- Added false memories to see
if people would falsely
remember them - People would
“remember” that those
things “actually
happened” based on
suggestion - Seeing your mother as
the trustworthy source
Misinformation effect
Altering memories
by providing misleading information after
event
- Loftus & Palmer (1974)
* Asked people to estimate the speed of cars that collided in a car crash
* Everyone had same source, but people were questioned using different language
–> Estimate speed when
they “smashed” into
each other?
–> Estimate speed when
they “contacted” each
other
* Wording used changed
reported memories
Eyewitness testimony
- often extremely influential in court cases
- eyewitness certainty and accuracy do not correlate
- Uncertainty but usually
correct? - Certainty but usually
incorrect? - Many eyewitnesses incorrectly identify culprits
- When people are stressed, their memory is impaired
- Cross-race identification is especially poor
- Presence of a qun lowers
reliability
–> Less time focusing on
person’s face
–> Guns are stressful!!!
Amnesia
- retrograde
- anterograde
Retrograde amnesia
- Inability to remember old
things - Can think about it as the
“recall process” being broken - Reset on memory, can start from scratch and create new ones though
- Loss of episodic memory
Implicit and semantic
memories remain intact
–> Remember how to
walk, talk, speak
English
Anterograde amnesia
- Inability to form new
memories - Can think about it as the
“encoding process” being
broken - Loss of ability to form new explicit memories
- Implicit memory remains
intact - Can learn to drive a
manual car, then forget
that you know how to
HENRY MOLAISON:
- hippocampi removed to prevent seizures/ severe anterograde, some retrograde amnesia
- start-tracing task: required to trace an image in a mirror, challenging for everyone/ you get better at it over time.
- no explicit memory of the task, but got better at it; procedural memory remained intact
TEACHES US: implicit memory is stored somewhere other than hippocampi
CLIVE WEARING
hippocampi destroyed by a viral infection; severe anterograde amnesia
What did we learn from famous cases?
- hippocampus involved in forming new memory (but not in storing LTM)
- implicit/explicit memories rely on different parts of the brain
- semantic and episodic memory are stored and function separately
Cognitive Development
Humans’ development of the ability to think and reason about the world
Scheme
- mental representation of specific object
- What it does, what its for, how to interact with it
- Example: A child grows up with a cat and makes a mental representation of how to interact with it: Fluffy, you pet it, it meows, it likes to chase mice and laser pointers etc.
Assimilation:
- a new object is added to an existing scheme
- Example: a dog is added to the household and the child treats it the same as a cat: includes it in the same scheme as cats
Accommodation
- schemes are changed. Created or expanded in response to a new object
- Example: the child considers the dog different from a cat, and changes schemes to represent its unique behavior
Operation:
- a reversible action
- Like writing on a whiteboard, or turning on and off lights
Piaget’s Developmental Stages
- sensorimotor
- preoperational
- concrete operational
- Formal operational
Sensorimotor
- Birth - 2 years
- Children develop schemes for acting on objects
- Objects must be physically present
- Children in this stage have difficulty conceptualising absent objects
- Object Permanence: Realising an object continues to exist when out of sight
- Children graduate from this stage by gaining object permanence (and some other skills)
Preoperational
- Roughly age 2 - 7 years
- CAN use symbols to represent absent objects
- Pictures, language
- Objects and events no longer have to be present to be thought about
- Centration: focusing only on the most obvious feature of an object or situation
- Have trouble considering other people’s points of view
- Are easily captured by surface features
–> Halloween costumes! - Children in this stage can be convinced that you are the thing the costume represents and not someone in a costume!! - Conservation tasks: an operation is performed that changes only the appearance of an object
*Example: pouring water from a short and large beaker to a long and thin beaker - same amount of water, but it looks taller - To pass, children must realise nothing else has changed
- Fail because they focus on appearances, do not perform mental operations
- Children graduate by overcoming centration and learning other skills like perspective-taking
Concrete-Operational
- Roughly ages 7-12 years
- Correct understanding of objects based on principles, not appearances
- Reasoning is more rule-based
- But understanding is still closely tied to personal experience
Formal-Operational
- Roughly ages 12 and up
- Children are no longer tied to experiences for understanding:
- CAN reason theoretically about the world
- CAN conceptualise hypothetical situations
Critiques of Piaget’s Theory
- Piaget’s theory is influential, but has weaknesses
- Depicts children’s thinking as too consistent
- Underestimates abilities of children
- Understates role of the social world
Vygotsky’s Theory of Development
- Focused on social contribution to cognitive development
- Idea that children learn because people teach them, they don’t learn independently
- Scaffolding: when initial help is given, but gradually removed as children learn
- Zone of proximal development (ZPD): stage at which children benefit from instruction
Attachment:
- Strong emotional bond shared with those we are closest to
- Children form attachments to their parents (or PCG)
- Ensures the child does not wander away into danger
- Also important for normal development
Attachment in animals
- Imprinting: baby birds will follow and “attach to” the first large moving object they see
- Konrad Lorenz
- Humans don’t imprint…
Harlow’s monkey experiments (unethical)
- What is important for attachment? Nourishment?
- Baby rhesus monkeys separated from mothers at birth
- Raised them independently with…
- A wire “mother” who provided food - >1 hour/day
- A cloth “mother” who was soft - 18hrs/day
- Baby monkeys preferred the cloth mother - more time spent = attachment
- Contact comfort: positive emotion afforded by touch
- Monkeys would then be frightened by a loud mechanical “predator”
- Would run to the cloth mother, then gain confidence and “threaten” the mechanical predator.
- Scared monkey = bad. Unethical. horrible
Attachment in humans
- John Bowlby
- Theories for how attachment develops over time
- Mary Ainsworth
- Measurement of attachment quality
- Attachment provides a secure base to explore the world
The Strange Situation
- Used to measure children’s attachment
- Capitalises on stranger anxiety and separation anxiety
Attachment styles
- secure
- insecure-(avoidant)
- insecure-ambivalent
- disorganized
o Depends on both infant and parent:
- Child’s temperament
- Parent’s responsiveness
- Cross-cultural differences
- Percent secure is stable, but rates of insecure types vary
- Reactions are culturally defined, don’t apply to everyone
Secure
- Baby is upset by PCG’s departure, but comforted by their return
- ~60% of US infants
Insecure-avoidant
- baby is indifferent to PCG’s departure and return
- ~15% of US infants
Insecure-ambivalent (aka resistant, anxious)
- baby is upset by PCG’s departure, but not comforted by their return
- ~10-15% of US infants
Disorganized (aka disoriented)
- characterized by inconsistent or confused reactions to PCG’s departure and return
- ~10% of US infants
The strange situation:
- Used to measure children’s attachment
- Capitalizes on stranger anxiety and separation anxiety
- Attachment styles
- Based on reactions in the strange situation
o Reflects relationship/ expectations with PCG (primary caregiver)
Parenting styles fall into four main categories
o Permissive
o Authoritarian
o Authoritative
o Uninvolved
* Based on levels of control and acceptance
* Authoritative parenting has the best outcome in
Motor Development definition
– the ability to move and coordinate one’s actions
Motor development
- Starts w/ reflexes
o Sucking (placing the nipple of the bottle in an infant’s mouth and in response the infant will suck on the bottle—often is challenging for newborns)
o Rooting (occurs when you stroke the side of an infant’s cheek and their mouth open) – inborn schemes/skills
o Grasping (place something in the palm of the infant and they grasp the object instinctively)
o Stepping (if you support the infant’s weight in a walking position, they will step)
o Babinski (occurs when you stroke the bottom of the infant’s foot, and the toes will fan out)
o Moro (occurs when an infant feels they’re losing support around the neck and head area, the baby will arch their back and flail their arms out) - Steps in locomotion
o Dependent on muscle strength/ physical development
o Tied to the development of other abilities too
~3 months
prone—pushing up with hands
5-6 months
sit up without support
~8.5 months:
crawling
10 months:
stand with support, pull up to standing
12 months
first steps
15 months
walking by themselves
18-24 months
running
Theory of mind
- Understanding other’s thoughts/perspectives
- Understanding of self
o Develops ~18-24 months, precursor to theory of mind
o Understanding YOU are an entity, separate from others
o Rouge test: do they recognize themselves in a mirror? - Understanding that others have beliefs, desires, and intentions
- AND that these can be different from ours, and reality
- Children develop theory of mind around 4 years of age
o False belief task - Location change
- False contents
Self-control
- the ability to inhibit our impulses
- Children are notoriously bad at it
- Related to frontal lobe functioning
- Delay-of-gratification predicts later life success
- Marshmallow test
Basic Components of Language
- morpheme
- syntax
- extra-linguistic information
Infants learn aspects of language even before birth
* Learn flow of their native language
* Prefer native language to other languages
Morpheme
- smallest units of meaning in a language
- Re- -ish -ed
Syntax
- rules for how words should be put together
- The cat chased the dog vs. the dog chased the cat
- -s = plural -ed = past tense
Extra Linguistic Information
- other clues to meaning
- tone, gestures, sarcasm
- pragmatics
Lang. 2 months
- cooing and vowel sounds
- “aaaahhhhhh” “eeeeeeee”
Lang. 3-4 months
- syllables and consonant sounds
- “gah” “bah”
Lang. 6 months
- reduplicative babbling
- “gagagaga”
Lang. 10 months
- conversational babbling
- “bagado voota?” “sebawagadaboo!”
- intonation
Lang. 10-12 months
- first words
- “dada” “cookie” “doggie”
- Comprehension precedes production
Lang. 1-1.5 years
- 20-100 words
- Holophrases: “doggie”
Lang. 2 years
- several hundred words
- Two-word phrases: “more juice”
- Telegraphic speech
Babies and language
- Babies are born with the ability to discriminate any phoneme in any language
- But, we lose this ability a after the first year
- Accents arise b/c 2nd language learners no longer hear all phonemes clearly
1st language
- languages infants learn from birth
- usually learn from family, at home
- no direct teaching
2nd language
- languages we learn later in life
- in school, due to moving, etc.
- Can involve direct teaching
Critical period
- deadline for acquiring a skill, ability
- After it passes you lose the ability to acquire it
Is there a critical period for 1st language learning?
- yes
- Genie
- Late deaf learners of sign language
Genie
- Good at communication
- Trouble with syntax
- Not able to acquire native levels of 1st language
Is there a critical period for 2nd language learning
- No, but it gets harder
- After age 7 it becomes increasingly difficult to acquire native levels of a 2nd language
- Bottom line: if you’re planning to learn a 2nd language, do it now
