Psych 100 Exam 2

Week 6: Sensation and Perception

Sensation: detecting physical energy with our sense organs (eye, nose, ears, skin)

Perception: The brain's interpretation of the raw sensory information 

Illusion: The way we perceive a stimulus doesn't match its physical reality 

• Illusions tell us that perception is a process

Transduction: conversion of an external stimulus into a neural signal

Sensory receptors: Specialized cells designed to convert energy into a neural signal 

Sensory Adaptation: sensory neurons adjust their sensitivity based on recent stimulus history

• Examples: Perceiving smells, motion effects, Color after-images

Aftereffects: Opposing sensory or perceptual distortions that occur after adaptations

Waves

Both sound and light are waves

Crest- The highest point in a wave

Trough- Lowest point in a wave

Wavelength- Distance between one wave to the next

• Pitch corresponds to the wavelength of sound

• Color corresponds to the wavelength of light

Amplitude-

Frequency- How many waves occur in a period of time

Psychophysics: is the study of how our sensations correspond to physical events in the world

Absolute threshold: The lowest level of stimulus needed for the nervous system to 

Just noticeable difference (JND): the smallest change in the intensity of a stimulus that we can detect

Weber’s Law: the stronger the stimulus, the bigger the change needed to detect it

Signal detection theory: how stimuli are detected under different conditions

Signal- what we are trying to detect

Noise- similar stimuli that might compete with the signal interfere with your ability to detect the signal

• For example, Bird amongst the leaves

Signal-to-noise ratio

Difficulty detecting the signal depends on the strength of the signal in relation to the strength of the noise

Attention- taking sensory information and focusing on the important part

• Dichotic Listening: play different information through each ear of headphones. Information reported only from attended ear

  • The cocktail party effect happens when important information pops out in a conversation that you are not attending

• Inattentional blindness: occurs when unattended stimuli are ignored as if they weren’t there

  • Change blindness is a version of this that occurs when you fail to detect

Bottom-up processing: constructing a representation from parts and basic features 

Top-down processing: processing influenced by previous experience and knowledge

Sensation is bottom-up processing

Perception is top-down processing

Perceptual sets= sets are formed when our expectations influence our perceptions 

Vision

Structure of the eye:

Sclera- the white part

Pupil- the circular hole where light enters

Iris- Colored portion of the eye that controls pupil size (letting in more or less light)

Cornea: Curved transparent layer covering the iris and pupil that helps focus light

Lens: the oval-shaped disc that bends light

Accommodation: Changing of the lens shape to focus on near/far object

• If your eye is too long: Myopia (nearsightedness)

• If your eye is too short: Hyperopia (farsightedness)

Retina: Membrane at the back of the eye responsible for converting  light into a neural signal

• Fovea: Central portion of the retina, responsible for visual  acuity

• Acuity: sharpness of vision

• Saccades: small jerky movements of the eye allowing for rapid changes of focus

Rods:

• Respond  under low levels of light

• Not color sensitive 

• More common outside the fovea

Cones:

• Sensitive to fine detail

• Primarily located in fovea

• Color sensitive

• Less plentiful than rods

Optic Nerve: BUndle of axons that travel from the retina to the brain

Blind Spot: Area of the retina where the optic nerve exits the eye

Color perception

Hue: The color of light

• Corresponds to wavelength

Trichromatic theory: Color vision is based on three primary colors, blue, green, and red

We have three types of cones (ones like red, ones like blue, and ones like green wavelengths)

Opponent-process theory: We perceive colors in terms of three pairs of opponent colors:

• Red-green

• Blue-yellow

• Black-white

Color blindness: Inability to see some or all colors

• Due to the loss of one or more types of cones

Multiple objects in the world are 3D

Depth Perception- ability to judge distance and spatial relations

Depends on:

• Binocular depth cues: involve two eyes

  • Convergence: eyes converge to see near objects

• Monocular depth cues: Involve one eye

  • Relative size

  • Texture gradient

  • Interposition

  • Linear perspective

  • Height in plane

  • Light and shadow

  • Motion parallax

Perceptual Constancy:

Shape  Constancy: the perceived shape is constant, even though the shape of the image on the retina varies

Size Constancy:  perceive  stimuli as consistent  across various conditions

Color Constancy: perceive stimuli as consistent across varied conditions 

Perceptual Constancy: perceive stimuli as consistent across varied conditions

Gestalt Principles of Perceptual Groupings: 

• Figure Ground Separation: Your visual system automatically tries to identify figures

• Proximity: Elements arranged close to each other are perceived as more related than those placed further apart (groups/grouping)

• Continuity: Elements aligned in a way suggesting to be a continuous line or curve are perceived as being more related to each other

• Similarity: We relate objects based on how similar they are to one another (ex, color, shape, etc)

• Closure: Perceiving incomplete shapes or figures as complete

• Symmetry: when perceiving objects we tend to perceive them as symmetrical shapes that form around their center (ex, faces)

Gestalt Principles: Rules that govern how we perceive objects as wholes within their overall context

Week 7

What is learning?

Change in an organism's behavior or thoughts as a result of experience

• Relatively permanent 

Learning is adapatvice

• Species learn behaviors that aid in survival

Types of learning

• Non-associative learning

  • Habituation: responding less strongly to the stimulus over time

    • Adaption of sensory receptors

  • Sensitization: Process of responding more strongly to stimulus over time; usually dangerous or irritating stimulus

• Associative Learning: Making a connection between two or more stimulus/events that occur together in the environment

  • Classical Conditioning: A form of learning in which two stimuli are repeatedly paired

  • UC; Unconditioned response: something that doesn’t need to be learned (reflexive)

  • CS; Initially neutral, becomes associated with the UCS

  • CR; Automatic response to the now-conditioned stimuli

  • Acquisition: Learning phase when the tUCS is paired with NS

  • Extinction: CS appears alone and the CR weakens, CR is eventually eliminated

  • Spontaneous Recovery: Extinct CR suddenly emerges again after a delay, Relearning happens more rapidly than initial learning

  • Renewal effect: Sometimes a response is extinguished when the organism is in different contexts, but if the organism goes back to the original setting it may come back

  • Generalization: Respond to stimuli that are similar to the conditioned stimulus

  • Discrimination: Respond to a particular stimulus but not a similar stimuli; don't respond to stuff that is too different

  • Blocking: A prior association with a conditioned stimulus prevents learning of an association with another stimulus

  • Preparedness: Biological predispositions to learn some associations more quickly than other associations (based on survival value)

  • Taste aversion conditioning: Associating nausea with food, helps avoid food that has gone bad or is poisonous (example of preparedness) 

  • Fear Conditioning: Negative associations can be so powerful that they are learned extremely rapidly (easily generalized to other similar stimuli)

  • Chronic Drug use: When a drug is used, it is associated with the cues present at the same time

    • Ivan Pavlov

      • Russian physiologist

      • Known for work on dog digestion 

  • Operant Conditioning

Factors that Influence Classical Conditioning

• The intensity of the conditioned stimulus

• The temporal relationship between the CS and the UCS

• How reliably the CS predicts the UCS

• The number of pairings of the CS and the UCS

  • In general, the greater the number of pairings, the stronger the conditioned response

Operant Conditioning

• Change in voluntary behaviors as a result of the consequences

• Based on Thorndikes Law of Effect: behavior is a function of its consequence

  • If a certain behavior leads to favorable consequences → more likely to repeat said behavior

• Basic Assumption: Learning is controlled by the consequence of the organism's behavior

  • Depending on the consequences, the organism either increases or decreases the likelihood of conscious, voluntary behavior

• Behavior is now under stimulus control

  • Stimulus signals the consequence

• Discriminative Stimulus: Any stimulus that signals the presence of reinforcement 

• BF Skinner: Skinners Box

  • Behavior= Press lever when the light comes on

  • Change the behavior using food and shocks

Consequences of Behavior

Reinforcement: Increased likelihood of that behavior being repeated

• Behavior is strengthened

• Positive Reinforcement: The addition of a pleasant stimulus reinforces the behavior and strengths it

• Negative Reinforcement: The removal of the unpleasant stimulus reinforces the behavior and strengths it

Punishment: Decreased likelihood of that behavior being repeated

• Behavior is weakened

• Positive Punishment: The addition of an unpleasant stimulus that weakens the behavior occurring in the future

• Negative Punishment: The removal of a pleasant stimulus reduces the likelihood of performing that behavior in the future

Classical Conditioning:

• Automatic behaviors

• Associate: UCS + CS

• Result: CR

Operant Condittioning: 

• Voluntary Behaviors 

• Associated: Behaviors + Consequence

• Result: more/less behavior

• Operant conditioning involves more choice

  • Response requires choosing one behavior over others

Quantitative Law of Effect: The effects of reinforcing one behavior depend on how much reinforcement is earned for the behavior alternatives

Reinforcement Schedules

• Continuous: Behavior is rewarded every single time it is performed

  • Faster acquisition

  • Faster Extinction

• Partial: Behavior is rewarded only some of the time

  • Slower acquisition

  • Slower extinction

  • Fixed ratio, Variable ratio, fixed interval, variable interval

Time Amount

• The amount of time does matter between behavior and consequence

Punishment may not always be appropriate or productive

Children seem to learn better with reinforcement than with punishment

Problems with Punishment

• Can model bad/aggressive behaviors

• This may lead to sneaky behaviors to avoid punishment

• Can create anxiety or subversive behaviors

Applications of operant conditioning

• Training animals is usually done through operant conditioning

• We can learn good habits by operantly conditioning ourselves 

• Establishing token economies in clinical settings has been an effective way to encourage good behavior

Observational Learning

• Learning by observing and imitating others

  • Infants can do it

• Component of Social Learning Theory:

  • Learning is a cognitive process derived from social observation and does not necessarily require reinforcement

    • Learning from social models (ex. Parent, teachers, other authority figure)

    • Bobo Doll Study

  • Attention: You must pay attention ( for observational learning to occur)

  • Retention: you must be able to keep the behavior in your memory

  • Initiation: you must be able to execute (or initiate) the learned behavior

  • Motivation: you must possess motivation to engage in observational learning

Insight Learning

• Grasping the underlying nature of a problem

  • Immediate and clear understanding

  • Sometimes at the first try - so not through trial-and-error

• “Aha” moment

  • Get the solution and apply it in the future

Week 8

What is memory?

The capacity to store and receive information in order to facilitate learning

3 Stages of memory

• Encoding

  • Getting information into memory

  • Automatic Processing: Encoding of details like time, space, frequency, and the meaning of words

  • Effortful Processing: Encoding of details that require effort and attention on your part

  • Levels of processing: The multiple levels at which encoding can occur ranging for shallow to deep

  • Shallow → → → →→→→→→→→→→→→→Deep

    • Visual (surface) Acoustic (sound) Semantic (meaning)

  • Self-referential encoding

    • Based on an event related to our own self-concept 

• Storage

  • Keeping information in memory

  • Capacity: how much info can be held

  • Duration: How long can info be held

  • Atkinsons and Shiffrins Model of Memory

  • Sensory Memory: Sensory information on the order of milliseconds to seconds. Substantial storage capacity, but very limited duration 

    • Ear (echoic) → lasts 5-1 seconds

    • Eye (Iconic) Last 1 second or less

  • Short-term memory: retaining info for a short amount of time (15 to 30 seconds), Holding a limited amount  of info, Can be forgotten or transferred to our long-term memory

    • Chunking: organizing information into meaningful “chunks” 

    • Working Memory: Holding/manipulating/processing during that short time

      • Phonological loop

      • Visuospatial sketchpad

      • Central Executive

  • Long-term memory: retaining info for a long amount of time (minutes to decade), No limits in capacity or duration

    • Explicit Memory- Memories we can recall intentionally; can be stated.

      • Declarative memory 

      • Episodic Memory:  Recollection of events, and specific experiences, typically have time and place components

      • Semantic Memory: Recollection of facts, general knowledge

    • Implicit Memory: Memories we cannot recall deliberately. Nondeclarative

      • Procedural: Information about the way we do things, you do not think about it you just do it, we cannot describe them easily

      • Priming:  When exposure to one stimulus affects the response to a later stimulus

      • Emotional Conditioning: Type of memory involved in classically conditioned emotional responses, these emotional relationships cannot be reported or even recalled/ but can be associated with different stimuli

    • Serial Position Effect

      • Primacy effect: remembering the first things that occurred/on a list

      • Recency effect: remembering the last things on a list/or that occurred last

• Retrieval

  • Accessing information from memory

  • Recall: Generating remembered information

    • Free recall: No cues to aid retrieval

    • Cued-recall: Retrieval cues that help bring the memories back to mind

  • Recognition: Selecting the correct information from an array of options

  • Relearning: Learning the information that you previously learned

  • Encoding specificity principle

    • Remember best when retrieval conditions match encoding conditions

    • Greater match = better memory

    • Physical context: COntext dependent memory

    • Physiological state: State-dependent memory

    • Mood: Mood dependent memory

  • Context-dependent memory: better memory when encoding and retrieval

  • State-Dependent Memory: better memory when a person is in the same state during both encoding and retrieval

  • Mood Dependent Memory: Better memory when a person is in the same mood during both encoding and retrieval

Memory can be surprisingly good and surprisingly bad

• The paradox of memory

Memory is not a recording

Memory is reconstructive

Misinformation effect: Creation of false memories due to misleading information provided after the event

False memories: Recalling an event that did not actually happen or recalling an event differently from the way it happened

Emotional memories

• Flashbulb memories: Memories of important events might feel different than regular events

  • Seem clearer, more vivid, more persistent, exceptionally detailed

  • Don’t decay because rehearsed often and recalled fairly frequently

Schemas

Schema: Organized knowledge structure used for understanding and remembering; kind of mental model; framework

• Can be used to “fill in gaps” in memory unless more specific information is provided

• Can be used to generate expectations for what is likely to be true in a situation

Memory-Enhancing Strategies

• Rehearsal

• Chunking

• Elaborative Rehearsal: Instead of passively learning information, you think about the meaning of that information and its relation to other things that are already stored in your memory

• Mneumonic Devices: Memory aids that help us organize information for encoding

  • Ex, PEMDAS

• Writing and saying words aloud also boost memory

Tips for Successful Learning

1. Use elaborative rehearsal

   1. Make information meaningful for you

2. Apply the self-reference effect

   1. Connect the material to other personal information

3. Use distributed practice

   1. Spacing effect: The enhanced ability to remember information when encoding is distributed over time

4. Rehearse

   1. Review the material over time, in spaced and organized study sessions

5. Study Efficiently

   1. Make flashcards, etc

6. Be aware of interference

   1. Distractions may interfere with the information you studied

7. Exercise

8. Get Enough sleep

9. Make use of mnemonic devices

Forgetting

Loss of information from long-term memory

We forget as often as we remember

Encoding failure: Sometimes memory loss happens before the actual memory process begins

• This happens because we do not pay attention to the information in the first place

Interference

• Interference created by new information leads to forgetting

  • Proactive, retroactive

• Proactive interference: when old information interferes with our ability to remember new information

  • Old info → new info

• Retroactive interference: when new information interferes with or ability to remember old information 

  • Old info ← New info

• Amnesia

  • The loss of memory due to brain damage or trauma 

  • Retrograde amnesia

    • Forgetting the past (things that have already happened)

    • Very uncommon type of  amnesia

    • Recovery of memory (if any) happens very slowly

  • Antegrade amnesia

    • Can't learn new things

    • Caused by damage to the hippocampus

    • Most common type of amnesia

• Amnesia impairs explicit memory, but not implicit memory

  • Fear memories stored by the amygdala remain even when explicit memories in the hippocampus are gone

  • Procedural memory also remains intact in most amnesia patients

Eyewitness Misidentification

• Eyewitness memory can be fallible

  • Mistaken eyewitness identifications contributed to 71% of the wrongful convictions overturned by DNA evidence

• Example: Ronald Cottons Case

  • In 1984, Jennifer Thompson was sexually assaulted and stabbed

  • After the police contacted, a composite sketch was made

  • Jennifer was shown 6 photos

  • By the time of the trial, Jennifer had no doubt about her choice

  • Cotton was convicted 50+ years in prison

  • After 11 years in prison, DNA evidence showed that Ronald Cotton was innocent

  • Bobby Poole was the one who committed the crime

• Eyewitness memory is even worse when:

  • Talked to another witness (misinformation effect and source confusion)

  • When the witness is interviewed repeatedly

  • Situation was stressful

  • Witness is a child (more vulnerable to suggestions)

Memory Errors

Daniel Schacter identified seven ways our memories fail us; the seven sins of memory

1. Transcience: Accessibility of memory decreased over time

   1. We forget things that happened a long time ago

2. Absentmindedness: Forgetting caused by lapses in attention

   1. Forgetting where you left your phone

3. Blocking: Accessibility of information is temporarily blocked

   1. Tip of the tongue

4. Misattribution: The source of memory is confused

   1. Ex, Who told me that? What class did I learn that in?

5. Suggestibility: False memories due to the others’ suggestions

   1. Example: A therapist might lead you to believe that you experienced a traumatic event in the past -- even though that never happened

6. Bias: Memories distorted by the current belief system

   1. Ex, We tend to remember ourselves in a more positive manner

7. Persistence: Inability to forget undesirable memories

   1. Ex, You witness a horrific car accident on the way to work one morning, and you can’t concentrate on work because you keep remembering the scene

Week 9/Week 10

What is a rational decision?

• Are humans rational decision-makers?

  • We try to make rational decisions, but we are limited in some ways

  • Time and cost constraints limit the amount of information we have

  • Memory- we can only remember a limited amount

• Bounded willpower- we don’t always do what we know is best

• Bounded self-interest- We consider outcomes for others, not just ourselves

• Bounded ethicality- We may not even be aware of ways we violate our ethics

• Bounded awareness- we may fail to notice obvious information that is available

System 1 and System 2 Thinking

• We are prone to using heuristics (mental shortcuts) that can lead us astray 

System 1: Thinking that is fast, intuitive, automatic, implicit, effortless, emotional

• Automatic

• Involuntary/Cannot be turned off

• Can evaluate only one thing at a time, or simple relations like “alike”

• Generates intuitions, feelings, and impulsive responses

• Ex, The washing machine looks super!

System 2 Thinking: Thinking that is slow, deliberate, effortful, explicit, logical

• Effortful

• Feels voluntary, involves feelings of choice and agency

• Require attention

• Able to follow rules, switch “task sets”, compare options on multiple attributes, make deliberate choices

• Compare 2 washing machines for overall value

Biases and Heuristics that lead us astray

Biases- ways our reasoning and decision-making ends to be systematically distorted

• Confirmation Bias: Tendency to seek out evidence that supports our beliefs and deny, dismiss, or distort evidence that contradicts them

• Overconfidence bias: People tend to overestimate their ability

• Anchoring and Framing effect: 

  • Framing Effect: Being influenced by the way information is presented 

  • Anchoring effect: When making estimates, an initial anchor is likely to influence the size of our estimate

Heuristics- Shortcuts in reasoning that lead to errors

• Representative heuristic: Judging the probability of an event based on how similar it is to a prototype, rather than considering the base rates

• Availability heuristic: When asked to judge how likely something is, instead you judge how easy it is to recall it

  • Not a good way of getting an accurate estimate of the likelihood

Intelligence

What is intelligence?

Intelligence is multi-faceted, and even experts who study intelligence do not agree on what it is

There is no standard definition of intelligence, however, most definitions include

• Abstract Reasoning: ability to understand hypothetical concepts rather than concepts in the here and now

• Learning: the ability to acquire new knowledge

• Adapting to new circumstances

• Benefiting from experience

Chris Langan: Child prodigy, a man with one of the highest IQs

• Most would say he isn’t that intelligent as intelligence is not the same as life achievement

Ideas about intelligence: Spearman’s g

• g: General intelligence- a hypothetical factor that accounts for overall differences in intellect

• s: Particular ability in a narrow domain

Gardner Multiple Intelligences:

Linguistic: Speak and write well

Logico-mathematical: Use logic and mathematical skills to solve problems

Spatial: Think and reason about objects in 3D

Musical: Perform, understand and enjoy music

Bodily-Kinesthetic: Manipulate the body in sports, dance, and physical feats

Interpersonal: Understand and interact effectively with others

Intrapersonal: Have insight into oneself

Naturalistic: Recognize, identify and understand plants, animals,

living things

Sternbergs 3 Intelligences:

Analytical: Score well on standard IQ tests, logical abilities, do well in school

Practical: Plan a party, manage a work team

Creative: Novel ideas, compose music

Fluid Intelligence- Capacity to learn new ways of solving problems, to “think on your feet”

Crystallized Intelligence- Ability to use accumulated knowledge of the world to solve problems

Intelligence Tests

Standardized- Administered in the same way

Normed- Constructed so that results are normally distributed with a mean of 100

Flynn Effect: Over time, the average score on intelligence tests has increased

History of Intelligence Testing: Ideas and Applications

• Francis Galton

  • Intelligence is a fixed heritable trait associated with sensory processing speed

  • Francis Galton coined the term “Eugenics”

  • Eugenics- Selective breeding of the human population to improve desired characteristics 

• Alfred Binet

  • Measured intelligence in children in terms of mental age

    • Intelligence = Mental Age/Chronological Age x 100

  • Used to measure intelligence to help place children in an appropriate school setting in the early days of universal public education in France 

• Lewis Terman

  • Developed the Stanford-Binet Intelligence Test Sympathized with eugenics - wanted to eliminate reproduction of the feeble-minded and the elimination of an enormous amount of crime, pauperism, and industrial inefficiency 

  • Worked with the U.S Govt. to develop tests for army recruits, immigrants, vocational placement

Military - WWI - 1918

• Army Alpha Test (for English Speakers)

• Army Beta test (for non-English speakers)

• Used to place new recruits

• 47% scored mental age of 13 or less 

Tests were used in

• Immigration -- used to identify immigrants who might be “mentally defective”

Modern Tests

David Wechsler

• Developed the Wechsler Adult Intelligence Scale (WAIS)

• The most widely used modern intelligence test

Growth Mindset: Believing abilities are changeable

Fixed Mindset: Believing abilities are not changeable