principals of psych 2

Basic concepts of sensation and perception

• Sensation: detecting physical energy (a stimulus) in the environment and converts it to neural energy

  • Vision, hearing, smell, touch, taste

• Perception: process of organizing and interpreting sensory information

Sensation IS NOT perception

Basic principles: thresholds

• We do not perceive everything in our environment

• Absolute threshold: minimum stimulation (amount or strength) needed to detect stimulus

  • 50% accuracy

• How do you find absolute thresholds?

  • liminal: noticeable

  • No one is seeing it: subliminal

  • 50 % or more sees it: non subliminal

Subliminal persuasion pg 203

• Difference thresholds: minimal difference between two different stimuli (intensity/ strength) that someone can't erect 50% accuracy in detection

• Example: how much louder does music need to be so that you notice?

Basic principles of sensation

Transduction: converting one form of energy into another

• Transforming physical signals into neural signals

• Light waves -> transduced into action potentials -> perceived as “brightness”

1. Receive sensory information

2. Transform stimulation into neural impulses (transduction)

3. Deliver the neural information to brain

Basic principles: sensory adaptation

• Sensory adaptation: diminished sensitivity to sensory information as a result of constant stimulation

• “Getting used to it”

• Why is sensory adaptation important/ beneficial?

  • We are free to focus on changes in our environment

  • Sensory receptors sensitive to novelty and change

  • We perceive the world as it is useful for us to perceive it

Perception I Perceptual interpretation

• What affects the way we interpret and organize sensory information?

• Perceptual set: predisposition to perceive one thing and not another

  • Broad term! May be activated by experience, assumptions, and expectations

  • News headlines and media can give us a perceptual set to interpret certain kinds of information

  • Can “frame” information / push people to think one thing and not the other

• Context effects: immediate context can change perception

  • Hearing happy vs. sad music can change auditory perception

• Emotions and motivation can also affect perception

  • People throwing heavy things viewed target as further away than people throwing light things

  • Water bottles were perceived as closer for thirsty vs. non thirsty participants

2

Light energy

• The physical stimulus of the vision system

• 2 characteristics of light waves affect perception

1. Wavelength/ frequency

   1. Determines the actual color you perceive (hue)

   2. Short wavelength = high frequency = bluish color

2. Amplitude/ intensity

   1. Determines the brightness of color

   2. Great amplitude = high intensity = bright color

Eye

• Cornea: clear membrane that covers the front of the eye

  • Focuses light into eye

• Iris and Pupil

  • Iris is opaque, colored

  • Pupil is the hole in the iris; size of pupil controls how much light gets in

• Lens: focuses the light into the eye, onto surface of retina

  • Will bend and change shape to focus light from near/ far objects

  • Distortion in lens causes nearsightedness/ farsightedness

• Retina: thin membrane at the back of the eye

  • Contains the photoreceptors, the sensory neurons of vision

  • Contains fovea; optic nerve that sends visual info to brain

  • Image projected onto retina is upside down; the brain “flips” it right side up

• Fovea: pit in the back of the retina

  • Direct spot of retina that light focuses on

  • Highest concentration of photoreceptors

Features of retina

• Optic nerve connection:

  • Bipolar cells send messages from photoreceptors to ganglion cells, which bundle to form optic nerve

  • Where optic nerve exists to brain

• Blind spot

  •  

• Photoreceptors

  • 2 types:

  • Rods

    • General sensitivity and detection

    • Vision in dim light

    • No rods present in fovea

    • Active photochemical: rhodopsin

    • “Taller”

    • Spread across retina, more rods than cones

  • Cones

    • Detail and color

    • Vision in bright light

    • Most concentrated in fovea

    • Different phytochemicals for different colors

    • “Shorter”

Rhodopsin: vision in the dark

• Dark adaptation: adapting to darkness (turning off lights)

  • Bright -> Dim

    • Cones not sensitive enough for dim vision

    • Rhodopsin takes time to regenerate in dim light

    • Slower to adapt to dim vision

• Light adaptation: adapting to light (turning on lights)

  • Dim -> Bright

    • Light immediately disables rhodopsin

    • Much faster to adapt to light vision

Feature detection

• Neurons in visual cortex (occipital lobe) are feature detectors that are sensitive to orientation, color, movement

  • How does the brain combine separate features into one “thing”?

• Feature-integration theory: to perceive a stimulus, primary features (orientation, color, etc.) must be detected then integrated

  • Detection occurs in parallel: all at the same time

  • Integration occurs serially: step by step

Errors in detecting features

• Illusory conjunction: a perceptual mistake where features from multiple objects are incorrectly combined

  • Color + shape

• Easy to make errors about which color goes with which shape

• Difficult to make errors about which colors or shapes were present

• Feature detection is parallel (knowing all the shapes and colors)

  • Less affected by time limit

• Feature integration is serial (matching shape to color)

  • More affected by time limit

Perceptual organization

• Gestalt: “an organized whole”

  • Emphasize our tendency to integrate pieces into a meaningful whole

  • “The whole is greater than the sum of its parts”

  • Brain does more than registar information -> it interprets and gives meaning

Form perception

Figure vs ground

• Tendency to divide visual scenes into figurte (object attracting attention) and ground (background)

  • Reversible figures don't have many cues (hints, clues) about figure and ground

  • Or cues that suggest multiple figures/ grounds

Grouping

• Tendency to group things together

  • Proximity: nearby figures grouped together

  • Continuity: tendency to perceive continuous patterns

  • Closure: we fill in gaps to create whole objects

Depth perception

• Issue: how do we locate an object in a 3D world when all we have is a 2D image on our retina?

• Depth perception allows us to estimate distance between us and objects

Binocular cues

• Retinal disparity: view from each eye is slightly different

  • Images hit out eyes at different angles -> different images

  • We “know” that the greater the difference, the closer the object

Monocular cues

• Relative size: if two objects are similar in size, we perceive the “smaller” one to be farther away (but can also lead us astray)

• Interposition: if one object blocks our view of another, “blocker” must be closer

• Linear perspective: parallel lines (railroad tracks) appear to converge in the distance

  • therefore , the closer the lines, the further away it must be

• Relative motion

• Rest of monocular depth cues (figure pg 220)

Perceptual constancy

We perceive objects as unchanging (constant) even as lighting changes and retinal images change

Shape constancy

We still see a door as a rectangle, regardless of its angle

Color constancy

We perceive familiar objects as having consistent color even when changing illumination changes the light reflected

Visual illusions

• Ponzo illusion

  • “Railroad” lines create illusion of depth

• Muller lyer illusion

  • Angles of arrows create illusions popping “toward” you or “away” from you

Thatcher illusion

Our brains interpret and make sense of our sensory information

Hearing (pg 226-230)

What is the physical stimulus of an audition?

What aspects of that physical stimulus affect what we hear?

What are the parts of the ear, which are responsible for transduction?

How do we detect loudness, discriminate pitch, and locate sounds?

Learning

Process through which new and relatively long-lasting changes are acquired through experience

• Based on experience

• Produces changes in the organism

• Changes are relatively long-lasting

We learn by association (aka. “associative learning”)

• Our minds naturally connect events that occur together

Conditioning: the process of learning associations

1. Classical conditioning: associate two stimuli with each other (thunder + lightning)

2. Operant conditioning: associate response with consequence (hitting ball + getting fish)

Classical conditioning

Formation of new reflexes to neutral stimuli

Pavlov and his dogs

• Studied reflexive salivary response of dogs in response to food stimuli (old reflex)

• Observed that dogs began salivating to non-food stimuli like a bell (new reflex)

Components of classical conditioning

Unconditioned Stimulus (UCS)

• Stimulus that automatically produces a response before conditioning

Unconditioned Response (UCR)

• Automatic behavioral response to UCS

Neutral Stimulus (NS) -> Conditioned Stimulus (CS)

• Neutral stimulus is paired with the UCS

Conditioned Response (CR)

• New behavior in response to neutral stimulus (which is now CS)

Example:

• UCS = food

• UCR = salivating in response to food

• NS/ CS = ringing bell when food is presented

• CR = salivating in response to bell even without food

The processes of classical conditioning

1. Acquisition

Initial learning of the association between UCS + CS

• CS must be presented immediately before UCS - why?

  • Classical conditioning is adaptive: helps organisms predict good or bad events

    • CS is presented after or long before the UCS does not let you predict

• CS can be sights, smells, sounds, symbols

  • Example: onion breath a CS for sexual arousal

    • Pairing smell of onions with sexual-arousing stimuli

2. Extinction

Weakening of CR when CS is no longer paired with UCS

• If CS is no longer a good signal (predictor) of UCS -> CR becomes weaker

  • Food no longer arrives after bell

  • Mint no longer arrives after computer sound

• CS no longer produces CR

3. Spontaneous recovery

Reappearance of extinguished CR after a “pause”

4. Generalization

Tendency for CR to appear for similar stimuli to CS

5. Discrimination

The tendency for CR to appear ONLY for specific CS

• The opposite of generalization

• Discimination training

Importance of Pavlov's discoveries

• Virtually all organisms can undergo this kind of learning in order to adapt to their environment

  • Nausea in response to foods that have made us sick

  • Fear of animals after bad experience

  • Smart phones, vibrations, checking your phone

• Learning can be studied objectively

  • (behaviorism)

Operant conditioning

Formation of new active behaviors

Law of Effect: consequences of behavior will change future behavior

• make behavior more or less likely to happen in the future

• “If result is good, i do it again; if result is bad, i don't”

Operant conditioning leads to more complex behavior than reflexes

B.F. Skinner

• Operant Response: behavior that has some effect on the environment

• “Aka. “operant behavior”

• Tested with “Skinner box”

  • Manipulated consequence of actions

  • Actions: lever, buttons, light

  • Consequences: food, electric shock

• Operant conditioning: process by which the consequences of an operant response changes the likelihood of that response occurring in the future

  • Process can happen subconsciously

How operant conditioning works

Two types of consequences for operant responses:

• Reinforcers

  • Change that occurs after an operant response that increases the frequency of the response in the future

  • “The behavior was reinforced”

• Punishers

  • Change that occurs after an operant response that decreases the frequency of the response in the future

  • “The behavior was punished”

Reinforcement and punishment can work in two ways:

• Positive: something is presented

  • The arrival of something

  • The presence of something

• Negative: something is taken away

  • The removal of something

  • The absence of something

Putting it together

• Reinforcement

  • Positive: the arrival of something after a behavior that increases the likelihood of that behavior happening in the future

  • Negative: the removal of something after a behavior that increases the likelihood of that behavior happening in the future

• Punishment

  • Positive: the arrival of something after a behavior that decreases the likelihood of that behavior in the future

  • Negative: the removal of something after a behavior that decreases the likelihood of that behavior in the future

Example: your roommate doesn't do the dishes

1. What is the operant behavior?

   1. Roommate doing dishes

2. Do you want to increase or decrease its frequency?

   1. Increase! They should wash more dishes!

3. Positive or negative?

   1. Positive reinforcement: give a cookie every time they do the dishes 

(arrival of something that increases behavior)

2. Negative reinforcement: stop criticizing them every time they do the dishes (removal of something to increase behavior)

Extinction

Decline in response rate without reinforcement

Shaping

Reinforce close approximations to desired response

Partial reinforcement schedule

Two dimensions:

Can combine these

• Ratio vs interval

  • Does reinforcement depend on the number of responses(ratio) or on periods of time(interval)?

• Fixed vs variable

  • Does reinforcement occur in set increments(fixed) or changing increments(variable)?

Schedules of reinforcement

• Which is most effective?

  • Variable more effective than fixed- hard to predict

  • Ratio more effective than interval- hard to predict

Operant conditioning: a warning

• Overjustification effect: if you initially reward a behavior (reinforce it), then remove reward -> big drop in performance (extinction)

  • Without reward, there is no incentive for behavior

  • Read about extrinsic vs intrinsic motivation (pg 271)

Biology, cognition, and learning (end of chapter heading)

• What are the biological constraints on classical and operant conditioning?

• Learning by observation: what was the bobo doll experiment?

Memory

The information we store and the mental processes we use to store and retrieve that information

• Information

• Processes

• Mostly domain of cognitive psychologists

How do we study it?

Retention (memory strength) can be measured three ways:

1. Recall

   1. Retrieving information that is not currently in your conscious awareness

   2. Example: the photoreceptors responsible for vision in the dark are called? RODS

   3. Example: what did you have for dinner last night?

2. Recognition

   1. Identifying information that you previously learned

   2. Making decision about information that is in your conscious awareness

   3. Example: multiple choice questions

3. Relearning

   1. Learning something quicker the second (third, fourth…) time

Recall vs. recognition

• Recall: name the past 10 presidents

• Recognition: was barack obama the president of the USA

Recall is better for practicing and studying

Models of memory

1. Information-processing model

Describes different processes we use to store and retrieve information (memories)

• Encoding: getting information into our brain

Encoding ->

• Storage: retaining information

Encoding ->

<- Retrieval

• Retrieval: getting information out

2. Three stage model

Describes different memory “storage”

• Sensory memory

Encoding ->

• Working memory (short term memory)

Encoding ->

<- Retrieval

• Long term memory

… also includes processes from information-processing model

Sensory memory

• Short lived, fast- decaying memory store (lost in 1-3 seconds)

• Two types

  • Ionic: visual information

  • Echoic: auditory information

• Attention is needed to move information into working memory

Working memory (WM)

• What we are consciously thinking about right now

  • This is ~ our consciousness

  • Information lost in 10- 15 seconds, unless..

• Rehearsal is necessary to keep information in working memory

• Capacity: ~7 “units”

  • A phone number, address

• 3 components of WM

  • Visuospatial sketchpad and phonological loop store different types of sensory information

Central executive

• Focuses attention

• Encodes to long-term memory

Visuospatial sketch pad Phonological loop

(mentally picturing someones face) (mentally repeating someone's name)

Encoding “getting information in”

Some encoding is automatic..

• Procedural skills (kicking a ball)

• Classical conditioning

• Spatial relationships, time, frequency of events

  • What side of the screen was the picture on a few slides ago?

… other information is encoded effortfully

Effortful encoding strategies

Rehearsal:

Continuous repetition of information

Repeating phone numbers or info while studying

• Study

  • Participants learned a word list on day 1

    • Told to rehearse x8 or x16

  • Participants relearned the list on day 2

  • DV: how many minutes did it take to relearn?

  • More rehearsal on day 1 -> quicker relearning on day 2

Types of effortful encoding

• Encoding by images (“visual encoding”)

  • Storing information by converting into mental pictures

• Encoding by organization (organizational encoding”)

  • Categorizing information according to relationship between items

  • Examples: chunking

• Encoding meaning (“semantic encoding”)

  • Actively relating new information to knowledge already in memory

  • Example: connecting infot to previous knowledge, our own life, past experiences

  • This is why making your own examples is effective!

Organizational encoding

• Chunking: organizing items into familiar, manageable units

• Areas of expertise help people chunk more efficiently

• It is easier to encode information when there is structure organization

• Hierarchies: broad concepts divided into narrower concepts

Other things that affect encoding

• Distributed practice

  • Spacing effect: distributed practice better than last minute practice

  • Repeated self-tested easy way to distribute practice

  • Better to practice RECALL than recognition

• Depth of processing

  • The deeper you process information during encoding, the better it will be recalled

  • Study: participants aw list of words

    • Chair, dog, cold, spoon

    • Engage in 1 of 3 strategies

    • DV: memory for words

• Orthographic: based on physical characters

  • Is the word in capital letters?

• Phonological: based on sound

  • Does the word rhyme with “free”?

• Semantic: Based on meaning of information

  • Is the word an animal?

  • Related to past knowledge

Memory is NOT like an empty attic or a video camera

Long term memory (LTM)

• Essentially unlimited capacity

• What are the different kinds of LTM?

  • Explicit memory (declarative) (can describe)

    • Episodic memory (for events)

      • Personally experienced events

      • Remembering when you saw a dog yesterday

    • Semantic memory (for facts)

      • Knowledge of facts

      • General knowledge

      • Knowing what a dog is

  • Implicit memory (non-declarative) (can't talk about)

    • Skill learning

      • Learned abilities

        • Mirror drawing

        • Riding a bike

        • (hard but once you learn the skill, it gets easier)

    • Space, time, frequency

    • Conditioning

      • Stored associations

        • Classical conditioning (5 + CS)

        • Operant conditioning (behavior and its outcome)

Retrieval

Bringing something from long-term memory into consciousness (into working memory)

Spider web analogy

• Memories are not separate, individual items (example, furniture in attic, a recording)

• Information in our head is interconnected

• Activating one memory/ idea/ piece of information activates other related ones

Retrieval Cues

• Retrieval cues: any piece of information that aids retrieval

  • Information that helps you remember other information

  • Related concepts, idead, or contextual information from an event

• More retrieval cues -> better chance of activating information -> retrieval

• Priming: activation (often unconscious) of particular associations

  • Activating a “strand” of web associations

• Context effects:

  • Retrieval is better is the context at retrieval is the same as during encoding

    • Context-dependent memory (location)

    • State-dependent memory (mood, sobriety)

Forgetting

Why do we sometimes fail at retrieving information?

1. Amnesia

• NOT getting concussion/ car accident/ “how did i get home”/ anesthesia

1. Permanent memory loss caused by brain injury or psychological injury

• Anterograde amnesia: inability to form new memories

• Retrograde amnesia: inability to recall old memories

2. Encoding failure

3. Storage decay

4. Interference

Patient HM I example of anterograde amnesia

• Epilepsy started at age 10; surgery in late 20s

• Bilateral temporal lobectomy

  • In other words, the hippocampus was removed

After surgery

• Seizures reduced

• Intelligence increased

• Working memory still operational

… but he developed anterograde amnesia

• explicit/ declarative memory is typically affected in cases of anterograde amnesia

  • Never formed a new explicit memory

  • Couldn't remember that parents has passed away; whether he had lunch, etc

• Some implicit/ non-declarative memory still intact!

  • Skill learning (mirror drawing)

  • Associations

    • Would smile when she walked in; knew she was nice

Patient ML I example of retrograde amnesia

• Damage to right frontal lobe from bike accident

  • Coma for 6 days

Retrograde amnesia

• Often affects episodic memory, but leaves semantic memory intact

• Example: ML could learn about previous events to the accident (semantic), but could no longer re-experience them as a being part of his own life (episode)

• More rare than anterograde amnesia

Encoding failure

Sometimes we fail to retrieve information (forget) because we never encoded that information in the first place!

• Multiple reasons

  • Not paying attention in the moment

  • Never had reason or motivation to encode information

Storage decay

• Even properly-encoded information can be forgotten

• Ebbinghaus’ forgetting curve

  • Without continuous review/ testing, newly-learned information is forgotten relatively quickly, then levels off

Interference is an example of general retrieval failures

• Information was encoded properly, but still can not be retrieved

• “Tip of the tongue” feeling

• Proactive interference:Old information blocks new information

• Difficulty retrieving new phone number

• The old phone number interferes with new number

• Retroactive interference: new information blocks old information

  • Difficulty retrieving lyrics to old favorite song

  • Lyrics to new favorite song interferes with old favorite

Memory as a construction

• Memory is not a video recording

• Memory is a constructive and malleable process

• Reconsolidation: when a memory is retrieved, it is slightly changed

  • New context is added

• Memory construction errors

1. Misinformation effect (framing effect)

• Incorporating misleading information into memory of an event

1. First: participants see a film of a car accident

2. A week later, they are all asked one of two questions

   1. How fast were the cars going when they hit each other?

   2. How fast were the cars going when they smashed into each other?

^This is the independent variable manipulation

Those who answered “smashed into” question thought cars were going faster than “hit”

2. Source amnesia / misattribution (not sure where you learned the info)

Read in book (pg 308-310)

Source amnesia/misattribution

Children's eyewitness recall

Thinking (aka “cognition”)

• The process involved in thinking, knowing, remembering, and communicating information

Concepts and categories

Mental groups of similar “things”

• Essential for communication; simplify our thinking

• Concepts formed with definitions

• Formed by developing a prototype: mental “best example” of a concept

  • Involves physical features, behaviors, personalities, etc

  • Can be hard to categorize objects that are “far” from the prototype

  • Objects, gender, illnesses, etc

Problem-solving

• We do this every single day

• Trial and error: try a few things, and see if they work

Problem solving I Algorithms

• Step-by-step procedure that guarantees a solution

  • Time-consuming

  • Used by computers

Problem solving I Heuristics

Simple strategies that allow us to make judgements quickly and efficiently

• Mental “short cuts

• Quicker, but more prone to errors

• Example: if you can't find your cat, check her 3 favorite spots

Problem solving I Insight

• Sudden realization of a solution

  • “Ah ha moment”

Obstacles to problem solving

• Confirmation bias: tendency to prefer information that confirms our preexisting beliefs

  • “Prefer” = we pay more attention, search for it, remember better

• Functional fixedness: inability to see either uses or functions for an object

• Functional fixedness prevented some people from seeing a wrench also as a pendulum

• Experimenters could also inspire insight

Judgment and decision-making (JDM)

• We navigate hundreds of decisions every day

• Decision-making: process of making choices among possibilities

• Economists: normative, rational approach

  • What should people do?

  • Why do people make the wrong decision?

• Psychologists: descriptive approach

  • What do people actually do? How do people make choices in everyday life”

  • What influences people's decisions?

Use and misuse of heuristics

• Representativeness heuristic: judging the likelihood of something in terms of how well it represents prototype

• Availability heuristic: basic judgements on how easily something can be brought to mind (how cognitively “available” it is)

  • Frequency, dangerousness, popularity, etc

Other characteristics of JDM

• Overconfidence: we overestimate the accuracy of our beliefs and judgements

  • Example: estimating how long a task will take

• Belief perseverance: we cling to beliefs, even in the face of contrary evidence

  • Confirmation bias helps this occur

  • Example :attitudes about someone affects how you interpret their behavior, intentions

• JDM is affected by the framing of an issue (how an issue presented)

  • Example: beef marketing

    • “Is it better to market how much of it is lean or how much of it is fat?”

    • The way it is framed makes a difference

Framing

There is a new disease and one of the two programs must be adopted and counteract it. 600people in total are infected with this disease.

JDM summary

Humans do not follow “rules” of normative judgment and decision-making

Although reasoning can be illogical in terms of “rational” decisions, it's not random; our “errors” are sympathetic

Read thinking creatively (pg 324-326)