Psych Unit 2- Sensation and Perception

Relating the Psychological and Physical World

  • Sensation: The detection of stimulus

  • Perception: The processing, interpretation, and organization of sensory information

  • Psychophysical research: Studies the conscious, psychological experience of stimuli

Sensation

  • We know about visual the most, then auditory, then the rest much less

  • Vision: Light rays bounce off an object → Cornea (outer part of your eye (makes things sharp and clear)) → Pupil → Lens → Retina (back of the eye, turns light into electrical signals (by rods and cones) → Visual cortex

  • Hearing: Sound waves travel through the ear canal → make the eardrum vibrate → Rattles the cochlea (produces waves) → Hair cells in the cochlea move, create electrical signal → auditory complex

Perception

  • Why do people respond the way they do to stimuli?

  • Visual illusion: Two objects produce the same image on the back of the retina, they look different when our brain processes it

  • Top-down processing: Focuses on concepts, expectations, memories

    • Use pre-existing knowledge of the world

    • Ex.: A song was staticky and you can’t make it out but once you know the song, the lyrics are more discernable

    • Ex: Stereotypes

  • Bottom-up processing: No pre-existing ideas, perception based on senses and stimuli taken in

    • Figure-ground: Differentiating between an object and background

  • Top-down processing/bottom-up processing are a spectrum

    • As you get more knowledge, you do more top-down processing

    • Gestalt principle: Grouping things together

      • Infants do this

      • Laws of similarity, good figure, proximity, continuity, closure, common region

  • Carpentered-world hypothesis: Since we live in a world with many straight lines and right arrows, we were likely to fall for the illusion below. People who live in huts were not likely to fall for it

Detection question

  • Absolute threshold: The minimum amount of energy needed to dect a stimulus 50% of the time

  • Subliminal: Below threshold but also below the unconscious

Difference question

  • Difference threshold: The minimum difference between two stimuli that can be detected 50% of the time

  • Weber’s law: For each type of sensory judgement, the difference threshold is a constant fraction of the standard stimulus

    • The constant changes for different types of sensory stimuli

    • The smaller the constant, the less change needed for it to be noticeable

Depth perception

  • Binocular clues: Visual perception coming from two eyes

    • The closer the image, the more retinal disparity

  • Monocular clues: Help us perceive depth and distance

    • Relative size, interposition, relative clarity, texture, gradient, linear perspective, relative motion

Attention

  • Attention: The allocation of mental resources

  • Selective attention: When you zero in on one stimulus

    • Inattentional blindness: A failure to notice seemingly observable stimuli because your attention is engaged elsewhere

      • The lady walking with the umbrella, the gorilla

    • Change blindness: The inability to notices even significant changes when they’re right in front of your face

      • In-class example: Two images were switched between on the board with an intervening grey screen and we had to spot the difference

  • Divided attention: Simultaenously paying attention to multiple stimuli

    • Cocktail party phenomenon

      • Proves awareness comes after the initial processing stage

  • New and German: The visual system attends to stimuli of evolutionary importance

    • Study: There was was a fixation point with a cross at the center and sometimes a surprising object (spider, weird-looking spider, fly, needle) would pop up

      • Participants were much more likely to notice the spider than other things

        • The spider is what they’re more biologically prepared to fear

Motivated Seeing: Virtual Perception

  • Asked if people perceive the external environment as how it is or how they want it to be

    Causes of motivated seeing

  • Categorization: Identifying something based off desired outcome

    • Ex.: B vs 13

    • Observers don’t consciously misrepresent

  • Representation: Desire influences size/length/slope/proximity estimates

    • Ex.: Underthrowing a bean bag when trying to land it on a gift card

  • Perceptual sets: Mental associations before an object is originally viewed

    • Ex.: Activate thoughts of farm animals when it’s the desirable category, water when you’re thirsty

  • Attention: Narrows when focused on a desirable thing

Magic and the Brain

  • The curved hand trick diverted attention from what the Gentleman Thief was stealing

    • Due to smooth pursuit, where your eyes stay focused on a moving target

      • In the visionary cortex, one cell detects motion and another supresses the background

  • In Penn and Teller’s trick, the magician’s face distracted participants from the trick

ADHD and Inattentional Blindness

Attentional Deficit Disorder

  • The three proposed models of ADHD:

  • 1. The Neurological Model: ADHD is a disorder/deficit

    • Inattention/impulsivity are global distractibility impairments

    • High-perceptional load IB task experimental hypothesis: Noticing the gorilla would be at the expense of counting passes

  • 2. The Perceptual Load Theory: Perceptual load influences selective attention

    • Spare capacity “spills over” and causes distractions

    • High-perceptional load IB task experimental hypothesis: The high perceptual load would cause ADHD and control participants to perform similarly

  • 3. Hunter in a farmer’s society: People with ADHD are hungers prepared for action, able to tarck moving targets

    • High-perceptional load IB task experimental hypothesis: ADHD individuals would perform better at noticing the gorilla

    Low-perceptional load CPT (Continuous Performance Task)

  • The farmer task

  • Attention and hyperactivity were significant in ADHD individuals

  • Implicit (not conscious)

    High-perceptional load IB task

  • Count bounce/aerial/total passes

  • Gorilla coming in, member wearing black leaving, curtain changing color

  • Explicit (conscious)

  • See hypotheses above

    • HUNTER METHOD PROVEN!

  • Limitations:

    • Single study with specific tasks

    • Need replication

    • Not including students with self-reported disorders limits generalizability

Memory

Distinguishing long-term and short-term effects

  • Serial position effects: How the position of items in a sequence affects recall

    • 1. Primacy effect: Better recall for items at the beginning of a task

    • 2. Recency effect: Better recall for items at the end of a task

Process involved with memory

  1. Encoding: Putting into memory

  2. Storage: Keeping in memory

  3. Retrieval: Pulling from memory

Culture’s Effects on Memory

  • Eastern cultures are more likely to pick up on things happening in the background

Types of memory: The Structural Model

Long-term memory

  • Declarative (Explicit): Conscious recall

    • Episodic memory: Personal experimences

    • Semantic memory: Factual knowledge

  • Nondeclarative (Implicit): Doesn’t require conscious recall

    • Classical conditioning

    • Procedural memory: Motor and cognitive skills

      • Mr. Clive Wearing still had this though he had no long-term memory

    • Priming: How the response to an earlier stimulus affects a later one

  • Anterograde amnesia: The inability to form new long-term memories following surgery or trauma

    • Related to the hippocampus’ inability to convert short-term memories to long-term

  • Retrograde amnesia: The disruption of past memories

Encoding

  • Semantic: Meaning

  • Acoustic: How it sounds

  • Visual: What it looks like

    Models of memory

  • Structural: The boxes in the picture above

  • Process models:

    • The deep vs shallow continuum (How semantic it is)

    • Memory persistence and deep-processing

      • Elaboration: Issue-relevant thinking, integrating new information to old

  • Craik and Tulving

    • You can spend a lot of time studying but not process the information because you’re copying or reading notes

      • Deeper-level processing required

    Retrieval process

  • Memory is not like a camera

    • It is more reconstructed than retrieved

    • Ex.: Use of schemas (script)

      • Making omissions or normalizations: When retrieving memories, you’ll omit irregular things

    • Flashbulb memories: Detailed and with high emotion meaning we have high confidence in them

      • Doesn’t make them more accurate

      • Ex: Challenger Event

  • Proactive interference: An old memory interferes when trying to learn a new memory

  • Retroactive interference: A new memory interferes when trying to recall old memories

Short-term memory

  • A domed workbench where things will fall off in 25-30 seconds if it’s not repeated

  • Central executive: Allows you to keep track of things

    • Phonological loop: Repeating something to oneself

    • Episodic buffer: Understand the context and blend information

    • Visualspacial sketchpad

  • Dual-task paradigm: When performing two tasks simultaneously, you can better divide your attention when the tasks are less similar

  • Brown-Peterson task: Presenting participants with a string of letters then making them recite it backwards to avoid cheap memorization

Unconscious

Freud, psychoanalysis, and the unconscious

  • Freud’s book was called “The Interpretation of Dreams”

  • Psychoanalysis: Freud’s theory on psychology

  • Subliminal: Below the threshold of consciousness

  • If you were given a word with no preceeding one, you’d be likely to forget it

  • Three elements:

    • Three levels of awareness

    • Three parts of personality

    • Psychosexual stage theory of personality development

      • Erogenous zone and fixation

  • Three levels of awareness

    • Conscious mind

      • Short-term memory

      • Thoughts and perceptions

    • Preconscious mind

      • Holds the long-term memory → not currently in awareness but accessible

      • Holds stored information

    • Unconscious mind

      • Primary motivations instinctual drive, repressed thoughts, childhood experiences

      • Fears, violent/immoral urges, selfish needs

        • Analyze to help with mental issues

      • If you weren’t sure if you had a feeling, Freud would say it was in the unconscious

Three-part personality structure

  • Personality comes from dynamic interaction between the three systems

  • Disorders arise when a person is unable to effectively manage the three parts

  • Id: Original personality which drives instincts (Life- surivival/reproduction/pleasure), (Death- destruction and aggression)

    • Pleasure principle: Immediate gratification without concern for the consequences

  • Ego: A realistic outlook for the Id’s needs

    • Created during the 1st year of life

    • Reality principle: Weighs risks and pairs drives with reality and norms

    • The executive!

  • Superego: Conscious and idealized standard of behavior

    • Emerges during childhood

    • The moral compass, telling the ego how one should act

Repression

  • Repression: Pushes unnaceptable thoughts back to the unconscious

    • Use therapy to undo

  • Oedipus complex: Attraction toward the parent of opposite sex, hostility/envy toward the same-sex parent

    • Repressed because you fear the same-sex parent

  • Freudian slip: When you mean to say “x” but accidentally say “y”

    • Gives insight into what you really want

  • Free association: Saying whatever comes to mind

    • Freud hated this shit

  • Dream analysis: Boundaries are broken when you’re asleep, releasing ideas and memories

    • Manifest content: Stored memory

    • Latent content: Underlying meaning

Carl Jung

  • Disagreed with freud on the unconscious because he believed it was too sex-focused and did not focus on the collective

  • Personal unconscious: Unique fears/urges/desires

  • Collective unconscious: Shared/universal, basic sense of right/wrong

    • Diverse cultures have similar ideas

    • This theory is murky in content

Projective tests

  • Projective tests: Analyzing an individuals’ interpretation of an ambiguous stimulus

    • Rorschach inkblots

    • Thematic apperception tests: Ask an individual to create a story based on an image they’re presented with

A contemporary look

  • Early work on the unconscious lacked in science and was always negative

    • The unconscious was defined as “Mental processes that are inaccessible to consciousness but that influence judgement, feelings, or behaviors”

      • In reality, the unconscious isn’t secret but hidden and our workbench simply doesn’t have the space to focus on it

4 Horseman of automaticity

  • Intention: Did you intend for it to happen?

  • Awareness: Were you aware of it?

  • Control: Can you stop it?

  • Efficiency: How much effort does it take?

    • Typing on a keyboard has gone from controlled → Automatic

    • Knowing the process vs knowing the result

Development across the lifespan

The three sections of development: Physical, social, cognitive

  • Teratogens: Environmental agents that impair prenatal development

    • Look at the mother to find them

    • Look at a specific time and the specific result of the action

    • Look at patterns of postnatal development tp determine the teratogen

Research Issues

  • Measuring constructs

    • You need subjects to take the same test because what you’re measuring is a construct

  • Cross-sectional vs longitudinal method

    • Longitudinal: Track the same people over time

      • Pro: You control for outside factors by using the same subjects in the test

      • Issue: Takes a long time to complete

    • Cross-sectional: Track different people at different points in their life

      • Pro: Quick results

      • Issue: Possibility that you’re looking at cohort/generational effects rather than age effects

    • Cross-sequential

      • Both longitudinal and cross-sectional

  • Ethical concerns

    • Safety concerns: Infant swimming or testing infant strength

    • Consent: Someone may be incapable of making the best decisions for themselves

An aspect of social development

  • Erikson’s Theory of Psychosocial Development

    • Each stage of life has a different crisis that will be resolved healthily or unhealthily

      • How a person deals with the crisis affects their personality

      • First crisis: Basic trust vs. Mistrust

      • Young adult: Theme- Affiliation and love

        • Crisis: Intimacy vs. Isolation

    • When you resolve a crisis, you move on to the next stage

An aspect of cognitive development

  • Piaget’s theory of cognitive development

    • Operational: How you represent amounts, ideas, abstract oncepts

    • Changes in memory, thoughts, reasoning

    • Schemas: (Categories we create to make sense of the world)

      • Assimilation (Adding on to an existing schema) or accomodation (changing how you think of something because it doesn’t fit your pre-existing schema)

    • Stages:

      • 1. Sensorimotor (0-2):

        • Explore through sensory and motor contact

      • 2. Preoperational (2-6):

        • Use symbols to represent objects, able to play pretend, lack theory of mind, egocentric

      • 3. Concrete operational (7-12):

        • Think logically about concrete objects, conservation

      • 4. Formal operational (12+)

        • Think hypothetically

    • Milestones:

      • Sensorimotor: Object permanence

      • Preoperational: Conservation- Recognize that just because things look different doesn’t mean they’re not the same size

        • Video: Child couldn’t comprehend that quarters/sticks are the same size/amount if they’re presented differently

Attachment style

  • Types of attachment

    • Secure: 70%. Caregiver is a safe home base to observe

    • Insecure:

      • Resistant: Ambivalent. No stress whether the caregiver’s there

      • Avoidant: Stressed whether or not the caregiver’s there

      • Disorganized: Insecure but doesn’t fall intoo the two categories

  • Strange situation paradigm:

    • How attachment type is discovered. Different combinations of stranger/mom in/out of the room

      • If there issecure attachment, the child will be okay when the caregiver is there and cry when the caregiver’s gone